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The European Union (EU) continuously takes ensuring the safe use of manufactured nanomaterials (MNMs) in consumer products into consideration. The application of a common approach for testing MNMs, including the use of optimized protocols and methods' selection, becomes increasingly important to obtain reliable and comparable results supporting the regulatory framework. In the present study, we tested four representative MNMs, two titanium dioxides (NM100 and NM101) and two silicon dioxides (NM200 and NM203), using the EU FP7-NANoREG approach, starting from suspension and dispersion preparations, through to their characterization and final evaluation of biological effects. MNM dispersions were prepared following a refined NANOGENOTOX protocol and characterized by dynamic light scattering (DLS) in water/bovine serum albumin and in media used for in vitro testing. Potential genotoxic effects were evaluated on human bronchial BEAS-2B cells using micronucleus and Comet assays, and pro-inflammatory effects by cytokines release. Murine macrophages RAW 264.7 were used to detect potential innate immune responses using two functional endpoints (pro-inflammatory cytokines and nitric oxide [NO] production). The interaction of MNMs with RAW 264.7 cells was studied by electron microscopy. No chromosomal damage and slight DNA damage and an oxidative effect, depending on MNMs, were observed in bronchial cells. In murine macrophages, the four MNMs directly induced tumor necrosis factor α or interleukin 6 secretion, although at very low levels; lipopolysaccharide-induced NO production was significantly decreased by the titania and one silica MNM. The application of this approach for the evaluation of MNM biological effects could be useful for both regulators and industries.

Despite the widespread use of silver nanoparticles (AgNPs) in different fields and the amount of investigations available, to date, there are many contradictory results on their potential toxicity. In the present study, extensively characterized 20-nm AgNPs were investigated using optimized protocols and standardized methods to test several toxicological endpoints in different cell lines. The agglomeration/aggregation state of AgNPs in culture media was measured by dynamic light scattering (DLS). DNA and chromosomal damage on BEAS-2B and RAW 264.7 cells were evaluated by comet and micronucleus assays, while oxidative DNA damage by modified comet assay and 8-oxodG/8-oxodA detection. We also investigated immunotoxicity and immunomodulation by cytokine release and NO production in RAW 264.7 and MH-S cells, with or without lipopolysaccharide (LPS) stimulus. Transmission electron microscope (TEM) analysis was used to analyze cellular uptake of AgNPs. Our results indicate different values of AgNPs hydrodynamic diameter depending on the medium, some genotoxic effect just on BEAS-2B and no or slight effects on function of RAW 264.7 and MH-S in absence or presence of LPS stimulus. This study highlights the relevance of using optimized protocols and multiple endpoints to analyze the potential toxicity of AgNPs and to obtain reliable and comparable results.

Synthetic amorphous silica (SAS) consists of agglomerates and aggregates of primary particles in the nanorange (

International audience; Food additive E551 consists of synthetic amorphous silica (SAS), comprising agglomerates and aggregates of primary particles in the nanorange (

Beauvericin (BEA) and Enniatins (ENN) are mycotoxins produced by Fusarium fungi detected in food and feed; there are insufficient data to establish their reference values. To evaluate BEA and ENN oral toxicity, an integrated approach was applied. Among ENN, Enniatin B (ENNB) was selected as test substance. The approach is composed by: i) in vitro and acute in vivo genotoxicity tests; ii) a repeated-dose oral toxicity study focused on genotoxic, immune, endocrine, nervous endpoints and the reproductive/developmental toxicity screening. For BEA, all the genotoxicity endpoints yielded negative results excluding Comet assay in duodenum and kidney after repeated doses. BEA immunotoxicity was observed in female mice, concentrated in number and functional activity of effector T cells in the spleen. Based on the repeated-dose BEA study, the No Observed Adverse Effect Level (NOAEL) for female mice is 1 mg/kg b.w. per day (increased thyroid pycnotic nuclei and endometrial hyperplasia). In males, the NOAEL is 0.1 mg/kg b.w. per day (reduced colloid and altered T4 serum levels). Maternal NOAEL is 0.1 mg/kg b.w. per day (increased thymus weight), developmental NOAEL is 10 mg/kg b.w. per day. For ENNB, the results support a genotoxic effect in bone marrow and liver cells after acute treatment, but not after repeated exposure. Immunotoxic ENNB effects were observed in both genders, suggestive of a suppressive/inhibiting activity particularly evident in males. Based on the repeated-dose ENNB study, the NOAEL for females is 0.18 mg/kg b.w. per day (histomorphometrical effects on thymus, uterus and spleen). In male mice, the NOAEL is 1.8 mg/kg b.w. per day (enterocyte vacuolization in duodenum and increased Reactive Oxygen Species and reduced Glutathione brain levels). The maternal NOAEL is 1.8 mg/kg b.w. per day (decreased white pulp area and increased red/white pulp area ratio in spleen), developmental NOAEL is 18 mg/kg b.w. per day.

Scope: Among food allergies, peanut allergy is frequently associated with severe anaphylactic reactions. In the need for safe and effective therapeutic strategies, probiotics may be considered on the basis of their immunomodulatory properties. The aim of the present study was to investigate the immunological mediators involved in the effects of probiotic VSL#3 oral supplementation on Th2 inflammation and anaphylaxis in a mouse model of peanut allergy. Methods and results: VSL#3 supplementation to peanut-sensitized mice was effective in ameliorating anaphylaxis and Th2-mediated inflammation, by promoting regulatory responses in the jejunum mucosa and in the mesenteric lymph node, as evaluated by ELISA, real-time PCR, histologic, and immunohistochemical analysis. Probiotic-induced TGF- mediates its protective effects through the induction of regulatory T cells expressing FOXP3 and/or latencyassociated peptide, as proven by in vivo blockade of TGF- in VSL#3-treated mice with a neutralizing monoclonal antibody one day before challenge. Conclusion: TGF-, induced in the gut by VSL#3 supplementation, is capable of reducing the Th2 inflammation associated with food anaphylaxis in a mouse model of peanut sensitization. TGF- acts through the induction/maintenance of regulatory T cells expressing FOXP3 and/or latency-associated peptide. Probiotics supplementation may represent an effective and safe strategy for treating food allergies in adult population.

To cite this article: Schiavi E, Barletta B, Butteroni C, Corinti S, Boirivant M, Di Felice G. Oral therapeutic administration of a probiotic mixture suppresses established Th2 responses and systemic anaphylaxis in a murine model of food allergy. Allergy 2011; 66: 499–508. Abstract Background: No effective treatment is available for food allergy and its primary management still consists of avoiding relevant allergens. Probiotics are claimed to beneficially affect the immune system. We sought to investigate the therapeutic potential of VSL#3 probiotic mixture on specific immune responses and anaphylactic reaction induced in mice by the major food allergen shrimp tropomyosin (ST). Methods: The cytokine production by spleen cell from ST-sensitized mice upon allergen re-stimulation in the presence of VSL#3 was analysed. Next, the effects of oral administration of VSL#3 on allergen-induced anaphylaxis and Th2 response in the murine model of food allergy to ST was investigated by evaluating symptom score and histamine content in the faeces after allergen challenge, antibody response in serum and faeces, and cytokine and transcription factor expression in the jejunum. Results: The in vitro studies on mouse spleen cells indicates that the VSL#3 preparation has the capacity to shift a polarized Th2 response to a Th1/T regulatory-type profile. Oral therapeutic administration of VSL#3 to ST-sensitized mice significantly reduces symptom score and histamine release in the faeces following allergen challenge, as well as specific IgE response. In the jejunum, IL-4, IL-5 and IL-13 tissue content was significantly reduced, whereas FOXP3 and IL-27 mRNA expression, IL-10, TGF-β and IFN-γ tissue content were up-regulated. Conclusions: Oral therapeutic treatment with the probiotic mixture VSL#3 is effective in redirecting allergen-specific Th2-polarized immune responses towards Th1-T regulatory responses and in the protection against anaphylactic reactions induced by the allergen in a murine model of food allergy.

Appropriate murine models of shrimp tropomyosin (ST) allergy would be useful in investigating the mechanisms underlying food allergy in human subjects, as well as for the pre-clinical evaluation of efficacy and safety of novel therapeutic approaches. These models should mimic immune and clinical features of human disease, including anaphylactic response. We sensitized C3H/HeJ mice by the oral route with purified ST using cholera toxin (CT) as adjuvant. ST-specific IgE, IgG1, IgG2a and IgA responses were evaluated by ELISA. Spleen cell proliferation and cytokine production by allergen-specific activation were assessed. Jejunum and colon fragments were collected to evaluate the local expression of cytokine genes by PCR. Local and systemic anaphylactic reactions induced by oral ST challenge were scored according to symptoms observed. Faecal samples were collected to assess local IgA production and histamine levels. Oral sensitization with ST plus CT induced in mice significant levels of serum IgE and IgG1 and faecal IgA. ST-specific cell proliferation and IL-4, IL-13 and IFN-gamma cytokine production were induced in the spleen. After oral challenge, 100% of mice had anaphylactic symptoms while no symptoms were observed in challenged naive mice. Faecal histamine content after ST challenge appeared significantly increased in sensitized mice when compared with that observed in pre-immune mice. Jejunum mRNA expression of T(h)2 cytokines was up-regulated by ST sensitization. These results support the importance of the oral way of sensitization and of the in-depth characterization of the anaphylactic response for the development of a suitable in vivo model of food allergy.

Allergen specific immunotherapy has been introduced in the clinic more than 100 years ago showing effectiveness and, so far, it represents the only curative approach to treat allergic disorders ameliorating the symptoms, reducing the medication costs and blocking the onset of new sensitizations. However, some questions are still open regarding to the safety of the treatment and the need to reduce the dose and time of administration to improve the compliance of the patients. All preparations that are currently available may trigger side effects. For these reasons, new formulations and route of administration have been exploited demonstrating that such products presented improved efficacy and safety. Nanotechnology for biomedical applications offers many advantages, such as improved stability and bioavailability, favourable biodistribution profiles and targeting to specific cell populations whose impact on the immune system has been evaluated in animal systems. Nanoparticles interact with the immune system, and the final outcome of this interaction depends on their physico-chemical characteristics. Concerns can be raised when immunotoxic effect are induced, resulting in inflammatory dangerous responses or in the reduction of the normal defensive activity of the immune system. In this paper, we will review the most relevant data about the synthesis of allergen/nanoparticles systems and will discuss their impact on the immune system in terms of immunomodulatory activity and immunotoxicity risk assessment.

Summary Background With the development of genetically modified crop plants there has been a growing interest in the approaches available to assess the potential allergenicity of novel gene products. For additional assessment of the potential allergenicity of expressed proteins, informative data can be generated using animal models. Soybean is one of the major source of protein in human and animal nutrition, and has also been well characterized as a major allergenic source. Advances in biotechnology have resulted in an increasing number of genetically engineered foods, and among these soybean is one of the most widespread. Objective To develop and characterize a murine model of IgE-mediated soybean sensitization induced by intragastric immunization, in the presence of Cholera Toxin, with wild-type soybean extract (wt-SE) or with genetically modified soybean extract (gm-SE). Methods Balb/c mice born in our animal facilities, from females fed on soy-free food, were fed with the same soy-free food and used in all the experiments. Mice were sensitized by gavages with soybean extracts, and allergen-specific IgE and IgG responses were studied by direct ELISA and ELISA inhibition. Antigen-specific cell proliferation and cytokine production were evaluated in spleen cell cultures. Results Sensitization with both soybean extracts induced high levels of antigen-specific IgE and IgG1 and low levels of specific IgG2a. Both wt-SE and gm-SE were able to inhibit the binding of specific IgE from mice immunized with gm-SE to the same antigen used for the ELISA coating. A comparable proliferative response was obtained with the homologous as well as with the heterologous extracts. Conclusion In sensitized mice, we observed a predominantly T-helper type 2 (Th2)-type immune response, with increased soybean-specific IgE and IgG1 antibodies and a concomitant increase of IL-4 and IL-5 production. Results obtained by specific IgE ELISA inhibition and by antigen-specific T cell proliferation demonstrated that wt-SE and gm-SE shared B and T epitopes. The present murine model of soybean sensitization established by the oral route should provide valuable information about risk assessment for food allergy from new proteins of genetically modified foods.

Background: Recombinant DNA technology does provide pure, well-defined and reproducible products to be used for clinical purposes, by cloning and expressing the cDNA of allergens present in a specific extract. Ole e 5 is a pollen allergen of Olea europaea with an IgE-binding frequency of about 35%, which has been identified as a superoxide dismutase (SOD). The aim of this study was to clone the cDNA of Ole e 5, to express Ole e 5 in Escherichia coli and to characterize its immunoreactivity. Methods: cDNA of Ole e 5 was amplified by nested 3′-RACE PCR and cloned in pGEX vector 6P expression vector. After sequencing of some clones and homology analysis, the rOle e 5 was produced in an E. coli strain as a fusion protein with GST and purified. Then, the protein immunoreactivity was evaluated by patients’ IgE binding (ELISA, ELISA inhibition, and immunoblotting) and by rabbit anti-rOle e 5 binding (immunoblotting and immunoblotting inhibition). Results: The sequence analysis of Ole e 5 cDNA confirmed that Ole e 5 is a Cu/Zn SOD, with an identity from 90 to 80% with SOD from other species. rOle e 5 was recognized by IgE from 39% of olive pollen-allergic patients tested; moreover, this binding was inhibited by the olive pollen extract. An anti-rOle e 5 antiserum raised in rabbit strongly reacted with a natural component of about 16-kDa molecular weight present in the olive pollen extract; moreover, this binding was inhibited by the recombinant protein. Conclusions: Ole e 5 is the first Cu/Zn SOD identified as an allergen in a pollen source. Due to the widespread presence of this enzyme, rOle e 5 allergen, cloned and expressed in a complete form in E. coli, could represent a good tool to investigate the allergen cross-reactivity between O. europaea pollen and other allergenic sources, such as plant foods and other pollens.

Purified recombinant Parj1 and Parj2 allergens bind an IgE repertoire common to the Parietaria species, allowing their use as marker molecules for diagnosis and therapy of allergic disease induced by the Urticaceae family. Preclinical studies on the in vivo immunogenicity of recombinant Parj1, Parj2 and their isoforms indicated differential capacity to induce IgG1 antibody responses, as indication of potential clinical use. A recombinant hetero-dimeric hybrid derivative (PjED), encompassing the shorter Parj1 isoform (Parj1.0201) and Parj2 allergen, was characterised. In vivo immunisation with PjED induces IgG1 antibodies capable of binding all the isoforms of Parietaria major allergens, overcoming the poor immunogenicity of single monomeric allergens. This feature makes PjED a promising candidate molecule to be further characterised for clinical applications in the treatment of Parietaria allergy.

Summary Background Cypress pollinosis is an important cause of respiratory allergies. Recently, the Cupressus arizonica major allergen, Cup a1, has been cloned and expressed. The native counterpart of this allergen has been purified and characterized by our group. It has been suggested that sugar moieties play a role in the in vitro IgE binding on Cupressus arizonica pollen extract. Objective To characterize the immunoreactivity of the recombinant major allergen in comparison with its native counterpart. To evaluate the role of carbohydrate moieties in the IgE-mediated in vitro histamine release from basophils by using the native glycosylated Cup a1 as compared with the recombinant one. Methods Recombinant Cup a1 was expressed in E. coli. IgE reactivity of Cupressaceae-allergic patients on the native as well as the recombinant molecule was investigated by immunoblotting, ELISA experiments and histamine release test from passively sensitized basophils. Results Fourteen out of 17 Cup a1-positive sera had IgE antibodies reactive with the native molecule only and lost their reactivity after periodate deglycosylation of the allergen. Moreover, only native molecule was capable of inducing histamine release by this group of sera. Both the recombinant and the native molecules were recognized by three out of the 17 sera and were equally capable of triggering degranulation. Conclusion A large number of sera reactive with the major allergen recognize carbohydrate epitopes only. IgE from these sera are able to induce histamine release from basophils and they might play a functional role in the clinical symptoms of allergy.

Background: Airborne insect antigens represent important aeroallergens which have been widely investigated. Although it has been demonstrated that house dust contains significant silverfish (Lepisma saccharina) levels, none of the extracts obtained so far has been extensively characterized. Thus, we have prepared and characterized a silverfish extract and investigated its IgE-reactive components by testing the reactivity of sera from patients allergic to inhalant insect allergens. Methods: The extract from silverfish insect bodies was prepared by homogenizing frozen silverfish in Tris-HCl buffer. The soluble material (Sup) was filtered and the insoluble material (Ppt) was resuspended in 100 mM Tris pH 10.6. The two fractions were characterized by biochemical and immunochemical methods. IgE reactivity was investigated on both fractions before and after periodate treatment. Results: Protein content and total carbohydrates was 2 and 3% w/w for Sup and 1 and 0.3% w/w for Ppt. The SDS-PAGE profile of the two fractions showed a different pattern in the MW range of 5–175 kD. Sup and Ppt, probed with allergic sera, showed a complex pattern of IgE reactivity. When periodate-treated fractions were tested, IgE reactivity was either completely abrogated, reduced or not affected, depending on the allergic serum employed. Conclusions: The results obtained indicate that the classic aqueous-extraction procedures that have been used up to now for other insects might not be completely satisfactory, since several allergenic components are not soluble at the normally used pH. We developed a dedicated extraction procedure allowing the detection of a certain degree of reactivity in sera negative to allergens extracted following classic procedures.

SummaryBackground Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens. Methods We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical–physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization. Results The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies. Conclusion Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis.

Background: The immunological mechanisms responsible for the immunomodulatory and anti-allergic effects of probiotic bacteria are still poorly defined. The combined effects of mixtures of different species of probiotic bacteria have been explored only in part. The present study describes the immunomodulatory activity of the VSL#3 probiotic preparation in in vitro and in vivo systems. Methods: The activation and cytokine production by in vitro probiotic-stimulated bone-marrow dendritic cells (BM-DCs) and spleen cells isolated from naïve or Par j 1-sensitized mice were investigated. Mice were intranasally administered a sonicate preparation of VSL#3 before immunization with rPar j 1. Serum antibody levels and cytokine expression in the lung were determined. Results: Both live and sonicated VSL#3 preparations induced maturation and cytokine production by BM-DCs. Cytokine production by spleen cells from naïve or Par j 1-sensitized mice was modulated by the probiotic preparations towards a Treg/Th0 profile, characterized by increased IL-10 and IFN-γ production. In vivo prophylactic treatment with VSL#3 induced a significant reduction of serum specific IgG1. At lung level, VSL#3 pre-treatment remarkably reduced IL-13 and IL-4 mRNA expression and increased IL-10 expression. Conclusions: The VSL#3 preparations have not only the capacity to bias primary immune responses towards a Treg/Th0-type profile, but also to modify in the same way the functional characteristics of established in vitro Th2 responses. In vivo studies on a mouse model of Par j 1 sensitization indicate that the prophylactic intranasal treatment with probiotic bacteria is able to modulate the development of Th2-biased responses.

Background: Probiotics have anti-inflammatory effects in patients with inflammatory bowel disease and appear to regulate mucosal immune response through reductions in proinflammatory cytokines. The probiotic VSL#3 prevents pouchitis if started within a week of ileostomy closure and maintains remission following antibacterial treatment in patients with refractory or recurrent pouchitis. However, the efficacy of probiotics and their effects on regulatory cells if started at a greater time after surgery in patients undergoing ileal pouch anal anastomosis (IPAA) for ulcerative colitis are unknown. Methods: We conducted an open-label study in which 31 patients at different periods from surgery without signs and symptoms of pouchitis were randomized to 2 sachets of VSL#3 once daily or no treatment for 12 months. Pouchitis disease activity index (PDAI) was evaluated at baseline and after 3, 6, and 12 months. The percentage of CD4+ T lymphocytes expressing CD25 and the inactive form of transforming growth factor-β [latency-associated peptide (LAP)] were evaluated at baseline and after 3 and 6 months in peripheral-blood mononuclear cells and mucosal biopsies. Variation in tissue interleukin-1β and Foxp3 mRNA expression was also evaluated. Results: During the study period, VSL#3-treated patients showed a significant reduction in PDAI score and a significant increase in the percentage of mucosal CD4+CD25high and CD4+ LAP-positive cells compared with baseline values. Tissue samples at different points showed a significant reduction in IL-1β mRNA expression, and a significant increase in Foxp3 mRNA expression. Conclusions: We conclude that VSL#3 administration in patients with IPAA modulates the PDAI and expands the number of mucosal regulatory T cells. (Inflamm Bowel Dis 2008)

Summary Background The presence of specific IgE antibodies to invertebrates is common among patients with rhinitis and asthma. Tropomyosin has been described as an invertebrate cross-reactive allergen. We have recently characterized an allergenic extract from silverfish (Lepisma saccharina). Since this insect could be a new source of tropomyosin in the indoor environment, we have thought important to clone and characterize the tropomyosin from it. Methods Recombinant tropomyosin was cloned and characterized by means of immunoblotting with tropomyosin-specific monoclonal antibodies, rabbit polyclonal antibodies and IgE from allergic patients. Its allergenic activity was investigated in histamine release assays. Immunoblotting and ELISA inhibition were carried out to identify the natural tropomyosin in the silverfish extract and to study the cross-reactivity among other arthropod tropomyosins. Results Tropomyosin-specific antibodies recognized in immunoblotting the natural tropomyosin in the insoluble fraction of silverfish extract. The silverfish tropomyosin (Lep s 1) was cloned and fully expressed. It shared high homology with other arthropod tropomyosins. rLep s 1 was recognized by tropomyosin-specific monoclonal and polyclonal antibodies and by IgE of allergic patients. It was able to inhibit the IgE binding to the insoluble fraction of silverfish extract, and to induce histamine release by an arthropod-allergic serum. Inhibition experiments revealed IgE cross-reactivity between rLep s 1 and other arthropod tropomyosins. Conclusion rLep s 1 is the first allergen cloned and characterized from silverfish extract. It enabled us to identify the natural counterpart in the insoluble fraction of silverfish extract, suggesting that the tropomyosin is not readily extractable with a classic aqueous extraction procedure. rLep s 1 displayed biological activity, suggesting that it could be regarded as a useful tool to study the role of silverfish tropomyosin in the sensitization to invertebrate allergic sources.

Recombinant DNA technology does provide pure, well-defined and reproducible products to be used for clinical purposes, by cloning and expressing the cDNA of allergens present in a specific extract. Ole e 5 is a pollen allergen of Olea europaea with an IgE-binding frequency of about 35%, which has been identified as a superoxide dismutase (SOD). The aim of this study was to clone the cDNA of Ole e 5, to express Ole e 5 in Escherichia coli and to characterize its immunoreactivity.cDNA of Ole e 5 was amplified by nested 3'-RACE PCR and cloned in pGEX vector 6P expression vector. After sequencing of some clones and homology analysis, the rOle e 5 was produced in an E. coli strain as a fusion protein with GST and purified. Then, the protein immunoreactivity was evaluated by patients' IgE binding (ELISA, ELISA inhibition, and immunoblotting) and by rabbit anti-rOle e 5 binding (immunoblotting and immunoblotting inhibition).The sequence analysis of Ole e 5 cDNA confirmed that Ole e 5 is a Cu/Zn SOD, with an identity from 90 to 80% with SOD from other species. rOle e 5 was recognized by IgE from 39% of olive pollen-allergic patients tested; moreover, this binding was inhibited by the olive pollen extract. An anti-rOle e 5 antiserum raised in rabbit strongly reacted with a natural component of about 16-kDa molecular weight present in the olive pollen extract; moreover, this binding was inhibited by the recombinant protein.Ole e 5 is the first Cu/Zn SOD identified as an allergen in a pollen source. Due to the widespread presence of this enzyme, rOle e 5 allergen, cloned and expressed in a complete form in E. coli, could represent a good tool to investigate the allergen cross-reactivity between O. europaea pollen and other allergenic sources, such as plant foods and other pollens.

Background: Calcium-binding plant allergens can be grouped in different families according to the number of calciumbinding domains (EF hands). Objective: We sought to identify pollens containing crossreactive calcium-binding allergens and to investigate structural and immunologic similarities of members belonging to different families of calcium-binding allergens. Methods: By means of multiple sequence alignment and molecular modeling, we searched for structural similarities among pollen allergens with 2 (Phl p 7, timothy grass; Aln g 4, alder), 3 (Bet v 3, birch) and 4 EF hands (Jun o 4, prickly juniper). Purified recombinant Aln g 4 and Jun o 4 were used to determine the prevalence of IgE recognition in 210 patients sensitized to different pollens and to search, by means of ELISA competition, for the presence of cross-reactive epitopes in pollens from 16 unrelated plant species. IgE cross-reactivity among the allergen families was studied with purified rPhl p 7, rAln g 4, rBet v 3, and rJun o 4 and 2 synthetic peptides comprising the N-terminal and C-terminal EF hands of Phl p 7 by means of ELISA competition. Results: Structural similarities were found by using molecular modeling among the allergens with 2, 3, and 4 EF hands. Pollens from 16 unrelated plants contained Aln g 4- and Jun o 4-related epitopes. Twenty-two percent of the patients with multiple pollen sensitization reacted to at least one of the calcium-binding allergens. A hierarchy of IgE cross-reactivity (rPhl p7 > rAln g 4 > rJun o 4 > rBet v 3) could be established that identified rPhl p 7 as the EF-hand allergen containing most IgE epitopes in the population studied. Conclusion: The demonstration that members of different families of calcium-binding plant allergens share similarities suggests that it may be possible to use representative molecules for the diagnosis and therapy of allergies to EF-hand allergens. (J Allergy Clin Immunol 2002;109:314-20.)

Background: A rapid method for the purification of the major 43-kDa all_ergen of Cupressus arizonica pollen, Cup a 1, was developed. Methods: The salient feature was a wash of the pollen in acidic buffer, followed by an extraction of the proteins and their purification by chromatography. Immunoblotting, ELISA, and lectin binding were tested on both the crude extract and the purified Cup a 1. Biochemical analyses were performed to assess the Cup a 1 isoelectric point, its partial amino-acid sequence, and its glycan composition. Results: Immunochemical analysis of Cup a 1 confirmed that the all_ergenic reactivity is maintained after the purification process. Partial amino-acid sequencing indicated a high degree of homology between Cup a 1 and all_ergenic proteins from the Cupressaceae and Taxodiaceae families displaying a similar molecular mass. The purified protein shows one band with an isoelectric point of 5.2. Nineteen out of 33 sera (57%) from patients all_ergic to cypress demonstrated significant reactivity to purified Cup a 1. MALDI-TOF mass spectrometry indicated the presence of three N-linked oligosaccharide structures: GnGnXF3 (i.e., a horseradish peroxidase-type oligosaccharide substituted with two nonreducing N-acetylglucosamine residues), GGnXF3/GnGXF3 (i.e., GnGnXF with one nonreducing galactose residue), and (GF)GnXF3/Gn(GF)XF3 (with a Lewisa epitope on one arm) in the molar ratio 67:8:23. Conclusions: The rapid purification process of Cup a 1 all_owed some fine studies on its properties and structure, as well as the evaluation of its IgE reactivity in native conditions. The similarities of amino-acid sequences and some complex glycan stuctures could explain the high degree of cross-reactivity among the Cupressaceae and Taxodiaceae families.

Oct-4 is a transcription factor that is specifically expressed in mouse embryonic stem cells and in cell lines derived thereof. In these cells, Oct-4 activates transcription from remote binding sites due to as of yet unknown co-activators. Expression of Oct-4 in differentiated cells is not sufficient to activate transcription from a distance, rather it requires the co-expression of co-activators such as the adenoviral oncoprotein E1A. In this paper, we used phage display to identify Oct-4-interacting proteins. We first analyzed the interaction between Oct-4 and E1A in order to optimize the biochemical conditions that enable Oct-4-specific interactions with other interacting proteins. A panning approach was used to enrich Oct-4 interacting phages from a pool of excess unspecific phages. The biochemical conditions established in our interaction assays were then used to screen a P19 EC cell cDNA expression library in M13 filamentous phage. A number of phage clones displaying portions of unknown and known transcription factors were obtained, from which the HMG-1 transcription factor was identified. HMG-1, and the closely related factor HMG-2, interact with Oct-4 when co-expressed in mammalian cells. In addition, HMG-1 was found to cooperate with Oct-4 in P19 EC cells. These results provide the first evidence of a non-viral factor that enhances Oct-4 distance-dependent transactivation in stem cells.

Background Cypress pollen causes respiratory syndromes with different grades of severity, including asthma. IL-33, its receptor ST2, and dendritic cells (DCs) have been implicated in human respiratory allergy. Objective We sought to define a new mouse model of allergy to cypress pollen that recapitulates clinical parameters in allergic patients and to evaluate the implications of DCs and the IL-33/ST2 pathway in this pathology. Methods BALB/c mice, either wild-type or ST2 deficient (ST2 −/− ), were sensitized and challenged with the Cupressus arizonica major allergen nCup a 1. Local and systemic allergic responses were evaluated. Pulmonary cells were characterized by means of flow cytometry. DCs were stimulated with nCup a 1 and tested for their biological response to IL-33 in coculture assays. Results nCup a 1 causes a respiratory syndrome closely resembling human pollinosis in BALB/c mice. nCup a 1–treated mice exhibit the hallmarks of allergic pathology associated with pulmonary infiltration of eosinophils, T cells, and DCs and a dominant T H 2-type immune response. IL-33 levels were increased in lungs and sera of nCup a 1–treated mice and in subjects with cypress allergy. The allergen-specific reaction was markedly reduced in ST2 −/− mice, which showed fewer infiltrating eosinophils, T cells, and DCs in the lungs. Finally, stimulation of DCs with nCup a 1 resulted in ST2 upregulation that endowed DCs with increased ability to respond to IL-33–mediated differentiation of IL-5– and IL-13–producing CD4 T cells. Conclusions Our findings define a novel preclinical model of allergy to cypress pollen and provide the first evidence of a functionally relevant linkage between pollen allergens and T H 2-polarizing activity by DCs through IL-33/ST2.

The immunological mechanisms responsible for the anti-allergic effects of probiotic bacteria are still poorly defined. We tested the effect of a probiotic mixture (VSL#3) in in vitro, ex vivo and in vivo mouse systems. In vitro co-culture of naive bone marrow(BM)-derived DC (BM-DC) with VSL#3 induced the up-regulation of maturation marker and IL-10 and IL-12 production. Ex vivo analysis of mesenteric lymph node(MLN)-derived DC (MLN-DC) from naive mice receiving for three weeks VSL#3 by oral administration, indicated a different distribution and phenotype of DC within the MLN. In particular, VSL#3 treatment increased the frequency of plasmacytoid DC (pDC, B220+CD11clow), and upregulated the expression of maturation markers on conventional DC (cDC). Moreover, the frequency of IL-10-expressing cDC was increased. This finding was paralleled by the increase of CD4+CD25+ T cells and CD4+CD25- populations showing enhanced IL-10 production. Altogether, these results suggest that VSL#3 treatment can stimulate in the gut the activation of tolerogenic DC. Finally, we obtained in vivo preliminary data on therapeutic and preventive potential of VSL#3 in a mouse model of sensitization and anaphylaxis to peanut. Mice were orally sensitized and challenged with peanut extract to induce in vivo anaphylaxis. In the therapeutic experimental setting, animals received a three-weeks oral treatment with VSL#3 and were then re-challenged. In the preventive setting, oral probiotic treatment started one week before the beginning of the immunization schedule and continued until the challenge. In both approaches, VSL#3 was able to reduce anaphylaxis symptoms and IL-13 release in the jejunum of immunized mice upon post-treatment challenge. Furthermore, the therapeutic approach also induced allergen-specific IgA in the gut and TGF-β release. Then, the capacity of probiotics to induce protective immune responses linked to counter-regulation of Th2 responses might become an effective strategy in the treatment of type I allergy.

Exposure to indoor allergens is an important risk factor for sensitisation and respiratory allergy. The aim of this paper was to evaluate the levels of mite, cat and latex allergens in dust collected from an indoor workplace and to assess whether the exposure to these allergens was associated with the allergy symptoms reported by employees. Sixty dust samples were collected. Allergen concentrations were measured with antibody based ELISAs. All 144 participants compiled a questionnaire exploring possible symptoms of allergy. No association between latex allergen exposure and symptoms was found in spite of the high frequency of latex allergens. Mite allergens were detected in a minority of rooms. Cat allergen was the most important indoor allergen in the sampled workplace and exposure to this allergen could represent a risk for employees.

We used a colorimetric polymerase chain reaction (PCR)-based assay in kit form to detect directly human immunodeficiency virus type 1 (HIV-1) proviral gag sequences in peripheral blood cells from 68 healthy blood donors, 51 subjects at risk for HIV infection, 122 patients with HIV-1 infection, 11 patients with indeterminate Western blot (immunoblot) results, 4 blood donors HIV-1 positive by enzyme immunoassay, and 13 children born to HIV-1-seropositive mothers. The results obtained in the blood donors and HIV-1-infected patients demonstrated the high degree of diagnostic Specificity and sensitivity of the PCR method. HIV-1 infection was excluded in 10 of the 11 patients with indeterminate Western blot results and in all four enzyme immunoassay-positive blood donors. A diagnosis of HIV infection was ruled out by negative PCR results in 5 of 13 children from seropositive mothers, which excluded vertical transmission of the infection in these cases; these children were younger than 3 months and had positive serological results. Two at-risk patients with negative serological results had positive PCR results. All results were confirmed by conventional PCR. In conclusion, colorimetric PCR, which is commercially available in kit form, is an easy and reliable technique that can be used to detect proviral HIV-1 genomes in blood cells, and despite the limitations owing to HIV genome variability, it is useful in the clinical setting for the diagnosis of HIV infection in selected categories of patients.

Probiotic bacteria as modulators of the immune response have been intensively studied in reducing the risk of immune-mediated diseases, including atopic diseases. Results from in vitro studies demonstrated that probiotics may modify the polarization of immune cells, supporting potential therapeutic effects in atopic diseases. Several clinical studies have been designed to explore the effective role of probiotics in the modulation of allergic diseases. The results of these studies, although promising, are not conclusive yet and are considered insufficient to recommend probiotics as a part of standard therapy in any allergic conditions. In vivo studies on animal models can provide useful information on the immunologic mechanisms responsible for the potential antiallergic effects of probiotic bacteria. The immunomodulatory activity of the probiotic mixture VSL#3 has been studied in the mouse models of allergic sensitization and anaphylaxis developed in our laboratory with inhalant and food allergens, according to a prophylactic setting by the intranasal route (inhalant allergy model) or a therapeutic setting by the oral route (food allergy model). Intranasally delivered probiotic bacteria prevented the development of Parietaria major allergen-specific response, by down-regulating T helper cell 2 responses at the local and systemic level. Oral therapeutic treatment was able to reduce both systemic and local anaphylactic symptoms induced by oral challenge with the sensitizing allergen Shrimp Tropomyosin. The induction of protective immune responses at the sites of allergen exposure linked to counterregulatory local and systemic immune responses by mucosal delivery of probiotic bacteria mixtures might become an effective strategy in the prevention and therapy of allergic diseases.