L J Wysocki

The molecular evolution of the immune response

In recentyears the molecular basis of immunoglobulin diversity has been uncovered. Little is known, however, about its significance and the mechanisms that generate it in the whole organism. In this article Tim Manser and his colleagues discuss ways in which this diversity is used in the establishment of immunity, and seek to explain how genetically identical individuals generate widely diverse immune responses to the same antigen and some antigens reproducibly elicit similar immune responses (recurrent idiotypes) in all individuals.

Analysis of the anti-azobenzenearsonate response at the molecular level

We have analysed, at the molecular level, the antibodies associated with the anti-azobenzenearsonate response of A/J and BALB/c mice as well as the genes that encode them. All antibodies expressing the predominant idiotype are derived by somatic mutation from a single VH gene. Antibody molecules express the idiotype regardless of their light chains or the JH segments which encode them. The D segment, however, does seem to be important for idiotype expression. The anti-azobenzenearsonate antibodies possessing the minor idiotype (36-60) are encoded by single, highly homologous VH genes in A/J and BALB/c mice. The nucleotide sequences of the VH genes from these two strains show only two nucleotide disparities. However, as opposed to A/J mice, the 36-60 idiotype in BALB/c appears to be the dominant idiotype among anti-azobenzenearsonate antibodies.