Influences of a novel immunopotentiator polyactin A on interleukin 1 production and responsiveness in mice

Effects of a novel immunopotentiator Polyactin A (PAA), developed in China, on production and responsiveness of murine interleukin 1(IL-1) were investigated. The results demonstrated that: (1) PAA 0.01-100 micrograms.ml-1 directly induced IL-1 synthesis and secretion from murine peritoneal macrophages (PMO) and markedly enhanced IL-1 production of the mouse PMO stimulated by lipopolysaccharides (LPS) of E coli; (2) IL-1 release from the PMO cultured in PAA 0.1 micrograms.ml-1 was detectable as early as 2 h after the incubation, peaked at 24 h, and then decreased gradually; (3) PAA stimulated and enhanced both IL-1 synthesis and release, but its effect on IL-1 release was stronger; (4) PMO from the mice given po PAA 200 mg.kg-1.d-1 for 7 d produced a higher level of IL-1 than those from control group, and the increase in extracellular IL-1 was more significant than that in intracellular one; (5) in vivo, PAA had no effect on IL-1 receptor expression and IL-1 responsiveness of murine lymphocytes, but eliminated the suppressing effects of cyclophosphamide (Cyc) on IL-1 receptor expression and IL-1 responsiveness of mouse lymphocytes. The above findings provide new explanation for action of PAA and new basis for wider clinical applications of PAA.