Hormonal regulation of the expression of Ia antigens on mammary gland epithelium

Abstract

Guinea pig and mouse mammary gland epithelial cells express Ia antigen-like molecules that react specifically with a rabbit anti-Ia antigen antiserum. The murine Ia antigen-like molecules were shown to share alloantigenic determinants with regular spleen cell Ia antigens. The expression of the mammary gland Ia antigens is under hormonal control, i.e. the Ia antigen expression is induced by pregnancy and lactation and can also be induced by the exogenous administration of lactotropic hormones.