Turkeys are protected from infection withChlamydia psittaciby plasmid DNA vaccination against the major outer membrane protein

Abstract

Plasmid DNA expressing the major outer membrane protein (MOMP) of an avian Chlamydia psittaci serovar A strain has been tested for its ability to raise an immune response and induce protection against challenge with the same serovar. A combined parenteral (intramuscular injection) and mucosal route (DNA drops administered to the nares) of DNA inoculation was compared with gene gun-based immunization. The gene gun delivery of pcDNA1/MOMP as well as the intramuscular-intranasal DNA delivery primed both T-helper and B cell memory, although rMOMP-expressing cells did not induce high antibody responses. Evidence for the priming of the memory was provided by the fact that the pcDNA1/MOMP inoculations raised antibodies belonging to the IgG and not IgM isotype. However, in response to challenge only five out of 15 vaccinated turkeys showed four-fold increases in serum IgG after challenge. By contrast, evidence for the priming of T cell memory in response to challenge was found in all vaccinated turkeys, as shown by the significantly heightened proliferative responses of peripheral blood lymphocytes following vaccination. Both immunization methods produced similar serological and lymphocyte proliferative responses. Notwithstanding the immunization method, a significant level of protection was observed in all pcDNA1/MOMP-immunized turkeys. The efficacy of MOMP-based DNA vaccination as a means of preventing severe clinical signs, lesions and chlamydia excretion in a turkey model of C. psittaci infection was demonstrated.

Exacerbation ofChlamydophila psittacipathogenicity in turkeys superinfected byEscherichia coli

“…The results were scored as mentioned for the isolation in BGM cells. Staining controls consisted of sections from non-infected SPF turkeys as well as from C. psittaci positive SPF turkeys from previous experiments [30].…”

“…Negative control sera were obtained from one-week-old SPF turkeys (AFSSA, Ploufragan, France). Positive control sera originated from experimentally infected SPF turkeys of previous experiments [30].…”

Protection evaluation against Chlamydophila abortus challenge by DNA vaccination with a dnaK-encoding plasmid in pregnant and non-pregnant mice

“…Moreover, DNA immunization appears to be a promising method to resolve C. abortus infections since DNA vaccines have already been used with more or less success in Chlamydia trachomatis [33], C. pneumoniae [19] and in Chlamydophila psittaci [32] vaccination models.…”

Protection of budgerigars (Melopsittacus undulatus) againstChlamydophila psittacichallenge by DNA vaccination

“…Lymphocyte proliferative tests were performed as previously described [21]. Briefly, non-adherent cells were grown in duplicate in 96-well tissue culture plates at 6 · 10 5 cells in 150 lL of Dulbecco modified Eagle medium (DMEM) supplemented with 20% heat-inactivated foetal calf serum (FCS; Integro, Zaandam, The Netherlands), 1% non-essential amino acids (Life Technologies), 1% sodium pyruvate (Life Technologies), 1% L-glutamine (Life Technologies), 1% gentamycine (Life Technologies) and 5 · 10 À5 M b-mercaptoethanol (b-ME; Life Technologies).…”

“…However, DNA vaccination might be used for future vaccination of Psittaciformes, since the significance of DNA immunisation as a means of preventing severe clinical signs, lesions and bacterial excretion has already been demonstrated in a specific pathogen free turkey and chicken experimental model of Cp. psittaci infection [14,21,22,24,26]. Therefore, we evaluated the ability of plasmid DNA expressing the major outer membrane protein (MOMP) of a Cp.…”