CHARACTERIZATION OF A HUMAN X MOUSE T-CELL HYBRIDOMA AND IDENTIFICATION OF A CLONE SECRETING AND BINDING INTERLEUKIN-2

Human lymphocytes stimulated with phytohemagglutinin (PHA) were fused with an HGPRT- [hypoxanthine guanine phosphoribosyl-transferase] murine lymphoma, BW5147 and a hydridoma BwFc93-1 was isolated and cloned in agarose. This human .times. mouse hybrid and 9 clones derived from it were characterized by chromosome analysis, phenotypic and functional assays. Karyotyping and isoenzyme studies showed the presence of 5 human chromosomes in BwFc93-1 with preferential retention of three chromosomes-6, X and 15- in the clones. Membrane immunofluorescence analysis revealed that all the clones expressed human and mouse class I MHC [major histocompatibility complex] antigens and the mouse T cell antigens Thy-1 and T200, but were devoid of human OKT3, OKT8 and mouse Lyt-2. Human OKT4 and OKM1 phenotypes were transiently expressed by 1 clone and mouse Lyt 1 by 2 other clones. Several T4- , Lyt-1- clones produced and bound human interleukin, 2 (IL 2) indicating a lack of correlation between human T cell phenotype and function in those hybrids. There was also evidence of dichotomy in the secretion of IL 2 and expression of the IL 2 receptor since clones were identified which either bound or secreted IL 2. One clone expressing IL 2 receptors could be induced to produce human IL 2 by simultaneously stimulating with PHA and phorbol myristate acetate.