The effect of free oxgen radical scavengers and interleukin-2 on the UVB-induced suppression of human natural killer activity in vitro

Kim, Kwang; Suh, Kee Suck; Kim, Sang Tae

Abstract

BACKGROUND: Previous studies have shown that in vitro exposure to ultraviolet B(UVB) radiation resulted in a dose-dependent inhibition of natural killer activity(NK activity) of normal human peripheral blood mononuclear cella(PBMC), and that in vivo exposure to snlight also induced NK activity suppression. The precise meehanism of the UV-regulation on the riat iral killer system(NK system) is not established.
Objective
& METHOD: The purpose of this study is to examine whether the addition of interleukin-2(IL-2) and/or free oxygen radical scavengers, superoxide dismutas(SOD) or sodium azide(SA), is effective in reducing the UVJ3-induced suppression of NK activity of FBMC.
RESULTS
The results are as follows 1. The suppressive effect of UVB radiat,ion on NK activity could successfully be prevented in the presence of SOD(100 and 1,000U/ml) during the radiation. 2. SA( LO and 10 M/ml) did not prevent the suppression of NK activity. 3. IL-2(100U/ml) markedly enhanced the NK activity of nonirradiated PBMC, but had no effect on irradiated PBMC. 4. Combination treatment with both IL-2 and free radical scavengers on UVB-irradiated PBMC resulted in no additive or synergistic effect on the prevention of the suppression of NK activity compared with a single treatment with either IL-2 or free radical scavengers.
CONCLUSION
In the presserit study, we found that SOD providec a protective effect on NK activity during the UVB radiation and we suggest that superoxide anion(O ) might play a major role in the UV-regulatory mechanisms of the NK system.