Grant: Fellowship - Priority Announcement - HIV/AIDS and/or STBBI

The rates of syphilis have been rapidly increasing in Canada over the past decade, disproportionately affecting individuals from vulnerable populations. Syphilis continues to be a global public health concern and congenital syphilis is the second leading cause of preventable stillbirths worldwide. The goal of this project is to study the host response to infection to provide translational knowledge that will inform diagnostic test development and vaccine design, supporting efforts to reduce the burden of syphilis globally and in Canada. Syphilis is a multistage disease caused by the bacterium Treponema pallidum (Tp). Unlike other bacteria, Tp is difficult to grow in the lab, which has slowed progress in the syphilis field. A full understanding of how Tp establishes infection and gives rise to the symptoms of syphilis is still needed. Additionally, the correlates of protection for syphilis are unknown. Correlates of protection are the characteristics of an immune response that is able to provide protection against a pathogen and must be identified to develop an effective vaccine. This project will use proteomics and transcriptomics technologies to analyze clinical samples from individuals with syphilis to characterize the host response to infection. This project will identify 1) differences in the host response during primary and secondary stage infections and possible biomarkers of each stage, and 2) differences in the host response in individuals experiencing a first-time or repeat infection. Individuals with a reinfection often have reduced symptoms, which may indicate they have partial protection from infection. Understanding the processes responsible for this reduction in symptoms could help identify correlates of protection for syphilis. This project will provide novel insight into how Tp causes infection and the corresponding host response and will identify biomarkers and correlates of protection, which will inform improved diagnostic test and vaccine design.