Antigenic Expression and Cross Reactions in HL-A Variants of Lymphoid Cell Lines

Immunogenetic studies were carried out on an HL-A2/HL-A3 heterozygous lymphoid cell line, 8866, and on two HL-A2 negative variant sublines of 8866 which had arisen independently of one another. The parent 8866 line reacted positively with some W28 sera: these cross reactions were absent in both HL-A2 “loss” variant sublines. Other serum reactions, apparently characteristic of lymphoid cell lines, were present in 8866 and were retained in the variants. HL-A3 was expressed in hemizygous rather than homozygous dosage in the variants, ruling out mitotic crossing over as the mechanism producing HL-A2 loss. HL-A2 was undetectable either in the disrupted membranes or in the cytosol of the variant cells.