OLIGOCLONAL EXPANSION OF MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I RESTRICTED CYTOLYTIC T-LYMPHOCYTES DURING A PRIMARY IMMUNE-RESPONSE INVIVO - DIRECT MONITORING BY FLOW-CYTOMETRY AND POLYMERASE CHAIN-REACTION

Previous T cell receptor (TCR) sequence analysis of a panel of 23 H-2K (d) restricted cytotoxic T lymphocyte (CTL) clones recognizing the dec apeptide HLA-CW3 170-179 revealed a striking conservation of TCR struc ture, in that all clones examined used Vbeta10 and Jalpha pHDS58 segme nts. We show here that the primary response in vivo after intraperiton eal injection of DBA/2 mice with HLA-CW3 expressing transfectants of s yngeneic P815 (H-2d) tumor cells is characterized by a dramatic expans ion of CD8+ Vbeta10+ CTL in the peritoneal cavity and draining (mesent eric) lymph node, as well as in peripheral blood. Additional analysis of TCR on HLA-CW3 immune populations by flow cytometry and polymerase chain reaction further indicates that the vast majority of responding CD8+ cells express restricted Valpha domains, a dominant Jalpha segmen t (pHDS58), and a conserved CDR3 length for both alpha and beta chains . This novel system provides a unique opportunity to directly monitor an oligoclonal primary antigen specific immune response in vivo at the single cell level independently of functional assays.