OLIGOCLONAL EXPANSIONS OF CD8(-CELLS IN CHRONIC HIV-INFECTION ARE ANTIGEN-SPECIFIC() T)

Acute HIV infection is associated with a vigorous immune response char acterized by the proliferation of selected T cell receptor V beta (BV) -expressing CD8(+) T cells. These 'expansions', which are commonly det ected in the peripheral blood, can persist during chronic HIV infectio n and may result in the dominance of particular clones. Such clonal po pulations are most consistent with antigen-driven expansions of CD8(+) T cells. However, due to the difficulties in studying antigen-specifi c T cells in vivo, it has been hard to prove that oligoclonal BV expan sions are actually HIV specific. The use of tetrameric major histocomp atibility complex-peptide complexes has recently enabled direct visual ization of antigen-specific T cells ex vivo but has not provided infor mation on their clonal composition. We have now made use of these tetr americ complexes in conjunction with anti-BV chain-specific monoclonal antibodies and analysis of cytotoxic T lymphocyte lines/clones to sho w that chronically clonally expanded CD8+ T cells are HIV specific in vivo.