and specific aims): Eosinophils and their cationic granule proteins function as mediators of tissue damage and inflammation in asthma, allergic reactions, parasitic infections and other eosinophil-associated diseases. This application focuses on Charcot-Leyden crystal (CLC) protein, which forms distinctive hexagonal bipyramidal crystals observed in tissues and secretions, a hallmark of eosinophil participation in allergic and other inflammation. CLC is a lysophospholipase (LPLase); lysolecithin acylhydrolase), but the physiologic role remains a mystery. Quantitative considerations alone (CLC is approximately 10% of total eosinophil protein), but also its secretion during eosinophil activation, elevated levels in the blood of patients with eosinophilia, and increased levels of sputum and BAL fluids of patients with asthma, argue for its importance in eosinophil effector function. The overall goal of this project is to investigate the mechanisms by which eosinophils, through the LPLase or galectin activities of CLC protein, function in eosinophil-associated inflammation. Three specific questions are addressed with regard to CLC protein's structure-function relationships, mechanisms of catalytic activation, secretion and regulation, and potential pathophysiologic inflammatory activities in asthma: 1) What are the structure-function relationships for the LPLase activity of CLC protein and regulation of its expression? Based on the 3D structure of CLC protein, site-specific mutagenesis will be used to characterize the active site of the enzyme and elucidate the mechanisms regulating its activation and expressions by eosinophils; 2) What are the structure-function relationships for CLC protein's carbohydrate-binding (galectin) activities? Recombinant expression and site-specific mutagenesis will be used to characterize its carbohydrate recognition domain. We will identify physiologically relevant oligosaccharide or oligosaccharide-containing ligands and assess CLC's role in eosinophil adhesions; 3) What is the role of CLC protein in eosinophil effector function in asthma pathophysiology? Does this LPLase play a pro- or anti-inflammatory role, or alter surfactant function and airways architecture in asthma? This aim will analyze the effects of this LPLase on pulmonary surfactant function in vitro, CLC secretion and localization in the distal airways in asthmatic lung, relationships of CLC levels and LPLase activity in the lung with asthma severity, and the effects of LPLase administration in animal models of airways inflammation.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Lung Biology and Pathology Study Section (LBPA)
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University of Illinois at Chicago
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Kwatia, Mark A; Doyle, Christine B; Cho, Wonwha et al. (2007) Combined activities of secretory phospholipases and eosinophil lysophospholipases induce pulmonary surfactant dysfunction by phospholipid hydrolysis. J Allergy Clin Immunol 119:838-47
Wijewickrama, Gihani T; Kim, Jin-Hahn; Kim, Young Jun et al. (2006) Systematic evaluation of transcellular activities of secretory phospholipases A2. High activity of group V phospholipases A2 to induce eicosanoid biosynthesis in neighboring inflammatory cells. J Biol Chem 281:10935-44
Furuta, Glenn T; Nieuwenhuis, Edward E S; Karhausen, Jorn et al. (2005) Eosinophils alter colonic epithelial barrier function: role for major basic protein. Am J Physiol Gastrointest Liver Physiol 289:G890-7
Gomes, Ignatius; Mathur, Sameer K; Espenshade, Bruce M et al. (2005) Eosinophil-fibroblast interactions induce fibroblast IL-6 secretion and extracellular matrix gene expression: implications in fibrogenesis. J Allergy Clin Immunol 116:796-804
Lee, James J; Dimina, Dawn; Macias, MiMi P et al. (2004) Defining a link with asthma in mice congenitally deficient in eosinophils. Science 305:1773-6
Ackerman, Steven J; Kwatia, Mark A; Doyle, Christine B et al. (2003) Hydrolysis of surfactant phospholipids catalyzed by phospholipase A2 and eosinophil lysophospholipases causes surfactant dysfunction: a mechanism for small airway closure in asthma. Chest 123:355S
Ackerman, Steven J; Liu, Li; Kwatia, Mark A et al. (2002) Charcot-Leyden crystal protein (galectin-10) is not a dual function galectin with lysophospholipase activity but binds a lysophospholipase inhibitor in a novel structural fashion. J Biol Chem 277:14859-68
Swaminathan, G J; Weaver, A J; Loegering, D A et al. (2001) Crystal structure of the eosinophil major basic protein at 1.8 A. An atypical lectin with a paradigm shift in specificity. J Biol Chem 276:26197-203
Paul, C C; Aly, E; Lehman, J A et al. (2000) Human cell line that differentiates to all myeloid lineages and expresses neutrophil secondary granule genes. Exp Hematol 28:1373-80
Du, J; Alsayed, Y M; Xin, F et al. (2000) Engagement of the CrkL adapter in interleukin-5 signaling in eosinophils. J Biol Chem 275:33167-75

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