CARBOHYDRATE ANTIGEN EXPRESSION IN MURINE EMBRYONIC STEM-CELLS AND EMBRYOS .1. LACTO AND NEO-LACTO DETERMINANTS

A comparative study of lacto- and neo-lacto series carbohydrate antigens between the undifferentiated and differentiated derivatives of the embryonic stem (ES) cell line E14 and expression in the early embryo is reported. Antibodies to neo-lacto and lacto (type 1 and 2) precursor chains and blood group antigens such as H (types 1 and 2) A, B and Lewis (Le-a, Le-b, Le-x, Le-y) were examined. Backbone lacto- and neo-lacto structures were present on undifferentiated cells, as were terminal alpha-gal, SSEA-1, Le-y and low levels of Le-a. On differentiation, Le-x (SSEA-1 determinant) disappeared as has been found for embryonal carcinoma (EC) cells, and other determinants became restricted to cells of particular morphology. These observations will aid determination of the status and phenotypic stability of long-term embryonic stem-cell cultures.