We recently reported the identification of a mechanism by which dendritic cells (DCs) influence T helper cells to mount allergic airway inflammation in the lung. The allergen house dust mite caused dual upregulation of c-kit and its ligand, stem cell factor (SCF), on DCs stimulating production of interleukin-6 (IL-6) and expression of the Notch ligand, Jagged-2, but downregulated IL-12 production. This, in turn, promoted Th2/Th17 development but inhibited Th1 differentiation. DCs lacking functional c-kit were unable to produce IL-6 or express Jagged-2. When adoptively transferred into mice, unlike their wild-type counterparts, DCs expressing mutant c-kit were unable to induce a robust Th2/Th17 response or allergic airway inflammation in the recipient mice. DCs generated from mice with defects in PI3 kinase secreted lower levels of IL-6 upon stimulation with a mucosal adjuvant. These findings collectively lead us to hypothesize that the c-kit/Jagged-2/IL-6 pathway in DCs plays an important role in the promotion of allergic airways disease by regulating cytokine (IL-6/IL-12) balance and expression of Jagged-2 that together influence the immune response to allergens. Disabling c-kit in DCs would help control asthma in response to particular allergens that promote this pathway. To address these hypotheses we will:
Aim I. Characterize the effect of common allergens on c-kit/Jagged-2/IL-6 expression in lung DCs and the consequence of blockade of c-kit function with a modified form of Gleevec.
Aim II. Generate transgenic mice inducibly expressing a dominant-negative mutant of c-kit in DCs to investigate effects on the asthma phenotype in response to the above allergens.

Public Health Relevance

The goal of this project is to understand the role of a cell surface molecule, c-kit, in promoting allergic immune response to various common allergens using murine models of allergic asthma.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21AI093116-01A1
Application #
7994621
Study Section
Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section (HAI)
Program Officer
Davidson, Wendy F
Project Start
2010-09-01
Project End
2012-08-31
Budget Start
2010-09-01
Budget End
2011-08-31
Support Year
1
Fiscal Year
2010
Total Cost
$227,250
Indirect Cost
Name
University of Pittsburgh
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Oriss, Timothy B; Krishnamoorthy, Nandini; Ray, Prabir et al. (2014) Dendritic cell c-kit signaling and adaptive immunity: implications for the upper airways. Curr Opin Allergy Clin Immunol 14:7-12
Oriss, Timothy B; Krishnamoorthy, Nandini; Raundhal, Mahesh et al. (2014) Cutting Edge: MMP-9 inhibits IL-23p19 expression in dendritic cells by targeting membrane stem cell factor affecting lung IL-17 response. J Immunol 192:5471-5475
Poe, S L; Arora, M; Oriss, T B et al. (2013) STAT1-regulated lung MDSC-like cells produce IL-10 and efferocytose apoptotic neutrophils with relevance in resolution of bacterial pneumonia. Mucosal Immunol 6:189-99
Krishnamoorthy, Nandini; Khare, Anupriya; Oriss, Timothy B et al. (2012) Early infection with respiratory syncytial virus impairs regulatory T cell function and increases susceptibility to allergic asthma. Nat Med 18:1525-30