The spirochete Borrelia burgdorferi, the causative agent of Lyme disease, is transmitted to humans and other warm-blooded animals through the bite of infected Ixodes spp. ticks. The establishment of B. burgdorferi infection involves numerous interactions between the bacteria and a variety of vertebrate host and arthropod vector tissues. Different bacterial proteins are required at specific points of this infectious cycle, and precise regulation of the synthesis of such proteins is essential for successful infection to occur. We have discovered that these spirochetes utilize a regulatory mechanism to control protein expression patterns that involves a chemical signal known as autoinducer-2 (AI-2). This molecule is produced by the B. burgdorferi LuxS protein, which we have demonstrated to be a functional enzyme. Our preliminary studies suggest that B. burgdorferi can regulate LuxS synthesis. Addition of AI-2 to cultured B. burgdorferi dramatically alters the expression of more than 50 different proteins, increasing expression levels of some proteins, while decreasing expression of others. Through this mechanism, a population of Lyme disease spirochetes may synchronize production of proteins needed for infection processes. We hypothesize that B. burgdorferi uses AI-2 as an important signaling molecule to control expression of proteins during the natural infectious cycle of the Lyme disease spirochetes. The proposed studies will characterize the expression of LuxS during bacterial infection, the mechanisms by which B. burgdorferi controls synthesis of AI-2, and functions of AI-2-regulated proteins. Results from these studies will enhance our understanding of the complex interactions between B. burgdorferi and its hosts, as well as identifying potential bacterial targets for improved therapies to prevent and treat Lyme disease.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Special Emphasis Panel (ZRG1-BM-1 (01))
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Baker, Phillip J
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University of Kentucky
Schools of Medicine
United States
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Arnold, William K; Savage, Christina R; Antonicello, Alyssa D et al. (2015) Apparent role for Borrelia burgdorferi LuxS during mammalian infection. Infect Immun 83:1347-53
von Lackum, Kate; Ollison, Kristina M; Bykowski, Tomasz et al. (2007) Regulated synthesis of the Borrelia burgdorferi inner-membrane lipoprotein IpLA7 (P22, P22-A) during the Lyme disease spirochaete's mammal-tick infectious cycle. Microbiology 153:1361-71
Bykowski, Tomasz; Babb, Kelly; von Lackum, Kate et al. (2006) Transcriptional regulation of the Borrelia burgdorferi antigenically variable VlsE surface protein. J Bacteriol 188:4879-89
von Lackum, Kate; Babb, Kelly; Riley, Sean P et al. (2006) Functionality of Borrelia burgdorferi LuxS: the Lyme disease spirochete produces and responds to the pheromone autoinducer-2 and lacks a complete activated-methyl cycle. Int J Med Microbiol 296 Suppl 40:92-102
von Lackum, Kate; Stevenson, Brian (2005) Carbohydrate utilization by the Lyme borreliosis spirochete, Borrelia burgdorferi. FEMS Microbiol Lett 243:173-9
Babb, Kelly; von Lackum, Kate; Wattier, Rachel L et al. (2005) Synthesis of autoinducer 2 by the lyme disease spirochete, Borrelia burgdorferi. J Bacteriol 187:3079-87
Stevenson, Brian; von Lackum, Kate; Wattier, Rachel L et al. (2003) Quorum sensing by the Lyme disease spirochete. Microbes Infect 5:991-7