Abstract
We have studied the expression of the human sialophorin (CD43) molecule in a human x mouse somatic cell hybrid (H-8). The CD43 molecule was detected on the cell surface by immunofluorescence analysis and the hybrid cell possessed human chromosome 16 which carries the gene for CD43. Biochemical analysis showed that the cell line expressed a low molecular form of CD43, which was due to altered glycosylation. The cells reacted with anti-CD43 antibodies but behaved differently in response to the antibodies in the aggregation process. This indicates the crucial importance of the sugar moieties and epitope position in aggregation and subsequent activation mediated by CD43.