Asthma is characterized by eosinophilic inflammation of the airways. Interleukin-5 (IL-5) is one of the most important regulators of eosinophil differentiation and function. IL-5 activates eosinophils by stimulating a number of tyrosine kinases. However, which tyrosine kinase plays an essential role in transducing IL-5-specific signals is unknown. Based upon preliminary results we hypothesize that Lyn kinase plays an essential and non-redundant role in IL-5 -stimulated eosinophil differentiation and in the development of airway eosinophilic inflammation. In the first specific aim we will examine the physical association of Lyn with IL-5 receptor alpha subunit (IL-5Ra) and study its ability to phosphorylate the receptor. The biological relevance of Lyn for eosinophil differentiation from stem cells will be examined using Lyn knockout mice. Further, we will examine the effect of Lyn null mutation on the development of airway allergic inflammation using an ovalbumin-sensitized mouse model of asthma. The second specific aim is devoted to delineating the molecular mechanism of activation of Lyn kinase by IL-5Ra. In order to identify IL-5Ra-associated molecules that might activate Lyn kinase, we have performed yeast two-hybrid screening of a human cDNA library and cloned a novel SH2/SH3 ligand--IRIP (ImmunoReceptor-Interactive Protein). We hypothesize that IRIP activates Lyn kinase by interacting through its SH3 domain. To test the foregoing hypothesis we will map the binding sites of IRJP and Lyn kinase using recombinant Lyn domains and site directed mutagenesis. The importance of IRIP SH2/SH3 motifs for Lyn activation will be examined using motif peptides and site directed mutagenesis. Finally, the relevance of IRIP for eosinophil differentiation will be studied by overexpressing wild type and dominant negative mutants of IRIP in murine stem cells and HL-60 cells and by examining their differentiation into eosinophils. The proposed studies are designed to identify key IL-5-specific signaling molecules that are important for eosinophil differentiation and eosinophilic inflammation. The cloning and functional characterization of IRIP as a novel activator of Src-type tyrosine kinases will advance basic knowledge and will help understand the molecular mechanism of activation receptor-associated tyrosine kinases in general. Lyn and IRIP may represent excellent therapeutic targets for intervention in asthma and other allergic diseases.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Lung Biology and Pathology Study Section (LBPA)
Program Officer
Adams, Ken
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Texas Medical Br Galveston
Internal Medicine/Medicine
Schools of Medicine
United States
Zip Code
Goplen, Nicholas; Gorska, Magdalena M; Stafford, Susan J et al. (2008) A phosphosite screen identifies autocrine TGF-beta-driven activation of protein kinase R as a survival-limiting factor for eosinophils. J Immunol 180:4256-64
Gorska, Magdalena M; Liang, Qiaoling; Stafford, Susan J et al. (2007) MK2 controls the level of negative feedback in the NF-kappaB pathway and is essential for vascular permeability and airway inflammation. J Exp Med 204:1637-52
Vepachedu, Ramarao; Gorska, Magdalena M; Singhania, Neil et al. (2007) Unc119 regulates myofibroblast differentiation through the activation of Fyn and the p38 MAPK pathway. J Immunol 179:682-90
Gorska, Magdalena M; Cen, Osman; Liang, Qiaoling et al. (2006) Differential regulation of interleukin 5-stimulated signaling pathways by dynamin. J Biol Chem 281:14429-39
Gorska, Magdalena M; Stafford, Susan J; Cen, Osman et al. (2004) Unc119, a novel activator of Lck/Fyn, is essential for T cell activation. J Exp Med 199:369-79
Cen, Osman; Gorska, Magdalena M; Stafford, Susan J et al. (2003) Identification of UNC119 as a novel activator of SRC-type tyrosine kinases. J Biol Chem 278:8837-45
Adachi, Tetsuya; Stafford, Susan; Kayaba, Hiroyuki et al. (2003) Myosin light chain kinase mediates eosinophil chemotaxis in a mitogen-activated protein kinase-dependent manner. J Allergy Clin Immunol 111:113-6
Stafford, Susan; Lowell, Clifford; Sur, Sanjiv et al. (2002) Lyn tyrosine kinase is important for IL-5-stimulated eosinophil differentiation. J Immunol 168:1978-83
Beebe, A M; Dua, N; Faith, T G et al. (1994) Primary stage of feline immunodeficiency virus infection: viral dissemination and cellular targets. J Virol 68:3080-91
Dua, N; Reubel, G; Moore, P F et al. (1994) An experimental study of primary feline immunodeficiency virus infection in cats and a historical comparison to acute simian and human immunodeficiency virus diseases. Vet Immunol Immunopathol 43:337-55

Showing the most recent 10 out of 12 publications