Generation of functional human T cell hybrids.

Abstract

Human T cell hybrids were generated by fusing lectin-activated normal and leukemic human T cells with an aminopterin-sensitive human T cell line. This mutant cell line, designated CEM-T15, was derived from the human T cell line CEM after chemical mutagenesis with ethane methylsulfonate and subsequent culture in medium containing 6-thioguanine. After polyethylene glycol-induced fusion, the cells were cultured in hypoxanthine-aminopterin-thymidine selective medium. More than 5 wk after fusion, evidence for successful hybridization was obtained by 3 independent criteria: most cultures contained cells expressing the OKT3 surface antigen, which is expressed on normal T cells but not on CEM-T15 cells; most cultures contained polyploid cells; and some cultures provided helper activity in the generation of antibody-forming cells, a functional activity absent in the CEM-T15 parental cell line. Evidence for functional stability of the hybrids > 20 wk after fusion was provided by several clones that not only continue growing exponentially but also maintain expression of OKT3 surface antigen and high levels of helper function. These T cell hydrids and similar hybrids constructed using antigen-specific human T cells should be of considerable importance in further studies of the immunobiology of human T cells.