COMPARISON OF ACTIVATION MARKER AND TCR V-BETA GENE-PRODUCT EXPRESSION BY CD4(+) AND CD8(+) T-CELLS IN PERIPHERAL-BLOOD AND LYMPH-NODES FROM HIV-INFECTED PATIENTS

Since lymphoid organs constitute the site of active and progressive HIV disease, analysis of their lymphocytes may provide more accurate information on T cell abnormalities than that obtained from studying peripheral blood lymphocytes. The objective of this study was to compare the expressions of activation markers and T cell receptor (TCR) V beta gene products by CD4(+) and CD8(+) T cells in lymph nodes (LN) and peripheral blood (PB) from healthy individuals and asymptomatic HIV-infected patients to determine whether anomalies that could be identified at the HIV replication site could support the hypothesis of T cell activation by HIV-encoded antigens or superantigens. CD4(+) and CD8(+) T cells in paired LN and PB obtained from six healthy controls and five asymptomatic HIV-infected individuals were analysed by flow cytometry, using anti-CD38, anti-HLA-DR and 13 anti-V beta MoAbs that cover, approximately, 45% of the T cell repertoire. Analysis of T cell activation marker expression indicated that the percentages of CD4(+) and CD8(+) T cells bearing CD38 or CD38 and HLA-DR molecules were higher in patients than in controls and, in patients, higher in LN than in PB. Comparison between the V beta repertoires of CD4(+) and CD8(+) T cells in LN and PB showed that, in each healthy individual, a limited number of V beta families expressed by CD4(+) or CD8(+) T cells had different repartition in LN and PB, whereas in each HIV+ patient, more V beta families exhibited different distributions and these differences recurred among certain V beta segments, such as V beta 5.3 and V beta 21 in the CD4(+) T cell population and V beta 5.2/5.3, V beta 12 and V beta 21 in the CD8(+) T cell population. Taken together, these data argue for a skewed TCR repertoire in HIV infection and sustained activation of T cells by HIV-encoded antigens at the site of HIV replication, and further demonstrate that a high proportion of CD4(+) T cells are in an activation state that may, indirectly, participate in their functional abnormalities.