CD4+ T cells and antibody are required for optimal major outer membrane protein vaccine-induced immunity to Chlamydia muridarum genital infection.
Despite effective antimicrobial chemotherapy, control of Chlamydia trachomatis urogenital infection will likely require a vaccine. We have assessed the protective effect of an outer membrane protein-based vaccine by using a murine model of chlamydial genital infection. Female mice were first vaccinated with Chlamydia muridarum major outer membrane protein (MOMP) plus the adjuvants CpG-1826 and Montanide ISA 720; then they were challenged with C. muridarum. Vaccinated mice shed 2 log(10) to 3 log(10) fewer inclusion-forming units (IFU) than ovalbumin-vaccinated or naïve animals, resolved infection sooner, and had a lower incidence of hydrosalpinx. To determine the relative contribution of T cells to vaccine-induced protection, mice were vaccinated, depleted of CD4(+) or CD8(+) T cells, and then challenged vaginally with C. muridarum. Depletion of CD4(+) T cells, but not depletion of CD8(+) T cells, diminished vaccine-induced protection, with CD4-depleted mice shedding 2 log(10) to 4 log(10) more IFU than CD8-depleted or nondepleted mice. The contribution of antibodies to vaccine-induced protection was demonstrated by the absence of protective immunity in vaccinated B-cell-deficient mice and by a 2 log(10) to 3 log(10) decrease in bacterial shedding by mice passively administered an anti-MOMP serum. Thus, optimal protective immunity in this model of vaccine-induced protection depends on contributions from both CD4(+) T cells and antibody.
Farris
Christina M
CM
Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Morrison
Sandra G
SG
Morrison
Richard P
RP
D000818:Animals; D001402:B-Lymphocytes; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology; D002690:Chlamydia Infections / Q000517:prevention & control*; D023502:Chlamydia muridarum / Q000276:immunology*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D016585:Vaginosis, Bacterial / Q000382:microbiology / Q000517:prevention & control
D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines