Sunlight suppressing rejection of 280- to 320-nm UV-radiation-induced skin tumors in mice.
Repeated exposure of female C3H/HeNCR- mice to sunlight prevented the normal immunologic rejection of a UV-induced tumor. This systemic immunologic alteration was transferred to syngeneic lethally X-irradiated animals with lymphoid cells from mice exposed to sunlight. The lymphoid cells also were able to suppress the capacity of lymphoid cells from normal animals to reject a UV-induced tumor. The 295- to 320-nm wave band appeared to be responsible for this immunosuppressive effect of sunlight because suppression was prevented by filtration of the radiation through Mylar and by application of a sunscreen containing para-aminobenzoic acid. These observations may have importance in understanding the pathogenesis of sunlight-induced skin cancer in humans.
D000818:Animals; D005260:Female; D007108:Immune Tolerance; D051379:Mice; D008809:Mice, Inbred C3H; D009381:Neoplasms, Radiation-Induced / Q000276:immunology*; D012878:Skin Neoplasms / Q000276:immunology*; D013472:Sunlight / Q000009:adverse effects*; D014466:Ultraviolet Rays