Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease

• Autor(a) principal: Ndhlovu, L. C.
• Data de Publicação: 2009
• Outros Autores: Snyder-Cappione, J. E., Carvalho, Karina Inacio [UNIFESP], Leal, F. E., Loo, C. P., Bruno, F. R., Jha, A. R., Devita, D., Hasenkrug, A. M., Barbosa, H. M. R. [UNIFESP], Segurado, A. C., Nixon, D. F., Murphy, E. L., Kallas, Esper Georges [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1111/j.1365-2249.2009.04019.x; http://repositorio.unifesp.br/handle/11600/31961
• topic: CD8; HTLV-1 infection; innate immunity; NK T cells; CD4

Human T lymphotropic virus type 1 (HTLV-1) infects 10-20 million people worldwide. the majority of infected individuals are asymptomatic; however, approximately 3% develop the debilitating neurological disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There is also currently no cure, vaccine or effective therapy for HTLV-1 infection, and the mechanisms for progression to HAM/TSP remain unclear. NK T cells are an immunoregulatory T cell subset whose frequencies and effector functions are associated critically with immunity against infectious diseases. We hypothesized that NK T cells are associated with HAM/TSP progression. We measured NK T cell frequencies and absolute numbers in individuals with HAM/TSP infection from two cohorts on two continents: São Paulo, Brazil and San Francisco, CA, USA, and found significantly lower levels when compared with healthy subjects and/or asymptomatic carriers. Also, the circulating NK T cell compartment in HAM/TSP subjects is comprised of significantly more CD4(+) and fewer CD8(+) cells than healthy controls. These findings suggest that lower numbers of circulating NK T cells and enrichment of the CD4(+) NK T subset are associated with HTLV-1 disease progression.