ANALYSIS OF T-CELL ANTIGEN RECEPTOR (TCR) EXPRESSION BY HUMAN PERIPHERAL-BLOOD CD4-8-ALPHA BETA T-CELLS DEMONSTRATES PREFERENTIAL USE OF SEVERAL V-BETA GENES AND AN INVARIANT TCR ALPHA-CHAIN/

CD4-CD8- (double negative [DN]) alpha/beta T cells are a largely uncha racterized subpopulation of unknown function. To investigate whether t hese cells are selected to recognize particular antigens or antigen-pr esenting molecules, DN alpha/beta T cells were purified from the-perip heral blood of five normal donors and their T cell receptor (TCR) alph a and beta chains were examined. Random cloning of TCR alpha chains by single-sided polymerase chain reaction (PCR) amplification identified an invariant rearrangement between Valpha24 and JalphaQ, with no N re gion diversity, which was expressed preferentially by DN alpha/beta T cells from all donors. Random cloning also identified a precise Valpha 7.2-Jalpha(IGRJa14) rearrangement, with two variable amino acids encod ed in the V-J junction, which was enriched in the DN alpha/beta T cell preparations from some, but not all, donors. Analysis of TCR beta cha ins by quantitative PCR amplification demonstrated that the expression of four Vbeta gene families, Vbeta2, 8, 11, and 13, was markedly incr eased in these DN alpha/beta T cell preparations. The expression of pa rticular TCRs by DN alpha/beta T cells from multiple donors indicates that these cells, or at least a subpopulation of cells with this pheno type, recognize a limited spectrum of antigens and suggests that they may use nonpolymorphic antigen-presenting molecules.