Lyme disease is a multisystem, multistage, inflammatory illness caused by the tick-borne spirochete, Borrelia burgdorferi. In North America, Lyme arthritis is the major manifestation of the disease. Although inflammation directed at persistence of B. burgdorferi antigens plays an important role in persistent arthritis, little is known about the Borrelia proteins involved in infection and pathogenesis. Our long-term goal is to elucidate virulence determinants and mechanisms of virulence as a prerequisite to developing therapeutic protocols for treatment of Lyme arthritis and prevention of the disease. The objective of this application is to identify new Borrelia virulence factors and immunogens that are important for Lyme borreliosis. The proposed research is based on our recent finding that the Hk2-Rrp2 two-component signaling pathway, which is essential for Borrelia virulence in the mammalian host, governs expression of a group of mammalianinfection associated immunogens of B. burgdorferi. We hypothesize that these immunogens play important roles in Borrelia infection and pathogenesis. To test this hypothesis, we propose 1), to identify the mammalian infection-associated immunogens controlled by the Hk2-Rrp2 two-component signaling pathway; 2), to construct isogenic mutants defective in producing these immunogens in a virulent strain of B. burgdorferi, and 3) to examine the mutants' ability to infect mice and cause disease in the murine Lyme arthritis model. ? ?

Public Health Relevance

Accomplishing the specific aims outlined in this proposal will likely yield the discovery of new virulence factors that are essential for Borrelia infection and pathogenesis in mammalian hosts, which will not only advance our understanding the molecular mechanism of the pathogenesis of Lyme disease, but also will identify new potential vaccine target(s) for prevention and treatment of Lyme arthritis, and/or an agents of serological tests for Lyme disease. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Small Research Grants (R03)
Project #
1R03AR054023-01
Application #
7139304
Study Section
Special Emphasis Panel (ZAR1-EHB-J (M1))
Program Officer
Mancini, Marie
Project Start
2006-08-01
Project End
2009-07-31
Budget Start
2006-08-01
Budget End
2007-07-31
Support Year
1
Fiscal Year
2006
Total Cost
$75,750
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Blevins, Jon S; Xu, Haijun; He, Ming et al. (2009) Rrp2, a sigma54-dependent transcriptional activator of Borrelia burgdorferi, activates rpoS in an enhancer-independent manner. J Bacteriol 191:2902-5
He, Ming; Oman, Tara; Xu, Haijun et al. (2008) Abrogation of ospAB constitutively activates the Rrp2-RpoN-RpoS pathway (sigmaN-sigmaS cascade) in Borrelia burgdorferi. Mol Microbiol 70:1453-64
He, Ming; Boardman, Bethany K; Yan, Dalai et al. (2007) Regulation of expression of the fibronectin-binding protein BBK32 in Borrelia burgdorferi. J Bacteriol 189:8377-80