Natural killer (NK) cells are lymphocytes that serve important functions in defense against disease and maintenance of health. Several characteristics of NK cells make them an excellent model to pursue studies in intracellular signaling and cytoskeletal biology and their relation to immune function. These include a well characterized set of inhibitory receptors that downregulate cell activities through phosphatase activity and specific activating receptor-induced kinase pathways having notable distinctions from those in other lymphocytes. The candidate presents preliminary data suggesting that cytoskeletal regulatory processes are important to NK cell function. Studies of patients with Wiskott-Aldrich syndrome (WAS) having a mutation in the gene encoding the WAS protein (WASp) have proven particularly useful in this regard. WASp, which promotes the branching of actin networks, was found to accumulate with filamentous actin at NK cell activating immunologic synapses and intact WASp function was required for actin rearrangement and NK cell function. It is likely that the deficits found in NK cells of patients with WAS contribute to their clinical presentation. The studies proposed in this application will test the hypothesis that the regulation of cytoskeletal activation in NK cells is a critical process for the induction and inhibition of NK cell function. In particular, the investigator proposes: 1) certain key intracellular signaling events link activating receptor ligation to cytoskeletal activation and function in NK cells; 2) there is a critical interrelationship between the actin cytoskeleton and microtubular network in NK cells; and 3) the cytoskeleton is a target of NK cell inhibitory receptor-mediated inhibition of NK cell function. These studies hold the potential to uncover novel pathways of cytoskeletal regulation and address the interdependence of cytoskeletal events leading to immune cell function. The candidate has an extensive background in mouse cellular immunology and in vivo immune responses. By undertaking this project he will develop skills in biochemistry and become proficient in the investigation of intracellular signaling. Furthermore the candidate will greatly expand his molecular biology capabilities and continue to gain proficiency in human cellular immunology. The applicant will be mentored in these efforts by Dr. Raif Geha, an authority on immunodeficiency as well as the cytoskeleton as it relates to immune function, and Dr. Jack Strominger an expert in natural killer cell biology and biochemistry. Ultimately, the candidate plans to use his position as a pediatric immunologist to better understand NK cell function and the role NK cells play in maintenance of human health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Clinical Investigator Award (CIA) (K08)
Project #
7K08AI055602-02
Application #
6831105
Study Section
Allergy & Clinical Immunology-1 (AITC)
Program Officer
Prograis, Lawrence J
Project Start
2003-06-01
Project End
2007-05-31
Budget Start
2003-10-01
Budget End
2004-05-31
Support Year
2
Fiscal Year
2003
Total Cost
$81,108
Indirect Cost
Name
Children's Hospital of Philadelphia
Department
Type
DUNS #
073757627
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Orange, Jordan S (2007) The lytic NK cell immunological synapse and sequential steps in its formation. Adv Exp Med Biol 601:225-33
Andzelm, Milena M; Chen, Xi; Krzewski, Konrad et al. (2007) Myosin IIA is required for cytolytic granule exocytosis in human NK cells. J Exp Med 204:2285-91
Banerjee, Pinaki P; Pandey, Rahul; Zheng, Rena et al. (2007) Cdc42-interacting protein-4 functionally links actin and microtubule networks at the cytolytic NK cell immunological synapse. J Exp Med 204:2305-20
Krzewski, Konrad; Chen, Xi; Orange, Jordan S et al. (2006) Formation of a WIP-, WASp-, actin-, and myosin IIA-containing multiprotein complex in activated NK cells and its alteration by KIR inhibitory signaling. J Cell Biol 173:121-32
Orange, Jordan S (2006) Human natural killer cell deficiencies. Curr Opin Allergy Clin Immunol 6:399-409
Orange, Jordan S; Ballas, Zuhair K (2006) Natural killer cells in human health and disease. Clin Immunol 118:1-10
Orange, Jordan S; Levy, Ofer; Geha, Raif S (2005) Human disease resulting from gene mutations that interfere with appropriate nuclear factor-kappaB activation. Immunol Rev 203:21-37
Li, Yuan; Zhang, Ting; Ho, Chun et al. (2004) Natural killer cells inhibit hepatitis C virus expression. J Leukoc Biol 76:1171-9
Orange, Jordan S; Jain, Ashish; Ballas, Zuhair K et al. (2004) The presentation and natural history of immunodeficiency caused by nuclear factor kappaB essential modulator mutation. J Allergy Clin Immunol 113:725-33
Orange, Jordan S; Levy, Ofer; Brodeur, Scott R et al. (2004) Human nuclear factor kappa B essential modulator mutation can result in immunodeficiency without ectodermal dysplasia. J Allergy Clin Immunol 114:650-6

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