T-cell hybrids. III. Low tumorigenicity of hybrid cells derived from fusion of high tumorigenic (BW5147 X EL-4R) cell lines.

Tumorigenicity of two thymic lymphoma cell lines BW5147 (H-2k/H-2k; HGPRT-) and EL-4R (H-2b/H-2b; TK-) was compared with that of their hybrid cell line BH2 (H-2k/H-2k x H-2b/H-2b; HGPRT+; TK+). Tumour inocula from the parental and hybrid cell lines grew in syngeneic but not allogeneic recipients; the possible admixture of the revertant parental cells (BW5147HGPRT+, EL-4RTK+) in the hybrid cell population was, according to the transplantation tests, lower than 10(-4). The tumorigenicity of the hybrid cell line BH2 in the (B10 X AKR)F1 hybrid recipients was substantially lower than the tumorigenicity of the parental cell lines in both semisyngeneic (B10 X AKR)F1 and syngeneic mice.