DNA repair in the UV irradiation of human peripheral blood lymphocytes (healthy donors and xeroderma pigmentosum patients) in relation to the dedifferentiation process in phytohemagglutinin exposure

: UV-induced unscheduled DNA synthesis has been studied in lymphocytes of healthy donors and of Xeroderma pigmentosum patients (the classic form, and a form with an increased sensitivity to gamma-ray). In order to study the influence of PHA-induced differentiation on repair capacity of cells, lymphocytes were cultured in the presence or in the absence of PHA. The data obtained show that PHA-induced differentiation of human lymphocytes leads to an increase in the intensity of repair after UV-irradiation of these cells, and, accordingly, the repair is completed in a shorter time. In the case of the classic form of Xeroderma pigmentosum, the effect of differentiation on the repair level is more distinct, but no effect is observed in cells of Xeroderma pigmentosum sensitive both to UV and gamma-ray.