312-nanometer ultraviolet B light (narrow-band UVB) induces apoptosis of T cells within psoriatic lesions. Academic Article uri icon

Overview

abstract

  • Narrow-band (312 nm) ultraviolet B light (UVB) is a new form of therapy for psoriasis, but its mechanism of action is unknown. In a bilateral comparison clinical study, daily exposure of psoriatic plaques to broad-band UVB (290-320 nm) or 312-nm UVB depleted T cells from the epidermis and dermis of psoriatic lesions. However, 312-nm UVB was significantly more depleting in both tissue compartments. To characterize the mechanism of T cell depletion, assays for T cell apoptosis were performed on T cells derived from UVB-irradiated skin in vivo and on T cells irradiated in vitro with 312-nm UVB. Apoptosis was induced in T cells exposed to 50-100 mJ/cm2 of 312-nm UVB in vitro, as measured by increased binding of fluorescein isothiocyanate (FITC)-Annexin V to CD3(+) cells and by characteristic cell size/granularity changes measured by cytometry. In vivo exposure of psoriatic skin lesions to 312-nm UVB for 1-2 wk also induced apoptosis in T cells as assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) reaction in tissue sections, by binding of FITC-Annexin V to CD3(+) T cells contained in epidermal cell suspensions, and by detection of apoptosis-related size shifts of CD3(+) cells. Induction of T cell apoptosis could be the main mechanism by which 312-nm UVB resolves psoriasis skin lesions.

publication date

  • February 15, 1999

Research

keywords

  • Apoptosis
  • Psoriasis
  • Skin
  • Ultraviolet Therapy

Identity

PubMed Central ID

  • PMC2192929

Scopus Document Identifier

  • 0033557174

Digital Object Identifier (DOI)

  • 10.1084/jem.189.4.711

PubMed ID

  • 9989986

Additional Document Info

volume

  • 189

issue

  • 4