ABSTRACT
Upon transmission to humans by a vector tick bite, the Lyme disease bacterium, Borrelia burgdorferi sensu lato, can establish a local skin infection and may then disseminate further to multiple tissues, including the joints, heart, skin, and nervous system (Steere 2001). Clinical manifestations of infection in humans are quite variable and have been associated with genotypic differences in infecting strains. Interactions with mammalian cells and extracellular matrix (ECM) are critical for colonization of diverse sites in the mouse model of infection and many B. burgdorferi cell-or ECM-binding surface-localized attachment factors (adhesins) have been identifi ed. Adhesins, which are likely to promote chronic multisystem disease and contribute to human disease diversity, often target host glycosaminoglycans (GAGs). An understanding of this infectious process is complicated by the multiplicities of target tissues and adhesins, many of which exhibit multiple attachment functions and vary in sequence. Detailed analysis of DbpA and BBK32, two adhesins that recognize dermatan sulfate GAG, indicate that (a) GAG-recognition by B. burgdorferi promotes colonization in a tissue-specifi c manner; and (b) sequence variation in adhesins infl uences the spectrum of tissues colonized. Recently, the B. burgdorferi-encoded OspF-related protein family, which
1 Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111.
