Regulation of IgL Chain Recombination

The immunoglobulin light chain loci (Igĸ and Igλ) are recombined via V(D)J recombination at the pre-B cell stage during B cell differentiation. The recombination process is highly regulated on multiple levels to ensure proper timing and locus specificity. In this article, we focus on several mechanisms that contribute to the tight control of the rearrangement, focusing on the Igĸ locus, the primary IgL chain utilized in mice and humans. We explain how regulation of locus accessibility, cellular signaling pathways, and transcription factor binding influence the recombination process. We also note regulation of the ‘allelic exclusion’ phenomenon, where only one B cell receptor is expressed in a single lymphocyte. We also underscore the mechanistic principles that govern the light chain recombination in pre-B cells.