Abstract
The in vitro incubation of phytohemagglutinin (PHA)-or alloantigen-stimulated peripheral blood T cells with prothymosin a (ProTα) resulted in a marked and reproducible increase in the production of interleukin-2 (IL-2). Incubation of T cells with ProTα, in the absence of PHA or alloantigen, failed to induce any production of IL-2. ProTa by itself did not exert any IL-2 activity. Finally, ProTα was shown to increase the expression of IL-2 receptors on phytohemagglutinin—or alloantigen-activated T cells. These data provide the basis for understanding the in vitro immunoenhancing effects of ProTα in cellular immune systems.