A vaccine formulated with the major outer membrane protein can protect C3H/HeN, a highly susceptible strain of mice, from a Chlamydia muridarum genital challenge. Issue 3 (1st October 2015)

• Record Type: Journal Article
• Authors: Pal, Sukumar; Tatarenkova, Olga V.; de la Maza, Luis M.
• Is Part Of: Immunology. Volume 146:Issue 3(2015:Nov.)
• Page Start: 432
• Page End: 443
• Publication Date: 2015-10-01
• Subjects: Immunology -- Periodicals
• DOI: 10.1111/imm.12520
• Languages: English
• ISSNs: 0019-2805

Abstract

<abstract abstract-type="main" id="imm12520-abs-0001"> <title>Summary</title> <p>C3H/HeN female mice were vaccinated with native <italic>Chlamydia muridarum</italic> major outer membrane protein (MOMP), using Montanide+CpG or Alum+CpG as adjuvants. Negative control groups were immunized with ovalbumin (OVA) and the same adjuvants. As positive control, mice were inoculated intranasally with live <italic>Chlamydia</italic>. Mice were challenged in the ovarian bursa with 10<sup>5</sup><italic>C. muridarum</italic> inclusion forming units. Six weeks after the genital challenge the animals were caged with male mice and monitored for pregnancy. Mice vaccinated with MOMP+Montanide+CpG developed high levels of <italic>C. muridarum</italic>‐specific antibodies, with a high IgG2a/IgG1 ratio and neutralizing titres. Animals immunized using Alum+CpG had low antibody levels. Cellular immune responses were significantly higher in mice vaccinated with MOMP and Montanide+CpG, but not with Alum+CpG, when compared with negative controls. Following the genital challenge, only 20% (4/20) of mice vaccinated with MOMP+CpG+Montanide had positive vaginal cultures whereas 100% (9/9) of mice immunized with MOMP+CpG+Alum had positive cultures. Of the positive control animals inoculated with live <italic>Chlamydia</italic> only 15% (3/20) had positive vaginal cultures. In contrast, 100% (20/20) of mice immunized with OVA+CpG+Montanide, or minimal essential medium, had positive cultures. Following mating, 80% (16/20) of mice vaccinated with MOMP+CpG+Montanide, and 85% (17/20) of animals inoculated intranasally with live <italic>C. muridarum</italic> carried embryos in both uterine horns. No protection against infertility was observed in mice immunized with MOMP and CpG+Alum or OVA. In conclusion, this is the first time that a subunit vaccine has been shown to elicit a protective immune response in the highly susceptible C3H/HeN strain of mice against an upper genital challenge.</p> </abstract>