Fig. 8.

Summary of the effects of epratuzumab on CD22 and CD32B phosphorylation events in B cells. 1: In resting B cells, the BCR, CD22 and CD32B are not in close association; 2: Epratuzumab directly induces the phosphorylation of Tyr⁸²² and, modestly, Tyr⁸⁰⁷ on CD22, leading to the recruitment of SHP-1 and Grb2, respectively, and co-localisation of CD22 and the BCR (see also Sieger et al 2013); 3: Phosphorylation of Tyr²⁹² on CD32B also supports diminished B cell activation