The long-term objective of this proposal is to gain insight into mechanisms of cutaneous host defense against bacterial skin pathogens. There are an increasing number of studies demonstrating that Toll-like receptors (TLRs) respond to components of bacteria and other microbial pathogens and subsequently initiate innate and adaptive immune responses. Our preliminary data in a mouse model system of Staphylococcus aureus induced skin ulceration suggest that TLRs and TLR signaling molecules are important in cutaneous host defense against bacterial skin infections. We hypothesize that TLRs play a crucial role in initiating innate and adaptive immune responses that are important in controlling bacterial skin infections. We propose experiments to investigate the role of TLRs and TLR related signaling molecules in cutaneous host defense against the most common skin pathogen, Staphylococcus aureus. The ability of TLRs to sense an infection and to generate immune responses such as production of antimicrobial peptides, recruitment immune system cells, and initiation of innate and adaptive immune responses will be investigated. In addition, since cultured keratinocytes and epidermal keratinocytes from human skin specimens have been shown to express TLRs, we will also investigate the functional role that human keratinocytes have in sensing and initiating cutaneous host defense mechanisms against Staphylococcus aureus in culture. We believe the insights obtained from the study of TLRs in bacterial skin infections will help broaden our understanding of cutaneous host defense and allow for much needed novel antibacterial therapies, which may be of particular importance since there are increasing numbers of bacterial strains that are resistant to conventional antibiotic therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Clinical Investigator Award (CIA) (K08)
Project #
1K08AI062985-01
Application #
6855998
Study Section
Microbiology and Infectious Diseases B Subcommittee (MID)
Program Officer
Prograis, Lawrence J
Project Start
2005-02-15
Project End
2009-01-31
Budget Start
2005-02-15
Budget End
2006-01-31
Support Year
1
Fiscal Year
2005
Total Cost
$102,600
Indirect Cost
Name
University of California Los Angeles
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Miller, Lloyd S (2008) Toll-like receptors in skin. Adv Dermatol 24:71-87
Miller, Lloyd S; Pietras, Eric M; Uricchio, Lawrence H et al. (2007) Inflammasome-mediated production of IL-1beta is required for neutrophil recruitment against Staphylococcus aureus in vivo. J Immunol 179:6933-42
Miller, Lloyd S; O'Connell, Ryan M; Gutierrez, Miguel A et al. (2006) MyD88 mediates neutrophil recruitment initiated by IL-1R but not TLR2 activation in immunity against Staphylococcus aureus. Immunity 24:79-91
Miller, Lloyd S; Sorensen, Ole E; Liu, Philip T et al. (2005) TGF-alpha regulates TLR expression and function on epidermal keratinocytes. J Immunol 174:6137-43