A deficiency in the repair of UV and γ-ray damaged DNA in fibroblasts from Cockayne's syndrome

The host-cell reactivation of V antigen production for irradiated adenovirus was examined in fibroblasts from 5 unrelated patients with Cockayne's syndrome (CS) and 2 CS heterozygotes. The fibroblast cultures were infected with either irradiated or non-irradiated adenovirus and subsequently examined for the presence of viral structural antigens using immunofluorescent staining. All CS-homozygous strains showed a reduced host-cell reactivation (HCR) of this viral function for both UV-and gamma-irradiated virus. For UV-irradiation of the virus, D37 values expressed as a percentage of that obtained on normal strains, ranged from 14 to 35%. For gamma-irradiation of the virus these values ranged from 61 to 80%. These results indicate some defect in the repair of both UV- and gamma-ray-induced DNA damage for CS. 1 CS-heterozygote strain tested also showed a reduced HCR for UV-irradiated adenovirus intermediate between that of the patient strain and normal, whereas another CS-heterozygote strain showed apparently normal HCR level.