Glycolipid Antigens and Genetic Markers

Abstract

The classical immunological phenomena described as species specificity and tissue specificity were intensively studied in the early part of this century. Some of these antigens were identified as “lipoid,” namely, those extractable with ethanol or ethanol-ether mixtures, and had extremely complex chemical composition containing phosphorus, nitrogen, sugars, and other constituents.(1,2) These properties were considered to be equivalent to those of type- specific antigens of bacteria that are currendy known as “lipopolysaccharides.” In these classical studies, heterologous antisera were prepared against whole tissue homogenates, and specific reactions were observed between the antisera and the alcohol-soluble fraction of cells or tissues by complement-fixation tests (for reviews, see Landsteiner,(3) Day,(4) and Rapport and Graf(12)). These “alcohol-soluble antigens” were not immunogenic unless they were mixed and co-injected with carrier proteins (“Schlepper”).(5) Thus, the serological concept of “lipid hapten” was well established during the Landsteiner era, although the chemical properties and structures of these haptens were far from being known.