Mechanisms of Neonatal Mucosal Antibody Protection

• Published in: Journal of Immunology Vol. 177; no. 9; pp. 6256 - 6262
• Main Authors: Harris, Nicola L, Spoerri, Iris, Schopfer, Jacqueline F, Nembrini, Chiara, Merky, Patrick, Massacand, Joanna, Urban, Joseph F. Jr, Lamarre, Alain, Burki, Kurt, Odermatt, Bernhard, Zinkernagel, Rolf M, Macpherson, Andrew J
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.11.2006
• Subjects: Animals; Animals, Newborn; Antibodies - immunology; bacteria; Bacterial Infections - immunology; Bacterial Infections - prevention & control; breast milk; Female; Heligmosomoides polygyrus; Histocompatibility Antigens Class I - metabolism; humoral immunity; ileum; Immunity, Maternally-Acquired - immunology; Immunity, Mucosal; immunocytochemistry; immunoglobulin A; Immunoglobulin A, Secretory - immunology; immunoglobulin G; Immunoglobulin G - blood; Immunoglobulin G - immunology; intestinal microorganisms; intestinal mucosa; Intestinal Mucosa - immunology; Intestinal Mucosa - microbiology; Intestinal Mucosa - parasitology; Mice; Mice, Inbred C57BL; Milk - immunology; nematode infections; Nematospiroides dubius - immunology; neonates; Receptors, Fc - metabolism; secretory immunoglobulin A; Strongylida Infections - immunology; Strongylida Infections - prevention & control; suckling
• ISSN: 1550-6606; 0022-1767; 1550-6606; 1365-2567
• DOI: 10.4049/jimmunol.177.9.6256

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.