Lower numbers of natural killer T cells in HIV-1 and Mycobacterium leprae co-infected patients

• Autor(a) principal: Carvalho, Karina I.
• Data de Publicação: 2012
• Outros Autores: Bruno, Fernanda R., Snyder-Cappione, Jennifer E., Maeda, Solange M. [UNIFESP], Tomimori, Jane [UNIFESP], Xavier, Marilia B., Haslett, Patrick A., Nixon, Douglas F., Kallas, Esper G. [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• dARK ID: ark:/48912/001300000nk6m
• Texto Completo: http://dx.doi.org/10.1111/j.1365-2567.2012.03563.x; http://repositorio.unifesp.br/handle/11600/34819
• topic: co-infection; HIV-1; interferon-; leprosy; Mycobacterium leprae; natural killer T cell

Natural killer T (NKT) cells are a heterogeneous population of lymphocytes that recognize antigens presented by CD1d and have attracted attention because of their potential role linking innate and adaptive immune responses. Peripheral NKT cells display a memory-activated phenotype and can rapidly secrete large amounts of pro-inflammatory cytokines upon antigenic activation. in this study, we evaluated NKT cells in the context of patients co-infected with HIV-1 and Mycobacterium leprae. the volunteers were enrolled into four groups: 22 healthy controls, 23 HIV-1-infected patients, 20 patients with leprosy and 17 patients with leprosy and HIV-1-infection. Flow cytometry and ELISPOT assays were performed on peripheral blood mononuclear cells. We demonstrated that patients co-infected with HIV-1 and M.leprae have significantly lower NKT cell frequencies [median 0.022%, interquartile range (IQR): 0.0070.051] in the peripheral blood when compared with healthy subjects (median 0.077%, IQR: 0.0320.405, P < 0.01) or HIV-1 mono-infected patients (median 0.072%, IQR: 0.0300.160, P < 0.05). Also, more NKT cells from co-infected patients secreted interferon-? after stimulation with DimerX, when compared with leprosy mono-infected patients (P = 0.05). These results suggest that NKT cells are decreased in frequency in HIV-1 and M.leprae co-infected patients compared with HIV-1 mono-infected patients alone, but are at a more activated state. Innate immunity in human subjects is strongly influenced by their spectrum of chronic infections, and in HIV-1-infected subjects, a concurrent mycobacterial infection probably hyper-activates and lowers circulating NKT cell numbers.