Cytokines in Radioprotection. Comparison of the Radioprotective Effects of IL-1 to IL-2, GM-CSF and IFN Gamma

摘要

Immunomodulatory agents are radioprotective when administered to animals prior to irradiation. The mechanisms for this radioprotection have as yet not been determined, but may involve endogenously released cytokines. We have recently demonstrated that murine IL-1 is radioprotective in mice (Neta et al. J. Immunol.,136, 2483, 1986). In this study we have further explored this effect and investigated whether the radioprotective effest of IL-1 is mediated by other cytokines. Optimal radioprotection with IL-1 was obtained wil with administration 20 hr prior to irradiation and was greatly reduced with administration 45 or 4 hr before or 1 hr after irradiation with 950 cGY, and LD50/30 was an LD100/30 dose. The dose reduction factor (DRF) measured by LD50/30 was 1.25 for C57B1/6 mice. The presence of lag period in IL-1 induced radioprotection suggests that the effect of IL-1 may be indirect.