Induction of protection against vaginal shedding and infertility by a recombinant Chlamydia vaccine.

A vaccine formulated with the Chlamydia muridarum recombinant major outer membrane protein, plus the adjuvants CpG and Montanide, was tested for its ability to protect BALB/c mice against a vaginal challenge. Mice were immunized by mucosal [intravaginal (i.vag.) plus colonic (col.), or intranasal (i.n.) plus sublingual (s.l.)], or systemic [intramuscular (i.m.) plus subcutaneous (s.c.)] routes, and a combination of mucosal priming and systemic boosting routes. A negative control group was vaccinated with the Neisseria gonorrhoeae porin B (Ng-rPorB) and a positive control group was inoculated in the nares with live Chlamydia. The strongest Chlamydia-specific humoral and cell-mediated immune responses were observed in the groups immunized by a combination of mucosal and systemic routes. Following the vaginal challenge, groups immunized using mucosal priming followed by systemic immunization had a significant decrease in the number of mice with positive vaginal cultures. For example, of the mice immunized i.n./s.l.+i.m./s.c., 24% had positive cultures during the six weeks of the experiment versus 69% for the negative control group immunized with Ng-rPorB (P<0.05). Similarly, the groups of mice primed by the mucosal routes and boosted by the systemic routes had significantly less IFU in the vaginal cultures when compared to the Ng-rPorB animals (P<0.05). These combination groups were also protected against infertility. The two groups had fertility rates of 100% (i.n./s.l.+i.m./s.c.) and 81% (i.vag./col.+i.m./s.c.) equivalent to the positive-control group immunized with live Chlamydia (100% fertility; P>0.05). These results show the importance of the schedule and routes of vaccination and represent the first study to show protection against infertility by a Chlamydia recombinant subunit vaccine.

Carmichael JR ，Pal S ，Tifrea D ，de la Maza LM ... -  《-》

Enhancement of the protective efficacy of a Chlamydia trachomatis recombinant vaccine by combining systemic and mucosal routes for immunization.

Chlamydia trachomatis causes respiratory and sexually transmitted infections. Here, we tested a vaccine formulated with the recombinant major outer membrane protein from C. trachomatis mouse pneumonitis (CT-MoPn) for its ability to protect mice against an intranasal (i.n.) challenge. The adjuvants CpG and Montanide were used for systemic routes, intramuscular (i.m.) and subcutaneous (s.c.), and cholera toxin for mucosal routes, sublingual (s.l.) and colonic (c.l.). Mucosal immunizations were performed either alone or in combination with systemic routes. Mice inoculated i.n. with 10(4) inclusion-forming units (IFU) of CT-MoPn served as a positive control and the Neisseria gonorrhoeae recombinant porin B (Ng-rPorB) as the negative antigen control. Immunized animals were challenged i.n. with 10(4)IFU of CT-MoPn. Following immunization the combination groups showed high chlamydial serum IgG titers (s.l.+i.m.+s.c. 25,600; c.l+i.m.+s.c. 102,400) and the IgG2a/IgG1 ratios indicated a Th1 response. Following the i.n. challenge the s.l.+i.m.+s.c. group showed the best protection as demonstrated by an increase in body weight of 0.3% over the 10 day course of infection. A statistically significant difference was found when compared with the Ng-rPorB immunized animals that had lost 20% of their original body weight (P<0.05). In addition, the repeated measures ANOVA test showed significant difference in body weight change for the combined immunized groups vs their mucosal counterparts and also the systemic immunized group. A statistically significant difference (P<0.05) was also observed in the number of IFUs recovered from the lungs when the s.l.+i.m.+s.c. (2.8×10(6)) and c.l.+i.m.+s.c. (3.4×10(6)) groups were compared to their respective mucosal only groups (s.l.: 61.9×10(6) and c.l: 136.2×10(6)) and the control Ng-rPorB immunized mice (198.2×10(6)) (P<0.05). In conclusion, a combined systemic plus mucosal vaccination provides better protection against a respiratory challenge with C. trachomatis than either systemic or mucosal immunizations alone.

Ralli-Jain P ，Tifrea D ，Cheng C ，Pal S ，de la Maza LM ... -  《-》

Protection against an intranasal challenge by vaccines formulated with native and recombinant preparations of the Chlamydia trachomatis major outer membrane protein.

Sun G ，Pal S ，Weiland J ，Peterson EM ，de la Maza LM ... -  《-》

Vaccination with the recombinant major outer membrane protein elicits antibodies to the constant domains and induces cross-serovar protection against intranasal challenge with Chlamydia trachomatis.

Tifrea DF ，Ralli-Jain P ，Pal S ，de la Maza LM ... -  《-》

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.

C3H/HeN female mice were vaccinated with native Chlamydia muridarum 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 Chlamydia. Mice were challenged in the ovarian bursa with 10(5) C. muridarum 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 C. muridarum-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 Chlamydia 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 C. muridarum 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.

Pal S ，Tatarenkova OV ，de la Maza LM 《-》