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Role of Polymeric Immunoglobulin Receptor in IgA and IgM Transcytosis

Hao Wei1, Ji-Yang Wang1,2,3

  • 1Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.

International Journal of Molecular Sciences
|March 6, 2021
PubMed

Transcytosis of polymeric IgA and IgM from the basolateral surface to the apical side of the epithelium and subsequent secretion into mucosal fluids are mediated by the polymeric immunoglobulin receptor (pIgR). Secreted IgA and IgM have vital roles in mucosal immunity in response to pathogenic infections. Binding and recognition of polymeric IgA and IgM by pIgR require the joining chain (J chain), a small protein essential in the formation and stabilization of polymeric Ig structures. Recent studies have identified marginal zone B and B1 cell-specific protein (MZB1) as a novel regulator of polymeric IgA and IgM formation. MZB1 might facilitate IgA and IgM transcytosis by promoting the binding of J chain to Ig. In this review, we discuss the roles of pIgR in transcytosis of IgA and IgM, the roles of J chain in the formation of polymeric IgA and IgM and recognition by pIgR, and focus particularly on recent progress in understanding the roles of MZB1, a molecular chaperone protein.

Keywords:
antibody secretionimmunoglobulin A (IgA)immunoglobulin M (IgM)immunoglobulin transcytosisjoining chain (J chain)marginal zone B and B1 cell-specific protein (MZB1)mucosal immunitypolymeric immunoglobulin receptor (pIgR)

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