ANTIGEN-INDEPENDENT IN-VITRO EXPANSION OF T-CELLS DOES NOT AFFECT THET-CELL RECEPTOR V-BETA REPERTOIRE

Analysis of the variable chains (V alpha/V beta) of the specific T cel l receptor (TCR) of organ-infiltrating T cells may provide further ins ights into the pathogenesis of many infectious diseases, malignancies, and autoimmune disorders, To determine the TCR V beta repertoire of t hese small T cell populations antigen-independent in vitro expansion i s necessary but may select for certain T cell subpopulations. In this study various antigen independent T cell activation protocols were use d to stimulate peripheral blood mononuclear cells (PBMC) of six health y blood donors, and TCR V beta molecules were analyzed by flow cytomet ry and semiquantitative reverse transcriptase polymerase chain reactio n. In addition, the analysis of in vitro expanded liver-infiltrating T cells and autologous peripheral blood T cells derived from five patie nts with autoimmune hepatitis but none of six controls revealed a sele ctive overexpression of single TCR V beta molecules in the liver tissu e. In contrast to freshly isolated ed PBMC, no preferential expansion of single TCR V beta families was observed using phytohemagglutinin, a nti-CD3 antibodies, or oxidative stress for antigen-independent T cell activation. In conclusion, antigen-independent T cell activation offe rs the chance to analyze small populations of organ-infiltrating T cel ls without skewing the TCR V beta repertoire.