Prophylactic Multi-Subunit Vaccine against Chlamydia trachomatis: In Vivo Evaluation in Mice
Christian Lanfermann1, Sebastian Wintgens2, Thomas Ebensen3
1Institute of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hannover, Germany.
Vaccines
|July 2, 2021
Summary
A new five-component Chlamydia trachomatis vaccine, delivered intranasally, provides broad cross-serovar protection against urogenital and ocular infections in mice. This mucosal vaccine shows promise for preventing serious complications of Chlamydia trachomatis.
Area of Science:
- Immunology
- Vaccinology
- Microbiology
Background:
- Chlamydia trachomatis is a leading cause of sexually transmitted infections and trachoma, necessitating urgent vaccine development.
- Current Chlamydia trachomatis infections can lead to severe health issues including pelvic inflammatory disease and infertility.
- Existing treatments are insufficient, highlighting the need for effective preventative strategies.
Purpose of the Study:
- To characterize a novel five-component subunit vaccine against Chlamydia trachomatis.
- To evaluate the vaccine's efficacy and protective mechanisms in a mouse model.
- To assess the potential of the vaccine in preventing both urogenital and ocular Chlamydia trachomatis infections.
Main Methods:
- A five-component subunit vaccine was formulated using recombinant Pmp proteins and Ctad1 from C. trachomatis serovar E, combined with cyclic-di-adenosine monophosphate mucosal adjuvant.
- The vaccine was administered intranasally to mice, followed by challenge infection with C. trachomatis.
- Efficacy was assessed by monitoring body weight, clinical scores, chlamydial load, granulocyte markers, and cytokine levels (IFN-γ, TNF-α).
Main Results:
- Intranasal vaccination induced significant cross-serovar protection against both urogenital and ocular C. trachomatis strains, lasting at least five months.
- Protection correlated with vaccine antigen-specific antibodies and a mixed Th1/Th2/Th17 T cell response, including multi-functional CD4+ and CD8+ T cells.
- Serum transfer experiments indicated that circulating antibodies play a minor role in protection, suggesting a stronger role for cell-mediated immunity.
Conclusions:
- The novel five-component intranasal vaccine effectively elicits protective immunity against diverse Chlamydia trachomatis serovars in a mouse model.
- The findings suggest that this vaccine strategy holds potential for preventing the long-term sequelae of human Chlamydia trachomatis infections.
- Further research and development could lead to a viable vaccine candidate for widespread use.
