Lewis blood group antigen expression by cultured normal ureteral epithelial cells

The importance of Lewis blood group antigens in recurrent urinary tract infections has led to a more detailed study of the expression of these antigens in an in vitro culture system. Expression of A, B, H, and Lewis blood group antigens by primary cultures of ureter epithelial cells was analyzed by flow cytometry. Cells maintained blood group determinants for up to 7 weeks in culture over three passages. In several specimens, the cells that exhibited expression of Lewis A (Le(a) and Lewis B (Le(b)) antigens increased dramatically over 2-3 passages in culture. Lewis Y (Le(y)) antigen expression was positive on all primary cultures tested. The effect of fetal bovine serum (FBS) on blood group antigen expression was evaluated. Increased concentrations of FBS in the growth media increased the expression of Le(a) and Le(b) antigens in certain specimens, but did not affect expression of the other blood group antigens. The effect of FBS on blood group antigen expression of cultured cells depended on the Lewis blood type of the individual donating the specimen. To evaluate the heterogeneity often seen in Le(a) and Le(b) antigen expression, dual staining of cells for Le(a) and Le(b) antigens was performed. The results of these studies show for the first time that Lewis blood group antigens are expressed by cultured normal ureteral epithelial cells and that the pattern of expression of Le(a) and Le(b) changes over time. Furthermore, an individual cell may simultaneously express more than one Lewis antigen on its surface.