title: Amphipols stabilize the Chlamydia major outer membrane protein and enhance its protective ability as a vaccine.
abstract: The native major outer membrane protein (nMOMP) from Chlamydia was purified in its trimeric form using the zwitterionic detergent Z3-14. In aliquots from this preparation, Z3-14 was exchanged for amphipol (APol) A8-35. CD analysis showed that trapping with A8-35 improved the thermostability of nMOMP without affecting its secondary structure. Recombinant MOMP (rMOMP) was also formulated with Z3-14 or A8-35. Four groups of mice were vaccinated with nMOMP/Z3-14, nMOMP/A8-35, rMOMP/Z3-14 or rMOMP/A8-35 using CpG and Montanide as adjuvants. A positive control group was inoculated intranasally with live Chlamydia and a negative control group with culture medium. Mice were challenged intranasally with live Chlamydia and protection was assessed based on changes in body weight, the weight of the lungs and the number of chlamydial inclusion forming units recovered from the lungs 10 days after the challenge. Overall, vaccines formulated with nMOMP elicited better protection than those using rMOMP. Furthermore, the protection afforded by nMOMP/A8-35 was more robust than that achieved with nMOMP/Z3-14. In contrast, no differences in protection were observed between rMOMP/Z3-14 and rMOMP/A8-35 preparations. These findings suggest that the higher protection conferred by nMOMP/A8-35 complexes most likely results from a better preservation of the native structure of MOMP and/or from a more efficient presentation of the antigen to the immune system, rather than from an adjuvant effect of the amphipol. Thus, amphipols can be used in vaccine formulations to stabilize a membrane-protein component and enhance its immunogenicity.
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical Sciences I, Room D440, University of California, Irvine, Irvine, CA 92697-4800, USA.
authors.forename: Delia F
authors.initials: DF
authors.lastname: Tifrea
authors.forename: Guifeng
authors.initials: G
authors.lastname: Sun
authors.forename: Sukumar
authors.initials: S
authors.lastname: Pal
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zardeneta
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Cocco
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Popot
authors.forename: Luis M
authors.initials: LM
authors.lastname: de la Maza
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology*; D002690:Chlamydia Infections / Q000382:microbiology / Q000517:prevention & control*; D002692:Chlamydia trachomatis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D002942:Circular Dichroism; D003902:Detergents / Q000737:chemistry; D005260:Female; D008168:Lung / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011108:Polymers / Q000737:chemistry*; D011437:Propylamines / Q000737:chemistry*; D055550:Protein Stability; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D003902:Detergents; D011108:Polymers; D011437:Propylamines; D011994:Recombinant Proteins; C499017:amphipol A8-35