Effect of ultraviolet irradiation on selected host cell proteins including Ro/SS-A and Epstein-Barr virus in cultured lymphoblastoid cell lines.

Although systemic lupus erythematosus (SLE) and Sj?gren's syndrome (SS) are distinct collagen vascular illnesses, they share certain features. Both have clinical manifestations involving skin and mucous membranes and characteristically have high titers of circulating autoantibodies to the cellular components Ro/SS-A, calreticulin/Ro, 52 kDa Ro and La/SS-B. Viruses have been postulated to be involved in the pathogenesis of both diseases. Sensitivity to sun is a cardinal feature of SLE, and UV light may be involved in its pathogenesis. Using human B-lymphoblastoid cell lines, the effect of the resident Epstein-Barr virus on the expression of the above cellular components was investigated by flow cytometry. Sublethal irradiation with ultraviolet B light appeared to diminish EBV antigen expression (gp350/220) during the first 48 to 72 hours in culture, whereas there was no change in the expression of MHC class I or immunoglobulin host cell proteins, and an apparent increase in the expression of host cell autoantigens. The virus appeared to be more sensitive to UVB-induced damage yet did appear to be able to undergo repair. No direct correlation could be made between the presence of the virus and the increase in autoantigen expression. La/SS-B and/or 52 kDa Ro antigen(s) were found to be present in the cytoplasm of the B lymphoblastoid cells at a higher base level in EBV-infected cell lines than in the EBV-negative cell lines.