Chlamydophila abortus is a species in Chlamydiae that causes abortion and fetal death in mammals, including humans. Chlamydophila abortus was previously classified as Chlamydia psittaci along with all Chlamydiae except Chlamydia trachomatis. This was based on a lack of evident glycogen production and on resistance to the antibiotic sulfadiazine. In 1999 C. psittaci and C. abortus were recognized as distinct species based on differences of pathogenicity and DNA–DNA reassociation. C. abortus is endemic among ruminants and has been associated with abortion in a horse, a rabbit, guinea pigs, mice, pigs and humans. Infected females shed bacteria near the time of ovulation, so C. abortus is transmitted orally and sexually among mammals. All C. abortus strains were isolated or PCR-amplified from placenta or fetal organs after spontaneous abortion. C. abortus infection generally remains inapparent until an animal aborts late in gestation or gives birth to a weak or dead foetus (Wiki: Chlamydophila abortus).
4. Host Ranges and Animal Models
C. abortus is endemic among ruminants and has been associated with abortion in a horse, a rabbit, guinea pigs, mice, pigs and humans (Wiki: Chlamydophila abortus).
II. Vaccine Related Pathogen Genes
1. CAB049 putative penicillin-binding protein
Gene Name :
CAB049 putative penicillin-binding protein
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. CP #5 (Transglycolase/transpeptidase, CAB049 putative penicillin-binding protein) was significantly more protective than the genes encoding fewer than 50 amino acids (p-value of less than 0.05 when comparing lung weights). The chlamydial loads generally tracked with protection and the most protective genes were significantly lower than in unvaccinated controls (p < 0.05 in the Mann–Whitney U-test for genes CP #1, 2, 4–7, 9, 10) (Stemke-Hale et al., 2005).
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Of the 14 individually tested clones, CP #1 through CP #9 had positive relative protection scores. CP #8 (CAB613, Oligopeptidase) was found to confer protection (Stemke-Hale et al., 2005).
Molecule Role Annotation :
In pregnant mice, the dnaK vaccine induced a non-specific partial protection from abortion after challenge with Chlamydophila abortus (Héchard et al., 2002).
>CAH63776.1 DNA polymerase III subunit gamma/tau [Chlamydia abortus S26/3]
MTSATYQVSSRKYRPQTFAEMLGQDAVVTVLKNALQFQRVAHAYLFSGIRGTGKTTLARIFAKALNCKEL
TPEHEPCNQCCVCKEISSGTSLDVIEIDGASHRGIEDIRQINETVLFTPAKSQYKIYIIDEVHMLTKEAF
NSLLKTLEEPPSHVKFFLATTENYKIPSTILSRCQKMHLKRIPETMIVDKLASISQAGGIETSREALLPI
ARAAQGSLRDAESLYDYVIGLFPTSLSPELVADALGLLSQDTLATLSECIRTQKYAEALLPVTTAINSGV
APITFLHDLTVFYRDVLLNKDQGNSPLSAIAMHYSSECLLEIIDFLGEAAKHLQQTIFEKTFLETVIIHL
IRICQRPSLETLFSQLKTSTFDTVRNVPQQQEPSKPSIQPEKHYQDQSFLTSPSPTPKVQHQKEASPSLV
GSATIDTLLQFAVVEFSGILTKE
Molecule Role :
Protective antigen
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. DNA pol III Gamma and Tau (CP #1, dnaX) was found to be protective. CP #1 (dnaX) was more protective than the live-vaccine, positive control. (Stemke-Hale et al., 2005).
>YP_219703.1 aspartyl/glutamyl-tRNA amidotransferase subunit A [Chlamydophila abortus S26/3]
MYQKSALELRNAVVSGESSATAIAKYFYNRIKTEDNQIGAFLSLCEERAYEKAAIIDAKVARGEPLGKLA
GVPIGIKDNIHIRGLRTTCASKMLENYIAPFDATVVERIEAEDGVILGKLNMDEFAMGSTTQYSAFHPTK
NPWGLSCVPGGSSGGSAAAVSARFCPIALGSDTGGSIRQPAAFCGVVGFKPSYGAVSRYGLVAFGSSLDQ
IGPLTTVVEDVALAMDVFAGKDDRDATSQKFFTGSFQEALSLDVPSLIGVPMGFLDGLRDDVKENFFASL
SILERQGSRIVEVDLNILDHAVSVYYIVASAEAATNLARFDGIRYGYRSPEAHSIEDIYTISRVQGFGKE
VMRRILLGNYVLSTERQNVYYKKGSAIRAKIIQAFQKAYEKCDVIAMPVCSCPAFADGEILDPTSLYLQD
IYTVAMNLAYLPAIAVPSGFSREGLPLGFQVIGQKGKDQQVCQVGYSFQEHSGIKNLYPKGCNKLVDGEV
K
Molecule Role :
Protective antigen
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Glu-tRNA Gln Amidotransferase (CP #3, gatA) was found to be protective. Three of the clones (CP #1–3) elicited protection that was statistically higher than the unvaccinated control, which has high variance (Stemke-Hale et al., 2005).
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Glu-tRNA Gln Amidotransferase (CP #3, gatB) was found to be protective. Three of the clones (CP #1–3) elicited protection that was statistically higher than the unvaccinated control, which has high variance (Stemke-Hale et al., 2005).
>YP_219702.1 aspartyl/glutamyl-tRNA amidotransferase subunit C [Chlamydophila abortus S26/3]
MTQPYVTREDIILLAKSSALELSEEFIQEYESSLNEVIKTMAASIAMDVTDVVIEVGLSHVISPEDLRED
IVASSFSREEFLTNVPESLGGLVKVPTVIK
Molecule Role :
Protective antigen
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Glu-tRNA Gln Amidotransferase (CP #2, gatC) was found to be protective. Three of the clones (CP #1–3) elicited protection that was statistically higher than the unvaccinated control, which has high variance (Stemke-Hale et al., 2005).
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. CP #7 (omlA) was significantly more protective than the genes encoding fewer than 50 amino acids (p-value of less than 0.05 when comparing lung weights). The chlamydial loads generally tracked with protection and the most protective genes were significantly lower than in unvaccinated controls (p < 0.05 in the Mann–Whitney U-test for genes CP #1, 2, 4–7, 9, 10) (Stemke-Hale et al., 2005).
>CAA36152.1 major outer membrane protein [Chlamydia abortus]
MKKLLKSALLFAATGSALSLQALPVGNPAEPSLLIDGTMWEGASGDPCDPCSTWCDAISIRAGYYGDYVF
DRVLKVDVNKTITGMGAVPTGTAAANYKTPTDRPNIAYGKHLQDAEWFTNAAFLALNIWDRFDIFCTLGA
SNGYFKASSAAFNLVGLIGVKGSSIAADQLPNVGITQGIVEFYTDTTFSWSVGARGALWECGCATLGAEF
QYAQSNPKIEMLNVVSSPAQFVVHKPRGYKGTAFPLPLTAGTDQATDTKSATIKYHEWQVGLALSYRLNM
LVPYISVNWSRATFDADAIRIAQPKLAAAVLNLTTWNPTLLGEATALDTSNKFADFLQIASIQINKMKSR
KACGVAVGATLIDADKWSITGEARLINERAAHMNAQFRF
Molecule Role :
Protective antigen
Molecule Role Annotation :
The MOMP (omp1) DNA immunization induced a non-specific and partial protection in OF1 outbred mice fetuses against challenge with C. abortus (Héchard et al., 2003).
Molecule Role Annotation :
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Protective clone CP #4 (OMP90A, pomp90A) was diluted 1/2000 in a non-protective sublibrary pool of clones. This CP #4-spiked sublibrary conferred protection. Five clones were significantly more protective than the genes encoding fewer than 50 amino acids (CP #1–5 and 7, p-value of less than 0.05 when comparing lung weights). (Stemke-Hale et al., 2005).
C. abortus CAB049 putative penicillin-binding protein
e. Gene Engineering of
CAB049 putative penicillin-binding protein
Type:
DNA vaccine construction
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. CP #5 (Transglycolase/transpeptidase, CAB049 putative penicillin-binding protein) was significantly more protective than the genes encoding fewer than 50 amino acids (p-value of less than 0.05 when comparing lung weights). The chlamydial loads generally tracked with protection and the most protective genes were significantly lower than in unvaccinated controls (p < 0.05 in the Mann–Whitney U-test for genes CP #1, 2, 4–7, 9, 10) (Stemke-Hale et al., 2005).
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Of the 14 individually tested clones, CP #1 through CP #9 had positive relative protection scores. CP #8 (CAB613, Oligopeptidase) was found to confer protection (Stemke-Hale et al., 2005).
Description:
The dnaK gene was amplified by the polymerase chain reaction (PCR) and cloned in the appropriate vectors. PCR was performed using chlamydial genomic DNA (80 ng) as the template. The resulting fragment was inserted into the pcDNA3.1 (Invitrogen) eukaryotic vaccinal vector carrying the human cytomegalovirus immediate early-promoter and the bovine growth hormone polyadenylation signal after linearization by BamHI-XbaI double digestion to generate pcDNA3.1::DnaK. pcDNA3.1::DnaK and pcDNA3.1 control plasmid were purified after an overnight Luria Bertani (LB) culture of recombinant DH5a E. coli using the EndoFree™ (Héchard et al., 2002).
Vaccination Protocol:
Prior to DNA immunization, each mouse was injected with cardiotoxin (Latoxan, Rosans, France) into the tibialis anterior muscles of both ind legs. Cardiotoxin induces a local inflammation and enhances the uptake of plasmid DNA. Five days later, the mice were anesthetized by intraperitoneal injection of ketamine and xylazine (80 and 8 mg/kg of body weight, respectively) and immunized with pcDNA3.1 or pcDNA3.1::DnaK plasmids by intramuscular injections (50 mg in each tibialis anterior). The mice were boosted in the same way at days 21 and 42, mated at day 51 and challenged at day 63 by an intraperitoneal injection of 2 ´ 10^5 plaque forming units (pfu) of C. abortus AB7 (Héchard et al., 2002).
Challenge Protocol:
Four groups of 16 non-pregnant mice were made for immunological trials. Non-pregnant mice were used in order to collect samples without affecting the pregnancy of the mice. Moreover, a good vaccine must be able to protect pregnant and non-pregnant animals. As for the mice of the abortion test, these non-pregnant mice were immunized with the 1B vaccine, pcDNA3.1 or pcDNA3.1::DnaK.One additional group was immunized by PBS (same quantity, site and time as the DNA injections) and consequently was related as the virulence control group (Héchard et al., 2002).
Efficacy:
In pregnant mice, the dnaK vaccine induced a non-specific partial protection from abortion after challenge with Chlamydophila abortus (Héchard et al., 2002).
Host Gene Response of
Ighv1-9
Gene Response:
In non-pregnant mice, the dnaK vaccine induced a specific humoral response with the predominant serum IgG2a isotope. No antibody response was detected in non-immunized mice or with the control plasmid. Increases in serum IgG2a were seen at day 41, increasing until day 61 with a drop on day 68 to levels similar to those seen on day 41 (Héchard et al., 2002).
C. abortus DNA polymerase III subunit gamma/tau antigen dnaX
e. Gene Engineering of
dnaX
Type:
DNA vaccine construction
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. DNA pol III Gamma and Tau (CP #1, dnaX) was found to be protective. CP #1 (dnaX) was more protective than the live-vaccine, positive control. (Stemke-Hale et al., 2005).
C. abortus Glu-tRNA Gln Amidotransferase gatA and gatB
e. Gene Engineering of
gatA
Type:
DNA vaccine construction
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Glu-tRNA Gln Amidotransferase (CP #3, gatA/gatB) was found to be protective. Three of the clones (CP #1–3) elicited protection that was statistically higher than the unvaccinated control, which has high variance (Stemke-Hale et al., 2005).
C. abortus aspartyl/glutamyl-tRNA amidotransferase subunit C
e. Gene Engineering of
gatC
Type:
DNA vaccine construction
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Glu-tRNA Gln Amidotransferase (CP #2, gatC) was found to be protective. Three of the clones (CP #1–3) elicited protection that was statistically higher than the unvaccinated control, which has high variance (Stemke-Hale et al., 2005).
Description:
The momp (omp1) gene was amplified by PCR and cloned into the vector pcDNA3.1 (Invitrogen) carrying the human cytomegalovirus immediate early promoter and the bovine growth hormone polyadenylation signal. The PCR was performed using chlamydial genomic DNA (80 ng) as template with dNTPs (200 µM each), specific primers (1 µM each) and 1 U Pfu DNA polymerase (Promega) in a Perkin Elmer 9600 thermocycler. The resulting fragment was inserted into the vector pcDNA3.1 after linearization by EcoRI/XhoI double digestion to generate pcDNA3.1 : : MOMP. The plasmid pcDNA3.1 : : MOMP and the pcDNA3.1 control plasmid were purified after an overnight Luria–Bertani culture of recombinant Escherichia coli DH5 using the EndoFree Plasmid Mega kit (Qiagen). Plasmid DNA was dissolved at 1 µg µl-1 in endotoxin-free PBS (Sigma) (Héchard et al., 2003).
Vaccination Protocol:
Prior to DNA immunization, each mouse was injected with cardiotoxin (Latoxan) into the tibialis anterior muscles of both hind legs to enhance the uptake of plasmid DNA (Davis et al., 1993). Five days later, mice were anaesthetized by an intraperitoneal injection of ketamine and xylazine (respectively 80 and 8 mg kg-1 body weight) and immunized with pcDNA3.1 : : MOMP plasmid by intramuscular injections (50 µg in each tibialis anterior). Mice were boosted in the same way at days 21 and 42. The negative-control mice were immunized intramuscularly with endotoxin-free PBS (virulence control) or pcDNA3.1 plasmid. Positive-control mice were immunized with one subcutaneous injection of 4 x 10^4 p.f.u. of the live attenuated 1B vaccine at day 1 (Héchard et al., 2003).
Challenge Protocol:
The five groups of pregnant mice were mated at day 44. Non-pregnant and pregnant mice were challenged at day 58 by an intraperitoneal injection of 4 x 10^4 p.f.u. C. abortus AB7. One group of pregnant mice neither immunized nor challenged was kept as a control for the pregnancy (gestation control) (Héchard et al., 2003).
Efficacy:
The MOMP (omp1) DNA immunization induced a non-specific and partial protection in OF1 outbred mice fetuses against challenge with C. abortus (Héchard et al., 2003).
Host Gene Response of
Ighv1-9
Gene Response:
In non-pregnant mice, the MOMP DNA vaccine elicited a specific humoral response with predominantly serum IgG2a antibodies, suggesting a Th1-type immune response. No antibody response was detected in non-immunized mice or mice immunized with the control plasmid. The anti-MOMP IgG titre reached a maximum in the non-pregnant mice immunized with pcDNA3.1 : : MOMP after the third DNA injection (day 56) and decreased after challenge (day 63) (Héchard et al., 2003).
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. CP #7 (omlA) was significantly more protective than the genes encoding fewer than 50 amino acids (p-value of less than 0.05 when comparing lung weights). The chlamydial loads generally tracked with protection and the most protective genes were significantly lower than in unvaccinated controls (p < 0.05 in the Mann–Whitney U-test for genes CP #1, 2, 4–7, 9, 10) (Stemke-Hale et al., 2005).
C. abortus polymorphic outer membrane protein 90A (pomp90A)
e. Gene Engineering of
pomp90A
Type:
DNA vaccine construction
Description:
To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
Vaccination Protocol:
Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
Challenge Protocol:
In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
Efficacy:
Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. Protective clone CP #4 (OMP90A, pomp90A) was diluted 1/2000 in a non-protective sublibrary pool of clones. This CP #4-spiked sublibrary conferred protection. Five clones were significantly more protective than the genes encoding fewer than 50 amino acids (CP #1–5 and 7, p-value of less than 0.05 when comparing lung weights). (Stemke-Hale et al., 2005).
Live temperature-sensitive mutant strain for subcutaneous or intramuscular injection(Chalmers et al., 1997)
V. References
1. Bandholtz et al., 2002: Bandholtz L, Kreuger MR, Svanholm C, Wigzell H, Rottenberg ME. Adjuvant modulation of the immune responses and the outcome of infection with Chlamydia pneumoniae. Clinical and experimental immunology. 2002; 130(3); 393-403. [PubMed: 12452828].
2. Chalmers et al., 1997: Chalmers WS, Simpson J, Lee SJ, Baxendale W. Use of a live chlamydial vaccine to prevent ovine enzootic abortion. The Veterinary record. 1997; 141(3); 63-67. [PubMed: 9257434].
5. Héchard et al., 2004: Héchard C, Grépinet O, Rodolakis A. Molecular cloning of the Chlamydophila abortus groEL gene and evaluation of its protective efficacy in a murine model by genetic vaccination. Journal of medical microbiology. 2004; 53(Pt 9); 861-868. [PubMed: 15314192].
6. Stemke-Hale et al., 2005: Stemke-Hale K, Kaltenboeck B, DeGraves FJ, Sykes KF, Huang J, Bu CH, Johnston SA. Screening the whole genome of a pathogen in vivo for individual protective antigens. Vaccine. 2005; 23(23); 3016-3025. [PubMed: 15811648].
