Avaliação do efeito da expressão do gene da interleucina 32 (IL-32) humana em modelo murino de infecção por Leishmania (Leishmania) amazonensis

• Ano de defesa: 2016
• Autor(a) principal: Silva, Muriel Vilela Teodoro
• Orientador(a): Dias, Fátima Ribeiro
• Banca de defesa: Dias, Fátima Ribeiro, Santiago, Helton da Costa, Galdino Junior, Hélio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Biologia das Interações Parasito-Hospedeiro (IPTSP)
• Departamento: Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG)
• País: Brasil
• Palavras-chave em Português: Leishmania (Leishmania) amazonensis; IL-32; Modelo murino
• Palavras-chave em Inglês: Leishmania (Leishmania) amazonensis; IL-32; Murine model
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::IMUNOLOGIA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/6333

IL-32 is a proinflammatory cytokine which has different isoforms. IL-32γ isoform is the most powerful and was detected in lesions of patients with cutaneous leishmaniasis. Murine cells respond to IL-32, however mice lack the gene for this cytokine. To understand the role of IL- 32 in Leishmania (L.) amazonensis, we used transgenic mice for human IL-32γ (IL-32γTg). C57BL/6 mice (WT) and C57BL/6 IL-32γTg were infected with L. amazonensis promastigotes in the ear. The lesion development was followed weekly with a digital caliper (measured in mm of injury). After 3, 6 and 9 weeks, the animals were euthanized for tissue parasitism analysis by the limiting dilution technique, in infected ears, draining lymph node and spleen of mice. The draining lymph node cells were incubated (48 h) in the presence or absence of L. amazonensis antigen (Ag) for analysis of cytokines by ELISA. IL-32γTg mice present IL-32 production in spleen, liver, lymph node and ear. IL-32γTg mice have a lower injury than the WT mice during the third week of infection. From the 5th to the 9th week of infection, the two groups had similar lesion development profiles. Interestingly, in the 3rd week of infection, the parasitic load in the lesion of IL-32γTg mice was 100 times greater than that of WT mice. After three weeks, IL-32γTg mice maintained the same parasitic load up to nine weeks. In WT mice, however, the number of parasites increased exponentially during weeks evaluated. The parasite load in the spleen and lymph node was lower in IL-32γTg mice when compared with WT mice. There was no difference in histological sections of the lesions in WT and IL-32γTg mice infected with L. amazonensis. We did not observe differences between WT and IL-32γTg groups on the product -10) by lymph node cells stimulated with Ag, in the 3rd, 6th and 9th week of infection. Our data suggest that IL-32γ favors infection by L. amazonensis in the early stages, allowing the growth of the parasites. However, this cytokine seems to limit the growth and spread of parasites in the later stages of infection. In vitro analyzes show the similar percentage of infected cells and the number of parasites per infected cell in WT macrophages and IL-32γTg after 3 and 48h of infection with L. amazonensis. However, the production of NO by macrophages seems to be lower in IL- 32γTg mouse cells during infection with L. amazonensis. Understanding the mechanisms by which IL-32γ modulates Leishmania amazonensis infection in mice is essential to define the components that control cutaneous leishmaniasis caused by this specie in humans.