R01AI169724

The roles of Lyme spirochete adhesins in hematogenous dissemination - Upon transmission by a vector tick bite, Lyme disease spirochetes, primarily B. burgdorferi (BB) in the US, establish a local skin infection, then disseminate to multiple tissues. Chronic infection by BB is often associated with arthritis.

Our laboratories have identified and/or characterized many BB cell- or extracellular matrix (ECM)-binding adhesins using multiple approaches, overcoming the challenges of defining their roles in BB biology. Our approaches include analyses of biochemical activities and generation of targeted mutants selectively defective for a single adhesive activity, and analysis of the mutants in multiple murine infection models.

To gain detailed mechanistic insight into interactions that may occur during BB dissemination in vivo, following intravenous inoculation, we used intravital microscopy to characterize vascular attachment and transmigration in skin and joint-proximal tissue. These studies revealed that adhesins BBK32 and Vlse account for virtually all of the transient BB-endothelium binding occurring minutes after inoculation, termed "meeting" interactions. A distinct set of adhesins, DbpB/A, OspC, and P66, mediate contacts required for invasion into extravascular joint space after 24 hours (hr), termed "transmigrating" interactions.

Using isogenic strain sets that have acquired or lost specific adhesive activities in multiple short-term and long-term infection models, we showed roles for five of the six meeting or transmigrating adhesins in short-term tissue localization and/or long-term colonization in other murine infection models. While transmigrating adhesins do not promote "meeting" interactions, our discovery of enhanced adhesive capacity of the endothelium as infection progresses has helped clarify why different adhesins have roles at different stages of infection.

Within hr, "endothelial activation" permits BBK32- and Vlse-independent ("greeting") interactions. After ~24 hr, "endothelial potentiation" occurs, reflected by the ability of the joint vasculature to support BB transmigration. Although both OspC and P66 function as transmigrating adhesins, only P66, an integrin-binding adhesin that alters transcription in cultured endothelial cells, is also potentiating, i.e., required to promote the rapid transmigration of a second BB strain. Activation is mimicked by exogenous treatment of mice with several cytokines produced by infected mice, but potentiation is seen only with TNF-A, MCP-1 or IL-10.

These findings reveal previously unrecognized steps that are critical for BB spread and provide a means to distinguish roles for each adhesin in distinct infection stages: meeting, greeting, potentiating, transmigrating, and colonizing. In Aim 1, we will identify known adhesins that facilitate greeting interactions; to better prioritize our adhesin list, we propose a genome-wide screen that may also identify novel adhesins. In Aim 2, we will clarify the roles of known (and, if applicable, novel) adhesins in endothelial potentiation and transmigration.

Our use of rigorous genetic analyses in infection models from visualization of key interactions in vivo to quantitative analysis of BB at different stages of infection will result in a detailed understanding of a critical facet of BB biology: dissemination.

The Medical College Of Wisconsin

TO ASSIST PUBLIC AND PRIVATE NONPROFIT INSTITUTIONS AND INDIVIDUALS TO ESTABLISH, EXPAND AND IMPROVE BIOMEDICAL RESEARCH AND RESEARCH TRAINING IN INFECTIOUS DISEASES AND RELATED AREAS, TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS. TO ASSIST PUBLIC, PRIVATE AND COMMERCIAL INSTITUTIONS TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS, TO PROVIDE RESEARCH SERVICES AS REQUIRED BY THE AGENCY FOR PROGRAMS IN INFECTIOUS DISEASES, AND CONTROLLING DISEASE CAUSED BY INFECTIOUS OR PARASITIC AGENTS, ALLERGIC AND IMMUNOLOGIC DISEASES AND RELATED AREAS. PROJECTS RANGE FROM STUDIES OF MICROBIAL PHYSIOLOGY AND ANTIGENIC STRUCTURE TO COLLABORATIVE TRIALS OF EXPERIMENTAL DRUGS AND VACCINES, MECHANISMS OF RESISTANCE TO ANTIBIOTICS AS WELL AS RESEARCH DEALING WITH EPIDEMIOLOGICAL OBSERVATIONS IN HOSPITALIZED PATIENTS OR COMMUNITY POPULATIONS AND PROGRESS IN ALLERGIC AND IMMUNOLOGIC DISEASES. BECAUSE OF THIS DUAL FOCUS, THE PROGRAM ENCOMPASSES BOTH BASIC RESEARCH AND CLINICAL RESEARCH. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM EXPANDS AND IMPROVES PRIVATE SECTOR PARTICIPATION IN BIOMEDICAL RESEARCH. THE SBIR PROGRAM INTENDS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM STIMULATES AND FOSTERS SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. RESEARCH CAREER DEVELOPMENT AWARDS SUPPORT THE DEVELOPMENT OF SCIENTISTS DURING THE FORMATIVE STAGES OF THEIR CAREERS. INDIVIDUAL NATIONAL RESEARCH SERVICE AWARDS (NRSAS) ARE MADE DIRECTLY TO APPROVE APPLICANTS FOR RESEARCH TRAINING IN SPECIFIED BIOMEDICAL SHORTAGE AREAS. IN ADDITION, INSTITUTIONAL NATIONAL RESEARCH SERVICE AWARDS ARE MADE TO ENABLE INSTITUTIONS TO SELECT AND MAKE AWARDS TO INDIVIDUALS TO RECEIVE TRAINING UNDER THE AEGIS OF THEIR INSTITUTIONAL PROGRAM.

93.855 - Allergy and Infectious Diseases Research

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

Milwaukee, Wisconsin 53226 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 384% from $742,563 to $3,597,695.