Evidence for the existence of an IL-2-like lymphocyte growth promoting factor in a bony fish, Cyprinus carpio.

Activity promoting the growth of carp T-like cells has been found in supernatants of mitogen (PHA)- and alloantigen (MLR)-stimulated carp leukocyte cultures. Activity level in culture supernatants was elevated by phorbol myristate acetate. Proliferation of carp T-like lymphoblasts was also promoted in the presence of Il-2-containing supernatants of mammalian origin. The significance of these findings is discussed.