Dr. Janis Weis has recently received a 5-year grant renewal for her research on arthritis development following infection by the bacterium Borrelia burgdorferi.

The story begins with the bite of a tick (Ixodes scapularis), native in the east/north east United States, that is infected with B. burgdorferi.  The tick transmits the bacterial infection to the host and, if untreated, the bacterium can invade many tissues, including the joint.  Infection of the knee joint is typical, with tremendous swelling, inflammatory infiltrate into synovial fluid, and pathological changes characteristic of inflammatory arthritis.

The interest for Dr. Weis’s Lab lies in the fact that not all who are infected with B. biurgdorferi develop arthritis, suggesting that genetically regulated responses to infection dictate the pathological outcome.   

The pathology is studied in mice, specifically looking for the inflammatory pathways that are activated by the bacterium when it invades joint tissue.  Current research is looking at response differences in two strains of mice, one that develops severe arthritis and one that develops mild arthritis.  It has been recently discovered that severely arthritic mice experience activation of an unexpected inflammatory pathway involving interferon.  This was a surprising finding, as interferon has classically been linked to the host defense to viral infections, not bacterial infections.  The grant proposes to characterize how the bacteria are actually inducing these interferons and how they participate in the development of arthritis.     

Future research for Dr. Weis and her colleagues will be focused on identifying the different types of interferons produced, the cell types of joint tissue that are activated, and the involvement of the skin as the first point of regulation in the bacterial response pathway.

We congratulate Dr. Weis on her newly received grant.