Structural and Biochemical Requirements for Secretory Component Interactions with Dimeric IgA.

Secretory (S) IgA is the predominant mucosal Ab that protects host epithelial barriers and promotes microbial homeostasis. SIgA production occurs when plasma cells assemble two copies of monomeric IgA and one joining chain (JC) to form dimeric (d) IgA, which is bound by the polymeric Ig receptor (pIgR) on the basolateral surface of epithelial cells and transcytosed to the apical surface. There, pIgR is proteolytically cleaved, releasing SIgA, a complex of the dIgA and the pIgR ectodomain, called the secretory component (SC).

Structural and biochemical requirements for secretory component interactions with dimeric Immunoglobulin A.

Secretory (S) Immunoglobulin (Ig) A is the predominant mucosal antibody that protects host epithelial barriers and promotes microbial homeostasis. SIgA production occurs when plasma cells assemble two copies of monomeric IgA and one joining-chain (JC) to form dimeric (d) IgA, which is bound by the polymeric Ig receptor (pIgR) on the basolateral surface of epithelial cells and transcytosed to the apical surface. There, pIgR is proteolytically cleaved, releasing SIgA, a complex of the dIgA and the pIgR ectodomain, called secretory component (SC).

The structure of the teleost Immunoglobulin M core provides insights on polymeric antibody evolution, assembly, and function.

Polymeric (p) immunoglobulins (Igs) serve broad functions during vertebrate immune responses. Typically, pIgs contain between two and six Ig monomers, each with two antigen binding fragments and one fragment crystallization (Fc). In addition, many pIgs assemble with a joining-chain (JC); however, the number of monomers and potential to include JC vary with species and heavy chain class.

Engineered Secretory Immunoglobulin A provides insights on antibody-based effector mechanisms targeting .

Secretory (S) Immunoglobin (Ig) A is the predominant mucosal antibody, which mediates host interactions with commensal and pathogenic microbes, including . SIgA adopts a polymeric IgA structure that is bound by secretory component (SC). Despite significance, how SIgA supports diverse effector mechanisms is poorly characterized and SIgA-based therapies nonexistent.

Suppression of epithelial proliferation and tumourigenesis by immunoglobulin A.

Immunoglobulin A (IgA) is the most abundant antibody isotype produced across mammals and plays a specialized role in mucosal homeostasis . Constantly secreted into the lumen of the intestine, IgA binds commensal microbiota to regulate their colonization and function with unclear implications for health. IgA deficiency is common in humans but is difficult to study due to its complex aetiology and comorbidities .