ABSTRACT
Modem techniques in lipid biochemistry and immunology have definitively demonstrated the antigenic nature of phospholipids. Both antibody-and cell-mediated recognition of membrane phospholipids have now been reported to occur. The occurrence of antibodies that bind phospholipids is well documented. Anticholinephospholipid, antiaminophospholipid, and anticardiolipin antibodies have been described both clinically and experimentally and have been implicated in the pathogenesis of disease as well as in the generation of protective immunity. Antibodies to phosphocholine, the head group of phosphatidylcholine, occur spontaneously in mice treated with pristane and have been influential in the conceptual development of the antigen combining site of antibodies. Antibodies to phosphatidylcholine can be found in normal mouse sera, and titers can be increased by injection of mice with lipopolysaccharide. Identification of these antiphosphatidylcholine antibodies came about through investigations on a "cryptic" antigen made accessible on erythrocytes following treatment with bromelin. A conceptual basis exists implicating the direct involvement of membrane phospholipids in the immunologic discrimination of self and nonself.
