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Tuberculosis remains one of the leading public health problems in the world. The mechanisms that lead to the activation of the immune response against Mycobacterium tuberculosis have been extensively studied, with a focus on the role of cytokines as the main signals for immune cell communication. However, less is known about the role of other signals, such as extracellular vesicles, in the communication between immune cells, particularly during the activation of the adaptive immune response. In this study, we determined that extracellular vesicles released by human neutrophils infected with M. tuberculosis contained several host proteins that are ectosome markers. In addition, we demonstrated that extracellular vesicles released by human neutrophils infected with M. tuberculosis released after only 30 min of infection carried mycobacterial antigens and pathogen-associated molecular patterns, and we identified 15 mycobacterial proteins that were consistently found in high concentrations in extracellular vesicles released by human neutrophils infected with M. tuberculosis; these proteins contain epitopes for CD4 T-cell activation. We found that extracellular vesicles released by human neutrophils infected with M. tuberculosis increased the expression of the costimulatory molecule CD80 and of the coinhibitory molecule PD-L1 on immature monocyte-derived dendritic cells. We also found that immature and mature dendritic cells treated with extracellular vesicles released by human neutrophils infected with M. tuberculosis were able to induce IFN-γ production by autologous M. tuberculosis antigen-specific CD4 T cells, indicating that these extracellular vesicles acted as antigen carriers and transferred mycobacterial proteins to the antigen-presenting cells. Our results provide evidence that extracellular vesicles released by human neutrophils infected with M. tuberculosis participate in the activation of the adaptive immune response against M. tuberculosis.

The clinical presentation of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ranges between mild respiratory symptoms and a severe disease that shares many of the features of sepsis. Sepsis is a deregulated response to infection that causes life-threatening organ failure. During sepsis, the intestinal epithelial cells are affected, causing an increase in intestinal permeability and allowing microbial translocation from the intestine to the circulation, which exacerbates the inflammatory response. Here we studied patients with moderate, severe and critical COVID-19 by measuring a panel of molecules representative of the innate and adaptive immune responses to SARS-CoV-2, which also reflect the presence of systemic inflammation and the state of the intestinal barrier. We found that non-surviving COVID-19 patients had higher levels of low-affinity anti-RBD IgA antibodies than surviving patients, which may be a response to increased microbial translocation. We identified sFas and granulysin, in addition to IL-6 and IL-10, as possible early biomarkers with high sensitivity (73 %) and specificity (51 %) to discriminate between surviving and non-surviving COVID-19 patients. Finally, we found that the microbial metabolite d-lactate and the tight junction regulator zonulin were increased in the serum of patients with severe COVID-19 and in COVID-19 patients with secondary infections, suggesting that increased intestinal permeability may be a source of secondary infections in these patients. COVID-19 patients with secondary infections had higher disease severity and mortality than patients without these infections, indicating that intestinal permeability markers could provide complementary information to the serum cytokines for the early identification of COVID-19 patients with a high risk of a fatal outcome.

Most individuals infected with Mycobacterium tuberculosis (Mtb) have latent tuberculosis (TB), which can be diagnosed with tests (such as the QuantiFERON-TB Gold test [QFT]) that detect the production of IFN-γ by memory T cells in response to the Mtb-specific antigens 6 kDa early secretory antigenic target EsxA (Rv3875) (ESAT-6), 10 kDa culture filtrate antigen EsxB (Rv3874) (CFP-10), and Mtb antigen of 7.7 kDa (Rv2654c) (TB7.7). However, the immunological mechanisms that determine if an individual will develop latent or active TB remain incompletely understood. Here we compared the response of innate and adaptive peripheral blood lymphocytes from healthy individuals without Mtb infection (QFT negative) and from individuals with latent (QFT positive) or active TB infection, to determine the characteristics of these cells that correlate with each condition. In active TB patients, the levels of IFN-γ that were produced in response to Mtb-specific antigens had high positive correlations with IL-1β, TNF-α, MCP-1, IL-6, IL-12p70, and IL-23, while the proinflammatory cytokines had high positive correlations between themselves and with IL-12p70 and IL-23. These correlations were not observed in QFT-negative or QFT-positive healthy volunteers. Activation with Mtb-soluble extract (a mixture of Mtb antigens and pathogen-associated molecular patterns [PAMPs]) increased the percentage of IFN-γ-/IL-17-producing NK cells and of IL-17-producing innate lymphoid cell 3 (ILC3) in the peripheral blood of active TB patients, but not of QFT-negative or QFT-positive healthy volunteers. Thus, active TB patients have both adaptive and innate lymphocyte subsets that produce characteristic cytokine profiles in response to Mtb-specific antigens or PAMPs. These profiles are not observed in uninfected individuals or in individuals with latent TB, suggesting that they are a response to active TB infection.

Listeria monocytogenes (L.m) is efficiently controlled by several cells of the innate immunity, including the Mast Cell (MC). MC is activated by L.m inducing its degranulation, cytokine production and microbicidal mechanisms. TLR2 is required for the optimal control of L.m infection by different cells of the immune system. However, little is known about the MC receptors involved in recognizing this bacterium and whether these interactions mediate MC activation. In this study, we analyzed whether TLR2 is involved in mediating different MC activation responses during L.m infection. We found that despite MC were infected with L.m, they were able to clear the bacterial load. In addition, MC degranulated and produced ROS, TNF-α, IL-1β, IL-6, IL-13 and MCP-1 in response to bacterial infection. Interestingly, L.m induced the activation of signaling proteins: ERK, p38 and NF-κB. When TLR2 was blocked, L.m endocytosis, bactericidal activity, ROS production and mast cell degranulation were not affected. Interestingly, only IL-6 and IL-13 production were affected when TLR2 was inhibited in response to L.m infection. Furthermore, p38 activation depended on TLR2, but not ERK or NF-κB activation. These results indicate that TLR2 mediates only some MC activation pathways during L.m infection, mainly those related to IL-6 and IL-13 production.

Leprosy, a human chronic granulomatous disease caused by Mycobacterium leprae (M. leprae), remains endemic in certain countries despite the use of multidrug therapy. Recently, several host genes modulating the immune responses to M. leprae infection have been suggested to influence the acquisition and clinical course of leprosy. Lymphoid protein tyrosine phosphatase, encoded by the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene, serves a negative regulatory role in T cell activation. The non-synonymous single-nucleotide polymorphism (SNP) rs2476601 (1858C>T) has been associated with autoimmune diseases. Here, the present study investigated if rs2476601 polymorphism was associated with leprosy in a Mexican mestizo population. Genotyping was performed in patients with leprosy (n=189) and control subjects (n=231) from regions with higher incidence of leprosy. Genotypic (P=0.44) and allelic frequencies (P=0.45) of the rs2476601 polymorphism were similar between patients and controls; genotypic frequencies were 91 vs. 94% for CC and 9 vs. 6% for CT, and the TT genotype was absent in both groups. Allelic frequencies were 96 vs. 97% for C, and 4 vs. 3% for T. In the same way, the genotypic (P=0.46) and allelic frequencies (P=0.47) from MB patients and controls were similar. In conclusion, there was a lack of association of the PTPN22 rs2476601 polymorphism with the development of leprosy, which suggests that this SNP was not a genetic risk factor for leprosy in the Mexican mestizo population studied.

The immune response plays a critical role in the pathophysiology of SARS‐CoV‐2 infection ranging from protection to tissue damage and all occur in the development of acute respiratory distress syndrome (ARDS). ARDS patients display elevated levels of inflammatory cytokines and innate immune cells, and T and B cell lymphocytes have been implicated in this dysregulated immune response. Mast cells are abundant resident cells of the respiratory tract and are able to release different inflammatory mediators rapidly following stimulation. Recently, mast cells have been associated with tissue damage during viral infections, but their role in SARS‐CoV‐2 infection remains unclear. In this study, we examined the profile of mast cell activation markers in the serum of COVID‐19 patients. We noticed that SARS‐CoV‐2‐infected patients showed increased carboxypeptidase A3 (CPA3) and decreased serotonin levels in their serum when compared with symptomatic SARS‐CoV‐2‐negative patients. CPA3 levels correlated with C‐reactive protein, the number of circulating neutrophils, and quick SOFA. CPA3 in serum was a good biomarker for identifying severe COVID‐19 patients, whereas serotonin was a good predictor of SARS‐CoV‐2 infection. In summary, our results show that serum CPA3 and serotonin levels are relevant biomarkers during SARS‐CoV‐2 infection. This suggests that mast cells and basophils are relevant players in the inflammatory response in COVID‐19 and may represent targets for therapeutic intervention., Graphical Abstract Serum levels of CPA3 and serotonin are affected during SARS‐CoV‐2 infection and can be considered as biomarkers during COVID‐19.

Valproic acid (VPA) is a drug commonly used for epileptic seizure control. Recently, it has been shown that VPA alters the activation of several immune cells, including Natural Killer (NK) cells, which play an important role in the containment of viruses and intracellular bacteria. Although VPA can increase susceptibility to extracellular pathogens, it is unknown whether the suppressor effect of VPA could affect the course of intracellular bacterial infection. This study aimed to evaluate the role of VPA during Listeria monocytogenes (L.m) infection, and whether NK cell activation was affected. We found that VPA significantly augmented mortality in L.m infected mice. This effect was associated with increased bacterial load in the spleen, liver, and blood. Concurrently, decreased levels of IFN-γ in serum and lower splenic indexes were observed. Moreover, in vitro analysis showed that VPA treatment decreased the frequency of IFN-γ-producing NK cells within L.m infected splenocytes. Similarly, VPA inhibited the production of IFN-γ by NK cells stimulated with IL-12 and IL-18, which is a crucial system for early IFN-γ production in listeriosis. Finally, VPA decreased the phosphorylation of STAT4, p65, and p38, without affecting the expression of IL-12 and IL-18 receptors. Altogether, our results indicate that VPA increases the susceptibility to Listeria monocytogenes infection and suggest that NK cell is one of the main targets of VPA, but further work is needed to ascertain this effect.

Mast cell activation through the high-affinity IgE receptor (FcεRI) plays a central role in allergic reactions. FcεRI-mediated activation triggers multiple signaling pathways leading to degranulation and synthesis of different inflammatory mediators. IgE-mediated mast cell activation can be modulated by different molecules, including several drugs. Herein, we investigated the immunomodulatory activity of the histone deacetylase inhibitor valproic acid (VPA) on IgE-mediated mast cell activation. To this end, bone marrow-derived mast cells (BMMC) were sensitized with IgE and treated with VPA followed by FcεRI cross-linking. The results indicated that VPA reduced mast cell IgE-dependent degranulation and cytokine release. VPA also induced a significant reduction in the cell surface expression of FcεRI and CD117, but not other mast cell surface molecules. Interestingly, VPA treatment inhibited the phosphorylation of PLCγ2, a key signaling molecule involved in IgE-mediated degranulation and cytokine secretion. However, VPA did not affect the phosphorylation of other key components of the FcεRI signaling pathway, such as Syk, Akt, ERK1/2, or p38. Altogether, our data demonstrate that VPA affects PLCγ2 phosphorylation, which in turn decreases IgE-mediated mast cell activation. These results suggest that VPA might be a key modulator of allergic reactions and might be a promising therapeutic candidate.

Mast cells play an essential role in different immunological phenomena including allergy and infectious diseases. Several bacteria induce mast cell activation leading to degranulation and the production of several cytokines and chemokines. However, mast cells also have different microbicidal activities such as phagocytosis and the release of DNA with embedded granular proteins known as Mast Cell Extracellular Traps (MCETs). Although previous reports indicate that extracellular bacteria are able to induce MCETs little is known if intracellular bacteria can induce these structures. In this work, we evaluated MCETs induction by the intracellular bacteria Listeria monocytogenes. We found that mast cells released DNA after stimulation with L. monocytogenes, and this DNA was complexed to histone and tryptase. Before extracellular DNA release, L. monocytogenes induced modifications to the mast cell nuclear envelope and DNA was detected outside the nucleus. L. monocytogenes stimulated mast cells to produce significant amounts of reactive oxygen species (ROS) and blocking NADPH oxidase diminished DNA release by mast cells. Finally, MCETs showed antimicrobial activity against L. monocytogenes that was partially blocked when β-hexosaminidase activity was inhibited. These results show that L. monocytogenes induces mast cells to produce microbicidal MCETs, suggesting a role for mast cells in containing infection beyond the induction of inflammation.

Despite the use of multidrug therapy, leprosy remains endemic in some countries. The association of several human leucocyte antigen (HLA) alleles and gene polymorphisms with leprosy has been demonstrated in many populations, but the major immune contributors associated to the spectrum of leprosy have not been defined yet. In this study, genotyping of HLA-A, -B, -DR, and -DQ alleles was performed in leprosy patients (n = 113) and control subjects (n = 117) from the region with the highest incidence for the disease in Mexico. The odds of developing leprosy and lepromatous subtype were 2.12- and 2.74-fold higher in carriers of HLA-A*28, and 2.48- and 4.14-fold higher for leprosy and dimorphic subtype in carriers of DQB1*06. Interestingly, DQB1*07 was overrepresented in healthy individuals, compared to patients with leprosy (OR = 0.08) and the lepromatous subtype (OR = 0.06). These results suggest that HLA-A*28 is a marker for predisposition to leprosy and the lepromatous subtype and DQB1*06 to leprosy and the dimorphic subtype, while DQB1*07 might be a resistance marker in this Mestizo population.

Transferon® is a complex drug based on a mixture of low molecular weight peptides. This biotherapeutic is employed as a coadjuvant in clinical trials of several diseases, including viral infections and allergies. Given that macrophages play key roles in pathogen recognition, phagocytosis, processing, and antigen presentation, we evaluated the effect of Transferon® on phenotype and function of macrophage-like cells derived from THP-1 monocytes. We determined the surface expression of CD80 and CD86 by flow cytometry and IL-1β, TNF-α, and IL-6 levels by ELISA. Transferon® alone did not alter the steady state of PMA-differentiated macrophage-like THP-1 cells. On the contrary, simultaneous stimulation of cells with Transferon® and LPS elicited a significant increase in CD80 (P≤0.001) and CD86 (P≤0.001) expression, as well as in IL-6 production (P≤0.05) compared to the LPS control. CD80 expression and IL-6 production exhibited a positive correlation (r=0.6, P≤0.05) in cells exposed to Transferon® and LPS. Our results suggest that the administration of Transferon® induces the expression of costimulatory molecules and the secretion of cytokines in LPS-activated macrophages. Further studies are necessary to determine the implication of these findings in the therapeutic properties of Transferon®.

Tuberculosis (TB), although a curable disease, remains a major cause of morbidity and mortality worldwide. It is necessary to develop a short-term therapy with reduced drug toxicity in order to improve adherence rate and control disease burden. Granulocyte-macrophage colony-stimulating factor (GM-CSF) may be a key cytokine in the treatment of pulmonary TB since it primes the activation and differentiation of myeloid and non-myeloid precursor cells, inducing the release of protective Th1 cytokines. In this work, we administrated by intratracheal route recombinant adenoviruses encoding GM-CSF (AdGM-CSF). This treatment produced significant bacterial elimination when administered in a single dose at 60 days of infection with drug sensitive or drug resistant Mtb strains in a murine model of progressive disease. Moreover, AdGM-CSF combined with primary antibiotics produced more rapid elimination of pulmonary bacterial burdens than conventional chemotherapy suggesting that this form of treatment could shorten the conventional treatment.

Reconstitution of the hematopoietic system during immune responses and immunological and neoplastic diseases or upon transplantation depends on the emergent differentiation of hematopoietic stem/progenitor cells within the bone marrow. Although in the last decade the use of dialyzable leukocyte extracts (DLE) as supportive therapy in both infectious and malignant settings has increased, its activity on the earliest stages of human hematopoietic development remains poorly understood. Here, we have examined the ability of DLE to promote replenishment of functional lymphoid lineages from CD34+cells. Our findings suggest that DLE increases their differentiation toward a conspicuous CD56+CD16+CD11c+NK-like cell population endowed with properties such as IFNy production, tumor cell cytotoxicity, and the capability of inducingγδT lymphocyte proliferation. Of note, long-term coculture controlled systems showed the bystander effect of DLE-stromal cells by providing NK progenitors with signals to overproduce this cell subset. Thus, by direct effect on progenitor cells and through activation and remodeling of the supporting hematopoietic microenvironment, DLE may contribute a robust innate immune response by promoting the emerging lymphopoiesis of functional CD11c+NK cells in a partially TLR-related manner. Unraveling the identity and mechanisms of the involved DLE components may be fundamental to advance the NK cell-based therapy field.

Tuberculosis is one of the leading causes of mortality worldwide, it is caused by Mycobacterium tuberculosis (Mtb), a bacteria that employs several strategies to evade the host immune response. For instance, Mtb interferes with the overexpression of class II transactivator (CIITA) in macrophages exposed to IFN-γ by inhibiting histone acetylation at its promoter, which can be reverted by the histone deacetylase inhibitor (HDACi) sodium butyrate. In this work, we evaluated whether a different HDACi, valproic acid (VPA), could revert the inhibition of gene expression induced by Mtb. J774 macrophages treated with VPA and IFN-γ unexpectedly induced a higher expression of the inducible nitric oxide synthase and a higher production of nitric oxide when exposed to the 19 kDa lipoprotein of Mtb or the whole bacteria. However, VPA was unable to revert the inhibition of CIITA expression induced by the 19 kDa lipoprotein of Mtb. Finally, macrophages infected with Mtb and treated with VPA and IFN-γ showed a significant reduction in intracellular bacteria. Our findings suggest a new therapeutic potential of VPA for the treatment of tuberculosis.

Valproic acid (VPA) is widely recognized for its use in the control of epilepsy and other neurological disorders in the past 50 years. Recent evidence has shown the potential of VPA in the control of certain cancers, owed in part to its role in modulating epigenetic changes through the inhibition of histone deacetylases, affecting the expression of genes involved in the cell cycle, differentiation, and apoptosis. The direct impact of VPA in cells of the immune system has only been explored recently. In this review, we discuss the effects of VPA in the suppression of some activation mechanisms in several immune cells that lead to an anti-inflammatory response. As expected, immune cells are not exempt from the effect of VPA, as it also affects the expression of genes of the cell cycle and apoptosis through epigenetic modifications. In addition to inhibiting histone deacetylases, VPA promotes RNA interference, activates histone methyltransferases, or represses the activation of transcription factors. However, during the infectious process, the effectiveness of VPA is subject to the biological nature of the pathogen and the associated immune response; this is because VPA can promote the control or the progression of the infection. Due to its various effects, VPA is a promising alternative for the control of autoimmune diseases and hypersensitivity and needs to be further explored.

Tuberculosis is one of the leading causes of human morbidity and mortality. Mycobacterium tuberculosis (Mtb) employs different strategies to evade and counterattack immune responses persisting for years. Mast cells are crucial during innate immune responses and help clear infections via inflammation or by direct antibacterial activity through extracellular traps (MCETs). Whether Mtb induce MCETs production is unknown. In this study, we report that viable Mtb did not induce DNA release by mast cells, but heat-killed Mtb (HK-Mtb) did. DNA released by mast cells after stimulation with HK-Mtb was complexed with histone and tryptase. MCETs induced with PMA and HK-Mtb were unable to kill live Mtb bacilli. Mast cells stimulated with HK-Mtb induced hydrogen peroxide production, whereas cells stimulated with viable Mtb did not. Moreover, MCETs induction by HK-Mtb was dependent of NADPH oxidase activity, because its blockade resulted in a diminished DNA release by mast cells. Interestingly, catalase-deficient Mtb induced a significant production of hydrogen peroxide and DNA release by mast cells, indicating that catalase produced by Mtb prevents MCETs release by degrading hydrogen peroxide. Our findings show a new strategy employed by Mtb to overcome the immune response through inhibiting MCETs formation, which could be relevant during early stages of infection.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis (Mtb). In the lungs, macrophages and neutrophils are the first immune cells that have contact with the infecting mycobacteria. Neutrophils are phagocytic cells that kill microorganisms through several mechanisms, which include the lytic enzymes and antimicrobial peptides that are found in their lysosomes, and the production of reactive oxygen species. Neutrophils also release extracellular vesicles (EVs) (100–1,000 nm in diameter) to the extracellular milieu; these EVs consist of a lipid bilayer surrounding a hydrophilic core and participate in intercellular communication. We previously demonstrated that human neutrophils infected in vitro with Mtb H37Rv release EVs (EV-TB), but the effect of these EVs on other cells relevant for the control of Mtb infection, such as macrophages, has not been completely analyzed. In this study, we characterized the EVs produced by non-stimulated human neutrophils (EV-NS), and the EVs produced by neutrophils stimulated with an activator (PMA), a peptide derived from bacterial proteins (fMLF) or Mtb, and observed that the four EVs differed in their size. Ligands for toll-like receptor (TLR) 2/6 were detected in EV-TB, and these EVs favored a modest increase in the expression of the co-stimulatory molecules CD80, a higher expression of CD86, and the production of higher amounts of TNF-α and IL-6, and of lower amounts of TGF-β, in autologous human macrophages, compared with the other EVs. EV-TB reduced the amount of intracellular Mtb in macrophages, and increased superoxide anion production in these cells. TLR2/6 ligation and superoxide anion production are known inducers of autophagy; accordingly, we found that EV-TB induced higher expression of the autophagy-related marker LC3-II in macrophages, and the co-localization of LC3-II with Mtb inside infected macrophages. The intracellular mycobacterial load increased when autophagy was inhibited with wortmannin in these cells. In conclusion, our results demonstrate that neutrophils produce different EVs in response to diverse activators, and that EV-TB activate macrophages and promote the clearance of intracellular Mtb through early superoxide anion production and autophagy induction, which is a novel role for neutrophil-derived EVs in the immune response to Mtb.

Transferon, a human dialyzable leukocyte extract (hDLE), is a biotherapeutic that comprises a complex mixture of low-molecular-weight peptides (

Lungs are indispensable organs for the respiratory process, and maintaining their homeostasis is essential for human health and survival. However, during the lifetime of an individual, the lungs suffer countless insults that put at risk their delicate organization and function. Many cells of the immune system participate to maintain this equilibrium and to keep functional lungs. Among these cells, mast cells have recently attracted attention because of their ability to rapidly secrete many chemical and biological mediators that modulate different processes like inflammation, angiogenesis, cell proliferation, etc. In this review, we focus on recent advances in the understanding of the role that mast cells play in lung protection during infections, and of the relation of mast cell responses to type I hypersensitivity-associated pathologies. Furthermore, we discuss the potential role of mast cells during wound healing in the lung and its association with lung cancer, and how mast cells could be exploited as therapeutic targets in some diseases.

Tuberculosis (TB) is an airborne disease caused by Mycobacterium tuberculosis. Only 10% of the infected individuals develop an active disease, while 90% of the infected individuals contain the mycobacteria inside structures known as granulomas, in a latent, asymptomatic state. The lung granuloma is formed by a core of infected macrophages, foam cells and epithelioid macrophages, surrounded by several lymphocyte subsets (CD4 T cells, CD8 T cells, Tγδ cells, NK cells, and B cells). M. tuberculosis releases extracellular vesicles, both spontaneously and under stress conditions; these vesicles carry components, derived from the mycobacterial cell wall, that are ligands for human Toll-like receptors (TLR) 2/6 and 4; as a result, these vesicles activate the innate immune system. To determine if M. tuberculosis extracellular vesicles induce the formation of a granuloma-like structure, we used an in vitro granuloma model, with peripheral blood mononuclear cells from individuals with latent TB (positive for the Quantiferon test). We found that M. tuberculosis extracellular vesicles induced the formation of granuloma-like structures that were similar in numbers, diameters and cellular composition (percentage of monocytes, T cells, Tγδ cells, NK cells and ILCs) to the granuloma-like structures formed in response to live M. tuberculosis H37Rv. These results suggest that M. tuberculosis extracellular vesicles participate in the cellular activation and migration processes that lead to granuloma formation in the lungs of TB patients. Supported by a grant 20190106 from Secretaría de Investigación y Posgrado, Instituto Politécnico Nacional.

Ulcerative dermatitis (UD) is common in captive sea turtles and manifests as skin erosions and ulcers associated with gram-negative bacteria. This study compared clinically healthy and UD-affected captive turtles by evaluating hematology, histopathology, immunoglobulin levels, and delayed-type hypersensitivity assay. Turtles with UD had significantly lower weight, reduced delayed-type hypersensitivity (DTH) responses, and higher heterophil:lymphocyte ratios. This study is the first to assay DTH in green turtles (Chelonia mydas) and suggests that UD is associated with immunosuppression.

Enterotoxigenic Escherichia coli (ETEC) are a major cause of diarrheal disease in humans, calves and pigs. In humans, these infections mainly occur in developing countries leading to a high diarrheal morbidity and infant mortality and to travellers' diarrhea. ETEC strains constitute a phenotypically and genetically diverse pathotype with as common characteristics the production of heat-labile (LT) and/or heat-stable enterotoxins (ST) as well as of one or more fimbrial colonization factors. Despite the global importance of these pathogens, a broadly ETEC protective vaccine is not yet available, partially due to the lack of a suitable animal model for human ETEC. Such model would allow to test more ETEC molecules as potential vaccine candidates. The C57-CD40 ligand deficient (C57-cd40l(-/-)) mouse has been successfully used to develop infection models of intestinal pathogens, but little is known about its humoral immune response. Therefore, the aims of this study were to characterize the humoral immune response of C57 and C57-cd40l(-/-) mice and to determine the persistence of ETEC H10407 and two of its variants after oral inoculation. The serum IgM, IgG and IgA and faecal IgG and IgA concentrations, of twelve mice per mouse strain (C57 and C57-cd40l(-/-)), were determined by ELISA. All serum immunoglobulins and the faecal IgG concentration were significantly lower in C57-cd40l(-/-) than in C57 mice. In contrast the faecal IgA concentration was significantly higher in the C57-cd40l(-/-) mice. This high intestinal IgA concentration might be a compensatory T cell-independent production of IgA production. Both mouse strains were orally inoculated with 5×10(8) ETEC H10407 (LT(+), ST-colonization factor antigen I (CFA/I)(+)) and ETEC in animal faeces was established by culture followed by st and lt loci identification by PCR until day 14 post infection. Most C57 mice eliminated the strain within 3 days whereas infection remained in C57-cd40l(-/-) mice until day 14. Subsequently both mouse strains were inoculated with ETEC H10407 variants and followed up until day 113. Likewise C57 mice eliminated both ETEC variants within 4 days. All C57-cd40l(-/-) mice had eliminated the LT(-) variant at day 31, whereas the ST-CFA/I(-) variant remained in mice stools until day 113. These observations suggest that C57-cd40l(-/-) mice are permissive for ETEC H10407 colonization.

Summary BALB/c mice with pulmonary tuberculosis (TB) develop a T helper cell type 1 that temporarily controls bacterial growth. Bacterial proliferation increases, accompanied by decreasing expression of interferon (IFN)-γ, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). Activation of dendritic cells (DCs) is delayed. Intratracheal administration of only one dose of recombinant adenoviruses encoding granulocyte–macrophage colony-stimulating factor (AdGM-CSF) 1 day before Mycobacterium tuberculosis (Mtb) infection produced a significant decrease of pulmonary bacterial loads, higher activated DCs and increased expression of TNF-α, IFN-γ and iNOS. When AdGM-CSF was given in female mice B6D2F1 (C57BL/6J X DBA/2J) infected with a low Mtb dose to induce chronic infection similar to latent infection and corticosterone was used to induce reactivation, a very low bacilli burden in lungs was detected, and the same effect was observed in healthy mice co-housed with mice infected with mild and highly virulent bacteria in a model of transmissibility. Thus, GM-CSF is a significant cytokine in the immune protection against Mtb and gene therapy with AdGM-CSF increased protective immunity when administered in a single dose 1 day before Mtb infection in a model of progressive disease, and when used to prevent reactivation of latent infection or transmission.

Major depressive disorder (MDD) is a psychiatric illness that presents as a deficit of serotonergic neurotransmission in the central nervous system. MDD patients also experience alterations in cortisol and cytokines levels. Treatment with selective serotonin reuptake inhibitors (SSRIs) is the first-line antidepressant regimen for MDD. The aim of this study was to determine the effect of a combination of SSRIs and an immunomodulator—human dialyzable leukocyte extract (hDLE)—on cortisol and cytokines levels. Patients received SSRIs or SSRIs plus hDLE. The proinflammatory cytokines IL-1β, IL-2, and IFN-γ; anti-inflammatory cytokines IL-13 and IL-10; and 24-h urine cortisol were measured at weeks (W) 0, 5, 20, 36, and 52 of treatment. The reduction in cortisol levels in the SSRI-treated group was 30% until W52, in contrast, the combined treatment induced a 54% decrease at W36. The decline in cortisol in patients who were treated with SSRI plus hDLE correlated with reduction of anti-inflammatory cytokines and increases levels of proinflammatory cytokines at the study conclusion. These results suggest that the immune-stimulating activity of hDLE, in combination with SSRIs, restored the pro- and anti-inflammatory cytokine balance and cortisol levels in depressed patients versus those who were given SSRIs alone.

O-glycosidically-linked glycans have been involved in development, maturation, homing, and immune regulation in T cells. Previous reports indicate thatAmaranthus leucocarpuslectin(ALL), specific for glycans containing galactose-N-acetylgalactosamine and N-acetylgalactosamine, recognizes human naïve CD27+CD25+CD4+T cells. Our aim was to evaluate the phenotype of CD4+T cells recognized byALLin peripheral blood mononuclear cells obtained from healthy volunteers. CD4+T cells were isolated by negative selection using magnetic beads-labeled monoclonal antibodies; the expression of T regulatory cell phenotypic markers was assessed onALL-recognized cells. In addition, IL-4, IL-10, IFN-γ, and TGF-βintracellular production inALL+cells was also evaluated. The analyses of phenotypic markers and intracellular cytokines were performed through flow cytometry.ALL-recognized CD4+T cells were mainly CD45RA+, CCR7+cells. Although52±10% CD25+Foxp3+cells were positive toALL, only34±4% ofALL+cells corresponded to CD25+Foxp3−cells. Intracellular cytokines in freshly obtainedALL+CD4+T cells exhibited 8% of IL-4, 15% of IL-10, 2% of IFN-γ, and 15% of TGF-β, whereasALL−CD4+T cells depicted 1% of IL-4, 2% of IL-10,<1% of IFN-γ, and 6% of TGF-β. Our results show that galactose-N-acetylgalactosamine and N-galactosamine-bearing CD4+T cells expressed phenotypic markers of NnTreg cells.

Streptococcus pneumoniae infection continues to be a major source of morbidity and mortality in children in Mexico. The aim of this study was to evaluate the immune response to six serotypes in children5 years of age after immunization with a 23-valent pneumococcal polysaccharide vaccine.A prospective study was conducted among children aged from 18 months to 4 years. Pre- and postvaccination titers for the serotypes selected in this project demonstrate a substantial response among all age groups.We identified mild adverse events in 62% of the participants in this study. No serious adverse events were reported during the study.Pneumococcal polysaccharide vaccine produced adequate immunogenicity in all age groups evaluated.

Leprosy is an infectious disease caused byMycobacterium leprae, which is a noncultivable bacterium. One of the principal goals of leprosy research is to develop serological tests that will allow identification and early treatment of leprosy patients.M. habanais a cultivable nonpathogenic mycobacterium and candidate vaccine for leprosy, and several antigens that cross-react betweenM. lepraeandM. habanahave been discovered. The aim of the present study was to extend the identification of cross-reactive antigens by identifyingM. habanaproteins that reacted by immunoblotting with antibodies in serum samples from leprosy patients but not with antibodies in sera from tuberculosis (TB) patients or healthy donors (HDs). A 28-kDa antigen that specifically reacted with sera from leprosy patients was identified. To further characterize this antigen, protein spots were aligned in two-dimensional polyacrylamide gels and Western blots. Spots cut out from the gels were then analyzed by mass spectrometry. Two proteins were identified: enoyl-coenzyme A hydratase (lipid metabolism; ML2498) and antigen 85B (Ag85B; mycolyltransferase; ML2028). These proteins represent promising candidates for the design of a reliable tool for the serodiagnosis of lepromatous leprosy, which is the most frequent form in Mexico.

To understand the role of the immune system with respect to disease in reptiles, there is the need to develop tools to assess the host's immune response. An important tool is the development of molecular markers to identify immune cells, and these are limited for reptiles. We developed a technique for the cryopreservation of peripheral blood mononuclear cells and showed that a commercially available anti-CD3 epsilon chain antibody detects a subpopulation of CD3 positive peripheral blood lymphocytes in the marine turtle Chelonia mydas. In the thymus and in skin inoculated with phytohemagglutinin, the same antibody showed the classical staining pattern observed in mammals and birds. For Western blot, the anti-CD3 antibodies identified a 17.6k Da band in membrane proteins of peripheral blood mononuclear cell compatible in weight to previously described CD3 molecules. This is the first demonstration of CD3+ cells in reptiles using specific antibodies.

Armadillos are apparently important reservoirs of Mycobacterium leprae and an animal model for human leprosy, whose immune system has been poorly studied. We aimed at characterizing the armadillo's langerhans cells (LC) using epidermal sheets instead of tissue sections, since the latter restrict analysis only to cut-traversed cells. Epidermal sheets by providing an en face view, are particularly convenient to evaluate dendritic morphology (cells are complete), spatial distribution (regular vs. clustered), and frequency (cell number/tissue area). Lack of anti-armadillo antibodies was overcome using LC-restricted ATPase staining, allowing assessment of cell frequency, cell size, and dendrites extension. Average LC frequency in four animals was 528 LC/mm(2), showing a rather uniform non-clustered distribution, which increased towards the animal's head, while cell size increased towards the tail; without overt differences between sexes. The screening of antibodies to human DC (MHC-II, CD 1a, langerin, CD86) in armadillo epidermal sheets, revealed positive cells with prominent dendritic morphology only with MHC-II and CD86. This allowed us to test DC mobilization from epidermis into dermis under topical oxazolone stimulation, a finding that was corroborated using whole skin conventional sections. We hope that the characterization of armadillo's LC will incite studies of leprosy and immunity in this animal model.

Individuals with X-HIGM syndrome fail to express functional CD40 ligand; consequently they cannot mount effective protective antibody responses against pathogenic bacteria. We evaluated, compared, and characterized the humoral immune response of wild type (WT) and C57-CD40L deficient (C57-CD40L−/−) mice infected withCitrobacter rodentium. Basal serum isotype levels were similar for IgM and IgG3 among mice, while total IgG and IgG2b concentrations were significantly lower in C57-CD40L−/−mice compared with WT. Essentially IgG1 and IgG2c levels were detectable only in WT mice. C57-CD40L−/−animals, orally inoculated with2×109CFU, presented several clinical manifestations since the second week of infection and eventually died. In contrast at this time point no clinical manifestations were observed among C57-CD40L−/−mice infected with1×107CFU. Infection was subclinical in WT mice inoculated with either bacterial dose. The serum samples from infected mice (1×107CFU), collected at day 14 after infection, had similarC. rodentium-specific IgM titres. Although C57-CD40L−/−animals had lower IgG and IgG2b titres than WT mice, C57-CD40L−/−mice sera displayed complement-mediated bactericidal activity againstC. rodentium.C. rodentium-infected C57-CD40L−/−mice are capable of producing antibodies that are protective. C57-CD40L−/−mouse is a useful surrogate model of X-HIGM syndrome for studying immune responses elicited against pathogens.

Mast cells are crucial elements of the innate immune response. They reside in tissues that are commonly exposed to the external environment, such as the skin and mucosae, where they can rapidly detect the presence of pathogens and mount a potent inflammatory response that recruits other cellular effectors of the immune response. The contribution of mast cells to the immune response to viruses, bacteria, protozoa and multicellular parasites is well established, but there is scarce information about the role of these cells in fungal infections. In this study, we analyzed if mast cells are activated by Candida albicans and if the C-type lectin receptor Dectin-1 is involved in its recognition. We found that both yeasts and hyphae of C. albicans-induced mast cell degranulation and production of TNF-α, IL-6, IL-10, CCL3 and CCL4, while only yeasts were able to induce IL-1β. Mast cells also produced ROS after stimulation with both dimorphic phases of C. albicans. When mast cells were activated with yeasts and hyphae, they showed decreased expression of IκBα and increased presence of phosphorylated Syk. Blockade of the receptor Dectin-1, but not Toll-like receptor 2, decreased TNF-α production by mast cell in response to C. albicans. These results indicate that mast cells are capable of sensing the two phases of C. albicans, and suggest that mast cells participate as an early inductor of inflammation during the early innate immune response to this fungus.

Systemic lupus erythematosus is characterized by dysregulated activation of T and B cells and autoantibodies to nuclear antigens and, in some cases, lipid antigens. Liposomes with nonbilayer phospholipid arrangements induce a disease resembling human lupus in mice, including IgM and IgG antibodies against nonbilayer phospholipid arrangements. As the effect of these liposomes on the innate immune response is unknown and innate immune system activation is necessary for efficient antibody formation, we evaluated the effect of these liposomes on Toll-like receptor (TLR) signaling, cytokine production, proinflammatory gene expression, and T, NKT, dendritic, and B cells. Liposomes induce TLR-4- and, to a lesser extent, TLR-2/TLR-6-dependent signaling in TLR-expressing human embryonic kidney (HEK) cells and bone marrow-derived macrophages. Mice with the lupus-like disease had increased serum concentrations of proinflammatory cytokines, C3a and C5a; they also had more TLR-4-expressing splenocytes, a higher expression of genes associated with TRIF-dependent TLR-4-signaling and complement activation, and a lower expression of apoptosis-related genes, compared to healthy mice. The percentage of NKT and the percentage and activation of dendritic and B2 cells were also increased. Thus, TLR-4 and TLR-2/TLR-6 activation by nonbilayer phospholipid arrangements triggers an inflammatory response that could contribute to autoantibody production and the generation of a lupus-like disease in mice.

Human dialyzable leukocyte extracts (DLEs) are heterogeneous mixtures of low-molecular-weight peptides that are released on disruption of peripheral blood leukocytes from healthy donors. DLEs improve clinical responses in infections, allergies, cancer, and immunodeficiencies. Transferon is a human DLE that has been registered as a hemoderivate by Mexican health authorities and commercialized nationally. To develop an animal model that could be used routinely as a quality control assay for Transferon, we standardized and validated a murine model of cutaneous HSV-1 infection. Using this model, we evaluated the activity of 27 Transferon batches. All batches improved the survival of HSV-1-infected mice, wherein average survival rose from 20.9% in control mice to 59.6% in Transferon-treated mice. The activity of Transferon correlated with increased serum levels of IFN-γand reduced IL-6 and TNF-αconcentrations. Our results demonstrate that (i) this mouse model of cutaneous herpes can be used to examine the activity of DLEs, such as Transferon; (ii) the assay can be used as a routine test for batch release; (iii) Transferon is produced with high homogeneity between batches; (iv) Transferon does not have direct virucidal, cytoprotective, or antireplicative effects; and (v) the protective effect of Transferonin vivocorrelates with changes in serum cytokines.

Iron is known to play an important role in different bacterial infections and, in particular, in their development. One example is infection with Mycobacterium tuberculosis where iron contributes to growth and survival of the bacteria within the host cell. The majority of studies performed on tuberculosis have focused on the direct effect of iron on bacterial growth; however, little is known about how iron modifies the mycobacterial-host interaction. In order to address this, we have investigated the effect of iron on intracellular growth of M. tuberculosis in J774 macrophages and the molecular mechanisms that are affected during this interaction. We observed that iron modifies intracellular growth of the mycobacteria and that their growth kinetics was modified from that observed for the extracellular situation in the presence of iron. Similarly, when iron was present during the infection, there was a reduced release of tumour necrosis factor-alpha and it was related to a higher number of bacilli inside the host cell and low expression of interleukin-1 (IL-1) and IL-6 mRNA. Hence, this work demonstrates that iron, besides promoting mycobacterial growth, also regulates the relationship between macrophage and bacteria.

Immunodeficiencies might be caused not only by the lack of cytokine production, but also by defective expression and/or function of the cytokine receptors. We have measured by flow cytometry, within 2 days, not only the production of IL-2, IFN-gamma, IL-12 and TNF-alpha, but also the functional expression of the receptors for these cytokines in blood samples obtained from 15 healthy donors and 13 patients suffering from tuberculosis. Cytoplasmic and surface staining with monoclonal antibodies (mAbs) was used to assess the production of cytokines and their receptors, respectively, after polyclonal stimulation. To evaluate receptor activity, peripheral blood mononuclear cells (PBMC) were first incubated with the corresponding recombinant human (rh) cytokine. CD69 was detected on lymphocytes after incubation with rhIL-2; IFN-gamma was detected in lymphocytes after co-stimulation with rhIL-12 plus PHA; iNOS induction and upregulation of major histocompatibility complex (MHC) II and MHC I was detected on monocytes after recombinant human interferon-gamma (rhIFN-gamma) stimulation; finally, COX-2 expression and MHC II upregulation were detected on monocytes after rhTNF-alpha stimulation. The assay that was developed can be used clinically to assess the activities of components of the cytokine signaling pathways of patients with immunodeficiencies or those with chronic intracellular infections such as tuberculosis.

We have previously shown that human neutrophils (NEU) stimulated with live Mycobacterium tuberculosis H37Rv (Mtb) release exovesicles, named EXO-Mtb. When autologous macrophages were incubated with EXO-Mtb, they increased the expression of CD86 and MHC II and produced inflammatory cytokines. Here we demonstrate that EXO-Mtb can also reduce the intracellular load of Mtb in autologous macrophages. Since autophagy has been shown to control mycobacterial growth, LC3II expression was measured on infected macrophages after incubation with EXO-Mtb (4, 6 and 24h). Control EXO preparations included those released spontaneously from NEU, or after stimulation with PMA or fMLP. Our results showed that of all EXO preparations used, EXO-Mtb induced the largest amounts of LC3II protein, which correlates with a significant reduction of colony forming units (CFU). This phenomenon could be reverted with the addition of Wortmannin, an autophagy inhibitor. It is important to remark that there was not a 100% control of intracellular mycobacterial growth. Further experiments should be done to better understand the role of ectosomes in NEU-macrophage communication through exovesicles.

Dialyzable leukocyte extracts (DLE) transfer specific cell-mediated immune responses from sensitized donors to non-immune recipients. In addition, DLE have several immunomodulatory effects and are used for the treatment of several infectious and non-infectious diseases. Previous studies showed that human DLE obtained from virus-infected leukocytes and bovine DLE decrease the production of the pro-inflammatory cytokine TNF-α in response to bacterial lipopolysaccharide, in vitro and in vivo. In the present work, we inquire as to whether DLE from uninfected human leukocytes have the ability to regulate cytokine production in peripheral blood mononuclear cells (PBMC) in vitro. We observed that PBMC from healthy individuals were able to produce TNF-α, IL-12 and IL-10 after stimulation with DLE. Moreover, we identified monocytes as the main cell population that produced TNF-α after DLE stimulation. Interestingly, we found that DLE contain unidentified ligands that activate Toll-like receptor (TLR)-2. Finally, we observed that DLE directly activated monocytes through TLR-2. These results reveal a new biological activity of DLE, and suggest that part of the immunomodulatory properties of DLE could be attributed to TLR-2 activation on monocytes and to the induction of a pro-inflammatory environment that is crucial for control of infectious diseases.

Mycobacterium tuberculosis (Mtb) inhibits dendritric cells (DC) function in order to delay T cell response. Furthermore, there is increasing evidence that genetic diversity of Mtb strains can affect their interaction with the immune system. Beijing genotype has attracted attention because of its high prevalence and multi-drug resistance. Although it is known that this genotype is hypervirulent and differentially activates macrophages when compared to other genotypes, little is known about its interaction with DC. In order to address this issue, murine bone marrow derived DC (BMDC) were stimulated with soluble extracts (SE) from BCG, H37Rv, Canetti and Beijing genotypes. We observed that unlike other mycobacteria strains, SE-Beijing was unable to induce maturation of DC as assessed by cell surface MHC-II expression. DC stimulated with SE-Beijing failed to produce IL-12 and TNF-α, but did secrete IL-10. Interestingly, SE-Beijing induced CCR7 and PDL-1 on BMDC, but did not induce the expression of CD86. When BMDC stimulated with SE-Beijing were used to activate CD4+ cells they were unable to induce a Th1 response when compared with less virulent genotypes. These results indicate that Beijing is able to modulate DC activation and function, which may be related to the pathogenesis induced by this genotype.

Background.Leprosy is a chronic infectious disease caused by the intracellular acid-fast bacilliMycobacterium leprae; it has been determined that genetic factors of the host play an important role in the disease susceptibility. Thus, in this case-control study, we evaluated the possible association between theIL-17A G-197A(rs227593) andIL-17F A7488G(His161Arg, rs763780) gene SNPs and susceptibility to leprosy disease in Mexican population.Methods.Seventy-five leprosy patients and sixty-nine control subjects were included. Both SNPs were genotyped with the polymerase chain reaction-restriction fragment length polymorphism technique.Results.We found nonsignificant differences in genotype and allele frequencies related toIL-17A G-197A(rs227593) andIL-17F A7488G(His161Arg, rs763780) gene SNPs in MB as well as subclinical forms of leprosy disease versus healthy individuals.Conclusions.Since the sample size is not large enough, it is difficult to sustain an association of susceptibility to leprosy with genotypes or allele frequencies ofIL-17A G-197A(rs227593) andIL-17F A7488G(His161Arg, rs763780), suggesting thatIL-17polymorphisms have no significant role in the genetic susceptibility to development of this disease in the Mexican Mestizo population.

En la mayoría de los sistemas intensivos de producción porcina se desteta a los lechones a las 3 semanas de edad, lo que genera estrés por el cambio de alimentación y jerarquización. Esto aumenta la incidencia de cuadros respiratorios, diarreas, baja las ganancias de peso y causa pérdidas económicas. El extracto leucocitario dializable (DLE) puede mejorar la respuesta inmune al aumentar los niveles de IFN-γ. En el presente trabajo se valoró el efecto del DLE porcino (DLEp) al ser aplicado 7 veces por vía intradérmica en lechones durante las primeras cuatro semanas del destete a dos dosis diferentes. Se utilizaron 48 lechones divididos en 3 grupos de 16 animales. Grupo A: dosis alta (77 μg/kg), grupo B: dosis baja (17 μg/kg), grupo C: testigos (solución salina). Se obtuvieron muestras de sangre completa y suero a los días 0, 14 y 30 para realizar cuentas leucocitarias por hemograma y la cuantificación de IFN-γ por ELISA. Además se determinó la incidencia diaria de diarreas y cuadros respiratorios y se midió el peso de todos los animales estudiados. La dosis alta (77 μg/kg), produjo un aumento significativo en la concentración de IFN-γ sérico en el tercer muestreo (d = 2,288, α = 0,05, P = 0,003). El resto de las variables analizadas no mostraron diferencia significativa entre los grupos tratados y el testigo (P > 0,05).

Reactivation of varicella herpes virus (VHV), latent in individuals who have previously suffered varicella, gives rise to herpes zoster and in some cases leads to a sequela of post herpetic neuritis with severe pain which is refractory to analgesics. Many different antiviral agents have been tried without achieving satisfactory results. Of all the antiviral agents employed, acyclovir has been the most successful in reducing post herpetic pain. However acyclovir has not been as reliable as interferon alpha (IFN-alpha). We have previously looked into the use of transfer factor (TF) as a modulator of the immune system, specifically with respect to its effectiveness in the treatment of herpes zoster. In this work findings from a comparative clinical evaluation are presented. A double blind clinical trial of TF vs acyclovir was carried out in which 28 patients, presenting acute stage herpes zoster, were randomly assigned to either treatment group. Treatment was administered for seven days and the patients were subsequently submitted to daily clinical observation for an additional 14 days. An analogue visual scale was implemented in order to record pain and thereby served as the clinical parameter for scoring results. The group treated with TF was found to have a more favorable clinical course, Por = 0.015. Laboratory tests to assess the immune profile of the patients were performed two days prior and 14 days after initial treatment. The results of these tests showed an increase in IFN-gamma levels, augmentation in the CD4+ cell population but not the percentage of T rosettes in the TF treated group. These parameters were however insignificantly modified in patients receiving acyclovir. Although TF treated patients showed an increase in CD4+ counts these cells remained below the levels for healthy individuals. The fact that IFN-gamma levels as well as the counts for CD4+ cells rose in the TF treated group and not in the acyclovir one is very significant and confirms the immunomodulating properties of TF.

Despite the introduction of multidrug therapy and the overall reduction of leprosy prevalence in Mexico, the disease remains endemic in certain regions of the country. A genetic basis for the immune susceptibility to Mycobacterium leprae has already been established in different populations worldwide. In this study, we investigated the possible association of the HLA-DRB1 alleles with leprosy in a Mexican Mestizo popula- tion. The results demonstrated that the HLA-DRB1*01 allele is associated with lepromatous and dimorphic leprosy (P

The ocular surface is a functional unit mainly formed by the conjunctival and corneal epi‐ thelium (structural component), and tear film (soluble component). Microorganisms and environmental allergens can interact with the tear film, reach the structural component and generate an immune response against them. Understanding the cellular and soluble mediators that are involved in these inflammatory responses not only helps in under‐ standing the mechanisms of current treatments, but also is needed to identification and development of new therapeutics targets. The aim of this review was to investigate the novel and developing therapies, with special emphasis in immunomodulatory drugs/ molecules that could have some clinical indication in the treatment of infectious and aller‐ gic conjunctivitis in few years.

Candida albicanscauses opportunistic systemic infections with high mortality (30%–50%). Despite significant nephrotoxicity, amphotericin (AmB) is still used for the treatment of this serious fungal infection. Therefore, alternative treatments are urgently needed. Dialyzable leukocyte extracts have been used successfully to treat patients with mucocutaneous candidiasis, but their effectiveness in systemic candidiasis has not been evaluated. In this study, low-dose AmB (0.1 mg/kg) plus 10 pg of murine dialyzable spleen extracts (mDSE) were tested in a systemic candidiasis mouse model. Survival, tissue fungal burden, kidney damage, kidney cytokines, and serum levels of IL-6 and hepcidin were evaluated. Our results showed that the combined treatment of low-dose AmB plus mDSE improved survival and reduced kidney fungal burden and histopathology; these effects correlated with increased kidney concentration of IFN-γand TGF-β1, decreased levels of TNF-α, IL-6, and IL-10, as well as high levels of systemic IL-6 and hepcidin. Low-dose AmB and mDSE synergized to clear the infectious agent and reduced tissue damage, confirming the efficacy of a low dose of AmB, which might decrease the risk of drug toxicity. Further studies are necessary to explore these findings and its implications in future therapeutic approaches.

Non-bilayer phospholipid arrangements are three-dimensional structures that form when anionic phospholipids with an intermediate structure of the tubular hexagonal phase II are present in a bilayer of lipids. Antibodies that recognise these arrangements have been described in patients with antiphospholipid syndrome and/or systemic lupus erythematosus and in those with preeclampsia; these antibodies have also been documented in an experimental murine model of lupus, in which they are associated with immunopathology. Here, we demonstrate the presence of antibodies against non-bilayer phospholipid arrangements containing mycolic acids in the sera of lepromatous leprosy (LL) patients, but not those of healthy volunteers. The presence of antibodies that recognise these non-bilayer lipid arrangements may contribute to the hypergammaglobulinaemia observed in LL patients. We also found IgM and IgG anti-cardiolipin antibodies in 77% of the patients. This positive correlation between the anti-mycolic-non-bilayer arrangements and anti-cardiolipin antibodies suggests that both types of antibodies are produced by a common mechanism, as was demonstrated in the experimental murine model of lupus, in which there was a correlation between the anti-non-bilayer phospholipid arrangements and anti-cardiolipin antibodies. Antibodies to non-bilayer lipid arrangements may represent a previously unrecognised pathogenic mechanism in LL and the detection of these antibodies may be a tool for the early diagnosis of LL patients.

Tuberculosis (TB), one of the major world health problems, is a chronic infection caused by members of the Mycobacterium tuberculosis complex (MTC). In 2009, tuberculosis (TB) caused 1.7 million deaths and 9.4 million new cases. Although recent efforts to improve TB prevention, diagnosis and treatment have contributed to a 35% decrease in the death rate, the emergence of mycobacterial strains with highly virulent phenotypes combined with pandemic HIV infections has added new challenges to control TB.

To evaluate the lipopolysaccharide (LPS)-induced pro-inflammatory cytokine response by peripheral blood mononuclear cells (PBMCs) from XLA patients. Thirteen patients with XLA were included in the study. LPS-induced TNF-α, IL-1β, IL-6, and IL-10 production was determined in PBMCs from patients and matched healthy controls by ELISA. Cytokine production was correlated with the severity of mutation, affected domain and clinical characteristics. In response to LPS, PBMCs from XLA patients produced significantly higher amounts of pro-inflammatory cytokines and IL-10 compared to controls, and this production was influenced neither by the severity of the mutation nor the affected domain. PBMCs from patients with a history of more hospital admissions before their diagnosis produced higher levels of TNF-α. PBMCs from patients with lower serum IgA levels showed a higher production of TNF-α and IL-1β. Less severe (punctual) mutations in the Btk gene were associated with higher serum IgG levels at diagnosis. Our results demonstrate a predominantly inflammatory response in XLA patients after LPS stimulation and suggest a deregulation of TLR signaling in the absence of Btk. This response may be influenced by environmental factors.

Contains fulltext : 124298.pdf (Publisher’s version ) (Closed access) Members of the Mycobacterium tuberculosis (Mtb) Beijing genotype are a major concern due to their high prevalence in tuberculosis patients and their high rate of multi-drug resistance. Although it has been shown that Beijing modifies macrophage behavior, little is known about how this genotype could affect the cellular immune response. In order to address this issue, peripheral blood mononuclear cells (PBMC) from healthy BCG vaccinated individuals were stimulated with protein extracts from three Mycobacterium tuberculosis genotypes: Canetti, H37Rv and Beijing evaluating T cell proliferation and cytokine production. In this system both CD4+ and CD8+ proliferated in a similar manner independently of the Mtb genotype used for stimulation. Regarding cytokines, all strains induced similar levels of IFN-gamma, but were unable to induce IL-4 and TGF-beta. Contrasting, Canetti strain induced lower production of IL-10, TNF-alpha and IL-12 compared to H37Rv and Beijing. Interestingly, PBMC stimulated with the Beijing strain produced the highest levels of IL-12 and IL-10 than those stimulated with other strains. This differential cytokine expression could affect the pathogenesis induced by Beijing strain through the modulation of inflammatory process in the host, but the precise mechanisms by which this cytokine environment affects the Beijing strain pathogenesis needs further characterization.