Immunomodulating activity of 3-(p-chlorophenyl)thiazolo-[3,2-a] benzimidazole-2-acetic acid (Wy-18,251, NSC 310633) in mice implanted with Lewis lung tumor. Effect of Wy-18,251 on lymphocyte proliferation and phagocytosis.

Proliferation of B lymphocytes is depressed in Lewis lung tumor bearing mice. Treatment of these mice with Wy-18,251 (5 mg/kg) significantly increased the responsiveness of their splenic T cells to concanavalin A in cell culture. Levamisole (5 mg/kg) acted more weakly than Wy-18,251. Neither Wy-18,251 nor levamisole elevated the depressed B cell mitogenesis. Wy-18,251 significantly increased macrophage phagocytosis against 51chromium labeled opsonized chicken red blood cells. Levamisole behaved differently: it either had no effect on phagocytosis, or depressed it.