CROSSREACTIVITY BETWEEN HUMAN AND CANINE Ia ANTIGENS USING A MOUSE MONOCLONAL ANTIBODY (CIA)

Abstract

A mouse monoclonal antibody (CIA) produced against human Ia antigens that reacts with 20-30% of human peripheral blood lymphocytes was found to react with more than 90% of dog lymphocytes. Less than 41% of the Ia-positive dog lymphocytes expressed surface Ig. Immunoprecipitation studies with 125I-labeled cells precipitated heavily labeled Ia bands at 28K [kilodaltons] and 35K from human cells, but from dog cells the 29K .beta. chain of Ia was much more heavily labeled than the .alpha. chain.