While there is evidence that chronic inflammation and infection promotes plaque formation, acute infections are associated with a transient five-fold increased risk of unstable coronary and vascular syndromes caused by platelet dependent thrombosis. While many strains of bacteria induce platelet aggregation, the mechanisms by which bacteria stimulate platelets has had minimal investigation. In preliminary data utilizing comprehensive microarray analyses, and a large community cohort of almost 2,000 subjects, we found distinct patterns of platelet gene expression in patients with cardiovascular disease. While several TLRs were detected in platelets, the expression of TLR2 and IL1R in particular were increased in patients with cardiovascular disease. Importantly, the functionality of TLR in platelets was established as incubation of platelets with TLR2 ligands dose-dependently induced platelet activation and aggregation. In addition, we found enhanced platelet function and platelet-monocyte/neutrophil binding with C. pneumoniae infection in vivo, and P. gingivalis incubation. The central hypothesis of the overall program project is that """"""""Pathogen stimulation via innate immune recognition modulates inflammatory mediator regulation of host immune cell function resulting in chronic inflammatory disorders"""""""". The central hypothesis of Project 1 is that bacteria mediate pro-thrombotic and -inflammatory processes in platelets via innate immune pathways. To investigate this hypothesis, we propose the following Aims:
Aim 1. To define the role of TLR2 and IL-1R in C. pneumoniae and P. gingivalis enhanced platelet function.
Aim 2. To define C. pneumoniae and P. gingivalis mediated modulation of TLR2- and IL1R-dependent signaling pathways in platelets and NFkappaB-dependent transcription in megakaryocytes.
Aim 3. To define the role of TLR2 and IL-1 R in platelet specific responses to C. pneumoniae and P. gingivalis dependent thrombosis in vivo.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Program Projects (P01)
Project #
5P01AI078894-05
Application #
8711207
Study Section
Special Emphasis Panel (ZAI1)
Project Start
Project End
Budget Start
2014-08-01
Budget End
2015-07-31
Support Year
5
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Boston University
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02118
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Huang, N; Shaik-Dasthagirisaheb, Y B; LaValley, M P et al. (2015) Liver X receptors contribute to periodontal pathogen-elicited inflammation and oral bone loss. Mol Oral Microbiol 30:438-50
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Shaik-Dasthagirisaheb, Yazdani B; Huang, Nasi; Gibson 3rd, Frank C (2014) Inflammatory response to Porphyromonas gingivalis partially requires interferon regulatory factor (IRF) 3. Innate Immun 20:312-9
Koupenova, Milka; Vitseva, Olga; MacKay, Christopher R et al. (2014) Platelet-TLR7 mediates host survival and platelet count during viral infection in the absence of platelet-dependent thrombosis. Blood 124:791-802
Kramer, Carolyn D; Weinberg, Ellen O; Gower, Adam C et al. (2014) Distinct gene signatures in aortic tissue from ApoE-/- mice exposed to pathogens or Western diet. BMC Genomics 15:1176

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