Effects of Low-doses of X-rays on the Expression of Human Cell Surface CD2 Antigen in CD2⁺ CHO Cells

Abstract

Thioguanine resistant CHO cells (HPRT⁻) were stably cotransfected with pSV2-gpt and πH3-CD2 vectors using the calcium phosphate coprecipitation technique. The effects of single low doses of ionizing radiation were studied in a CD2⁺ CHO clone. The CD2⁺ phenotype responsible for binding sheep erythrocytes and rosette formation, was not affected by X-rays doses in the range 2–6 cGy. However, after 10 cGy of X-irradiation, 50% of the cells lost the CD2⁺ phenotype. These results suggest that this CD2⁺ clone might be a very sensitive indicator of very low X-ray doses. The implications of the phenotypic changes, observed after very low doses of irradiation, are discussed.