Platelet-activating Factor Does Not Mediate UVB-induced Local Immune Suppression

Authors

  • Ravi P. Sahu,

    1. Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN
    2. Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN
    Search for more papers by this author
    • These two authors contributed equally to this manuscript.

  • Yongxue Yao,

    1. Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN
    Search for more papers by this author
    • These two authors contributed equally to this manuscript.

  • Raymond L. Konger,

    1. Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN
    2. Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN
    Search for more papers by this author
  • Jeffrey B. Travers

    Corresponding author
    1. Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN
    2. Department of Pediatrics and the H.B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN
    3. Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN
    4. The Richard L. Roudebush V.A. Medical Center, Indiana University School of Medicine, Indianapolis, IN
    Search for more papers by this author

Corresponding author email: jtravers@iupui.edu (Jeffrey B. Travers)

Abstract

The lipid mediator Platelet-activating factor (PAF) and oxidized glycerophosphocholine PAF agonists produced by UVB have been demonstrated to play a pivotal role in UVB-mediated systemic immunosuppression. Importantly, employing the ability of distant UVB irradiation to inhibit contact hypersensitivity (CHS) responses to the chemical antigen dinitrofluorobenzene (DNFB) to an area of unirradiated murine skin, we and others have demonstrated that UVB-mediated systemic immunosuppression was only observed in PAF-R expressing wild type (WT) mice and not in PAF-R-knockout (Pafr−/−) mice. As it is not known if PAF is involved in UVB-mediated local immunosuppression, these studies compared local UVB on CHS responses in WT versus Pafr−/− mice. We demonstrate that the application of DNFB onto UVB-exposed (locally) area of mouse skin resulted in a similar significant inhibition of subsequent CHS responses in both WT and Pafr−/− mice compared to sham-irradiated control mice. Furthermore, the expression of langerin, a marker for the presence of Langerhans cells was substantially reduced equally in the epidermal ears of UVB-irradiated WT and Pafr−/− mice compared to their respective sham control groups. These findings indicate that the PAF-R is not involved UVB-induced local immunosuppression.

Ancillary