Skin inflammation involves local production of cytokines, which mediate recruitment of leucocytes and altered gene expression and cellular phenotypes of keratinocytes and other cells residing in the skin. lnterleukin-1 (IL-1) is an important mediator of local and systemic inflammation. IL-1 acts via a receptor complex involving the IL-1 receptor type I (IL-1RI) and membrane bound IL-1 receptor accessory protein (mlL-1 RAcP). A soluble isoform of IL-1 RAcP (slL-1 RAcP) appears to be an inhibitor of IL-1 signaling. The Principal Investigator has identified a novel soluble isoform of IL-1 RAcP, slL-1RAcP-(3, which has a unique C-terminus. Recently discovered cytokines, related to IL-1, appear to have activities similar to IL-1, but act via a different membrane receptor, IL-1 receptor related protein 2 (IL-1Rrp2). IL-1Rrp2 is primarily expressed in epithelial tissues, and preliminary data suggests that different IL-1 family members orchestrate distinct immune responses by inducing distinct cytokine expression profiles in primary human keratinocytes. Interestingly, IL-1 Rrp2 also utilizes mlL-1 RAcP for intracellular signaling. The primary hypothesis is that the two different isoforms of soluble IL-1 RAcP, slL-1 RAcP and slL-1 RAcP-|3, may inhibit the activities of all IL-1 family members or a sub-set of these. Furthermore, proportional expression of the three different isoforms of IL-1 RAcP may determine cellular responses to inflammatory stimuli. Since IL-1Rrp2 is primarily expressed in epithelial cells the involved mechanism may play a significant role in skin homeostasis and inflammation. ecombinant soluble IL-1 RAcP proteins will be expressed and purified. Human keratinocytes will be treated with agonist IL-1 family members and activation of gene expression will be examined using quantitative reverse transcription PCR and ELISA assays. Activities of the two soluble IL-1 RAcP isoforms will be examined in co-treatment experiments with individual cytokines. Expression of the three different IL-1 RacP isoforms and the IL-1 family members in keratinocytes will be determined following treatments with known modulators of IL-1 RAcP proportional expression and members of the IL-1 family. This project will provide novel information about the function(s) of the novel IL-1 related cytokines and the two soluble IL-1 RacP isoforms. The ultimate goals are to elucidate molecular mechanisms regulating inflammation, identify defective pathways in diseases and utilize this knowledge to develop novel anti-inflammatory therapies. of this work would greatly benefit arthritic and musculoskeletal therapeutic areas.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Small Research Grants (R03)
Project #
5R03AR053672-03
Application #
7663131
Study Section
Special Emphasis Panel (ZAR1-EHB-M (O1))
Program Officer
Cibotti, Ricardo
Project Start
2007-09-01
Project End
2010-06-30
Budget Start
2009-09-01
Budget End
2010-06-30
Support Year
3
Fiscal Year
2009
Total Cost
$57,146
Indirect Cost
Name
University of Pennsylvania
Department
Pharmacology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
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Uribe-Herranz, Mireia; Lian, Li-Hua; Hooper, Kirsten M et al. (2013) IL-1R1 signaling facilitates Munro's microabscess formation in psoriasiform imiquimod-induced skin inflammation. J Invest Dermatol 133:1541-9
Lian, Li-Hua; Milora, Katelynn A; Manupipatpong, Katherine K et al. (2012) The double-stranded RNA analogue polyinosinic-polycytidylic acid induces keratinocyte pyroptosis and release of IL-36?. J Invest Dermatol 132:1346-53
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