Influence of maternal antibodies on Chlamydophila psittaci-specific immune responses in turkeys elicited by naked DNA.
Plasmid DNA (pcDNA1::MOMP D) expressing the major outer membrane protein (MOMP) of an avian Chlamydophila psittaci serovar D strain was tested for its ability to induce protective immunity against C. psittaci challenge in the presence of maternal antibodies. A combined parenteral (intramuscular injection) and mucosal route (DNA drops administered to the nares) of DNA inoculation was used. Following pcDNA1::MOMP vaccination, both T helper and B cell memory were primed. However, high maternal antibodies titres affected the induction of vaccine-specific antibody responses as assessed by MOMP-specific antibody levels in enzyme-linked immunosorbent assay (ELISA). Cell-mediated immunity was unaltered as demonstrated by the significantly heightened proliferative responses of peripheral blood lymphocytes (PBL) following vaccination. DNA vaccination could significantly reduce clinical symptoms, pharyngeal and cloacal excretion as well as Chlamydophila replication, even in the presence of maternal antibodies.
Van Loock
M
M
Department of Animal Sciences, Catholic University of Leuven, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
Lambin
S
S
Volckaert
G
G
Goddeeris
B M
BM
Vanrompay
D
D
D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D002691:Chlamydophila psittaci / Q000276:immunology* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000276:immunology*; D004531:Eggs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D007273:Injections, Intramuscular; D008214:Lymphocytes / Q000276:immunology; D009956:Psittacosis / Q000276:immunology / Q000473:pathology; D012137:Respiratory System / Q000382:microbiology; D014422:Turkeys / Q000276:immunology*; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D019444:Vaccines, DNA