Polyclonal and specific antibodies mediate protective immunity against enteric helminth infection.
Anti-helminth immunity involves CD4+ T cells, yet the precise effector mechanisms responsible for parasite killing or expulsion remain elusive. We now report an essential role for antibodies in mediating immunity against the enteric helminth Heligmosomoides polygyrus (Hp), a natural murine parasite that establishes chronic infection. Polyclonal IgG antibodies, present in naive mice and produced following Hp infection, functioned to limit egg production by adult parasites. Comparatively, affinity-matured parasite-specific IgG and IgA antibodies that developed only after multiple infections were required to prevent adult worm development. These data reveal complementary roles for polyclonal and affinity-matured parasite-specific antibodies in preventing enteric helminth infection by limiting parasite fecundity and providing immune protection against reinfection, respectively. We propose that parasite-induced polyclonal antibodies play a dual role, whereby the parasite is allowed to establish chronicity, while parasite load and spread are limited, likely reflecting the long coevolution of helminth parasites with their hosts.
Institute of Experimental Immunology, Department of Pathology, Universitätsspital, CH8091 Zürich, Switzerland. kmccoy@mcmaster.ca
Kathy D
KD
McCoy
Maaike
M
Stoel
Rebecca
R
Stettler
Patrick
P
Merky
Katja
K
Fink
Beatrice M
BM
Senn
Corinne
C
Schaer
Joanna
J
Massacand
Bernhard
B
Odermatt
Hans C
HC
Oettgen
Rolf M
RM
Zinkernagel
Nicolaas A
NA
Bos
Hans
H
Hengartner
Andrew J
AJ
Macpherson
Nicola L
NL
Harris
D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007411:Intestinal Diseases, Parasitic / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009351:Nematospiroides dubius / Q000276:immunology*; D010270:Parasite Egg Count; D017206:Strongylida Infections / Q000276:immunology*
D000909:Antibodies, Helminth; D007070:Immunoglobulin A; D007074:Immunoglobulin G