Navegando por Palavras-chave "CD4"

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    Cell cycle distribution of CD4(+) lymphocytes in HIV-1-infected subjects
    (Wiley-Blackwell, 2004-11-01) Sauer, Mariana Melillo [UNIFESP]; Kallas, Esper Georges [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Background: Apoptosis is one of the possible explanations for the progressive loss of CD4(+) T lymphocytes in infection with the human immunodeficiency virus (HIV), which may interfere with cell cycle distribution. This study evaluated the cell cycle of CD4(+) and CD8(+) lymphocytes in HIV-infected subjects and controls.Methods: Two methods to identify lymphocytes for cell cycle analysis were evaluated, magnetic beads and concurrent staining, and both were followed by propidium iodide DNA labeling. the chosen method was used to evaluate the cell cycle of lymphocytes in HIV-1-infected subjects and controls.Results: There was no significant difference between the two methods, although a higher variability was observed with the magnetic bead cell separation method. A higher proportion of cells in the S phase was observed in HIV-1 patients (2.69% vs. 1.19%, P = 0.016), coupled with a decrease in G, (96.11% vs. 98.10%, P = 0.005) in CD4(+) lymphocytes, a phenomenon not observed in CD8(+) lymphocytes. No correlation was detected between the different cell cycle phases and T-lymphocyte counts or viral load.Conclusions: the present work developed a new approach to evaluate lymphocyte cell cycle distribution, applied in the setting of HIV-1 infection. It may contribute to the understanding of the CD4(+) T-Iymphocytes depletion seen in these patients. (C) 2004 Wiley-Liss, Inc.
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    Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease
    (Wiley-Blackwell, 2009-12-01) Ndhlovu, L. C.; 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]; Univ Calif San Francisco; Blood Syst Res Inst; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    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.