title: Irradiation of light emitting diode at 850nm inhibits T cell-induced cytokine expression.
abstract: BACKGROUND
  An anti-inflammatory effect of light obtained from light-emitting diodes (LEDs) has been discovered, however, limited ranges of wavelengths have been used and the action mechanism has been rarely demonstrated.
  
  
  OBJECTIVE
  We sought to analyze the immunomodulatory effect of LED on Jurkat T cells and human T cells.
  
  
  METHODS
  Jurkat T cells with/without stimulation were irradiated once or five times using seven ranges of LED wavelengths, from 415nm to 940nm. Cytotoxic effects were examined by an MTT assay. Changes in T cell-induced cytokines, including IL-2, IL-4, IL-10, IL-12 and IFN-gamma, and their upstream signaling molecules, ZAP-70 and PKCθ, were examined by real-time PCR, ELISA, and Western blot analysis. The effect of the LED wavelength, whose effect was identified on Jurkat T cells, was also examined in human CD3+ T cells with/without stimulation and in Dermatophagoides farinae-induced atopic dermatitis (AD) NC/Nga mice.
  
  
  RESULTS
  Lower doses of LED irradiation at 850nm inhibited T cell-derived cytokines without inducing cell death in both Jurkat T cells and human T cells. Repeated exposure resulted in a greater increase of inhibitory effects than that observed with a single exposure, and these effects were identified in the NC/Nga AD model.
  
  
  CONCLUSIONS
  Although more remains to be clarified, these results may support the clinical application of LED for immune regulation.
authors: Department of Dermatology, Dongguk University Ilsan Hospital, 814 Siksa-dong, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-773, South Korea.
authors: Kyung Ah
authors: KA
authors: Cheong
authors: Chang-Hyun
authors: CH
authors: Kim
authors: Yunseok
authors: Y
authors: Choi
authors: Chan Do
authors: CD
authors: Park
authors: Ai-Young
authors: AY
authors: Lee
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D015153:Blotting, Western / Q000379:methods; D017252:CD3 Complex / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis*; D003876:Dermatitis, Atopic / Q000378:metabolism; D040001:Dermatophagoides farinae / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D019169:Jurkat Cells; D008027:Light; D051379:Mice; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D013601:T-Lymphocytes / Q000166:cytology* / Q000528:radiation effects; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D017252:CD3 Complex; D016207:Cytokines