Immune response to the Chlamydia trachomatis outer membrane protein PorB.

The antigenicity of the outer membrane protein PorB during exposure to Chlamydia trachomatis was evaluated in humans and its immunogenicity was tested in mice. Although natural human infection resulted in strong serological responses to the major outer membrane protein (OmpA), antibodies to PorB were low or absent. Analogous to the responses observed in humans, mice inoculated with EB or challenged with EB produced weak anti-PorB antibody responses. PorB immunization of mice previously exposed to EB elicited strong PorB antibody responses. These findings support the fact that OmpA antibodies dominate the humoral immune response during natural infections and demonstrate that immunization with PorB overcomes the lack of immune response to PorB elicited during natural infection.