A comparison of the effects of human rIL-2 and autologous TCGF on Xenopus laevis splenocytes in vitro.

Prior studies have shown that intraperitoneal (ip) injection of 25 IU of human rIL-2 can effectively modulate in vivo immune reactivity to thymus-dependent and thymus-independent type 2 immunogens in Xenopus laevis, the South African clawed toad, but is less successful at affecting toad cells in vitro. Here we compare the capacities of human rIL-2 and autologous TCGF to modulate Xenopus splenocytes in vitro and find that autologous TCGF (1) is more effective at stimulating mitogenesis, (2) can serve as a ligand for inducible receptors that will also bind rIL-2 and an F1*-mouse anti-human p55 antibody, and (3) will regulate the expression these receptors.