Lectin-dependent and anti-CD3 induced cytotoxicity are preferentially mediated by peripheral blood cytotoxic T lymphocytes expressing Leu-7 antigen.

摘要: Monoclonal antibodies against the CD3 antigen and certain lectins can induce interleukin 2 dependent antigen-specific T cell clones to mediate non-antigen specific cytotoxicity. On basis of this observation, we predicted that it may be possible identify cytotoxic lymphocytes (CTL) in peripheral blood without knowing specificity these vivo primed CTL. By using strategy, were separated into low high-density fractions on Percoll gradients tested for activity presence or absence concanavalin A (Con A) anti-Leu-4 antibody. Lectin-dependent cellular cytotoxicity (LDCC) anti-CD3 induced both natural killer (NK)-insensitive NK-sensitive targets exclusively mediated by low-density CD3+ lymphocytes. Additional studies indicated co-expressing Leu-7 preferentially activity, although some individuals, significant was also observed cells lacking Leu-7. In contrast, CD16+ (Leu-11+) NK (both Leu-7+) did not nonantigen-specific under conditions. The finding cell-mediated unaffected refutes hypothesis lectin-dependent is simply a result effector target agglutination. lectin antibody specific. Phytohemagglutinin, Con A, pokeweed mitogen cytolytic Leu-7+ cells, whereas wheat germ agglutinin not. Of cell-associated differentiation antigens (anti-Leu-2,3,4, 5), only This anti-CD3-induced essentially completely inhibited anti-LFA-1 anti-CD2 monoclonal antibodies, implicating molecules triggering process. proportion CD3+, CTL expressed HLA-DR antigens, indicating activation. Because previous clinical have with phenotype elevated situations associated immunosuppression chronic viral infection, unique subset represent population possibly antigens.