Circulating HIV-specific CD8+ cytotoxic T cells express CD38 and HLA-DR antigens
Autor: | H N, Ho, L E, Hultin, R T, Mitsuyasu, J L, Matud, M A, Hausner, D, Bockstoce, C C, Chou, S, O'Rourke, J M, Taylor, J V, Giorgi |
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Rok vydání: | 1993 |
Předmět: |
Cytotoxicity
Immunologic Male Membrane Glycoproteins CD8 Antigens Gene Products env Gene Products gag Gene Products pol HIV HIV Infections HLA-DR Antigens ADP-ribosyl Cyclase 1 Antigens Differentiation Binding Competitive Immunophenotyping Antigens CD Humans Binding Sites Antibody ADP-ribosyl Cyclase T-Lymphocytes Cytotoxic |
Zdroj: | Journal of immunology (Baltimore, Md. : 1950). 150(7) |
ISSN: | 0022-1767 |
Popis: | CD38, a molecule with multilineage distribution but unknown function, and the MHC class II molecule HLA-DR (DR) have markedly elevated levels of expression on CD8+ cells of HIV-infected people. This study investigated the expression of CD38 and DR Ag on circulating HIV-specific CD8+ CTL in HIV-seropositive subjects. Purified CD8+ lymphocytes from 22 participants in the University of California at Los Angeles Multicenter AIDS Cohort Study were screened for CTL activity against autologous EBV-immortalized lymphoblast targets infected with vaccinia vectors that carried HIVIIIB gag, pol, and env genes. Sixty-seven percent (14 of 21), 64% (14 of 22), and 9% (2 of 22), respectively, of the subjects had HIV-specific CD8+ CTL activity against gag, pol, and env proteins. CD8+ cells from 11 of the subjects who had high CTL activity were then FACS-separated using three-color immunofluorescence sorting. Circulating DR-CD38- CD8+ cells had little activity. Highly purified DR+CD38+ CD8+ cells had higher HIV-specific CTL activity than other CD8+ cells. DR+CD38- or DR-CD38+ CD8+ cells also mediated significant activity, but only about half as much on a per cell basis as DR+CD38+ CD8+ cells. This is the first report that the CD38 molecule is expressed in vivo on Ag-specific CD8+ CTL, and confirms previous reports that DR is expressed on these cells. Both asymptomatic HIV-seropositive subjects (144 +/- 132/mm3) and AIDS patients (253 +/- 178/mm3) had markedly elevated levels of DR+CD38+ CD8+ cells compared with the levels in HIV-seronegative controls (7 +/- 3/mm3). However, the level of anti-HIV CTL activity was not correlated with the level of DR+CD38+ CD8+ cells, indicating that enumeration of this lymphocyte population by flow cytometry most likely will not be a useful surrogate for measuring functional CTL activity. Low levels of HIV-specific CTL activity, especially against gag, were correlated with lower CD4+ cells numbers, suggesting that the loss of CD8+ T cell cytotoxic activity against HIV that has been reported to occur with advancing HIV disease progression may reflect in part the extent of CD4+ cell immunodeficiency in HIV-infected subjects. |
Databáze: | OpenAIRE |
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