Autor(es):
Carvalho, Lain Carlos Pontes de ; Passos, S. ; Bacellar, Maria Olívia Amado Ramos ; Lessa, M. ; Almeida, Roque Pacheco de ; Magalhães, A. ; Dutra, Walderez Ornelas ; Jesus, A. Ribeiro de ; Gollob, K. J. ; Machado, Paulo Roberto Lima ; Carvalho, Lain Carlos Pontes de ; Passos, S. ; Bacellar, Maria Olívia Amado Ramos ; Lessa, M. ; Almeida, Roque Pacheco de ; Magalhães, A. ; Dutra, Walderez Ornelas ; Jesus, A. Ribeiro de ; Gollob, K. J. ; Machado, Paulo Roberto Lima
Data: 2014
Origem: Oasisbr
Assunto(s): Activated T cells; Cutaneous leishmaniasis; Cytokines; Human leishmaniasis; Mucosal leishmaniasis
Descrição
Texto completo: acesso restrito. p. 251-258
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Cutaneous (CL) and mucosal leishmaniasis (ML) are characterized by a predominant type 1 immune response (IFN-γ and TNF-α production) and strong inflammatory response in the lesions with few parasites. This exacerbated type 1 response is more evident in ML as compared to CL. Our main hypothesis is that a differential immune regulation of T cell activation leads to over reactive T cells in ML. In the present study, we investigated immunological factors that could explain the mechanisms behind it by comparing some immune regulatory mechanisms between ML and CL patients: frequency of cells expressing co-stimulatory molecules, apoptotic markers, T cell activation markers; and ability of neutralizing antibodies to IL-2, IL-12 and IL-15 do down-regulate IFN-γ production in leishmania antigen-stimulated peripheral blood mononuclear cells (PBMC). Interestingly, in CL anti-IL-2 and anti-IL-15 significantly suppressed antigen-specific IFN-γ production, while in ML only anti-IL-2 suppressed IFN-γ production. Finally, higher frequency of CD4+ T cells expressing CD28−, CD69+ and CD62Llow were observed in ML as compared to CL. These data indicate that an exacerbated type 1 response in ML is differentially regulated and not appropriately down modulated, with increased frequencies of activated effectors T cells, maintaining the persistent inflammatory response and tissue damage observed in ML.
