Lyme disease is the leading tick-borne bacterial disease in the world resulting an estimated 300,000 cases per year in the US alone. Lyme disease is caused by tick-bite transmission of the pathogenic spirochete Borrelia burgdorferi (Bb). An increased understanding of the molecular mechanisms that Bb uses to survive throughout its infectious cycle is critical for the development of innovative diagnostic and therapeutic protocols to reduce the incidence of Lyme disease. Bb harbors a reduced genome lacking many canonical metabolic, virulence and host defense evasion functions and a large number of the genes in the Bb genome encode hypothetical proteins of unknown function uniquely conserved among Borrelia species, together suggesting that Bb has evolved unique mechanisms to survive in the host that remain largely unknown. In the previous funding cycle, we addressed one of the key challenges in the field of Bb molecular pathogenesis, definition of the transcriptional activity of Bb during mammalian infection. Our novel synergistic approach combined development and application of an in vivo expression technology (IVET)-method for Bb, genome-wide identification of the 5' end transcriptome of Bb during growth in culture and infectivity analysis of targeted Bb mutants. This work contributed significant insight into the Bb transcriptome in vitro and during infection and resulted in our discovery of a large number of novel infection-expressed genes likely to contribute to Bb pathogenesis. These findings catalyze our current efforts to address a critical unresolved gap in knowledge of the biology of this pathogen, which is elucidation of the molecular mechanisms that allow Bb to overcome barriers to infection in order disseminate to distal tissues, leading to persistent infection and therefore, the incapacitating symptoms of Lyme disease. The goal of this proposal is to elucidate the molecular mechanisms that Bb uses to overcome host barriers to infection in order to disseminate. To achieve this goal we have focused our studies on functional analysis of three novel genes, bb0318, bbk13 and bb0562, which our data indicate play critical roles in Bb infectivity and dissemination due to their distinct contributions to Bb's ability to evade the early immune responses of the host. We will elucidate the molecular mechanisms of bb0318-dependent resistance to oxidative stress and immune-cell killing (Aim 1) and bbk13-dependent evasion of host complement (Aim 2) as well as define the contribution of bb0562 to Bb infection (Aim 3). We propose a multidisciplinary approach for mechanistic analysis of each of these novel genes, using cutting edge technologies in biochemistry, cell biology, microscopy and innate immunity as well as in vivo live imaging, a diversity of mouse models and an experimental tick-mouse infectious cycle. The insight gained from our work will significantly impact the understanding of the mechanisms of Bb dissemination, which in turn will provide a foundation for novel approaches for Lyme disease interventions.

Public Health Relevance

Lyme disease is an emerging infectious disease caused by tick-bite transmission of the pathogenic bacteria Borrelia burgdorferi. It is not well understood how B. burgdorferi causes disseminated infection. This project investigates novel B. burgdorferi genes important for dissemination. These studies will contribute to an understanding of B. burgdorferi pathogenesis toward the development of improved treatments for Lyme disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI099094-07
Application #
9932878
Study Section
Host Interactions with Bacterial Pathogens Study Section (HIBP)
Program Officer
Ilias, Maliha R
Project Start
2013-06-01
Project End
2023-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
7
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Central Florida
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
150805653
City
Orlando
State
FL
Country
United States
Zip Code
32826
Adams, Philip P; Jewett, Mollie W (2018) Selection of Borrelia burgdorferi Promoter Sequences Active During Mammalian Infection Using In Vivo Expression Technology. Methods Mol Biol 1690:137-154
Molins, Claudia R; Ashton, Laura V; Wormser, Gary P et al. (2017) Metabolic differentiation of early Lyme disease from southern tick-associated rash illness (STARI). Sci Transl Med 9:
Adams, Philip P; Flores Avile, Carlos; Jewett, Mollie W (2017) A Dual Luciferase Reporter System for B. burgdorferi Measures Transcriptional Activity during Tick-Pathogen Interactions. Front Cell Infect Microbiol 7:225
Adams, Philip P; Flores Avile, Carlos; Popitsch, Niko et al. (2017) In vivo expression technology and 5' end mapping of the Borrelia burgdorferi transcriptome identify novel RNAs expressed during mammalian infection. Nucleic Acids Res 45:775-792
Showman, Adrienne C; Aranjuez, George; Adams, Philip P et al. (2016) Gene bb0318 Is Critical for the Oxidative Stress Response and Infectivity of Borrelia burgdorferi. Infect Immun 84:3141-3151
Jain, Sunny; Showman, Adrienne C; Jewett, Mollie W (2015) Molecular dissection of a Borrelia burgdorferi in vivo essential purine transport system. Infect Immun 83:2224-33
Ellis, Tisha Choudhury; Jain, Sunny; Linowski, Angelika K et al. (2014) Correction: In Vivo Expression Technology Identifies a Novel Virulence Factor Critical for Borrelia burgdorferi Persistence in Mice. PLoS Pathog 10:e1004260
Halpern, Micah D; Molins, Claudia R; Schriefer, Martin et al. (2014) Simple objective detection of human lyme disease infection using immuno-PCR and a single recombinant hybrid antigen. Clin Vaccine Immunol 21:1094-105
Ellis, Tisha Choudhury; Jain, Sunny; Linowski, Angelika K et al. (2013) In vivo expression technology identifies a novel virulence factor critical for Borrelia burgdorferi persistence in mice. PLoS Pathog 9:e1003567