Perfil de resposta imune induzida por extrato particulado de Leishmania braziliensis ou de Leishmania chagasi em camundongo C57BL/6

• Autor(a) principal: Valente, Samara Freire
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2356
• topic: Leishmania; Resposta imune; Anticorpo; Leishmania; Immune response; Antibody; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Among the many clinical and laboratory differences observed in leishmaniasis, a change that stands out is the hypergammaglobulinemia that occurs especially during visceral leishmaniasis caused by L. chagasi. Faced with the characteristic of this specie in activate B cell clones nonspecifically, leading to indiscriminate production of antibodies, the present study was designed to evaluate the effect of administration of crude extract of L. chagasi (EPLc) or L. braziliensis (EPLb), a specie which causes mucocutaneous leishmaniasis, associated or not with incomplete Freund's adjuvant (AIF) or alum (ALU), in the production of specific IgG antibodies against ovalbumin (OVA) in C57BL/6 mice. Furthermore the levels of mRNA to IFN-γ and IL4 in spleen cells from the same animals, aiming to evaluate the profile of immune response induced by the extracts. The results showed that: 1. Both EPLb as EPLc, in the absence of OVA, induce higher production of anti-OVA IgG than the control group (PBS). Interestingly, both extracts decrease the production of anti-OVA IgG in the presence of adjuvants and OVA, and only EPLb is able to decrease the production of IgG in the presence of OVA alone; 2. Only EPLb is able to reduce the levels of IgG1 induced by OVA; 3. EPLb, in the presence of OVA, seems to decrease the production of mRNA to IL4 more effectively than EPLc; 4. Considering the production of IFN-γ mRNA, both extracts show the same profile, and are not able to induce a marked production of this cytokine. These immunosuppressive properties of both extracts, particularly EPLb, may be target in future studies, in cases where it is desired to reduce immune system's reactions for mitigate symptoms, for example in hypersensitivity disorders.