The secretory component of immunoglobulin molecule is -: (A) Formed by epithelial cells of lining mucosa, (B) Formed by plasma cell, (C) Formed by epithelial cell and plasma cell, (D) Secreted by bone marrow
Answer is C. The secretory component is a component of immunoglobulin A (IgA). Secretory component is a proteolytic cleavage product of the polymeric immunoglobulin receptor which remains associated with dimeric IgA in sero-mucus secretions. Polymeric IgA binds to the polymeric immunoglobulin receptor on the basolateral surface of epithelial cells and is taken up into the cell transcytosis. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:97