Page 523 - Veterinary Immunology, 10th Edition

rearrangement is not entirely random. For example, in rabbits,
VetBooks.ir mice, and humans the most 3′ IGHV genes tend to be used most

often. This preferential use of certain genes results from a
combination of factors, including the recombination signal

sequences, the accessibility of the genes to the recombinase enzyme,
sequences at the splicing sites, and way in which DNA folds.

Receptor Editing

Although each new B cell expresses a specific antigen receptor,
developing B cells may continue to rearrange their V, D, and J genes
even after exposure to antigen. Thus a B cell expressing a specific κ
chain may restart V gene rearrangement by switching to the other
IGKV genes or even switching to either of the IGLV genes. The cell

can continue to rearrange upstream non-rearranged V genes or
downstream non-rearranged J genes. This receptor editing, which
occurs within germinal centers, may be a method of eliminating

receptors that bind to self-antigens (Chapter 36).

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