Haplotype exclusion: the solution to a problem in natural selection.
Antibody that possesses two identical paratopes (bivalent) is aggregated by antigen to trigger effector function. Antibody that possesses two different paratopes behaves as functionally monovalent. If these two antibodies interact with a given epitope, the monovalent antibody will block the aggregation of the bivalent antibody thereby inhibiting effector activation. We advance the hypothesis that haplotype exclusion is driven by the necessity to reduce the level of monovalent antibody. This assumption is compared to previous suggestions and quantitated. Further, several mechanisms of haplotype exclusion used by various species are analyzed in the light of this hypothesis.
Langman
Rodney
R
Conceptual Immunology Group, The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Cohn
Melvin
M
D000818:Animals; D002645:Chickens / Q000235:genetics / Q000276:immunology; D003198:Computer Simulation; D005785:Gene Conversion; D015322:Gene Rearrangement, B-Lymphocyte; D005803:Genes, Immunoglobulin; D006239:Haplotypes; D006801:Humans; D051379:Mice; D018448:Models, Immunological; D012641:Selection, Genetic; D012754:Sharks / Q000235:genetics / Q000276:immunology; D013269:Stochastic Processes