https://repositorio.ufba.br/handle/ri/15925
Tipo: | Artigo de Periódico |
Título: | Immunologic response and memory T cells in subjects cured of tegumentary leishmaniasis |
Título(s) alternativo(s): | BMC Infectious Diseases |
Autor(es): | Carvalho, Augusto M. Magalhães, Andréa Carvalho, Lucas Pedreira de Bacellar, Maria Olívia Amado Ramos Scott, Phillip Carvalho Filho, Edgar Marcelino de |
Autor(es): | Carvalho, Augusto M. Magalhães, Andréa Carvalho, Lucas Pedreira de Bacellar, Maria Olívia Amado Ramos Scott, Phillip Carvalho Filho, Edgar Marcelino de |
Abstract: | Background: The main clinical forms of tegumentary leishmaniasis are cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). L.braziliensis infection is characterized by an exaggerated production of IFN-gamma and TNF-alpha, cytokines involved in parasite destruction, but also in the pathology. Maintenance of an antigen-specific immune response may be important for resistance to re-infection and will contribute for vaccine development. In the present work we investigated the immune response in CL and ML cured individuals. Methods: Participants in the present study included 20 CL and 20 ML patients, who were evaluated prior to, as well as 2 to 15 years after therapy. IFN-gamma, IL-2 and TNF-alpha production were determined by ELISA in supernatants of mononuclear cells stimulated with soluble L.braziliensis antigen (SLA). The frequency of memory CD4+ T cell populations was determined by FACS. Results: Here we show that the majority of CL and ML patients did not produce in vitro IFN-gamma in response to SLA after cure. In the cured individuals who responded to SLA, effector memory (CD45RA-CCR7-) CD4+ T cells were the ones producing IFN-gamma. Because a large percent of CL and ML cured patients lost SLA-induced IFN-gamma production in peripheral blood, we performed Leishmania skin test (LST). A positive LST was found in 87.5% and 100% of CL and ML cured individuals, respectively, who did not produce IFN-gamma or IL-2 in vitro. Conclusion: This study shows that in spite of losing in vitro antigen-specific response to Leishmania, cured CL and ML subjects retain the ability to respond to SLA in vivo. These findings indicate that LST, rather than IFN-gamma production, may be a better assessment of lasting immunity to leishmaniasis in human studies, and thus a better tool for assessing immunization after vaccine. Furthermore, in cured individuals which maintains Leishmania-specific IFN-gamma production, effector memory CD4+ T cells were the main source of this cytokine. |
Palavras-chave: | Cured leishmaniasis IFN-gamma Effector memory CD4+ T cells |
Tipo de Acesso: | Acesso Aberto |
URI: | http://repositorio.ufba.br/ri/handle/ri/15925 |
Data do documento: | 2013 |
Aparece nas coleções: | Artigo Publicado em Periódico (EMV) |
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