Human immunodeficiency virus gag and pol-specific CD8 T cells in perinatalHIV infection

Background: Binding of fluorochrome-conjugated MHC class I tetramers is a p owerful means to detect antigen-specific CD8 T lymphocytes. In human immuno deficiency virus (HIV) infection, cellular immune response is essential in curtailing HIV disease progression but gaps persist in our understanding of HIV-specific cells during the disease course. In this study, we evaluated tetramer binding HIV-specific CD8 T cells in HIV-infected children. Methods : Fluorescently labeled tetramers for HIV gag and pol were utilized to quan tify antigen-specific cells by flow cytometry using a whole blood labeling method in a cohort of 19 HLA-A2+ HIV- infected children (age range 1 month to 17 years). Results: Fourteen children had detectable gag (median 0.4%) a nd pol (median 0.1%) binding CD8 T cells, three children had gag binding ce lls only, and two had neither. Numbers of gag and pol binding cells correla ted with each other and each correlated independently with total CD8 T cell s and total CD4 T cells. Conclusions: HIV gag and pol-specific CD8 T cells are maintained during the chronic phase of HIV infection in children and CD 4 lymphocytes appear to be important for sustaining their levels. (C) 2001 Wiley-Liss.