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Splenocyte Cultures (splenocyte + culture)
Selected AbstractsRegulation of immune responses to Strongyloides venezuelensis challenge after primary infection with different larvae dosesPARASITE IMMUNOLOGY, Issue 3 2010H. C. SCHILTER Summary Nematode infections are generally followed by high rates of reinfection, leading to elevated prevalence in endemic areas. Therefore, the effective control of nematode infections depends on understanding the induction and regulation of protective mechanisms. However, most experimental models for protective immune response against nematodes use high parasite exposure, not always reflecting what occurs naturally in human populations. In this study, we tested whether infecting mice with different Strongyloides venezuelensis larvae loads would affect protective responses against reinfection. Interestingly, we found that a previous infection with 10,500 larvae conferred high rate of protection against reinfection with S. venezuelensis in mice, by destroying large numbers of migrating larvae. However, low-dose priming did not abolish adult worm maturation, as detected in high-dose primed group. Results also indicated that a previous low-dose infection delayed the development of cellular infiltrate, while a high inoculum rapidly induced these inflammatory features. Cytokine production by splenocyte cultures of challenge infected mice demonstrated that low-dose priming had increased production of IL-4 and IFN-,, while high-dose induced IL-4 production but not IFN-,. Our data support the hypothesis that low-dose nematode infection does not induce a polarized type-2 immune response, allowing adult worm survival. [source] Pharmacology and immunological actions of a herbal medicine ASHMITM on allergic asthmaPHYTOTHERAPY RESEARCH, Issue 7 2010Tengfei Zhang Abstract Allergic asthma is a chronic and progressive inflammatory disease for which there is no satisfactory treatment. Studies reported tolerability and efficacy of an anti-asthma herbal medicine intervention (ASHMI) for asthma patients, developed from traditional Chinese medicine. To investigate the pharmacological actions of ASHMI on early- and late-phase airway responses (EAR and LAR), Ovalbumin (OVA)-sensitized mice received 6 weeks of ASHMI treatment beginning 24,h following the first intratracheal OVA challenge. EAR were determined 30,min following the fourth challenge and LAR 48,h following the last challenge. ASHMI effects on cytokine secretion, murine tracheal ring contraction and human bronchial smooth muscle cell prostaglandin (PG) production were also determined. ASHMI abolished EAR, which was associated with significantly reduced histamine, leukotriene C4, and OVA-specific IgE levels, as well as LAR, which was associated with significantly reduced bronchoalveolar lavage fluid (BALF) eosinophils, decreased airway remodeling, and lower Th2 cytokine levels in BALF and splenocyte cultures. Furthermore, ASHMI inhibited contraction of murine tracheal rings and increased production of the potent smooth muscle relaxer PGI2. ASHMI abrogation of allergic airway responses is associated with broad effects on asthma pathological mechanisms. Copyright © 2009 John Wiley & Sons, Ltd. [source] Hypoallergenic mutants of Ole e 1, the major olive pollen allergen, as candidates for allergy vaccinesCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2007E. G. Marazuela Summary Background The C-terminal region of Ole e 1, a major allergen from olive pollen, is a dominant IgE-reactive site and offers a target for site-directed mutagenesis to produce variants with reduced IgE-binding capability. Objective To evaluate in vitro and in vivo the immunogenic properties of three engineered derivatives of Ole e 1. Methods One point (Y141A) and two deletion (135,10 and 140,5) mutants were generated by site-directed mutagenesis of Ole e 1-specific cDNA and produced in Pichia pastoris. Ole e 1 mutants were analysed for IgE reactivity by ELISA using sera from olive pollen-allergic patients. Their allergenicity was also investigated in both a mouse model of allergic sensitization and in basophil activation assays. IgG1 response was assayed by immunoblotting and competitive ELISA. T cell reactivity was evaluated by proliferation assays and cytokine production in splenocyte cultures. Results The 135,10 mutant showed the strongest reduction in the IgE-binding capability of sera from olive pollen-allergic patients. Rat basophil leukaemia assays identified the deletion mutant 135,10 as the variant with the lowest ,-hexosaminidase-releasing capacity. Furthermore, the same 135,10 mutant induced the lowest IgE levels in a BALB/c mouse model of sensitization. All Ole e 1 mutants retained their allergen-specific T cell reactivity. Immunization of mice with the mutants induced IgG1 antibodies, which cross-reacted with Ole e 1 and Ole e 1-like allergens from ash, lilac and privet pollens. The ability of the human IgE to block the binding of anti-Ole e 1 mutant-specific mouse IgG1 antibodies to natural Ole e 1 demonstrated that Ole e 1 mutants are able to induce in vivo antibodies reactive to the natural allergen. Conclusion The 135,10 mutant with reduced allergenicity, intact T cell reactivity and capacity to induce blocking antibodies could provide a suitable candidate vaccine for efficient and safer therapy of olive pollen allergy. [source] The recombinant major allergen of Parietaria judaica and its hypoallergenic variant: in vivo evaluation in a murine model of allergic sensitizationCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2004A. Orlandi Summary Background Par j 1 represents the major allergenic component of Parietaria judaica pollen. Its three-dimensional structure is stabilized by four disulphide bridges. A family of three-dimensional mutants of the recombinant Par j 1 (rPar j 1) allergen, showing reduced allergenicity and retained T cell recognition has been recently developed by site-directed mutagenesis. Objective To develop and characterize a murine model of IgE sensitization to rPar j 1. To evaluate similarities between the murine model and the human IgE response. To investigate in this model the recognition of a hypoallergenic mutant of Par j 1, and to study the immune responses elicited in mice by the mutant itself. Methods BALB/c mice were sensitized by two intraperitoneal immunizations with rPar j 1 in alum on days 0 and 21. Allergen-specific serum IgE and IgG responses were studied by direct ELISA and immunoblotting, ELISA inhibition and competitive ELISA. Cell proliferation was evaluated in splenocyte cultures. Results Sensitization with rPar j 1 induced high levels of IgE and IgG1 vs. low levels of IgG2a. Mouse antibodies specific to rPar j 1 were able to compete with human IgE for recognition of rPar j 1. IgE from mice immunized with rPar j 1 showed a significantly reduced binding activity towards the hypoallergenic variant rPjC, which lacks three disulphide bridges. On the contrary, rPjC was recognized by IgG1 and IgG2a antibodies as well as rPar j 1. The proliferative response to rPjC by splenocytes from mice immunized with rPar j 1 was comparable to that stimulated by rPar j 1. Immunization with rPjC induced low levels of IgE antibodies to the rPjC itself, while IgG and proliferative responses were similar to those induced by rPar j 1. Conclusion Conformational variants of allergens, displaying reduced allergenicity accompanied by retained IgG and T cell recognition, offer a safe, specific and flexible approach to immunotherapy of type I allergy. Our mouse model of IgE sensitization to a recombinant allergen, mimicking the human response to its native counterpart, could provide valuable information for pre-clinical testing of such hypoallergenic molecules. [source] | ||||||||||