Mechanisms of neonatal mucosal antibody protection

NL Harris, I Spoerri, JF Schopfer… - The Journal of …, 2006 - journals.aai.org
NL Harris, I Spoerri, JF Schopfer, C Nembrini, P Merky, J Massacand, JF Urban, A Lamarre
The Journal of Immunology, 2006journals.aai.org
Following an abrupt transition at birth from the sterile uterus to an environment with
abundant commensal and pathogenic microbes, neonatal mammals are protected by
maternal Abs at mucosal surfaces. We show in mice that different Ab isotypes work in distinct
ways to protect the neonatal mucosal surface. Secretory IgA acts to limit penetration of
commensal intestinal bacteria through the neonatal intestinal epithelium: an apparently
primitive process that does not require diversification of the primary natural Ab repertoire. In …
Abstract
Following an abrupt transition at birth from the sterile uterus to an environment with abundant commensal and pathogenic microbes, neonatal mammals are protected by maternal Abs at mucosal surfaces. We show in mice that different Ab isotypes work in distinct ways to protect the neonatal mucosal surface. Secretory IgA acts to limit penetration of commensal intestinal bacteria through the neonatal intestinal epithelium: an apparently primitive process that does not require diversification of the primary natural Ab repertoire. In contrast, neonatal protection against the exclusively luminal parasite Heligmosomoides polygyrus required IgG from primed females. This immune IgG could either be delivered directly in milk or retrotransported via neonatal Fc receptor from the neonatal serum into the intestinal lumen to exert its protective effect.
journals.aai.org