title: Vaccination of koalas (Phascolarctos cinereus) with a recombinant chlamydial major outer membrane protein adjuvanted with poly I:C, a host defense peptide and polyphosphazine, elicits strong and long lasting cellular and humoral immune responses.
abstract: Chlamydial infections are wide spread in koalas across their range and a solution to this debilitating disease has been sought for over a decade. Antibiotics are the currently accepted therapeutic measure, but are not an effective treatment due to the asymptomatic nature of some infections and a low efficacy rate. Thus, a vaccine would be an ideal way to address this infectious disease threat in the wild. Previous vaccine trials have used a three-dose regimen; however this is very difficult to apply in the field as it would require multiple capture events, which are stressful and invasive processes for the koala. In addition, it requires skilled koala handlers and a significant monetary investment. To overcome these challenges, in this study we utilized a polyphosphazine based poly I:C and a host defense peptide adjuvant combined with recombinant chlamydial major outer membrane protein (rMOMP) antigen to induce long lasting (54 weeks) cellular and humoral immunity in female koalas with a novel single immunizing dose. Immunized koalas produced a strong IgG response in plasma, as well as at mucosal sites. Moreover, they showed high levels of C. pecorum specific neutralizing antibodies in the plasma as well as vaginal and conjunctival secretions. Lastly, Chlamydia-specific lymphocyte proliferation responses were produced against both whole chlamydial elementary bodies and rMOMP protein, over the 12-month period. The results of this study suggest that a single dose rMOMP vaccine incorporating a poly I:C, host defense peptide and polyphosphazine adjuvant is able to stimulate both arms of the immune system in koalas, thereby providing an alternative to antibiotic treatment and/or a three-dose vaccine regime.
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia. Electronic address: shahneazali.khan@student.qut.edu.au.
authors.forename: Shahneaz Ali
authors.initials: SA
authors.lastname: Khan
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia. Electronic address: cwaugh@usc.edu.au.
authors.forename: Courtney
authors.initials: C
authors.lastname: Waugh
authors.affiliation: Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia. Electronic address: galit@koala.net.
authors.forename: Galit
authors.initials: G
authors.lastname: Rawlinson
authors.affiliation: Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia. Electronic address: jacqui@koala.net.
authors.forename: Jacqui
authors.initials: J
authors.lastname: Brumm
authors.affiliation: Lone Pine Koala Sanctuary, Fig Tree Pocket, QLD 4519, Australia. Electronic address: karen@koala.net.
authors.forename: Karen
authors.initials: K
authors.lastname: Nilsson
authors.affiliation: Vaccine and Infectious Disease Organizations, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada. Electronic address: volker.gerdts@usask.ca.
authors.forename: Volker
authors.initials: V
authors.lastname: Gerdts
authors.affiliation: Vaccine and Infectious Disease Organizations, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada. Electronic address: andrew.potter@usask.ca.
authors.forename: Andrew
authors.initials: A
authors.lastname: Potter
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia. Electronic address: apolking@usc.edu.au.
authors.forename: Adam
authors.initials: A
authors.lastname: Polkinghorne
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia. Electronic address: k2.beagley@qut.edu.au.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Beagley
authors.affiliation: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave., Kelvin Grove, QLD 4059, Australia; Faculty of Science, Health, Education & Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD 4558, Australia. Electronic address: ptimms@usc.edu.au.
authors.forename: Peter
authors.initials: P
authors.lastname: Timms
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D057134:Antibodies, Neutralizing / Q000097:blood; D001388:Aziridines / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002690:Chlamydia Infections / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D018928:Immunity, Mucosal; D007074:Immunoglobulin G / Q000097:blood; D048368:Phascolarctidae / Q000276:immunology*; D011070:Poly I-C / Q000494:pharmacology; D011994:Recombinant Proteins / Q000276:immunology; D014611:Vaccination / Q000662:veterinary
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D057134:Antibodies, Neutralizing; D001388:Aziridines; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D011994:Recombinant Proteins; C008880:phosphazine; D011070:Poly I-C
keywords: Adjuvant; Chlamydia; Koala; Single dose; Vaccine