Related Experiment Video
Updated: Oct 22, 2025
A Human Fallopian Tube Model for Investigation of C. trachomatis Infections
Published on: August 11, 2012
Chlamydia trachomatis Cross-Serovar Protection during Experimental Lung Reinfection in Mice
Christian Lanfermann1, Martin Kohn1, Robert Laudeley1
1Institute of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hannover, Germany.
Abstract:
Chlamydia trachomatis causes most bacterial sexually transmitted diseases worldwide. Different major outer membrane proteins (MOMPs) define various serovars of this intracellular pathogen: In women, D to L3 can cause urethritis, cervicitis, salpingitis, and oophoritis, and, thus, infertility. Protective immunity might be serovar-specific since chlamydial infection does not appear to induce an effective acquired immunity and reinfections occur. A better understanding of induced cross-serovar protection is essential for the selection of suitable antigens in vaccine development. In our mouse lung infection screening model, we evaluated the urogenital serovars D, E, and L2 in this regard. Seven weeks after primary infection or mock-infection, respectively, mice were infected a second time with the identical or one of the other serovars. Body weight and clinical score were monitored for 7 days. Near the peak of the second lung infection, bacterial load, myeloperoxidase, IFN-γ, and TNF-α in lung homogenate, as well as chlamydia-specific IgG levels in blood were determined. Surprisingly, compared with mice that were infected then for the first time, almost independent of the serovar combination used, all acquired parameters of disease were similarly diminished. Our reinfection study suggests that efficient cross-serovar protection could be achieved by a vaccine combining chlamydial antigens that do not include nonconserved MOMP regions.
Insights
Chlamydia trachomatis reinfection in mice surprisingly showed diminished disease, suggesting cross-serovar protection. Vaccines combining conserved antigens, excluding variable outer membrane proteins, may induce broad immunity against chlamydia.
Area of Science:
- Immunology
- Microbiology
- Vaccinology
Background:
- Chlamydia trachomatis is a leading cause of bacterial sexually transmitted infections globally.
- Major Outer Membrane Proteins (MOMPs) differentiate C. trachomatis serovars, and current immunity is often serovar-specific, allowing reinfection.
- Understanding cross-serovar protection is crucial for developing effective C. trachomatis vaccines.
Purpose of the Study:
- To investigate the potential for cross-serovar protection against C. trachomatis infection using a mouse model.
- To evaluate the impact of prior infection with specific serovars on subsequent infections with homologous or heterologous serovars.
- To identify potential vaccine strategies for achieving broad immunity against C. trachomatis.
Main Methods:
- Mice were infected with C. trachomatis serovars (D, E, L2) and subsequently reinfected with the same or different serovars.
- Disease parameters including body weight, clinical score, and bacterial load were monitored.
- Immune responses, including myeloperoxidase, IFN-γ, TNF-α, and chlamydia-specific IgG levels, were assessed in lung homogenates and blood.
Main Results:
- Mice exhibited significantly diminished disease parameters upon secondary infection, irrespective of the serovar combination used.
- This suggests that prior infection induces a protective immune response that confers resistance to subsequent infections by different serovars.
- Immune markers indicated a robust inflammatory response, but overall disease severity was reduced.
Conclusions:
- A single C. trachomatis infection can induce a cross-serovar protective immune response in mice.
- Vaccine strategies should focus on conserved antigens rather than variable regions of MOMPs to achieve broad protection.
- These findings support the development of vaccines that elicit effective cross-serovar immunity against C. trachomatis.
