Dr. Zhu has the long-term goal of pursuing independent investigation in the field of allergic diseases. Receipt of a Mentored Clinical Scientist Development Award will facilitate the growth of Dr. Zhu's investigative skills by expanding his knowledge of molecular techniques, as outlined in the proposed studies. The learning objectives set out in this proposal, combined with the support of his Mentors, Drs. Alan R. Left and Kimm J. Hamann, and the critical environment within the Section of Pulmonary and Critical Care Medicine, and Ben May Institute for Cancer Research at the University of Chicago, will foster Dr. Zhu's progression to independent lines of investigation into the mechanisms of asthma. The central hypothesis of this proposal is that adhesion of eosinophils mediated by Beta2-integrin is regulated by cytosolic phospholipase A 2 (cPLA2) activation that is initiated by 1) Ras and 2) phosphoinositide 3 kinase (PI3K) induced extracellular signal-regulated kinase (ERK) activation. Three immediate goals are defined: (1) Determine the role of Ras in eosinophil adhesion. To test the hypothesis that Ras activation is required for eosinophil adhesion, we will determine the effects of Ras inhibition on IL-5 or eotaxin- stimulated eosinophil adhesion and CD1 lb avidity change, using pharmacological inhibitors and a dominant negative TAT-Ras fusion protein. Transfection of constitutively active Ras into eosinophilic AML14.3D10 cells also will be used to test whether Ras activation is sufficient for adhesion. (2) Determine the role of MAPK isoform activation in eosinophil adhesion. To test the hypothesis that Ras-mediated activation of ERK is essential for eosinophil adhesion, we will determine the effects of MAPK isoform inhibition on eosinophil adhesion using selective MAPK pathway inhibitors and dominant negative and active mutants of MEK1. Using dominant negative Ras and ERK pathway inhibitors, the causal relationship between Ras, ERK and cPLA 2 activation will be elucidated. (3) Determine the role of PI3K activation in eosinophil adhesion. To test the hypothesis that PI3K is required for eosinophil adhesion, we will determine the effects of PI3K inhibition on IL-5 or eotaxin- stimulated eosinophil adhesion and ERK phosphorylation using pharmacological inhibitors and a dominant negative TAT-PI3K fusion protein. Transfection of active PI3K into AML14.3D10 cells will be used to test whether PI3K activation is sufficient for adhesion. Knowledge of the signaling components required for eosinophil adhesion may provide insight into the pathogenesis of airway inflammation and lead to therapeutic interventions for human asthma.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08AI052109-02
Application #
6607023
Study Section
Allergy & Clinical Immunology-1 (AITC)
Program Officer
Prograis, Lawrence J
Project Start
2002-07-01
Project End
2007-03-31
Budget Start
2003-04-01
Budget End
2004-03-31
Support Year
2
Fiscal Year
2003
Total Cost
$77,090
Indirect Cost
Name
University of Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637
Gao, Xiao-Pei; Zhu, Xiangdong; Fu, Jian et al. (2007) Blockade of class IA phosphoinositide 3-kinase in neutrophils prevents NADPH oxidase activation- and adhesion-dependent inflammation. J Biol Chem 282:6116-25
Zhu, Xiangdong; Learoyd, Jonathan; Butt, Sanober et al. (2007) Regulation of eosinophil adhesion by lysophosphatidylcholine via a non-store-operated Ca2+ channel. Am J Respir Cell Mol Biol 36:585-93
Meliton, A Y; Munoz, N M; Lambertino, A et al. (2006) Phosphodiesterase 4 inhibition of beta2-integrin adhesion caused by leukotriene B4 and TNF-alpha in human neutrophils. Eur Respir J 28:920-8
Sano, Masaaki; Leff, Alan R; Myou, Shigeharu et al. (2005) Regulation of interleukin-5-induced beta2-integrin adhesion of human eosinophils by phosphoinositide 3-kinase. Am J Respir Cell Mol Biol 33:65-70
Liu, Jie; Zhu, Xiangdong; Myo, Saori et al. (2005) Glucocorticoid-induced surface expression of annexin 1 blocks beta2-integrin adhesion of human eosinophils to intercellular adhesion molecule 1 surrogate protein. J Allergy Clin Immunol 115:493-500
Myo, S; Zhu, X; Myou, S et al. (2004) Additive blockade of beta 2-integrin adhesion of eosinophils by salmeterol and fluticasone propionate. Eur Respir J 23:511-7
Myou, Shigeharu; Zhu, Xiangdong; Myo, Saori et al. (2003) Blockade of airway inflammation and hyperresponsiveness by HIV-TAT-dominant negative Ras. J Immunol 171:4379-84
Myou, Shigeharu; Leff, Alan R; Myo, Saori et al. (2003) Blockade of inflammation and airway hyperresponsiveness in immune-sensitized mice by dominant-negative phosphoinositide 3-kinase-TAT. J Exp Med 198:1573-82
Myou, Shigeharu; Leff, Alan R; Myo, Saori et al. (2003) Activation of group IV cytosolic phospholipase A2 in human eosinophils by phosphoinositide 3-kinase through a mitogen-activated protein kinase-independent pathway. J Immunol 171:4399-405
Zhu, Xiangdong; Lambertino, Anissa T; Houghton, Tom J et al. (2003) Structural determinants of blockade of eosinophil activation, adhesion and secretion by synthetic analogs of phomactin. Life Sci 73:3005-16