title: Topical application of a novel immunomodulatory peptide, RDP58, reduces skin inflammation in the phorbol ester-induced dermatitis model.
abstract: RDP58 is the first lead compound in a series of immunomodulating decapeptides discovered through activity-based screening and computer-aided, rational design. RDP58 disrupts cellular responses signaled through the Toll-like and tumor necrosis factor (TNF) receptor families and occludes important signal transduction pathways involved in inflammation, inhibiting the production of tumor necrosis factor alpha (TNFalpha), interferon-gamma, interleukin (IL)-2, IL-6, and IL-12. These pro-inflammatory cytokines are thought to be involved in the pathogenesis of several inflammatory and autoimmune diseases, including atopic dermatitis and psoriasis. The goal of this study was to determine the ability of RDP58 to inhibit skin inflammation following exposure to the well-characterized protein kinase C activator and tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Topical application of RDP58 to the epidermis following TPA treatment resulted in the amelioration of the phorbol ester-induced irritant contact dermatitis. Substantial reductions were observed in skin thickness and tissue weight, neutrophil-mediated myeloperoxidase activity, inflammatory cytokine production, and various histopathological indicators. We also found RDP58 to be effective in reducing the compounding inflammatory damage brought on by chronic TPA exposure, and that it is capable of targeting inflammatory mediators specifically in the keratinocyte. These results demonstrate that topically applied RDP58 is an effective anti-inflammatory treatment in the phorbol ester-induced dermatitis model, and suggest that it may have therapeutic potential in a variety of immune-related cutaneous diseases.
authors.affiliation: Department Discovery Research, Sangstat Medical Corporation, Fremont, California 94080, USA. devry@corgentech.com
authors.forename: Christopher G
authors.initials: CG
authors.lastname: De Vry
authors.forename: Marybeth
authors.initials: M
authors.lastname: Valdez
authors.forename: Mirella
authors.initials: M
authors.lastname: Lazarov
authors.forename: Evelyn
authors.initials: E
authors.lastname: Muhr
authors.forename: Roland
authors.initials: R
authors.lastname: Buelow
authors.forename: Timothy
authors.initials: T
authors.lastname: Fong
authors.forename: Suhasini
authors.initials: S
authors.lastname: Iyer
mesh_terms: D000287:Administration, Topical; D000818:Animals; D016207:Cytokines / Q000378:metabolism; D017453:Dermatitis, Irritant / Q000188:drug therapy* / Q000473:pathology; D007155:Immunologic Factors / Q000008:administration & dosage / Q000627:therapeutic use*; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D010455:Peptides / Q000008:administration & dosage / Q000627:therapeutic use*; D009195:Peroxidase / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D018836:Inflammation Mediators; D010455:Peptides; C092373:allotrap; D009195:Peroxidase; D013755:Tetradecanoylphorbol Acetate