Narrowband (312-nm) UV-B Suppresses Interferon γ and Interleukin (IL) 12 and Increases IL-4 Transcripts: Differential Regulation of Cytokines at the Single-Cell Level

Abstract

Objective To determine whether 312-nm UV-B alters production of effector and regulatory cytokines by viable T cells that remain in psoriatic lesions during UV-B phototherapy. Design Prospective study. Setting General clinical research center of The Rockefeller University Hospital. Patients Ten adult patients with moderate to severe psoriasis vulgaris that was difficult to manage were sequentially enrolled in our protocols, and biopsies were taken at various time points from resolving lesions. Intervention Narrowband (312-nm) UV-B was given starting at 50% of a minimum erythema dose, then increased daily 10% to 15% if no apparent erythema was induced. Patients continued with treatment until maximal benefit was noted. In some experiments, T cells were irradiated ex vivo with standard TL-01 fluorescent bulbs (Philips Lighting Co, Somerset, NJ). Main outcome measures Intracellular cytokine staining was done using flow cytometry to quantify numbers of cytokine-producing cells from epidermal and peripheral T cells. The production of messenger RNA for interleukin (IL) 12, interferon (IFN) gamma, tumor necrosis factor alpha, IL-4, and IL-10 was measured by quantitative reverse transcription-polymerase chain reaction. Results Ultraviolet-B treatment eliminated production of IL-12 messenger RNA and decreased production of IFN-gamma messenger RNA by more than 60% in irradiated psoriasis lesions (P Conclusions Therapeutic UV-B suppresses the type 1 (proinflammatory) axis as defined by IL…