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Updated: Aug 22, 2026

Isolation and Activation of Murine Lymphocytes
Published on: October 30, 2016
CD22 regulates B lymphocyte function in vivo through both ligand-dependent and ligand-independent mechanisms
Jonathan C Poe1, Yoko Fujimoto, Minoru Hasegawa
1Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Abstract:
The interaction of CD22 with alpha2,6-linked sialic acid ligands has been widely proposed to regulate B lymphocyte function and migration. Here, we generated gene-targeted mice that express mutant CD22 molecules that do not interact with these ligands. CD22 ligand binding regulated the expression of cell surface CD22, immunoglobulin M and major histocompatibility complex class II on mature B cells, maintenance of the marginal zone B cell population, optimal B cell antigen receptor-induced proliferation, and B cell turnover rates. However, CD22 negative regulation of calcium mobilization after B cell antigen receptor ligation, CD22 phosphorylation, recruitment of SHP-1 to CD22 and B cell migration did not require CD22 ligand engagement. These observations resolve longstanding questions regarding the physiological importance of CD22 ligand binding in the regulation of B cell function in vivo.
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