Enhancement by concanavalin A of the suppressive effect of prodigiosin 25-C on proliferation of murine splenocytes.

Proliferation of concanavalin A (Con A)-activated nylon-wool purified murine splenic T cells was increasingly suppressed by prodigiosin 25-C as higher concentrations of Con A were used for the activation. Enhancement of suppressive effect of prodigiosin 25-C was not observed when T cells were stimulated with phytohemagglutinin (PHA), anti-CD3 antibody, or allogeneic splenic adherent cells. The suppressive effect of prodigiosin 25-C was enhanced by the addition of Con A in various T cell subpopulations as well as in LPS-activated splenic B cells. Lectins that recognize mannose residue of biantennary-complex-type sugar chains significantly enhanced the suppressive effect of prodigiosin 25-C, whereas a lectin that binds to N-acetylglucosamine did not. These results suggest that binding of lectins to the mannose residue of biantennary-complex-type sugar chains on cell surface of both T and B lymphocytes plays a central role on the enhancement of the suppressive effect of prodigiosin 25-C.