Mechanisms of neonatal mucosal antibody protection.
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.
Harris
Nicola L
NL
Institute of Experimental Immunology, Universitätsspital, Zürich, Switzerland. nharris@ethz.ch
Spoerri
Iris
I
Schopfer
Jacqueline F
JF
Nembrini
Chiara
C
Merky
Patrick
P
Massacand
Joanna
J
Urban
Joseph F
JF
Lamarre
Alain
A
Burki
Kurt
K
Odermatt
Bernhard
B
Zinkernagel
Rolf M
RM
Macpherson
Andrew J
AJ
D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000276:immunology; D001424:Bacterial Infections / Q000276:immunology / Q000517:prevention & control; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D018928:Immunity, Mucosal; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007413:Intestinal Mucosa / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology; D051379:Mice; D008810:Mice, Inbred C57BL; D008892:Milk / Q000276:immunology*; D009351:Nematospiroides dubius / Q000276:immunology; D011961:Receptors, Fc / Q000378:metabolism; D017206:Strongylida Infections / Q000276:immunology / Q000517:prevention & control
D000906:Antibodies; D015395:Histocompatibility Antigens Class I; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D011961:Receptors, Fc; C100688:Fc receptor, neonatal