Mucosal receptor for IgA in the breast-fed neonate

Immunoglobulin A from human milk binds to neonatal buccal cells. Pretreatment of the cells with anti-secretory component antiserum blocks this binding, suggesting that secretory component (SC) contributes to the adhesive process. The concentrations of SC in saliva of preterm neonates is lower than that of full-term infants. This may lower the effectiveness of mucosal immunity passively transferred from the mother.