Serum-derived IgG1-mediated immune exclusion as a mechanism of protection against H. pylori infection.
The induction of protective immunity against Helicobacter challenge in a murine model was found to correlate with the magnitude of IgG (serum and gastric lavage) responsiveness to intra-nasal (i.n.) immunisation. IgG1-secreting hybridoma backpacks in Helicobacter pylori (H. pylori)-infected mice revealed serum transudation into the stomach. A Lpp20-specific monoclonal antibody was associated with significantly reduced H. pylori colonisation. Histology revealed aggregates of the remaining H. pylori in these mice, suggesting a role for IgG1-mediated immune exclusion of the bacteria. In vitro immunogold electron microscopy supported this hypothesis, but also suggested that a threshold of H. pylori-specific antibody needs to be maintained if immune exclusion by the host is to overcome immune evasion by the bacteria.
Department of Surgery, Christchurch School of Medicine, P.O. Box 4345, Christchurch, New Zealand. jacqui.keenan@chmeds.ac.nz
Jacqueline
J
Keenan
Stephanie
S
Neal
Randall
R
Allardyce
Justin
J
Roake
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines / Q000008:administration & dosage; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology* / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000097:blood*; D051379:Mice; D008807:Mice, Inbred BALB C; D016253:Microscopy, Immunoelectron; D013270:Stomach / Q000276:immunology / Q000382:microbiology
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G