The role of somatic hypermutation in the generation of deletions and duplications in human Ig V region genes and chromosomal translocations.

Abstract

In the course of T-cell dependent immune responses, antigen-activated B- lymphocytes migrate into B-cell follicles of secondary lymphoid organs and establish germinal centers (GC). In these structures, the proliferating GC B-cells activate the mechanism of somatic hypermutation, which introduces somatic mutations into rearranged immunoglobulin (Ig) V region genes [1, 2]. These mutations are (with rare exceptions) specific for Ig V genes and occur with a high rate of about 1 in 103–104 bp/cell cycle [1, 2]. In a selection process taking place within the GC, only GC B-cells which acquired favourable mutations, i. e. mutations that result in an increased affinity to the immunizing antigen, are allowed to survive and finally differentiate into either plasma cells or memory B-cells.KeywordsVersus GeneSomatic HypermutationRecombination Signal SequenceSomatic Point MutationHeavy Chain DiseaseThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.