The Furie Laboratory has a broad interest in how the body’s innate immune system interacts with bacterial pathogens, including Borrelia burgdorferi (the agent of Lyme disease) and Francisella tularensis (the cause of tularemia).  A particular focus is on recruitment of circulating leukocytes to infected tissues.  This recruitment is controlled by the endothelial cells that line the blood vessels.  When activated, endothelial cells express adhesion molecules and secrete attractants that direct the movement of the white cells from the blood into infected tissues.  These leukocytes play an essential role in host defense, but their anti-microbial weaponry can also injure healthy tissues if unleashed inappropriately or excessively.  Using in vitro and in vivo approaches, we have dissected the mechanisms whereby B. burgdorferi and F. tularensis regulate recruitment of leukocytes.  Another area of major interest is interactions of F. tularensis with hepatocytes, the main cells of the liver.  F. tularensis grows within hepatocytes, and we aim to understand how the bacteria and the host cells mutually adapt and respond to the intracellular infection.