Long-term culture of human antigen-specific cytotoxic T-cell lines

Long-term cultures of human cytotoxic T-cell lines (H-CTLL) were established. H-CTLL cells were strictly dependent on growth upon a T- cell growth factor (TCGF) produced by phytohemagglutinin-stimulated normal human peripheral blood lymphocytes. H-CTLL cells were maintained in TCGF-dependent exponential proliferative culture for over 4 mo during which time they continued to mediate stimulator antigen-specific cytotoxicity as measured by a 4-h 51Cr-release assay. H-CTLL cells recovered from cryopreserved stocks and re-established in long-term culture demonstrated similar high levels of antigen-specific cytotoxicity. H-CTLL cells were 95--100% E-rosette positive and expressed normal T and Ia-like cell surface markers. The ability to sustain differentiated antigen-specific T-effector cells in long-term culture may provide a new means for the study of both the mechanism and regulation of T-cell-mediated immunity.