T-CELL RECEPTOR V-BETA REPERTOIRE IN AN ACUTE INFECTION OF RHESUS-MONKEYS WITH SIMIAN IMMUNODEFICIENCY VIRUSES AND A CHIMERIC SIMIAN-HUMAN IMMUNODEFICIENCY VIRUS

Changes in T cell receptor (TCR) V beta repertoire and their correlati on with virologic events were investigated in rhesus monkeys after acu te infection with the simian immunodeficiency virus (SIV). 11 genetica lly defined rhesus monkeys were experimentally infected with SIVmac or a chimeric simian-human immunodeficiency virus (SHIV), and their peri pheral blood lymphocytes (PBL) and lymph nodes were prospectively asse ssed for TCR V beta gene expression. PBL and lymph nodes of the acutel y infected monkeys demonstrated an expansion of selected V beta-expres sing T lymphocyte subpopulations as early as 3 d after infection. Thes e expanded V beta-expressing lymphocyte subpopulations were comprised predominantly of CD8+ cells. Six of seven infected monkeys sharing a s ingle electrophoretically defined major histocompatibility complex cla ss I allele exhibited a similar expansion of V beta 14-expressing PBL. Sequence analyses of V-D-J segments of TCR-beta cDNA indicated that t he V beta-expressing T cell subpopulation expansion can be oligoclonal . SIVmac-specific CD8+ cytotoxic T lymphocytes were demonstrated in bo th PBL and lymph nodes of the infected monkeys at the time expansion o f the selected V beta-expressing cell subpopulations was seen. Finally , the expansion of the selected V beta-expressing lymphocytes in PBL c oincided with the emergence and clearance of SIV p27 from the plasma o f the infected monkeys. These results demonstrate that acute infection of rhesus monkeys with SIVmac or SHIV results in an expansion of CD8 lymphocyte subpopulations expressing selected V beta gene families. T he selectively expanded T lymphocytes may contribute to early viral cl earance after acute SIVmac or SHIV infection.