Molecular genetics of anti-carbohydrate antibodies
Antibodies directed against carbohydrate determinants provide useful model systems for understanding the structure and organisation of antibody genes and the generation of antibody diversity. We have used three such systems, PC, DEX and GAC, and have studied the heavy chains and VH gene segments of each. In two of these systems, PC and GAC, much of the diversity in heavy-chain protein sequences results from somatic mutation events superimposed on expression of a single VH gene. In the DEX system, it appears that germ-line sequence diversity may be an important contributor to the variability in heavy-chain sequence. Detailed structural analyses of this type will ultimately provide a complete picture of the mechanisms which underlie effective humoral immunity.