Development of an in vitro system for the analysis of ultraviolet radiation-induced suppression of natural killer cell activity

Previous studies have shown that natural killer (NK) cell activity was suppressed in volunteer subjects exposed to ultraviolet radiation (UVR) from solarium lamps. The present studies were carried out to determine the spectrum of UVR responsible for suppression of NK activity and to develop in vitro methods to analyze the effectiveness of sunscreen agents in prevention of UVR-mediated suppression of NK activity and other aspects of immune function. These studies suggest that when the greater proportion of UV-A in solar radiation and its greater penetration into skin is taken into account, UV-A may have equivalent or greater direct immunosuppressive effects than UV-B. The mechanisms of their immunosuppressive effects may, however, differ. The in vitro system described here would appear to provide a simple test system for further analysis of UVR-induced immunosuppression. (Author)