1 results for Altfeld, M

  • Limited immunogenicity of HIV CD8+ T-cell epitopes in acute clade C virus infection

    Radebe, M; Nair, K; Chonco, F; Bishop, Karen; Wright, JK; Van Stok, MD; Bassett, IV; Mncube, Z; Altfeld, M; Walker, BD; Ndung'u, T (2011)

    Journal article
    The University of Auckland Library

    Background. Human immunodeficiency virus type 1 (HIV-1)???specific CD81 responses contribute to the decline in acute peak viremia following infection. However, data on the relative immunogenicity of CD81 T-cell epitopes during and after acute viremia are lacking. Methods. We characterized CD81 T-cell responses in 20 acutely infected, antiretroviral-naive individuals with HIV-1 subtype C infection using the interferon-c enzyme-linked immunosorbent spot assay. Eleven of these had not fully seroconverted at the time of analysis. Viruses from plasma were sequenced within defined cytotoxic T-lymphocyte (CTL) cell epitopes for selected subjects. Results. At approximately 28 days after estimated initial infection, CD81 T-cell responses were directed against an average of 3 of the 410 peptides tested (range, 0???6); 2 individuals had no detectable responses at this time. At 18 weeks, the average number of peptides targeted had increased to 5 (range 0???11). Of the 56 optimal Gag CTL epitopes sequenced, 31 were wild-type in the infecting viruses, but only 11 of 31 elicited measurable CD81 T-cell responses. Conclusions. These data demonstrate that the majority of CD81 responses are not elicited during acute HIV infection despite the presence of the cognate epitope in the infecting strain. There is a need to define factors that influence lack of induction of effective immune responses and the parameters that dictate immunodominance in acute infection.

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