Antigen dose modulates the immunoglobulin isotype responses of pigs against intramuscularly administered F4-fimbriae.
Parenteral immunisation normally induces a systemic antibody response characterised by high IgG and low IgA responses. In the present study, the effect of different doses of F4-fimbriae on the isotype-specific antibody response after intramuscular immunisation was studied in pigs. Pigs were injected twice with a 9 weeks interval with either 1, 0.1 or 0.01 mg of F4-ETEC fimbriae. The dose of 1mg F4 induced significantly lower primary F4-specific IgG and IgM responses than the doses of 0.1 and 0.01 mg F4, but primed for an enhanced F4-specific IgM serum antibody response after the booster immunisation. Furthermore, the dose of 0.1mg induced the highest F4-specific IgA serum response which was significantly higher than after injection with 0.01 and 1mg F4. Moreover, both lower doses (0.1 and 0.01 mg) showed a higher number of F4-specific IgA and IgG antibody secreting cells (ASC) in the local draining lymph nodes of the pigs. This study demonstrated that low doses of purified F4-ETEC fimbriae, especially the 0.1mg dose, are optimal for inducing F4-specific IgA responses after IM immunisation.
Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Universiteit Gent, Salisburylaan 133, B-9820 Merelbeke, Belgium. yves.vanderstede@rug.ac.be
Y
Y
Van der Stede
E
E
Cox
B M
BM
Goddeeris
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000276:immunology; D010861:Fimbriae, Bacterial / Q000276:immunology*; D007117:Immunization, Secondary; D007132:Immunoglobulin Isotypes / Q000276:immunology*; D007273:Injections, Intramuscular; D008198:Lymph Nodes / Q000276:immunology; D013552:Swine / Q000276:immunology* / Q000382:microbiology; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D014611:Vaccination
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D007132:Immunoglobulin Isotypes