Production of interspecies T cell hybrids which retain differentiation specific surface antigens

Genetic mapping of differentiation specific surface antigens has been hampered by difficulty in preparation of interspecies hybrid cells which continue to express differentiated functions. A method has been developed for production of interspecies T cell hybrids which continue to express T cell specific cell surface molecules. Hybrids were constructed from either the human leukemic cell line MOLT-4 or freshly isolated human peripheral blood T cells and the mouse T lymphoma line BW5147. Optimal fusion efficiency resulted with pre-treatment of the human parental line with phytohemagglutinin followed by hybridization with 40% polyethylene glycol and plating without thymocyte feeder layers. Immortalization of hybrid lines was accomplished through addition of rat T cell growth factor to cultures.