T-cell responses associated with resistance to Leishmania infection in individuals from endemic areas for Leishmania (Viannia) braziliensis
Título del documento: T-cell responses associated with resistance to Leishmania infection in individuals from endemic areas for Leishmania (Viannia) braziliensis
Revista: Memorias do Instituto Oswaldo Cruz
Base de datos: PERIÓDICA
Número de sistema: 000351785
ISSN: 0074-0276
Autores: 1
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Instituciones: 1Instituto Oswaldo Cruz, Departamento de Imunologia, Rio de Janeiro. Brasil
2Fundacao Oswaldo Cruz, Instituto de Pesquisa Clinica Evandro Chagas, Rio de Janeiro. Brasil
Año:
Periodo: Ago
Volumen: 102
Número: 5
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, aplicado
Resumen en inglés Subclinical or asymptomatic infection is documented in individuals living in endemic areas for leishmaniasis suggesting that the development of an appropriate immune response can control parasite replication and maintain tissue integrity. A low morbidity indicates that intrinsic factors could favor resistance to Leishmania infection. Herein, leishmanial T-cell responses induced in subjects with low susceptibility to leishmaniasis as asymptomatic subjects were compared to those observed in cured cutaneous leishmaniasis (CCL) patients, who controlled the disease after antimonial therapy. All of them have shown maintenance of specific long-term immune responses characterized by expansion of higher proportions of CD4+ as compared to CD8+ Leishmania reactive T-lymphocytes. Asymptomatic subjects had lower indexes of in vitro Leishmania induced lymphoproliferative responses and interferon-gamma (IFN-g) production in comparison to CCL patients. On the other hand, interleukin (IL-10) production was much higher in asymptomatics than in CCL, while no differences in IL-5 levels were found. In conclusion, long lived T-cell responses achieved by asymptomatic individuals differed from those who had developed symptomatic leishmaniasis in terms of intensity of lymphocyte activation (proliferation or IFN-g) and regulatory mechanisms (IL-10). The absence of the disease in asymptomatics could be explained by their intrinsic ability to create a balance between immunoregulatory (IL-10) and effector cytokines (IFN-g), leading to parasite destruction without producing skin tissue damage. The establishment of profiles of cell-mediated immune responses associated with resistance against Leishmania infection is likely to make new inroads into understanding the long-lived immune protection against the disease
Disciplinas: Medicina
Palabras clave: Inmunología,
Parasitología,
Leishmaniasis cutánea,
Respuesta inmune,
Infección asintomática,
Células T,
Leishmania braziliensis
Keyword: Medicine,
Immunology,
Parasitology,
Cutaneous leishmaniasis,
Immune response,
Asymptomatic infection,
T cells,
Leishmania braziliensis
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