Editors' ChoiceImmunology

Switching Signals

STKE  07 Jan 2003:
Vol. 2003, Issue 164, pp. tw17-TW17
DOI: 10.1126/stke.2003.164.tw17

B cells mount distinct responses by altering the class of antibody they secrete, and this class switching is also evident at the B cell surface, where membrane-bound antibodies cooperate with common signaling components to form B cell receptors (BCRs). Although these transduction modules are the same in each BCR, one receptor, the immunoglobulin G (IgG)-containing BCR, possesses distinct signaling capabilities from the others. Wakabayashi et al. find that these capabilities arise through the selective activation of CD22, a transmembrane protein known to down-regulate B cell activation. Ligation of IgG-BCR failed to induce both efficient CD22-dependent recruitment of the phosphatase SHP-1 and inhibition of the extracellular signal-regulated kinases (ERK1 and ERK2) and calcium signaling. By protecting itself from the inhibitory effects of CD22, IgG-BCR may regulate efficient class-switching, as well as enhanced responsiveness of IgG+ memory B cells.

C. Wakabayashi, T. Adachi, J. Wienands, T. Tsubata, A distinct signaling pathway used by the IgG-containing B cell antigen receptor. Science 298, 2392-2395 (2002). [Abstract] [Full Text]