Polymorphonuclear cells (PMN, neutrophilis ) are primary generators and effectors of inflammation. Inhibition of their migration, activation, or effector mechanisms can be used to control inflammatory diseases. We have defined a PMN activation pathway that is involved in PMN migration into inflamed tissue and their activation once there. The experiments proposed here aim at understanding the mechanism of action of this activation pathway, with regulating inflammation through its inhibition as an ultimate goal. We present background information and preliminary data showing that the extracellular domain of Integrin- Associated Protein (IAP/CD47) is the primary integrator of this activation pathway, constituting an extracellular and specific target for potential intervention. We propose biochemical and genetical experiments that will define how the IAP extracellular domain interacts with its ligands: the alphavbeta3 integrin and thrombospondin. Our cell biological experiments will correlate this information with PMN migration, transendothelial migration, and activation, resulting in an understanding of the mechanism of IAP action, concrete information on how to inhibit it, and information on the result of such inhibition. Specifically, we will in specific aim 1 use surface plasmon resonance to analyze binding of the mutant of the IAP extracellular domain to thrombospondin and the alphavbeta3 integrin. We will then determine the effect of IAP and thrombospondin binding on integrin function.
In specific aim 2 we will use IAP-deficient cells, control cells, and mutant transfectants to investigate the function of IAP in systems of vitronectin particle binding, PMN migration, and transendothelial migration.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM057573-02
Application #
2910427
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1998-05-01
Project End
2003-04-30
Budget Start
1999-05-01
Budget End
2000-04-30
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
George Washington University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Washington
State
DC
Country
United States
Zip Code
20052
Isenberg, Jeff S; Qin, Yan; Maxhimer, Justin B et al. (2009) Thrombospondin-1 and CD47 regulate blood pressure and cardiac responses to vasoactive stress. Matrix Biol 28:110-9
Isenberg, Jeff S; Roberts, David D; Frazier, William A (2008) CD47: a new target in cardiovascular therapy. Arterioscler Thromb Vasc Biol 28:615-21
Isenberg, Jeff S; Romeo, Martin J; Maxhimer, Justin B et al. (2008) Gene silencing of CD47 and antibody ligation of thrombospondin-1 enhance ischemic tissue survival in a porcine model: implications for human disease. Ann Surg 247:860-8
Wang, Hui; Madariaga, Maria Lucia; Wang, Shumei et al. (2007) Lack of CD47 on nonhematopoietic cells induces split macrophage tolerance to CD47null cells. Proc Natl Acad Sci U S A 104:13744-9
Blazar, B R; Lindberg, F P; Ingulli, E et al. (2001) CD47 (integrin-associated protein) engagement of dendritic cell and macrophage counterreceptors is required to prevent the clearance of donor lymphohematopoietic cells. J Exp Med 194:541-9
Capo, C; Lindberg, F P; Meconi, S et al. (1999) Subversion of monocyte functions by coxiella burnetii: impairment of the cross-talk between alphavbeta3 integrin and CR3. J Immunol 163:6078-85
Pettersen, R D; Hestdal, K; Olafsen, M K et al. (1999) CD47 signals T cell death. J Immunol 162:7031-40