RESUMO
BACKGROUND: Chlamydia trachomatis (CT) testing and treatment strategies have not decreased infection rates, justifying need for a CT vaccine. A murine study showed that a vaccine consisting of MOMP and 4 polymorphic membrane proteins (Pmps E, F, G, H) elicited protective immunity; studies on human cellular immune responses to Pmps are sparse. METHODS: Interferon gamma (IFN-γ) responses to these 5 CT proteins were measured by ELISPOT in PBMCs from women returning for treatment of a positive CT screening test. Responses were compared in those with spontaneous CT clearance vs. persisting infection at baseline and no reinfection vs. reinfection at a 3-month follow-up visit. RESULTS: IFN-γ response to one or more proteins was detected in 39% at baseline and 51.5% at follow-up; PmpE and MOMP most often elicited positive responses. IFN-γ responses to MOMP were detected less often at follow-up vs. baseline in women with reinfection, but were maintained in those without reinfection. Women with spontaneous clearance had a higher magnitude of IFN-γ response to PmpE and MOMP. CONCLUSIONS: IFN-γ responses to these 5 CT vaccine candidate proteins were heterogenous and primarily directed against MOMP and PmpE. Spontaneous clearance of infection and absence of reinfection may be clinical correlates of protection.
