A role in B cell activation for CD22 and the protein tyrosine phosphatase SHP

Academic Article


  • CD22 is a membrane immunoglobulin (mlg)-associated protein of B cells. CD22 is tyrosine-phosphorylated when mlg is ligated. Tyrosine-phosphorylated CD22 binds and activates SHP, a protein tyrosine phosphatase known to negatively regulate signaling through mlg. Ligation of CD22 to prevent its coaggregation with mlg lowers the threshold at which mlg activates the B cell by a factor of 100. In secondary lymphoid organs, CD22 may be sequestered away from mlg through interactions with counterreceptors on T cells. Thus, CD22 is a molecular switch for SHP that may bias mlg signaling to anatomic sites rich in T cells.
  • Published In

  • Science  Journal
  • Digital Object Identifier (doi)

    Author List

  • Doody GM; Justement LB; Delibrias CC; Matthews RJ; Lin J; Thomas ML; Fearon DT
  • Start Page

  • 242
  • End Page

  • 244
  • Volume

  • 269
  • Issue

  • 5221