RESUMO

We investigated the role of the platelet activation factor (PAF) receptor (PAFR) in the outcome of infection with Leishmania amazonensis. PAFR deficient (PAFR(-/-)) mice were infected with L. amazonensis and the course of infection was followed. We found that PAFR(-/-) mice in the C57BL/6 background were more susceptible to infection with L. amazonensis than the wild-type controls, as seen both by lesion size and parasite number at the site of infection. Interferon (IFN)-gamma production was delayed in PAFR(-/-) mice, and lower levels of Ccl5 were found in lesions. Expression of nitric oxide synthase-2 mRNA was found impaired in PAFR(-/-) associated with higher levels of arginase-1 mRNA. Moreover, higher levels of antibodies were produced in response to L. amazonensis by PAFR(-/-) mice. We conclude that signaling through the PAFR is essential for the ability of the murine host to control L. amazonensis infection by driving an adequate immune response.

Assuntos

Interferon gama/biossíntese , Leishmania mexicana/imunologia , Leishmaniose Cutânea/imunologia , Glicoproteínas da Membrana de Plaquetas/deficiência , Receptores Acoplados a Proteínas G/deficiência , Animais , Anticorpos Antiprotozoários/sangue , Arginase/biossíntese , Quimiocina CCL1 , Quimiocina CCL5 , Quimiocinas CC/análise , Modelos Animais de Doenças , Suscetibilidade a Doenças , Expressão Gênica , Histocitoquímica , Imunoglobulina G/sangue , Interleucina-10/análise , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/biossíntese , Glicoproteínas da Membrana de Plaquetas/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , Receptores Acoplados a Proteínas G/genética , Fator de Necrose Tumoral alfa/análise , Regulação para Cima