In vivo effect of isoprinosine on interleukin-2 production, lymphocyte mitogenesis and NK activity in normal and cyclophosphamide immunosuppressed mice.

The in vivo effect of isoprinosine on IL-2 production, mitogen-induced proliferation and NK activity of lymphocytes from normal as well as cyclophosphamide (CY) treated mice has been investigated. Isoprinosine was given in a single dose (50 mg/kg or 5 mg/kg) to normal or CY treated mice (250 mg/kg i.p. simultaneously to isoprinosine). An enhancement of T lymphocyte proliferation and IL-2 production was observed in both cases. There was no correlation between the small effect observed in T lymphocyte proliferation and the enhancement of IL-2 levels found in the supernatants of Con A activated spleen cells, specially in normal mice. Administration of isoprinosine every day (50 mg/kg) augmented Con A induced mitogenesis, IL-2 production and NK activity in animals treated with cyclophosphamide, but not in normal mice. Isoprinosine could be of interest in a combined treatment with immunosuppressants for the restoration of certain immune functions. The effect of isoprinosine on immune responses may be mediated in part by changes in IL-2 activity.