Uncontrolled neutrophil adhesion and activation contributes to significantly to tissue damage in inflammatory diseases such as rheumatoid arthritis and vasculitis. Integrins are the major adhesive receptors on neutrophils that regulate cellular activation. Investigating the basic mechanisms of neutrophil integrin signaling is therefore critical to our understanding of the pathogenesis of inflammatory disease. This application is focused on the """"""""outside-in"""""""" integrin signaling pathway that induces neutrophil and macrophage activation. In previous work, we have demonstrated that outside-in integrin signaling is mediated by Src-family and Syk tyrosine kinases. In turn, these enzymes signal to SLP-76 leading to downstream activation of MAP kinases. The sequential involvement of Src-family kinases, Syk and SLP-76 is reminiscent of classical immunoreceptor signaling, such as B or T-cell receptor pathways, which depends on ITAM-containing adapter proteins. In preliminary data, we have found that neutrophils derived from DAP-12-/- FcRgamma-/- mice, which lack the two major ITAM adapters present in myeloid cells, are also completely defective in neutrophil integrin signaling. Based on these observations we hypothesize that leukocyte outside-in integrin signaling mimics classical immunoreceptor signaling pathways. We will test this hypothesis is a series of genetic and biochemical experiments. Using retroviral-mediated fetal liver hematopoietic stem cell transduction, we will introduce a series of mutant versions of Syk and DAP-12 into syk-/- or DAP-12-/- FcRgamma-/- mice that will test whether ITAM-Syk interactions are required for integrin signaling in primary neutrophils and macrophages. We will also test whether beta2 integrins form a complex with ITAM-containing DAP-12 and Syk, using biochemical methods and FRET-based microscopy techniques. If Syk and DAP12/FcRgamma are critical in outside-in integrin signaling, then deficiency of these molecules should result in equivalent defects in inflammatory processes in vivo. We will test this using two disease models that are known to be integrin dependent. If our hypothesis that integrin outside-in signaling mimics immunoreceptor pathways by use of ITAM molecules is validated, this will significantly change the view of integrin function in neutrophil-dependent inflammation. Therapeutic targeting of the integrin outside-in signaling pathway may provide novel classes of anti-inflammatory drugs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI065495-05
Application #
7587974
Study Section
Cellular and Molecular Immunology - B (CMI)
Program Officer
Palker, Thomas J
Project Start
2005-07-01
Project End
2011-03-31
Budget Start
2009-04-01
Budget End
2011-03-31
Support Year
5
Fiscal Year
2009
Total Cost
$352,300
Indirect Cost
Name
University of California San Francisco
Department
Pathology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Clemens, Regina A; Chong, Joshua; Grimes, Derayvia et al. (2017) STIM1 and STIM2 cooperatively regulate mouse neutrophil store-operated calcium entry and cytokine production. Blood 130:1565-1577
Poh, Ashleigh R; Love, Christopher G; Masson, Frederick et al. (2017) Inhibition of Hematopoietic Cell Kinase Activity Suppresses Myeloid Cell-Mediated Colon Cancer Progression. Cancer Cell 31:563-575.e5
Abram, Clare L; Lowell, Clifford A (2017) Shp1 function in myeloid cells. J Leukoc Biol 102:657-675
Chen, Jun; Zhong, Ming-Chao; Guo, Huaijian et al. (2017) SLAMF7 is critical for phagocytosis of haematopoietic tumour cells via Mac-1 integrin. Nature 544:493-497
Sinha, Meenal; Lowell, Clifford A (2017) Efficiency and Specificity of Gene Deletion in Lung Epithelial Doxycycline-Inducible Cre Mice. Am J Respir Cell Mol Biol 57:248-257
Kerr, Sheena C; Fischer, Gregory J; Sinha, Meenal et al. (2016) FleA Expression in Aspergillus fumigatus Is Recognized by Fucosylated Structures on Mucins and Macrophages to Prevent Lung Infection. PLoS Pathog 12:e1005555
Proekt, Irina; Miller, Corey N; Jeanne, Marion et al. (2016) LYN- and AIRE-mediated tolerance checkpoint defects synergize to trigger organ-specific autoimmunity. J Clin Invest 126:3758-3771
Sinha, Meenal; Lowell, Clifford A (2016) Isolation of Highly Pure Primary Mouse Alveolar Epithelial Type II Cells by Flow Cytometric Cell Sorting. Bio Protoc 6:
Volmering, Stephanie; Block, Helena; Boras, Mark et al. (2016) The Neutrophil Btk Signalosome Regulates Integrin Activation during Sterile Inflammation. Immunity 44:73-87
Rosales, Carlos; Demaurex, Nicolas; Lowell, Clifford A et al. (2016) Neutrophils: Their Role in Innate and Adaptive Immunity. J Immunol Res 2016:1469780

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