Utilize este identificador para referenciar este registo: http://hdl.handle.net/10451/18295
Título: Memory and naive-like regulatory CD4+ T cells expand during HIV-2 infection in direct association with CD4+ T-cell depletion irrespectively of viremia
Autor: Foxall, R. B.
Albuquerque, A. S.
Soares, R. S.
Baptista, A. P.
Cavaleiro, R.
Tendeiro, R.
Gomes, P.
Victorino, R. M.
Sousa, A. E.
Palavras-chave: HIV/AIDS
Immune activation
Regulatory T cells
Data: 2011
Citação: AIDS 2011, 25:1961–1970
Resumo: Objective: The dynamics of CD4+ regulatory T cells (Treg) during HIV-1 infection remains unclear. To further investigate Treg in this context, we characterized, for the first time, this population in HIV-2-positive individuals. Although both HIV infections are associated with hyperimmune activation and CD4+ T-cell lymphopenia, most HIV-2-positive individuals display slower disease progression and low-to-undetectable viremia. Design/methods: Samples were obtained from cohorts of untreated HIV-2-positive and HIV-1-positive, treated HIV-1-positive and seronegative individuals. The proportion of CD4+ T cells bearing a Treg phenotype, defined in terms of high-level CD25 or Foxp3 expression, was assessed by flow cytometry and correlated with markers of disease progression. The proportions of naive and memory-like subsets as well as cycling cells were determined. Results: We observed an increased proportion of Treg, associated with disease progression, as well as increased proportions of cycling (Ki67+) memory Treg, in untreated HIV-2-positive and HIV-1-positive individuals. We also noted an expansion of Treg that persisted over time in treated, immunologically discordant HIV-1-positive individuals, who, similarly to HIV-2-positive patients, present undetectable viremia and low CD4 T-cell count. Conclusion: Overall, we demonstrated that Treg frequency was increased in all lymphopenic HIV-2-positive and HIV-1-positive individuals irrespective of the presence or absence of viremia or antiretroviral treatment. This, in turn, suggests that the observed alterations in Treg frequency in HIV/AIDS are more directly related to the degree of CD4 depletion than to viremia.
Descrição: © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
Peer review: yes
URI: http://journals.lww.com/aidsonline/Fulltext/2011/10230/Memory_and_naive_like_regulatory_CD4__T_cells.4.aspx
ISSN: 0269-9370
Aparece nas colecções:FM - Artigos em Revistas Internacionais
IMM - Artigos em Revistas Internacionais

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