Immunologic Effects of Whole-Body Ultraviolet Irradiation: Selective Defect in Splenic Adherent Cell Function in vitro

Splenocytes from mice receiving whole-body UV irradiation do not make a normal primary in vitro plaque-forming cell (PFC) response to the soluble T-dependent antigen trinitrophenylated poly(L-glutamic acid60L-alanine30L-tyrosine$ ^{10}$). This impaired immune response results from a selective loss of antigen-presenting cell function in the splenic adherent cell (SAC) population of the UV-treated mice. SACs from UV-irradiated mice are unable to reconstitute a PFC response when added to normal splenocytes passed through Sephadex G-10 (which depletes adherent cells), whereas normal SACs, when added to Sephadex G-10-passed splenocytes from UV-treated mice, do restore a PFC response. The effect of in vivo UV irradiation on the SAC population is indistinguishable functionally from the effect of in vitro UV irradiation of SACs from normal mice. Possible explanations for this selective effect of external UV irradiation on SAC function are discussed.