A CD22‐Shp1 phosphatase axis controls integrin β 7 display and B cell function in mucosal immunity

The integrin α4β7 selectively regulates lymphocyte trafficking and adhesion in the gut gut-associated lymphoid tissues (GALT). Here we describe unexpected involvement of tyrosine phosphatase Shp1 B cell lectin CD22 (Siglec 2) regulation surface expression immunity. inhibited β7 endocytosis, enhancing display homing to GALT. In cells, associated a sialic acid-dependent manner with on target intracellular β7. restrained plasma membrane phosphorylation endocytosis without affecting β1 integrin. cells reduced activity, lacking CD22, or expressing mutated Shp1-binding carbohydrate-binding domains displayed parallel reductions Consistent specialized role intestinal immunity, deficiency antibody pathogen responses.