Suppression of delayed-type hypersensitivity to radiation [UV, 280-320 nm (UVB)]-induced tumor cells with serum factors from UVB-irradiated mice.

Irradiation--UV, 280-320 nm (UVB)--of the shaved dorsal skin of mice induces a systemic immunosuppression that interferes with the normal rejection of highly antigenic UVB radiation-induced skin cancers. Sera from C3H/HeNCr- female mice, exposed either to a single dose of UVB radiation (8.6 X 10(4) J/m2) or who received a 5-second thermal injury, were evaluated for ability to induce suppression of delayed-type hypersensitivity (DTH) to a syngeneic UVB-induced fibrosarcoma cell line, UV-2240. Sera from both UVB-irradiated and thermally injured donors could suppress the DTH responses of recipients, but only sera from UVB-irradiated donors could induce suppressor spleen cells to UV-2240 in recipient mice. The molecular-weight range of the UVB-induced serum factors is between 1,000 and 10,000.