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Ascaris is one of the most widespread helminth infections, leading to chronic morbidity in humans and considerable economic losses in pig farming. In addition, pigs are an important reservoir for the zoonotic salmonellosis , where pigs can serve as asymptomatic carriers. Here, we investigated the impact of an ongoing Ascaris infection on the immune response to Salmonella in pigs. We observed higher bacterial burdens in experimentally coinfected pigs compared to pigs infected with Salmonella alone. The impaired control of Salmonella in the coinfected pigs was associated with repressed interferon gamma responses in the small intestine and with the alternative activation of gut macrophages evident in elevated CD206 expression. Ascaris single and coinfection were associated with a rise of CD4 - CD8α + FoxP3 + Treg in the lymph nodes draining the small intestine and liver. In addition, macrophages from coinfected pigs showed enhanced susceptibility to Salmonella infection in vitro and the Salmonella- induced monocytosis and tumor necrosis factor alpha production by myeloid cells was repressed in pigs coinfected with Ascaris . Hence, our data indicate that acute Ascaris infection modulates different immune effector functions with important consequences for the control of tissue-invasive coinfecting pathogens.IMPORTANCEIn experimentally infected pigs, we show that an ongoing infection with the parasitic worm Ascaris suum modulates host immunity, and coinfected pigs have higher Salmonella burdens compared to pigs infected with Salmonella alone. Both infections are widespread in pig production and the prevalence of Salmonella is high in endemic regions of human Ascariasis, indicating that this is a clinically meaningful coinfection. We observed the type 2/regulatory immune response to be induced during an Ascaris infection correlates with increased susceptibility of pigs to the concurrent bacterial infection., Competing Interests: The authors declare no conflict of interest.

Helminth infections lead to an overdispersion of the parasites in humans as well as in animals. We asked whether early immune responses against migrating Ascaris larvae are responsible for the unequal distribution of worms in natural host populations and thus investigated a susceptible versus a resistant mouse strain. In mice, the roundworm larvae develop until the lung stage and thus early anti-Ascaris immune responses against the migrating larvae in the liver and lung can be deciphered. Our data show that susceptible C57BL/6 mice respond to Ascaris larval migration significantly stronger compared to resistant CBA mice and the anti-parasite reactivity is associated with pathology. Increased eosinophil recruitment was detected in the liver and lungs, but also in the spleen and peritoneal cavity of susceptible mice on day 8 post infection compared to resistant mice. In serum, eosinophil peroxidase levels were significantly higher only in the susceptible mice, indicating functional activity of the recruited eosinophils. This effect was associated with an increased IL-5/IL-13 production by innate lymphoid cells and CD4 + T cells and a pronounced type 2 macrophage polarization in the lungs of susceptible mice. Furthermore, a comparison of wildtype BALB/c and eosinophil-deficient dblGATA-1 BALB/c mice showed that eosinophils were not essential for the early control of migrating Ascaris larvae. In conclusion, in primary infection, a strong local and systemic type 2 immune response during hepato-tracheal helminth larval migration is associated with pathology rather than protection., (© 2024. The Author(s).)

Natural killer (NK) cells play a key role in defense against Salmonella infections during the early phase of infection. Our previous work showed that the excretory/secretory products of Ascaris suum repressed NK activity in vitro. Here, we asked if NK cell functionality was influenced in domestic pigs during coinfection with Ascaris and Salmonella enterica serotype Typhimurium. Ascaris coinfection completely abolished the IL-12 and IL-18 driven elevation of IFN-γ production seen in CD16 + CD8α + perforin + NK cells of Salmonella single-infected pigs. Furthermore, Ascaris coinfection prohibited the Salmonella-driven rise in NK perforin levels and CD107a surface expression. In line with impaired effector functions, NK cells from Ascaris-single and coinfected pigs displayed elevated expression of the inhibitory KLRA1 and NKG2A receptors genes, contrasting with the higher expression of the activating NKp46 and NKp30 receptors in NK cells during Salmonella single infection. These differences were accompanied by the highly significant upregulation of T-bet protein expression in NK cells from Ascaris-single and Ascaris/Salmonella coinfected pigs. Together, our data strongly indicate a profound repression of NK functionality by an Ascaris infection which may hinder infected individuals from adequately responding to a concurrent bacterial infection., (© 2024. The Author(s).)

Background: The standard diagnosis of Ascaris lumbricoides and other soil-transmitted helminth (STH) infections relies on the detection of worm eggs by copromicroscopy. However, this method is dependent on worm patency and shows only limited accuracy in low-intensity infection settings. We aimed to decipher the diagnostic accuracy of different antibodies using various Ascaris antigens in reference to copromicroscopy and quantitative PCR (qPCR), four months after national STH preventative chemotherapy among school children in western Kenya., Methodology: STH infection status of 390 school children was evaluated via copromicroscopy (Kato-Katz and mini-FLOTAC) and qPCR. In parallel, Ascaris-specific antibody profiles against larval and adult worm lysates, and adult worm excretory-secretory (ES) products were determined by enzyme-linked immunosorbent assay. Antibody cross-reactivity was evaluated using the closely related zoonotic roundworm species Toxocara cati and Toxocara canis. The diagnostic accuracy of each antibody was evaluated using receiver operating curve analysis and the correspondent area under the curve (AUC)., Principal Findings: Ascaris was the predominant helminth infection with an overall prevalence of 14.9% (58/390). The sensitivity of mini-FLOTAC and Kato-Katz for Ascaris diagnosis reached only 53.5% and 63.8%, respectively compared to qPCR. Although being more sensitive, qPCR values correlated with microscopic egg counts (R = -0.71, P<0.001), in contrast to antibody levels. Strikingly, IgG antibodies recognizing the ES products of adult Ascaris worms reliably diagnosed active Ascaris infection as determined by qPCR and microscopy, with IgG1 displaying the highest accuracy (AUC = 0.83, 95% CI: 0.75-0.91)., Conclusion: IgG1 antibody responses against adult Ascaris-ES products hold a promising potential for complementing the standard fecal and molecular techniques employed for monitoring Ascaris infections. This is of particular importance in the context of deworming programs as the antibody diagnostic accuracy was independent of egg counts., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Mugo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Ascariasis, caused by both Ascaris lumbricoides and Ascaris suum, is the most prevalent parasitic disease worldwide, affecting both human and porcine populations. However, due to the difficulties of assessing the early events of infection in humans, most studies of human ascariasis have been restricted to the chronic intestinal phase. Therefore, the Ascaris mouse model has become a fundamental tool for investigating the immunobiology and pathogenesis of the early infection stage referred to as larval ascariasis because of the model's practicality and ability to replicate the natural processes involved. The Ascaris mouse model has been widely used to explore factors such as infection resistance/susceptibility, liver inflammation, lung immune-mediated pathology, and co-infections and, notably, as a pivotal element in preclinical vaccine trials. Exploring the immunobiology of larval ascariasis may offer new insights into disease development and provide a substantial understanding of key components that trigger a protective immune response. This article focuses on creating a comprehensive guide for conducting Ascaris experimental infections in the laboratory as a foundation for future research efforts. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Acquisition and embryonation of Ascaris suum eggs from adult females Alternate Protocol: Cleaning and purification of Ascaris suum from female A. suum uteri Basic Protocol 2: Preparation of Ascaris suum eggs and murine infection Basic Protocol 3: Measurement of larval burden and Ascaris-larva-induced pathogenesis Basic Protocol 4: In vitro hatching and purification of Ascaris L3 larvae Support Protocol: Preparation of crude antigen from Ascaris infectious stages Basic Protocol 5: Ultrastructure-expansion microscopy (U-ExM) of Ascaris suum larval stages., (© 2024 Wiley Periodicals LLC.)

Ascaris spp. undergo extensive migration within the body before establishing patent infections in the small intestinal tract of humans and pigs. However, whether larval migration is critical for inducing efficient type 2 responses remains poorly understood. Therefore, we investigated systemic versus local adaptive immune responses along the hepato-tracheal migration of Ascaris suum during primary, single infections in conventionally raised pigs. Neither the initial invasion of gut tissue nor migration through the liver resulted in discernable Th2 cell responses. In contrast, lung-stage larvae elicited a Th2-biased pulmonary response, which declined after the larvae had left the lungs. In the small intestine, we observed an accumulation of Th2 cells upon the arrival of fourth-stage larvae (L4) to the small intestinal lumen. In parallel, we noticed robust and increasing Th1 responses in circulation, migration-affected organs, and draining lymph nodes. Phenotypic analysis of CD4+ T cells specifically recognizing A. suum antigens in the circulation and lung tissue of infected pigs confirmed that the majority of Ascaris -specific T cells produced IL-4 (Th2) and, to a much lesser extent, IL-4/IFN-g (Th2/1 hybrids) or IFN-g alone (Th1). These data demonstrate that lung-stage but not the early liver-stage larvae lead to a locally restricted Th2 response. Significant Th2 cell accumulation in the small intestine occurs only when L4 complete the body migration. In addition, Th2 immunity seems to be hampered by the concurrent, nonspecific Th1 bias in growing pigs. Together, the late onset of Th2 immunity at the site of infection and the Th1-biased systemic immunity likely enable the establishment of intestinal infections by sufficiently large L4 stages and pre-adult worms, some of which resist expulsion mechanisms., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Oser, Midha, Schlosser-Brandenburg, Rausch, Mugo, Kundik, Elizalde-Velázquez, Adjah, Musimbi, Klopfleisch, Helm, von Samson-Himmelstjerna, Hartmann and Ebner.)

Objective: To quantify the production of Th1/Th2/Th17 cytokines induced by Ascaris lumbricoides antigens in peripheral blood mononuclear cells (PBMCs) using a multiplex technique., Methods: PBMCs were cultured from individuals with mild A. lumbricoides infection (n = 20) and uninfected individuals (n = 21) and stimulated with A. lumbricoides extract (ExtAscaris), a mix of anti-CD2/CD3/CD28 (CDmix) as a positive control, and only medium (negative control). Cytokines in the supernatants were measured using the BD™ Cytometric Bead Array Human Th1/Th2/Th17 kit, to identify IFN-γ, TNF, IL-10, IL-6, IL-4, IL-2, and IL-17A. Readings were taken on a spectral cytometer (Northern Lights, Cytek, USA), and analysis was performed using R software with packages "tidyverse," "beadplexr," "flowCore," and "arsenal." Cytokine concentrations were calculated using a 5-parameter logistic curve. The t-test was used to compare cases and controls, and statistical significance was set at p < 0.05. The study was approved by the Ethics Committee of the University of Cartagena and the participants provided informed consent. This study was financially supported by the Colombian Sistema General de Regalías under the BPIN2020000100405 - BPIN2020000100364., Results: Efficient fluorescence intensity extraction for each cytokine was achieved using detection channel R8 and the "mclust" clustering model (Figure 1). No significant differences were found in the levels of the seven cytokines between cases and controls (Figure 2). Although the IFN-γ response to ExtAscaris was higher in cases than in controls (252.5 ng/mL vs. 173.1 ng/mL), the difference was not significant. IL-17A (detection limit: 18.9 pg/mL) was more detectable in cases than controls (5 cases, 23% vs. 2 controls, 9.5%). IL-4 was only detected in the supernatants from CDmix-stimulated cultures but not with the Ascaris extract (Figure 2)., Conclusions: The multiplex technique using spectral flow cytometry combined with open-source software analysis proved applicable for quantifying cytokines induced by A. lumbricoides antigens in PBMCs. However, a more sensitive method is needed to evaluate IL-4 response in the context of ascariasis. The results did not reveal significant differences in cytokine production between cases and controls for the evaluated stimuli.

Objective: To compare the relative frequencies of immune cell populations in the peripheral blood according to A. lumbricoides infection status., Methods: Peripheral blood samples were collected from participants infected (n = 35) and uninfected with A. lumbricoides (n=27) residing in different rural municipalities of Bolívar. Infection was diagnosed using two coprological examinations and the Kato-Katz technique. Immunophenotyping was performed using two panels of markers and staining in fresh blood. The flow cytometry reading was performed on a spectral cytometer (Northern Lights, Cytek, USA). The populations identified in the first panel (Figure 1) were T lymphocytes (CD45+ CD3+), CD4+ or CD8+, B lymphocytes (CD45+ SSClow CD3- CD19+), neutrophils (CD45+ SSChi CD3- CD16+), and eosinophils (CD45+ SSChi CD3- CD16low). Monocytes were identified in another panel (Figure 2): classical (CD14++ CD16 -), intermediate (CD14++ CD16+), and non-classical (CD14+ CD16++). Dendritic cells, including CD123 + + CD303 + (plasmacytoid), HLA-DR + + CD1c + (myeloid CD1c +), and CD14-CD141 + + (myeloid CD141 +), were also identified. The study received approval from the Ethics Committee of the University of Cartagena, and participants provided informed consent. Funding was provided by the Colombian Sistema General de Regalías under BPIN2020000100405 - BPIN2020000100364., Results: No significant differences were observed in age [mean cases: 35.69 (SD: 17.7) vs. controls: 37.04 (SD: 15.6) years] or sex (cases: 62.9% vs. controls: 74.1%) (Table 1). All infections were mild, with a median of 96 eggs (IQR, 48-216). A marginally significant difference was observed only in the percentage of neutrophils (45.37% in cases vs. 54.79% in controls, p=0.041) (Figure 3). Although the frequency of eosinophils was higher in the cases (8.1% vs. 6%), this difference was not significant (p=0.138) (Figure 3). No significant differences were observed in the populations of monocytes or dendritic cells between cases and controls (Figure 4)., Conclusion: Mild A. lumbricoides infection appears to affect the number of neutrophils in peripheral blood. The low infection intensity in the studied samples may explain the lack of a significant impact on other cellular populations.

Control of human ascariasis, the most prevalent neglected tropical disease globally affecting 450 million people, mostly relies on mass drug administration of anthelmintics. However, chemotherapy alone is not efficient due to the high re-infection rate for people who live in the endemic area. The development of a vaccine that reduces the intensity of infection and maintains lower morbidity should be the primary target for infection control. Previously, our group demonstrated that immunization with crude Ascaris antigens in mice induced an IgG-mediated protective response with significant worm reduction. Here, we aimed to develop a multipeptide chimera vaccine based on conserved B-cell epitopes predicted from 17 common helminth proteomes using a bioinformatics algorithm. More than 480 B-cell epitopes were identified that are conserved in all 17 helminths. The Ascaris -specific epitopes were selected based on their reactivity to the pooled sera of mice immunized with Ascaris crude antigens or infected three times with A. suum infective eggs. The top 35 peptides with the strongest reactivity to Ascaris immune serum were selected to construct a chimeric antigen connected in sequence based on conformation. This chimera, called ASCVac-1, was produced as a soluble recombinant protein in an Escherichia coli expression system and, formulated with MPLA, was used to immunize mice. Mice immunized with ASCVac-1/MPLA showed around 50% reduced larvae production in the lungs after being challenged with A. suum infective eggs, along with significantly reduced inflammation and lung tissue/function damage. The reduced parasite count and pathology in infected lungs were associated with strong Th2 immune responses characterized by the high titers of antigen-specific IgG and its subclasses (IgG1, IgG2a, and IgG3) in the sera and significantly increased IL-4, IL-5, IL-13 levels in lung tissues. The reduced IL-33 titers and stimulated eosinophils were also observed in lung tissues and may also contribute to the ASCVac-1-induced protection. Taken together, the preclinical trial with ASCVac-1 chimera in a mouse model demonstrated its significant vaccine efficacy associated with strong IgG-based Th2 responses, without IgE induction, thus reducing the risk of an allergic response. All results suggest that the multiepitope-based ASCVac-1 chimera is a promising vaccine candidate against Ascaris sp. infections., Competing Interests: AG-G and RF are inventors in a patent related to the chimeric protein against Ascaris sp. infection (Brazilian INPI Protocol #BR10 20200269682). The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Gazzinelli-Guimarães, Nogueira, Amorim, Oliveira, Coqueiro-Dos-Santos, Carvalho, Kraemer, Barbosa, Fraga, Santos, de Castro, Russo, Akamatsu, Ho, Bottazzi, Hotez, Zhan, Bartholomeu, Bueno and Fujiwara.)

Ascariasis is one of the most common infections in the world and associated with significant global morbidity. Ascaris larval migration through the host's lungs is essential for larval development but leads to an exaggerated type-2 host immune response manifesting clinically as acute allergic airway disease. However, whether Ascaris larval migration can subsequently lead to chronic lung diseases remains unknown. Here, we demonstrate that a single episode of Ascaris larval migration through the host lungs induces a chronic pulmonary syndrome of type-2 inflammatory pathology and emphysema accompanied by pulmonary hemorrhage and chronic anemia in a mouse model. Our results reveal that a single episode of Ascaris larval migration through the host lungs leads to permanent lung damage with systemic effects. Remote episodes of ascariasis may drive non-communicable lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and chronic anemia in parasite endemic regions., Competing Interests: The authors have declared that no competing interests exist.

Human ascariasis is the most prevalent but neglected tropical disease in the world, affecting approximately 450 million people. The initial phase of Ascaris infection is marked by larval migration from the host's organs, causing mechanical injuries followed by an intense local inflammatory response, which is characterized mainly by neutrophil and eosinophil infiltration, especially in the lungs. During the pulmonary phase, the lesions induced by larval migration and excessive immune responses contribute to tissue remodeling marked by fibrosis and lung dysfunction. In this study, we investigated the relationship between SIgA levels and eosinophils. We found that TLR2 and TLR4 signaling induces eosinophils and promotes SIgA production during Ascaris suum infection. Therefore, control of parasite burden during the pulmonary phase of ascariasis involves eosinophil influx and subsequent promotion of SIgA levels. In addition, we also demonstrate that eosinophils also participate in the process of tissue remodeling after lung injury caused by larval migration, contributing to pulmonary fibrosis and dysfunction in re-infected mice. In conclusion, we postulate that eosinophils play a central role in mediating host innate and humoral immune responses by controlling parasite burden, tissue inflammation, and remodeling during Ascaris suum infection. Furthermore, we suggest that the use of probiotics can induce eosinophilia and SIgA production and contribute to controlling parasite burden and morbidity of helminthic diseases with pulmonary cycles., Competing Interests: The authors have declared that no competing interests exist.

Background: Ascariasis and malaria are highly prevalent parasitic diseases in tropical regions and often have overlapping endemic areas, contributing to high morbidity and mortality rates in areas with poor sanitary conditions. Several studies have previously aimed to correlate the effects of Ascaris-Plasmodium coinfections but have obtained contradictory and inconclusive results. Therefore, the present study aimed to investigate parasitological and immunopathological aspects of the lung during murine experimental concomitant coinfection by Plasmodium berghei and Ascaris suum during larvae ascariasis., Methods: C57BL/6J mice were inoculated with 1 × 10 4 P. berghei strain NK65-NY-infected red blood cells (iRBCs) intraperitoneally and/or 2500 embryonated eggs of A. suum by oral gavage. P. berghei parasitaemia, morbidity and the survival rate were assessed. On the seventh day postinfection (dpi), A. suum lung burden analysis; bronchoalveolar lavage (BAL); histopathology; NAG, MPO and EPO activity measurements; haematological analysis; and respiratory mechanics analysis were performed. The concentrations of interleukin (IL)-1β, IL-12/IL-23p40, IL-6, IL-4, IL-33, IL-13, IL-5, IL-10, IL-17A, IFN-γ, TNF and TGF-β were assayed by sandwich ELISA., Results: Animals coinfected with P. berghei and A. suum show decreased production of type 1, 2, and 17 and regulatory cytokines; low leukocyte recruitment in the tissue; increased cellularity in the circulation; and low levels of NAG, MPO and EPO activity that lead to an increase in larvae migration, as shown by the decrease in larvae recovered in the lung parenchyma and increase in larvae recovered in the airway. This situation leads to severe airway haemorrhage and, consequently, an impairment respiratory function that leads to high morbidity and early mortality., Conclusions: This study demonstrates that the Ascaris-Plasmodium interaction is harmful to the host and suggests that this coinfection may potentiate Ascaris-associated pathology by dampening the Ascaris-specific immune response, resulting in the early death of affected animals.

The soil-transmitted helminth Ascaris lumbricoides infects ~800 million people worldwide. Some people are heavily infected, harbouring many worms, whereas others are only lightly infected. The mechanisms behind this difference are unknown. We used a mouse model of hepatic resistance to Ascaris, with C57BL/6J mice as a model for heavy infection and CBA/Ca mice as a model for light infection. The mice were infected with the porcine ascarid, Ascaris suum or the human ascarid, A. lumbricoides and immune cells in their livers and spleens were enumerated using flow cytometry. Compared to uninfected C57BL/6J mice, uninfected CBA/Ca mice had higher splenic CD4+ and γδ T cell counts and lower hepatic eosinophil, Kupffer cell and B cell counts. Infection with A. suum led to expansions of eosinophils, Kupffer cells, monocytes and dendritic cells in the livers of both mouse strains and depletions of hepatic natural killer (NK) cells in CBA/Ca mice only. Infection with A. lumbricoides led to expansions of hepatic eosinophils, monocytes and dendritic cells and depletions of CD8+, αβ, NK and NK T cells in CBA/Ca mice, but not in C57BL/6J mice where only monocytes expanded. Thus, susceptibility and resistance to Ascaris infection are governed, in part, by the hepatic immune system.

Background: Ascaris lumbricoides is the most common causative agent of soil-transmitted helminth infections worldwide, with an estimated 450 million people infected with this nematode globally. It is suggested that helminths are capable of evading and manipulating the host immune system through the release of a spectrum of worm proteins which underpins their long-term survival in the host. We hypothesise that the worm overexpresses these proteins when infecting adults compared to children to cirvumvent the more robust defence mechanisms of adults. However, little is known about the parasite's genes and encoded proteins involved during A. lumbricoides infection. Hence, this study was conducted to assess the expression profile of putative virulence-associated genes during an active infection of adults and children., Methods: In this study, quantitative PCR was performed to evaluate the expression profile of putative virulence-associated genes in A. lumbricoides isolated from infected children and adults. The study was initiated by collecting adult worms expelled from adults and children following anthelminthic treatment. High-quality RNA was successfully extracted from each of six adult worms expelled by three adults and three children, respectively. Eleven putative homologues of helminth virulence-associated genes reported in previous studies were selected, primers were designed and specific amplicons of A. lumbricoides genes were noted. The expression profiles of these putative virulence-associated genes in A. lumbricoides from infected adults were compared to those in A. lumbricoides from infected children., Results: The putative virulence-associated genes VENOM, CADHERIN and PEBP were significantly upregulated at 166-fold, 13-fold and fivefold, respectively, in adults compared to children. Conversely, the transcription of ABA-1 (fourfold), CATH-L (threefold) and INTEGRIN (twofold) was significantly suppressed in A. lumbricoides from infected adults., Conclusions: On the basis of the expression profile of the putative virulence-associated genes, we propose that the encoded proteins have potential roles in evasion mechanisms, which could guide the development of therapeutic interventions.

Genetic and epigenetic factors are considered to be critical for host-parasite interactions. There are limited data on the role of such factors during human infections with Ascaris lumbricoides . Here, we describe the potential role of genetic factors as determinants of the Th2 immune response to A. lumbricoides in Brazilian children. Stool samples were collected from the children to detect A. lumbricoides by microscopy and peripheral blood leukocytes (PBLs) were cultured in whole blood cultures for detection of cytokines (IL-5, IL-10, and IL-13) in vitro . Levels of anti- A. lumbricoides IgE and IgG4 were measured in plasma. DNA was extracted from PBLs and genotyped using Illumina 2.5 Human Omni Beadchip. Candidate genes associated with A. lumbricoides responses were identified and SNVs in these selected genes associated with the Th2 immune response to A. lumbricoides . Haplotype, gene expression, and epigenetic analyses were done to identify potential associations with Th2 immune responses. GWAS on samples from 1,189 children identified WSB1 as a candidate gene, and IL-21R was selected as a biologically relevant linked gene for further analysis. Variants in WSB1 and IL21R were associated with markers of Th2 immune responses: increased A. lumbricoides -specific IgE and IL-5/IL-13 by PBLs from infected compared to uninfected individuals. In infected children, WSB1 but not IL21R gene expression was suppressed and increased methylation was observed in the WSB1 promoter region. This is the first study to show an association between genetic variants in WSB1 and IL21R and Th2 immune responses during A. lumbricoides infections in children. WSB1 / IL21R pathways could provide a potential target for the treatment of Th2-mediated diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Carneiro, da Silva, Queiroz, Veiga, Oliveira, Carneiro, Pires, da Silva, Sena, Belitardo, Nascimento, Silva, Marques, Costa, Alcantra-Neves, Barreto, Cooper and Figueiredo.)

Parasitic helminths infect over one-fourth of the human population resulting in significant morbidity, and in some cases, death in endemic countries. Despite mass drug administration (MDA) to school-aged children and other control measures, helminth infections are spreading into new areas. Thus, there is a strong rationale for developing anthelminthic vaccines as cost-effective, long-term immunological control strategies, which, unlike MDA, are not haunted by the threat of emerging drug-resistant helminths nor limited by reinfection risk. Advances in vaccinology, immunology, and immunomics include the development of new tools that improve the safety, immunogenicity, and efficacy of vaccines; and some of these tools have been used in the development of helminth vaccines. The development of anthelminthic vaccines is fraught with difficulty. Multiple lifecycle stages exist each presenting stage-specific antigens. Further, helminth parasites are notorious for their ability to dampen down and regulate host immunity. One of the first significant challenges in developing any vaccine is identifying suitable candidate protective antigens. This review explores our current knowledge in lead antigen identification and reports on recent pre-clinical and clinical trials in the context of the soil-transmitted helminths Trichuris , the hookworms and Ascaris . Ultimately, a multivalent anthelminthic vaccine could become an essential tool for achieving the medium-to long-term goal of controlling, or even eliminating helminth infections., (Copyright © 2020 Zawawi and Else.)

Helminth infection represents a major health problem causing approximately 5 million disability-adjusted life years worldwide. Concerns that repeated anti-helminthic treatment may lead to drug resistance render it important that vaccines are developed but will require increased understanding of the immune-mediated cellular and antibody responses to helminth infection. IL-4 or antibody-activated murine macrophages are known to immobilize parasitic nematode larvae, but few studies have addressed whether this is translatable to human macrophages. In the current study, we investigated the capacity of human macrophages to recognize and attack larval stages of Ascaris suum, a natural porcine parasite that is genetically similar to the human helminth Ascaris lumbricoides. Human macrophages were able to adhere to and trap A suum larvae in the presence of either human or pig serum containing Ascaris-specific antibodies and other factors. Gene expression analysis of serum-activated macrophages revealed that CCL24, a potent eosinophil attractant, was the most upregulated gene following culture with A suum larvae in vitro, and human eosinophils displayed even greater ability to adhere to, and trap, A suum larvae. These data suggest that immune serum-activated macrophages can recruit eosinophils to the site of infection, where they act in concert to immobilize tissue-migrating Ascaris larvae., (© 2020 John Wiley & Sons Ltd.)

Africa is the second most populous continent and has perennial health challenges. Of the estimated 181 million school aged children in sub-Saharan Africa (SSA), nearly half suffer from ascariasis, trichuriasis, or a combination of these infections. Coupled with these is the problem of tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) infection, which is a leading cause of death in the region. Compared to the effect of the human immunodeficiency virus on the development of TB, the effect of chronic helminth infections is a neglected area of research, yet helminth infections are as ubiquitous as they are varied and may potentially have profound effects upon host immunity, particularly as it relates to TB infection, diagnosis, and vaccination. Protection against active TB is known to require a clearly delineated T-helper type 1 (Th1) response, while helminths induce a strong opposing Th2 and immune-regulatory host response. This Review highlights the potential challenges of helminth-TB co-infection in Africa and the need for further research., Competing Interests: The authors have declared that no competing interests exist.

Background: Epigenetic changes in response to allergen exposure are still not well understood. The aim of this study was to evaluate histone acetylation levels in peripheral blood leukocytes from humans naturally infected by intestinal parasites and perennially exposed to house dust mites (HDM)., Methods: Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation from 20 infected and 21 non-infected individuals living in a rural/village in Colombia. Histone 3 acetylation (H3Ac) and histone 4 acetylation (H4Ac) levels were measured in six immune genes previously associated with helminth immunity by chromatin immunoprecipitation (ChIP)-quantitative PCR. Then we analyzed the association between histone acetylation levels with total parasite egg burden and IgE levels., Results: We found an inverse correlation between H4Ac levels in the IL13 gene and egg worm burden that remained significant after adjustment by age [-0.20 (-0.32 to -0.09), p < 0.0001]. Moreover, we found significant associations between H4Ac levels in IL4 [0.32 (0.05-0.60), p = 0.02] and CHI3L1 [0.29 (0.08-0.51), p = 0.008] with the IgE levels to Ascaris lumbricoides . In addition, the levels of specific IgE antibodies to HDM were associated with H4Ac levels in the gene TNFSF13B encoding the B cell activating factor (BAFF) [0.51 (0.26-0.76), p < 0.001]. All values are presented as beta (95% CI)., Conclusion: Histone acetylation levels at key type-2 immune genes in humans were modified by nematode infection and HDM allergens and are associated with the intensity of the IgE response., (Copyright © 2020 Zakzuk, Acevedo, Harb, Eick, Renz, Potaczek and Caraballo.)

Background: Ascaris lumbricoides is one of the three major soil-transmitted gastrointestinal helminths (STHs) that infect more than 440 million people in the world, ranking this neglected tropical disease among the most common afflictions of people living in poverty. Children infected with this roundworm suffer from malnutrition, growth stunting as well as cognitive and intellectual deficits. An effective vaccine is urgently needed to complement anthelmintic deworming as a better approach to control helminth infections. As37 is an immunodominant antigen of Ascaris suum, a pig roundworm closely related to the human A. lumbricoides parasite, recognized by protective immune sera from A. suum infected mice. In this study, the immunogenicity and vaccine efficacy of recombinant As37 were evaluated in a mouse model., Methodology/principal Findings: As37 was cloned and expressed as a soluble recombinant protein (rAs37) in Escherichia coli. The expressed rAs37 was highly recognized by protective immune sera from A. suum egg-infected mice. Balb/c mice immunized with 25 μg rAs37 formulated with AddaVax™ adjuvant showed significant larval worm reduction after challenge with A. suum infective eggs when compared with a PBS (49.7%) or adjuvant control (48.7%). Protection was associated with mixed Th1/2-type immune responses characterized by high titers of serological IgG1 and IgG2a and stimulation of the production of cytokines IL-4, IL-5, IL-10 and IL-13. In this experiment, the AddaVax™ adjuvant induced better protection than the Th1-type adjuvant MPLA (38.9%) and the Th2-type adjuvant Alhydrogel (40.7%). Sequence analysis revealed that As37 is a member of the immunoglobulin superfamily (IgSF) and highly conserved in other human STHs. Anti-As37 antibodies strongly recognized homologs in hookworms (Necator americanus, Ancylostoma ceylanicum, A. caninum) and in the whipworm Trichuris muris, but there was no cross-reaction with human spleen tissue extracts. These results suggest that the nematode-conserved As37 could serve as a pan-helminth vaccine antigen to prevent all STH infections without cross-reaction with human IgSF molecules., Conclusions/significance: As37 is an A. suum expressed immunodominant antigen that elicited significant protective immunity in mice when formulated with AddaVax™. As37 is highly conserved in other STHs, but not in humans, suggesting it could be further developed as a pan-helminth vaccine against STH co-infections., Competing Interests: The authors have declared that no competing interests exist.

Introduction: The relationship of parasite infections and promotion or protection from allergy and asthma is controversial. Currently, over 1.5 billion people are infected with parasites worldwide, and Ascaris lumbricoides is the most frequent soil-transmitted helminth., Objectives: To evaluate the biological activity of recombinant A. lumbricoides tropomyosin and investigate IgE cross-reactive responses to tropomyosins by means of microarray methodology for the detection of sensitization to allergen components., Methods: Forty patients 12-75 years of age (25 males) with asthma and/or rhinitis and 10 nonallergic control subjects participated in this study. All patients presented positive skin tests to cockroach extracts and underwent skin prick testing (SPT) with recombinant (r) tropomyosins rPer a 7 from Periplaneta americana and rAsc l 3 from A. lumbricoides, at 10 μg/mL. IgE to cockroach and parasite tropomyosins were measured by chimeric ELISA and ImmunoCAP-ISAC, and total IgE was quantitated by ImmunoCAP. Agreement of results was assessed by κ statistics., Results: Recombinant A. lumbricoides showed biological activity, inducing positive skin tests in 50% patients with asthma and/or rhinitis. IgE to cockroach and parasite tropomyosins were detected in 55-62% of patients. There was good-to-excellent agreement of results of SPT and IgE measurements by ELISA and ImmunoCAP-ISAC, with κ indices of 0.66-0.95. No skin test reactivity or IgE antibodies to tropomyosins were found in nonallergic individuals., Conclusions: Our results suggest that IgE responses to tropomyosin from A. lumbricoides may enhance reactivity to homologous allergens upon exposure by inhalation or ingestion, promoting allergic reactions and asthma, or increasing the severity of these clinical conditions., (© 2019 S. Karger AG, Basel.)

Ascaris lumbricoides is the most common soil-transmitted helminth and infects 447 million people in impoverished areas worldwide. It causes serious morbidity including wheezing and influences various aspects of human immunity, such as type 2 innate lymphoid cells, regulatory T cell function, and acquired immunity. Thus, it is crucial to elucidate its influence on human immunity. We aimed to classify wheezing children based on their Ascaris infection intensity and other risk factors using hierarchical cluster analysis to determine the mechanisms of and the degree to which Ascaris contributes to childhood wheezing in rural Bangladesh. We analyzed relevant data collected in 2001. The participants included 219 5-year-old wheezing children who were randomly selected from 1705 children living in the Matlab Health and Demographic Surveillance area of the International Centre for Diarrhoeal Disease Research, Bangladesh. Hierarchical cluster analysis was conducted using variables of history of pneumonia, total and specific immunoglobulin E levels, Ascaris infection intensity, and parental asthma. Three distinct wheezing groups were identified. Children in Cluster 1 ( n = 50) had the highest titers of the total, anti- Ascaris , anti- Dermatophagoides pteronyssinus , and anticockroach IgEs and experienced the fewest episodes of pneumonia. Cluster 2 ( n = 114), the largest group, experienced few episodes of pneumonia and had the lowest titers of the total, anti- Ascaris , anti-Dp, and anticockroach IgEs. Cluster 3 ( n = 32) consisted of participants with the most episodes of pneumonia and lower titers of the total and specific IgEs. The extremely high prevalence of Ascaris infection found in Clusters 1-3 was 78%, 77%, and 72%, respectively. Childhood wheezing in rural Bangladesh could be divided into three groups, with 26% of wheezing attributable to anti- Ascaris IgE and 16% to history of pneumonia during early childhood, and 58% might have been due to Ascaris infection without elevated anti- Ascari s IgE., Competing Interests: All the authors confirm that there are no conflicts of interest to disclose., (Copyright © 2019 Haruko Takeuchi et al.)

Introduction: Immunological control of Mycobacterium tuberculosis infection is dependent on the cellular immune response, mediated predominantly by Th1 type CD4+ T cells. Polarization of the immune response to Th2 can inhibit the host immune protection against pathogens. Patients with tuberculosis coinfected with helminths demonstrate more severe pulmonary symptoms, a deficiency in the immune response against tuberculosis, and an impaired response to anti-tuberculosis therapy., Methods: We evaluated the cellular immune response and the impact of the presence of Ascaris lumbricoides on the immune and clinical response in pulmonary tuberculosis patients. Ninety-one individuals were included in the study: 38 tuberculosis patients, 11 tuberculosis patients coinfected with Ascaris lumbricoides and other helminths, 10 Ascaris lumbricoides patients, and 34 non-infected control individuals. Clinical evolution of pulmonary tuberculosis was studied on 0, 30, 60, and 90 days post-diagnosis of Mycobacterium tuberculosis and Ascaris lumbricoides. Furthermore, immune cells and plasma cytokine profiles were examined in mono/coinfection by Mycobacterium tuberculosis and Ascaris lumbricoides using flow cytometry., Results: There were no statistical differences in any of the evaluated parameters and the results indicated that Ascaris lumbricoides infection does not lead to significant clinical repercussions in the presentation and evolution of pulmonary tuberculosis., Conclusions: The association with Ascaris lumbricoides did not influence the Th1, Th2, and Th17 type responses, or the proportions of T lymphocyte subpopulations. However, higher serum levels of IL-6 in tuberculosis patients may explain the pulmonary parenchymal damage.

Ascariasis is a soil-sourced, second most common parasitic infection worldwide. Because of its wandering nature, it migrates from the intestine to other organs of the body like the lungs and biliary system. This results in complications such as biliary colic, acute cholecystitis, pyogenic cholangitis, liver abscesses, pancreatitis and loeffler's pneumonia. We report a unique case of an 8-year-old boy who presented with upper gastrointestinal bleed and chest infection. He was diagnosed as haemobilia and loeffler's pneumonia caused by ascaris lumbricoides., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Ascariasis is a neglected tropical disease that affects 800 million people worldwide. Whereas most people only experience light worm burden, some people experience heavy worm burdens even after several rounds of chemotherapy, a phenomenon known as predisposition. Such heavy infections are associated with more severe symptoms and increased chronic morbidity., Methods: In order to investigate potential mechanisms that may explain the observed predisposition, we infected mice with the porcine ascarid Ascaris suum using an established mouse model with two different mouse strains, where the C57BL/6J strain is more susceptible to infection and therefore a model for heavy infection and the CBA/Ca strain is more resistant and thus a model for light infection. At day 7 post-infection we investigated the liver proteome, using shotgun mass spectrometry, of both infected and control mice of each strain., Results: We identified intrinsic differences, between the two mouse strains, in both oxidative phosphorylation proteins and proteins involved in retinol metabolism. Additionally, we found differences between the two mouse strains in activation of the complement system, where the CBA/Ca strain has higher protein abundances for lectin pathway proteins and the C57BL/6J strain has higher protein abundances for complement inhibiting proteins. The CBA/Ca strain had a higher abundance of proteins involved in the activation of the complement cascade via the lectin pathway. In contrast, the C57BL/6J strain demonstrated a higher abundance of proteins involved in arresting the complement pathway., Conclusions: We observed clear differences between the two mouse strains both intrinsically and under infection.

This study investigates the relationship between helminth infection and allergic sensitization by assessing the influence of preexisting allergy on the outcome of helminth infections, rather than the more traditional approach in which the helminth infection precedes the onset of allergy. Here we used a murine model of house dust mite-induced (HDM-induced) allergic inflammation followed by Ascaris infection to demonstrate that allergic sensitization drives an eosinophil-rich pulmonary type 2 immune response (Th2 cells, M2 macrophages, type 2 innate lymphoid cells, IL-33, IL-4, IL-13, and mucus) that directly hinders larval development and reduces markedly the parasite burden in the lungs. This effect is dependent on the presence of eosinophils, as eosinophil-deficient mice were unable to limit parasite development or numbers. In vivo administration of neutralizing antibodies against CD4 prior to HDM sensitization significantly reduced eosinophils in the lungs, resulting in the reversal of the HDM-induced Ascaris larval killing. Our data suggest that HDM allergic sensitization drives a response that mimics a primary Ascaris infection, such that CD4+ Th2-mediated eosinophil-dependent helminth larval killing in the lung tissue occurs. This study provides insight into the mechanisms underlying tissue-specific responses that drive a protective response against the early stages of the helminths prior to their establishing long-lasting infections in the host.

Ascariasis is the most frequent soil transmitted helminthiasis and, as well as other helminth infections, is expected to influence the clinical presentation of allergic diseases such as asthma. Indeed, several clinical and experimental works have shown an important impact either increasing or suppressing symptoms, and the same effects have been detected on the underlying immune responses. In this review we analyze the work on this field performed in Colombia, a Latin American tropical country, including aspects such as the molecular genetics of the IgE response to Ascaris; the allergenic activity of Ascaris IgE-binding molecular components and the immunological and clinical influences of ascariasis on asthma. The analysis allows us to conclude that the impact of ascariasis on the inception and evolution of allergic diseases such as asthma deserves more investigation, but advances have been made during the last years. The concurrent parasite-induced immunostimulatory and immunosuppressive effects during this helminthiasis do modify the natural history of asthma and some aspects of the practice of allergology in the tropics. Theoretically it can also influence the epidemiological trends of allergic diseases either by its absence or presence in different regions and countries., (© 2018 John Wiley & Sons Ltd.)

Helminth parasites are highly prevalent in swine production, causing chronic infections and considerable morbidity due to growth retardation. Moreover, helminths actively modulate host immune responses to other pathogens and/or vaccines. Here, we investigated the modulatory effects of Ascaris suum adult body fluid (ABF) and Trichuris suis Soluble Products (TsSP) on the cytokine response in porcine peripheral blood mononuclear cells (PBMCs) and the intestinal epithelial cell line IPEC-J2. In PBMCs, TsSP induced the secretion of IL-6, IL-10 and IL-1β, but not TNF-α. Moreover, TsSP significantly enhanced the production of bacterial lipopolysaccharide (LPS)-induced IL-6 and IL-10 but suppressed the production of LPS-induced TNF-α. ABF did not induce cytokine secretion from PBMC, but suppressed LPS-induced secretion of TNF-α and IL-6. ABF did not have any effect on cytokine production in IPEC-J2 cells. In contrast, TsSP selectively induced the secretion of IL-6, and enhanced the IL-6 response induced by LPS. The IL-6 response appeared to be a conserved response to T. suis products, as significant secretion was also observed in alveolar macrophages. Thus, T. suis products have diverse modulatory effects on cytokine secretion in vitro, with IL-6 production a consistent feature of the innate host response., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ascaris lumbricoides (roundworm) is the most common helminth infection globally and a cause of lifelong morbidity that may include allergic airway disease, an asthma phenotype. We hypothesize that Ascaris larval migration through the lungs leads to persistent airway hyperresponsiveness (AHR) and type 2 inflammatory lung pathology despite resolution of infection that resembles allergic airway disease. Mice were infected with Ascaris by oral gavage. Lung AHR was measured by plethysmography and histopathology with hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) stains, and cytokine concentrations were measured by using Luminex Magpix. Ascaris -infected mice were compared to controls or mice with allergic airway disease induced by ovalbumin (OVA) sensitization and challenge (OVA/OVA). Ascaris -infected mice developed profound AHR starting at day 8 postinfection (p.i.), peaking at day 12 p.i. and persisting through day 21 p.i., despite resolution of infection, which was significantly increased compared to controls and OVA/OVA mice. Ascaris -infected mice had a robust type 2 cytokine response in both the bronchoalveolar lavage (BAL) fluid and lung tissue, similar to that of the OVA/OVA mice, including interleukin-4 (IL-4) ( P  < 0.01 and P < 0.01, respectively), IL-5 ( P  < 0.001 and P  < 0.001), and IL-13 ( P  < 0.001 and P  < 0.01), compared to controls. By histopathology, Ascaris -infected mice demonstrated early airway remodeling similar to, but more profound than, that in OVA/OVA mice. We found that Ascaris larval migration causes significant pulmonary damage, including AHR and type 2 inflammatory lung pathology that resembles an extreme form of allergic airway disease. Our findings indicate that ascariasis may be an important cause of allergic airway disease in regions of endemicity., (Copyright © 2018 American Society for Microbiology.)

Human ascariasis has a global and cosmopolitan distribution, and has been characterized as the most prevalent neglected tropical disease worldwide. The development of a preventive vaccine is highly desirable to complement current measures required for this parasitic infection control and to reduce chronic childhood morbidities. In the present study, we describe the mechanism of protection elicited by a preventive vaccine against ascariasis. Vaccine efficacy was evaluated after immunization with three different Ascaris suum antigen extracts formulated with monophosphoryl lipid A (MPLA) as an adjuvant: crude extract of adult worm (ExAD); crude extract of adult worm cuticle (CUT); and crude extract of infective larvae (L3) (ExL3). Immunogenicity elicited by immunization was assessed by measuring antibody responses, cytokine production, and influx of tissue inflammatory cells. Vaccine efficacy was evaluated by measuring the reductions in the numbers of larvae in the lungs of immunized BALB/c mice that were challenged with A. suum eggs. Moreover, lung physiology and functionality were tested by spirometry to determine clinical efficacy. Finally, the role of host antibody mediated protection was determined by passive transfer of serum from immunized mice. Significant reductions in the total number of migrating larvae were observed in mice immunized with ExL3 61% ( p < 0.001), CUT 59% ( p < 0.001), and ExAD 51% ( p < 0.01) antigens in comparison with non-immunized mice. For the Ascaris antigen-specific IgG antibody levels, a significant and progressive increase was observed with each round of immunization, in association with a marked increase of IgG1 and IgG3 subclasses. Moreover, a significant increase in concentration of IL-5 and IL-10 (pre-challenge) in the blood and IL-10 in the lung tissue (post-challenge) was induced by CUT immunization. Finally, ExL3 and CUT-immunized mice showed a marked improvement in lung pathology and tissue fibrosis as well as reduced pulmonary dysfunction induced by Ascaris challenge, when compared to non-immunized mice. Moreover, the passive transfer of specific IgG antibodies from ExL3, CUT, and ExAD elicited a protective response in naïve mice, with significant reductions in parasite burdens in lungs of 65, 64, and 64%, respectively. Taken together, these studies indicated that IgG antibodies contribute to protective immunity.

Epigenetic mechanisms, such as DNA methylation, determine immune cell phenotype. To understand the epigenetic alterations induced by helminth coinfections, we evaluated the longitudinal effect of ascariasis and schistosomiasis infection on CD4 + T cell DNA methylation and the downstream tuberculosis (TB)-specific and bacillus Calmette-Guérin-induced immune phenotype. All experiments were performed on human primary immune cells from a longitudinal cohort of recently TB-exposed children. Compared with age-matched uninfected controls, children with active Schistosoma haematobium and Ascaris lumbricoides infection had 751 differentially DNA-methylated genes, with 72% hypermethylated. Gene ontology pathway analysis identified inhibition of IFN-γ signaling, cellular proliferation, and the Th1 pathway. Targeted real-time quantitative PCR after methyl-specific endonuclease digestion confirmed DNA hypermethylation of the transcription factors BATF3 , ID2 , STAT5A , IRF5 , PPARg , RUNX2 , IRF4, and NFATC1 and cytokines or cytokine receptors IFNGR1 , TNFS11 , RELT (TNF receptor), IL12RB2, and IL12B ( p < 0.001; Sidak-Bonferroni). Functional blockage of the IFN-γ signaling pathway was confirmed, with helminth-infected individuals having decreased upregulation of IFN-γ-inducible genes (Mann-Whitney p < 0.05). Hypomethylation of the IL-4 pathway and DNA hypermethylation of the Th1 pathway was confirmed by Ag-specific multidimensional flow cytometry demonstrating decreased TB-specific IFN-γ and TNF and increased IL-4 production by CD4+ T cells (Wilcoxon signed-rank p < 0.05). In S. haematobium -infected individuals, these DNA methylation and immune phenotypic changes persisted at least 6 mo after successful deworming. This work demonstrates that helminth infection induces DNA methylation and immune perturbations that inhibit TB-specific immune control and that the duration of these changes are helminth specific., (Copyright © 2018 by The American Association of Immunologists, Inc.)

Parasitic worms (helminths) are known to actively modulate host immune responses and inflammation. The aim of this study was to investigate if adult body fluid (ABF) from the helminth Ascaris suum has immunomodulatory effects on different subtypes of human monocyte-derived macrophages (Mɸ) in vitro. Mɸs were exposed to A. suum ABF at different stages of their differentiation and/or polarization. Mɸ were first differentiated from monocytes into either uncommitted (M-), classically activated (M(GM-CSF)) or alternatively activated (M(M-CSF)) phenotypes and then stimulated with lipopolysaccharide (LPS). ABF strongly suppressed LPS-induced TNF-α, IL-6 and IL-10 secretion in M(GM-CSF)s, however in M(M-CSF)s only TNF-α was suppressed, with these cells secreting high levels of IL-10 which was not affected by ABF treatment. To determine if ABF modulated the differentiation of previously uncommitted Mɸ to either type 1 or type 2 Mɸ, monocytes were differentiated with human serum into (M-)s and then polarized by IFN-γ/LPS or IL-4 treatment in the presence of ABF. Under these conditions, ABF did not modulate cytokine secretion but did reduce CD80 expression in IFNγ/LPS-polarized cells but not IL-4-polarized cells. Finally, we demonstrate that when monocytes are differentiated into M(GMCSF)s in the presence of ABF, subsequent inflammatory responses are markedly suppressed. Our data suggest that ABF inhibits cytokine secretion and co-stimulatory molecule expression in classically activated Mɸ but not in alternatively activated Mɸ, indicating selective action of ABF depending on Mɸ subtype. Moreover, ABF appears to exert stronger activity when acting upon Mɸ that have already been polarized to the type 1 phenotype, rather than influencing the polarization process per se., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Ascaris suum is a helminth parasite of pigs closely related to its human counterpart, A. lumbricoides, which infects almost 1 billion people. Ascaris is thought to modulate host immune and inflammatory responses, which may drive immune hyporesponsiveness during chronic infections. Using transcriptomic analysis, we show here that pigs with a chronic A. suum infection have a substantial suppression of inflammatory pathways in the intestinal mucosa, with a broad downregulation of genes encoding cytokines and antigen-processing and costimulatory molecules. A. suum body fluid (ABF) suppressed similar transcriptional pathways in human dendritic cells (DCs) in vitro. DCs exposed to ABF secreted minimal amounts of cytokines and had impaired production of cyclooxygengase-2, altered glucose metabolism, and reduced capacity to induce interferon-gamma production in T cells. Our in vivo and in vitro data provide an insight into mucosal immune modulation during Ascaris infection, and show that A. suum profoundly suppresses immune and inflammatory pathways., (© The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

An evaluation of a localized intestinal allergic type-2 response concomitant with consumption of probiotic bacteria is not well documented. This study investigated the effect of feeding probiotic Bifidobacterium animalis subspecies lactis (Bb12) or a placebo in weaned pigs that were also inoculated with Ascaris suum (A. suum) eggs to induce a strong Th2-dependent allergic type 2 immune response. Sections of jejunal mucosa were mounted in Ussing chambers to determine changes in permeability and glucose absorption, intestine and liver samples were collected for analysis of type-2 related gene expression, jejunum examined histologically, and sera and intestinal fluid were assayed for parasite antigen specific antibody. The prototypical parasite-induced secretory response to histamine and reduced absorption of glucose in the jejunum were attenuated by feeding Bb12 without a change in mucosal resistance. Parasite antigen-specific IgA response in the serum and IgG1 and IgG2 response in the ileal fluid were significantly increased in A. suum-infected pigs treated with Bb12 compared to infected pigs given the placebo. Ascaris suum-induced eosinophilia in the small intestinal mucosa was inhibited by Bb12 treatment without affecting the normal expulsion of A. suum 4th stage larvae (L4) or the morphometry of the intestine. Expression of genes associated with Th1/Th2 cells, Treg cells, mast cells, and physiological function in the intestine were modulated in A. suum infected-pigs treated with Bb12. These results suggested that Bb12 can alter local immune responses and improve intestinal function during a nematode infection by reducing components of a strong allergenic type-2 response in the pig without compromising normal parasite expulsion.

Background: Animal and human studies indicate that definitive host helminth infections may confer protection from allergies. However, zoonotic helminths, such as Toxocara species (spp.), have been associated with increased allergies., Objective: We describe the prevalence of Toxocara spp. and Ascaris spp. seropositivity and associations with allergic diseases and sensitization, in 2 generations in Bergen, Norway., Methods: Serum levels of total IgG4, anti-Toxocara spp. IgG4 and Ascaris spp. IgG4 were established by ELISA in 2 cohorts: parents born 1945-1972 (n = 171) and their offspring born 1969-2003 (n = 264). Allergic outcomes and covariates were recorded through interviews and clinical examinations including serum IgEs and skin prick tests., Results: Anti-Ascaris spp. IgG4 was detected in 29.2% of parents and 10.3% of offspring, and anti-Toxocara spp. IgG4 in 17.5% and 8.0% of parents and offspring, respectively. Among offspring, anti-Toxocara spp. IgG4 was associated with pet keeping before age 15 (OR = 6.15; 95% CI = 1.37-27.5) and increasing BMI (1.16[1.06-1.25] per kg/m 2 ). Toxocara spp. seropositivity was associated with wheeze (2.97[1.45- 7.76]), hayfever (4.03[1.63-9.95]), eczema (2.89[1.08-7.76]) and cat sensitization (5.65[1.92-16.6]) among offspring, but was not associated with allergic outcomes among parents. Adjustment for childhood or current pet keeping did not alter associations with allergies. Parental Toxocara spp. seropositivity was associated with increased offspring allergies following a sex-specific pattern., Conclusions & Clinical Relevance: Zoonotic helminth exposure in Norway was less frequent in offspring than parents; however, Toxocara spp. seropositivity was associated with increased risk of allergic manifestations in the offspring generation, but not among parents. Changes in response to helminth exposure may provide insights into the increase in allergy incidence in affluent countries., (© 2017 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.)

Consumption of the probiotic bacteria Lactobacillus rhamnosus LGG and flavanol-rich cocoa have purported immune modulating effects. This study compared the host response to infection with Ascaris suum in three-month-old pigs fed a standard growth diet supplemented with a vehicle control: LGG, cocoa powder (CP) or LGG + CP. Pigs were inoculated with infective A . suum eggs during Week 5 of dietary treatment and euthanized 17 days later. Lactobacillus abundance was increased in pigs fed LGG or LGG + CP. Specific anti- A . suum IgG2 antibodies were decreased ( p < 0.05) in LGG + CP-fed pigs compared to pigs fed CP alone. Pigs fed LGG had significantly reduced expression ( p < 0.05) of Eosinophil peroxidase ( EPX) , Interleukin 13 ( IL-13) , Eotaxin 3 ( CCL26) , Toll-like receptor 2 ( TLR2 ), TLR4, and TLR9 and Interleukin-1Beta ( IL1B ) in the tracheal-bronchial lymph node (TBLN) independent of CP treatment. These results suggested that feeding LGG significantly reduced the localized prototypical Th2-related markers of infection with A . suum in the TBLN. Although feeding CP does not appear to affect the A . suum- induced Th2-associated cytokine response, feeding LGG + CP reduced anti- A . suum antibodies and delayed intestinal expulsion of parasitic larvae from the intestine., Competing Interests: The authors declare no conflict of interest.

Helminth infections have the ability to modulate host's immune response through mechanisms that allow the chronic persistence of the worms in the host. Here, we investigated the mechanisms involved on the suppressive effect of Ascaris suum infection using a murine experimental model of LPS-induced inflammation. We found that infection with A. suum markedly inhibited leucocyte influx induced by LPS into air pouches, suppressed secretion of pro-inflammatory cytokines (IL-1β, TNF-α and IL-6) and induced high levels of IL-10 and TGF-β. Augmented frequency of CD4 + CD25 high Foxp3 + T cells was observed in the mesenteric lymph nodes of infected mice. Adoptive transfer of purified CD4 + CD25 + T cells to recipient uninfected mice demonstrated that these cells were able to induce a suppressive effect in the LPS-induced inflammation in air pouch model. In addition, adoptive transfer of CD4 + CD25 + T cells derived from IL-10 knockout mice suggests that this suppressive effect of A. suum infection involves IL-10 cytokine. In conclusion, our results demonstrated that A. suum experimental infection was capable of suppressing LPS-induced inflammation by mechanisms, which seem to be dependent on responses of CD4 + CD25 + T cells and secretion of IL-10 cytokine., (© 2017 John Wiley & Sons Ltd.)

Dietary phytonutrients such as cinnamaldehyde (CA) may contribute to immune function during pathogen infections, and CA has been reported to have positive effects on gut health when used as feed additive for livestock. Here, we investigated whether CA could enhance antibody production and specific immune responses during infection with an enteric pathogen. We examined the effect of dietary CA on plasma antibody levels in parasite-naïve pigs, and subsequently acquisition of humoral immune responses during infection with the parasitic nematode Ascaris suum. Parasite-naïve pigs fed diets supplemented with CA had higher levels of total IgA and IgG in plasma, and A. suum-infected pigs fed CA had higher levels of parasite-specific IgM and IgA in plasma 14days post-infection. Moreover, dietary CA increased expression of genes encoding the B-cell marker CD19, sodium/glucose co-transporter1 (SCA5L1) and glucose transporter 2 (SLC2A2) in the jejunal mucosa of A.suum-infected pigs. Dietary CA induced only limited changes in the composition of the prokaryotic gut microbiota of A. suum-infected pigs, and in vitro experiments showed that CA did not directly induce proliferation or increase secretion of IgG and IgA from lymphocytes. Our results demonstrate that dietary CA can significantly enhance acquisition of specific immune responses in pigs. The underlying mechanism remains obscure, but apparently does not derive simply from direct contact between CA and host lymphocytes and appears to be independent of the gut microbiota., (Copyright © 2017 Elsevier B.V. All rights reserved.)

AbstractMore than 2 billion people are infected with parasites globally, and the majority have coinfections. Intestinal protozoa and helminths induce polarizing CD4 + T-helper cell 1 (Th1) mediated cytokine responses within the host. Such immune polarization may inhibit the ability of the host to mount an adequate immune response for pathogen clearance to concurrent pathogens. The current study evaluated the plasma cytokine profile in Ascaris and Giardia coinfected children compared with Giardia - and Ascaris -only infected children. Fecal samples and blood samples were collected from asymptomatic 3-year-old children living in the district of Quininde, Ecuador. Stool samples that tested positive for Giardia lamblia -only, Ascaris lumbricoides- only, or G. lamblia and A. lumbricoides coinfections were confirmed by quantitative real-time polymerase chain reaction. Plasma samples from the study subjects were used to quantitate cytokines. A total of 39 patients were evaluated. Children with coinfection had a significant decrease in Th1 cytokine production, interleukin 2 (IL-2) ( P < 0.05), IL-12 ( P < 0.05), and tumor necrosis factor alpha ( P < 0.05) compared with Giardia -only infected children. Coinfected children had an increase in IL-10/interferon gamma (IFN-γ) ratio compared with uninfected ( P < 0.05) and Ascaris alone ( P < 0.05). The increased IL-10/IFN-γ ratio in the setting of decreased Th1 cytokine response indicates Th2 polarization in the coinfected group. Reduced Th1 cytokines in children coinfected with Ascaris and Giardia may impair the host's ability to eradicate Giardia infection leading to chronic giardiasis.

A single nucleotide polymorphism on chromosome 4 (SNP TXNIP) has been reported to be associated with roundworm (Ascaris suum) burden in pigs. The objective of the present study was to analyse the immune response to A. suum mounted by pigs with genotype AA (n = 24) and AB (n = 23) at the TXNIP locus. The pigs were repeatedly infected with A. suum from eight weeks of age until necropsy eight weeks later. An uninfected control group (AA; n = 5 and AB; n = 5) was also included. At post mortem, we collected mesenteric lymph nodes and measured the expression of 28 selected immune-related genes. Recordings of worm burdens confirmed our previous results that pigs of the AA genotype were more resistant to infection than AB pigs. We estimated the genotype difference in relative expression levels in infected and uninfected animals. No significant change in expression levels between the two genotypes due to infection was observed for any of the genes, although IL-13 approached significance (P = 0.08; Punadjusted = 0.003). Furthermore, statistical analysis testing for the effect of infection separately in each genotype showed significant up-regulation of IL-13 (P<0.05) and CCL17 (P<0.05) following A. suum infection in the 'resistant' AA genotype and not in the 'susceptible' AB genotype. Pigs of genotype AB had higher expression of the high-affinity IgG receptor (FCGR1A) than AA pigs in both infected and non-infected animals (P = 1.85*10-11).

The aim of this work was to elucidate the immunopathological mechanisms of how helminths may influence the course of a viral infection, using a murine model. Severe virulence, a relevant increase in the virus titres in the lung and a higher mortality rate were observed in Ascaris and Vaccinia virus (VACV) co-infected mice, compared with VACV mono-infected mice. Immunopathological analysis suggested that the ablation of CD8 + T cells, the marked reduction of circulating CD4 + T cells producing IFN-γ, and the robust pulmonary inflammation were associated with the increase of morbidity/mortality in co-infection and subsequently with the negative impact of concomitant pulmonary ascariasis and respiratory VACV infection for the host. On the other hand, when evaluating the impact of the co-infection on the parasitic burden, co-infected mice presented a marked decrease in the total number of migrating Ascaris lung-stage larvae in comparison with Ascaris mono-infection. Taken together, our major findings suggest that Ascaris and VACV co-infection may potentiate the virus-associated pathology by the downmodulation of the VACV-specific immune response. Moreover, this study provides new evidence of how helminth parasites may influence the course of a coincident viral infection., (Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

Background: The pig parasite Ascaris suum plays and important role in veterinary medicine and represents a suitable model for A. lumbricoides, which infects over 800 million people. In pigs, continued exposure to Ascaris induces immunity at the level of the gut, protecting the host against migrating larvae. The objective of this study was to identify and characterize parasite antigens targeted by this local immune response that may be crucial for parasite invasion and establishment and to evaluate their protective and diagnostic potential., Methodology/principal Findings: Pigs were immunized by trickle infection for 30 weeks, challenged with 2,000 eggs at week 32 and euthanized two weeks after challenge. At necropsy, there was a 100% reduction in worms recovered from the intestine and a 97.2% reduction in liver white spots in comparison with challenged non-immune control animals. Antibodies purified from the intestinal mucus or from the supernatant of cultured antibody secreting cells from mesenteric lymph nodes of immune pigs were used to probe L3 extracts to identify antibody targets. This resulted in the recognition of a 12kDa antigen (As12) that is actively shed from infective Ascaris L3. As12 was characterized as a phosphorylcholine-containing glycolipid-like antigen that is highly resistant to different enzymatic and chemical treatments. Vaccinating pigs with an As12 fraction did not induce protective immunity to challenge infection. However, serological analysis using sera or plasma from experimentally infected pigs or naturally infected humans demonstrated that the As12 ELISA was able to detect long-term exposure to Ascaris with a high diagnostic sensitivity (98.4% and 92%, respectively) and specificity (95.5% and 90.0%) in pigs and humans, respectively., Conclusions/significance: These findings show the presence of a highly stage specific, glycolipid-like component (As12) that is actively secreted by infectious Ascaris larvae and which acts as a major antibody target in infected humans and pigs., Competing Interests: The authors have declared that no competing interests exist.

Background: Conventional diagnostic methods for human ascariasis are based on the detection of Ascaris lumbricoides eggs in stool samples. However, studies of ascariasis in pigs have shown that the prevalence and the number of eggs detected in the stool do not correlate well with exposure of the herd to the parasite. On the other hand, an ELISA test measuring antibodies to Ascaris suum haemoglobin (AsHb) has been shown to be useful for estimating transmission intensity on pig farms. In this study, we further characterized the AsHb antigen and screened samples from a population-based study conducted in an area that is endemic for Ascaris lumbricoides in Indonesia to assess changes in AsHb antibody rates and levels in humans following mass drug administration (MDA)., Methodology/principal Findings: We developed and evaluated an ELISA to detect human IgG4 antibodies to AsHb. We tested 1066 plasma samples collected at different times from 599 subjects who lived in a village in rural Indonesia that was highly endemic for ascariasis. The community received 6 rounds of MDA for lymphatic filariasis with albendazole plus diethylcarbamazine between 2002 and 2007. While the AsHb antibody assay was not sensitive for detecting all individuals with Ascaris eggs in their stools, the percentage of seropositive individuals decreased rapidly following MDA. Reductions in antibody rates reflected decreased mean egg output per person both at the community level and in different age groups. Two years after the last round of MDA the community egg output and antibody prevalence rate were reduced by 81.6% and 78.9% respectively compared to baseline levels., Conclusion/significance: IgG4 antibody levels to AsHb appear to reflect recent exposure to Ascaris. The antibody prevalence rate may be a useful indicator for Ascaris transmission intensity in communities that can be used to assess the impact of control measures on the force of transmission.

Ascaris spp. infection affects 800 million people worldwide, and half of the world population is currently at risk of infection. Recurrent reinfection in humans is mostly due to the simplicity of the parasite life cycle, but the impact of multiple exposures to the biology of the infection and the consequences to the host's homeostasis are poorly understood. In this context, single and multiple exposures in mice were performed in order to characterize the parasitological, histopathological, tissue functional and immunological aspects of experimental larval ascariasis. The most important findings revealed that reinfected mice presented a significant reduction of parasite burden in the lung and an increase in the cellularity in the bronchoalveolar lavage (BAL) associated with a robust granulocytic pulmonary inflammation, leading to a severe impairment of respiratory function. Moreover, the multiple exposures to Ascaris elicited an increased number of circulating inflammatory cells as well as production of higher levels of systemic cytokines, mainly IL-4, IL-5, IL-6, IL-10, IL-17A and TNF-α when compared to single-infected animals. Taken together, our results suggest the intense pulmonary inflammation associated with a polarized systemic Th2/Th17 immune response are crucial to control larval migration after multiple exposures to Ascaris.

Infection with intestinal helminths results in immunological changes that influence co-infections, and might influence fecundity by inducing immunological states affecting conception and pregnancy. We investigated associations between intestinal helminths and fertility in women, using 9 years of longitudinal data from 986 Bolivian forager-horticulturalists, experiencing natural fertility and 70% helminth prevalence. We found that different species of helminth are associated with contrasting effects on fecundity. Infection with roundworm (Ascaris lumbricoides) is associated with earlier first births and shortened interbirth intervals, whereas infection with hookworm is associated with delayed first pregnancy and extended interbirth intervals. Thus, helminths may have important effects on human fertility that reflect physiological and immunological consequences of infection., (Copyright © 2015, American Association for the Advancement of Science.)

Based on many years of experience in 2009, we developed the original concept of a mixed approach to the treatment of infectious diseases in patients. During 2.5 years(from 2013 to June 2015) to have applied for consultative-diagnostic help of 3965 patients who had not verified the primary diagnosis. The basic principle of verification of the pathology of the removal of various causes immunosuppression. Based on our extensive, research and observation was often found in patients ascaridosis (55%) and giardiasis (65%), as a possible cause of immunosuppression. In 13% of patients was found the mucosal candidiasis. Among frequently and chronically ill persons we identified the active forms of Epstein-Barr virus (quantitative polymerase chain reaction in saliva) in 40%. The criterion for assessing performance immunogram was a decrease of two sigmal deviation from the lower age limit. In the study of neutrophil myeloperoxidase content observed decline (< 60%) in 99 (9.7%) of 1015 patients, indicating a fairly common cause of long-term permit infection in the tissues and persistence C. albicans. In the study of lymphocyte subpopulations often demonstrated reduction in the number of natural killer cells (26.7% of subjects), which shows a decline of one of the most important factors of congenital immunity. Among the humoral immune disorders often noted the decrease of total IgG (2.4%) and its subclass IgG1 (22.1%), indicating a significant diagnostic value determination of IgG subclasses it even with normal serum total. Thus, approximately 76% of patients often suffer set of a decrease immunity. Patients developed with mixed infections caused by various bacterial, fungal, viral and protozoan agents and worms. Immunological study of patients should be redynamics after eliminating the causes immunosuppression and sanitation foci of infection. Only multi-level examination of the patient will determine the final diagnosis and adequate treatment.

It is not currently clear whether different parasites have distinct effects on the airway inflammatory response in asthma and whether exposure in early life to helminths have a stronger impact in a potential inhibitory effect on asthma. The aim of this study is to evaluate the effect of exposure to different helminth extracts on the development of allergic pulmonary response in mice, including early-life exposure. Different helminth extracts (Angiostrongylus costaricensis, Angiostrongylus cantonensis and Ascaris lumbricoides) were studied in female adult BALB/c and C57BL/6 IL-10-deficient mice in a protocol of murine asthma, injected intraperitoneally in different periods of exposure (early, pre-sensitization and post-sensitization). Cell counts in bronchoalveolar lavage (BAL), eosinophil peroxidase (EPO) from lung tissue, cytokine levels from BAL/spleen cell cultures, and lung histology were analyzed. Airway cellular influx induced by OVA was significantly inhibited by extracts of A. cantonensis and A. lumbricoides. Extracts of A. lumbricoides and A. costaricensis led to a significant reduction of IL-5 in BAL (p < 0.001). Only the exposure to A. lumbricoides led to an increased production of IL-10 in the lungs (p < 0.001). In IL-10-deficient mice exposed to A. costaricensis pre-sensitization, eosinophil counts and IL-5 levels in BAL and EPO in lung tissue were significantly reduced. In the early exposure to A. cantonensis, lung inflammation was clearly inhibited. In conclusion, different helminth extracts inhibit allergic lung inflammation in mice. IL-10 may not play a central role in some helminth-host interactions. Early exposure to helminth extracts could be a potential strategy to explore primary prevention in asthma., (Copyright © 2015 Elsevier Inc. All rights reserved.)

A humoral immune response following helminth infection in pigs is well documented. However, it has been difficult to confirm the existence of antibody mediated resistance against the large roundworm, Ascaris suum, and whipworm, Trichuris suis, in experimental settings by correlating worm burdens or egg excretion with specific antibody levels. We set out to investigate the association between worm load and T. suis and A. suum specific serum antibody levels (IgG1, IgG2 and IgA) against excretory-secretory products of adults and third stage larvae, respectively, measured at 0, 7 and 14 weeks p.i. in a trickle-infected F1-resource-population of crossbred pigs (n=195). Furthermore, we wanted to determine the heritability of these antibody isotypes during the course of infection. Most pigs remained infected with A. suum throughout the experiment while they expelled T. suis between 7 and 14 weeks post infection (p.i.). Parasite specific IgG1 and IgA were significantly (P<0.001) elevated after 7 and 14 weeks of infection, whereas parasite specific IgG2 levels only changed slightly at 14 weeks p.i.. However, the observed association between specific antibody isotype levels and faecal egg counts and macroscopic worm load was weak. The relative heritabilities of the different parasite specific isotypes were assessed and resulted in significant heritability estimates for parasite specific IgG1 and IgA. The highest heritabilities were found for A. suum specific IgG1 (h(2)=0.41 and 0.46 at 7 and 14 weeks p.i., respectively). Thus, the present study demonstrates that host genetic factors influence the IgG1 and IgA antibody isotype responses specific to two of the most common gastrointestinal nematodes of swine whereas specific antibody levels were poorly associated with egg excretion and the presence of macroscopic worms., (Copyright © 2015. Published by Elsevier B.V.)

Visceral larva migrans (VLM) syndrome caused by Toxocara canis larvae was first described in the 1950s. The role of other nematode larvae, i.e. the pig roundworm Ascaris suum as a causative agent of visceral larva migrans-associated symptoms like general malaise, cough, liver dysfunction, hypereosinophilia with hepatomegaly and/or pneumonia, was discussed controversially during the last decades. Recent serological screening studies for specific A. suum antibodies carried out in the Netherlands and Sweden yielded remarkable high seroprevalences, while a number of case reports from Japan report pulmonal, hepatic and cerebral symptoms caused by A. suum larvae after ingestion of infected raw meat (liver) or contaminated vegetables. We present here a sensitive and specific larval excretory-secretory (E/S) antigen-based immunoblot (As-IB) for the serodiagnosis of A. suum-infected patients suffering from symptoms associated to the VLM syndrome. In total, 34 sera from patients with hypereosinophilia and other clinical symptoms associated to the VLM syndrome tested negative for Toxocara sp. antibodies but positive in our newly established As-IB, 30 sera from healthy volunteers, 53 sera from patients with clinically and serologically confirmed toxocarosis and other helminthoses as well as 3 sera from patients with intestinal ascariosis due to Ascaris lumbricoides were included in the study. When evaluated with 30 sera from healthy volunteers and 53 sera from patients suffering from different helminthoses, the calculated specificity of our new As-IB is 95%. Problems hampering the establishment of simple serological screening tests for specific A. suum antibodies, like extensive antigenic similarities between the nematodes Ascaris and Toxocara or the absence of suitable experimental animals, are discussed. We assume that specific serological testing for antibodies of A. suum is very important for the treatment of individual patients on one hand and seroepidemiological investigations will help to clarify routes of transmission on the other hand. Further studies will be necessary to learn more about the extent of A. suum as a causative agent of the VLM syndrome and the role of pigs and their manure as the main source of human Ascaris infections in Austria and other industrialized countries.

The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.