Expression of self-reactive receptors by B lymphocytes generally leads to their demise through clonal deletion, yet some B cells appear to escape death by swapping their existing receptors for less dangerous ones. This process of receptor editing was first revealed through the transgenic expression of self-reactive receptor chains, which artificially forced some cells to express new receptors. However, these studies could not predict the extent to which this process contributed to the B cell repertoire. By tagging one of the antibody loci in mice with a human version of the light chain κ gene, Casellas et al. (see Perspective by King and Monroe) tracked which cells might undergo receptor editing during normal development. The results of these experiments suggest that revision of receptor specificity by B cell may be much more frequent than previously predicted.
R. Casellas, T.-A Y. Shih, M. Kleinewietfeld, J. Rakonjac, D. Nemazee, K. Rajewsky, M. C. Nussenzweig, Contribution of receptor editing to the antibody repertoire. Science 291, 1541-1544 (2001). [Abstract] [Full Text]
L. B. King, J. G. Monroe, B cell receptor rehabilitation--Pausing to reflect. Science 291, 1503-1505 (2001). [Full Text]