High-Level Expression ofChlamydia psittaciMajor Outer Membrane Protein in COS Cells and in Skeletal Muscles of Turkeys

Abstract

The omp1 genes encoding the major outer membrane proteins (MOMPs) of avian Chlamydia psittaci serovar A and D strains were cloned and sequenced. The nucleotide sequences of the avian C. psittaci serovar A and D MOMP genes were found to be 98.9 and 87.8% identical, respectively, to that of the avianC. psittaci serovar A strain 6BC, 84.6 and 99.8% identical to that of the avian C. psittaci serovar D strain NJ1, 79.1 and 81.1% identical to that of the C. psittaci guinea pig inclusion conjunctivitis strain, 60.9 and 62.5% identical to that of the Chlamydia trachomatis L2 strain, and 57.5 and 60.4% identical to that of the Chlamydia pneumoniae IOL-207 strain. The serovar A or D MOMPs were cloned in the mammalian expression plasmid pcDNA1. When pcDNA1/MOMP A or pcDNA1/MOMP D was introduced into COS7 cells, a 40-kDa protein that was identical in size, antigenicity, and electrophoretic mobility to native MOMP was produced. Recombinant MOMP (rMOMP) was located in the cytoplasm of transfected COS7 cells as well as in the plasma membrane and was immunoaccessible. Intramuscular administration of pcDNA1/MOMP in specific-pathogen-free turkeys resulted in local expression of rMOMP in its native conformation, after which anti-MOMP antibodies appeared in the serum.

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

“…In the present study, the eukaryotic expression vector pcDNA1/ MOMP, encoding the major outer membrane protein of an avian C. psittaci serovar A strain, was used to assess the potential of DNA-mediated immunization of turkeys against challenge with the homologous chlamydia strain. The chlamydial recombinant MOMP (rMOMP) expressed by pcDNA1/MOMP, assembled into a native conformation in COS7 cells and turkey muscle tissue and was expressed in the cytoplasm and on the host cell membrane [22]. The efficacy of combined intramuscular-intranasal administration of plasmid DNA in saline and of gene gun delivery of plasmid DNA-coated gold particles to the skin was evaluated.…”

Priming withChlamydia trachomatisMajor Outer Membrane Protein (MOMP) DNA followed by MOMP ISCOM Boosting Enhances Protection and Is Associated with Increased Immunoglobulin A and Th1 Cellular Immune Responses

“…We previously reported that MOMP DNA administered parenterally was also partially effective in inducing protective immunity against lung infection with MoPn. The result has been confirmed by some investigators and has been extended to protection against Chlamydia psittaci as well as Chlamydia pneumoniae infection (13,17,18). MOMP DNA vaccination was observed to induce variable protection from experiment to experiment, possibly due to the stochastic nature of cellular uptake and expression of the plasmid vector (Zhang et al, unpublished observations).…”

Prevalence of Chlamydophila psittaci infections in a human population in contact with domestic and companion birds

“…The rELISA was performed on twofold serum dilutions (starting at 1/100) as previously described (Verminnen et al, 2006). Briefly, rMOMP was produced in pcDNA1 : : MOMP A-transfected COS-7 cells (Vanrompay et al, 1998). IgG and IgM titres were determined using rMOMP-coated ELISA plates and 1 : 500 dilutions of horseradish peroxidase-labelled anti-human IgG (H+L) and anti-m-chain specific antibodies (Nordic Immunological Laboratories).…”