[Enhanced reactivation and induced mutagenesis of vaccinia virus in repair-defective cells of homocystinuria].

Two lines of fibroblasts isolated from patients with homocystinuria were characterized by the test of vaccinia virus host-cell reactivation. Xeroderma pigmentosum cells and normal fibroblasts were used as a control. Reduced host cell reactivation of the virus and an enhanced level of induced virus mutations in comparison with normal cells were revealed in homocystinuria cells after 4NQO and gamma-ray treatment. Enhanced reactivation and a corresponding reduced level of gamma-induced mutagenesis were found in preirradiated normal cells and in the xeroderma pigmentosum cells. The level of enhanced reactivation of the virus was virtually the same in preirradiated and nonirradiated homocystinuria cells, while the level of induced mutagenesis was reduced in both cells. This indicates the difference in the capability of the virus system for enhanced reactivation to repair potentially lethal and premutational DNA damages.