Immunisation with the glycolytic enzyme enolase inhibits dissemination of Treponema pallidum in C57BL/6 mice

Treponema pallidum (T. pallidum), an obligate extracellular bacterium, is the causative agent of sexually transmitted bacterial diseases. In this study, the glycolytic enzyme enolase (Tp Eno) of T. pallidum were injected intramuscularly into C57BL/6 mice, resulting in higher levels of specific anti-Tp Eno antibodies and Tp Enospecific splenocyte proliferation than those in the mice immunized with recombinant protein Tp Eno. Cytokine (IL-4, IL-6, IL-10, IFN-gamma, and TNF-alpha) analysis of splenocytes showed that the Tp Eno could slightly trigger the Th1-biased immune response. Furthermore, immunization of mice with Tp Eno elicited a significant production of IFN-gamma by CD4+ T-cells in the spleen. Subsequently, mice were inoculated intradermally (between the scapulae), intraperitoneally, intrarectally and via the corpora cavernosa with 2.5 x 106 organisms per site (1 x 107 total organisms). The bacterial organ burden detected in the blood, spleen, liver, testes or brain of immunized mice suggested that Tp Eno enhances protective immunity to inhibit T. pallidum colonization in distal tissues. Therefore, Tp Eno vaccination enhances Tp Eno-specific immunogenicity and provides protection against T. pallidum dissemination.

Automated summary

This study investigated the immunogenicity and protective efficacy of Treponema pallidum glycolytic enzyme enolase (Tp Enolase) in mice. Results showed that Tp Enolase induced the production of specific antibodies and splenocyte proliferation, as well as a Th1-biased immune response. In addition, immunization with Tp Enolase inhibited T. pallidum colonization in distal tissues.