Effects of 254 nm UV irradiation of human lymphocytes in vitro studied on chromosomes, cell cycle phase distribution and cell surface antigens.
Isolated human peripheral blood lymphocytes were exposed to 254 nm UV light and stimulated with PHA. Chromosome analysis revealed significant increases in sister chromatid exchanges (SCE's) and micronuclei, and also in gross chromosomal aberrations, but not in breaks and gaps on the chromatid level. By means of flow cytometry it was shown that UV exposure perturbed the cell cycle in that the S and G2/M fraction decreased when UV was given before stimulation with PHA. Labelling the cells with fluorescein-conjugated antibodies did not reveal any changes in the relative frequencies of lymphocyte subsets after exposure, but an overall diminished ability to bind antibody was observed.