title: The effects of light-emitting diode irradiation at 610 nm and 710 nm on murine T-cell subset populations.
abstract: OBJECTIVE
  The aim of this study was to investigate the effects of light-emitting diode (LED) irradiation (radiant power, 0.047 mW; irradiation area, 1.13 cm(2)) at 610 nm and 710 nm on T-lymphocyte subset populations and cytokine expression using an in vivo rat model.
  
  
  BACKGROUND
  The proliferation of CD4+ T lymphocytes was induced by polychromatic visible polarized light at the range of 540-780 nm in a previous study, but the specific target wavelength for this effect has not yet been identified.
  
  
  METHODS
  Before and after 4 weeks of LED phototherapy, whole blood samples were collected from 610 nm, 710 nm, and control groups. The percentages of CD4+ and CD8+ T lymphocyte populations were determined by flow cytometry. The transcript levels of representative cytokines of CD4+ T-cell (interleukin [IL]-4, interferon [IFN]gamma) and proinflammatory cytokines (IL-1beta, IL-6) were assessed with the reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  The population of CD4+ T cells increased significantly in 710 nm group on day 28 (p < 0.05), but it did not increase in the 610 nm or control group. The population of CD8+ T cells did not show any significant change after irradiation in all groups. The mRNA expression of IL-4 increased in both the 610 nm and 710 nm groups compared to the control group, but IFNgamma was not detected in any group. The transcripts of IL-1beta and IL-6 were slightly induced in the 710 nm group.
  
  
  CONCLUSIONS
  The in vivo irradiation of 710 nm wavelength LED significantly increases the population of murine CD4+ T cells, which suggests that this new phototherapeutic regimen might be promising for CD4+ T lymphocyte-mediated immune modulation therapy.
authors.affiliation: Department of Rehabilitation Medicine, Konkuk University Medical Center, Seoul, South Korea.
authors.forename: Jeong H
authors.initials: JH
authors.lastname: Lim
authors.forename: Jongmin
authors.initials: J
authors.lastname: Lee
authors.forename: Jida
authors.initials: J
authors.lastname: Choi
authors.forename: Jaewoo
authors.initials: J
authors.lastname: Hong
authors.forename: Hyunjhung
authors.initials: H
authors.lastname: Jhun
authors.forename: Jinsoo
authors.initials: J
authors.lastname: Han
authors.forename: Soohyun
authors.initials: S
authors.lastname: Kim
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000528:radiation effects*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism / Q000528:radiation effects*; D016207:Cytokines / Q000096:biosynthesis*; D005434:Flow Cytometry; D008297:Male; D023421:Models, Animal; D010789:Phototherapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D016176:T-Lymphocyte Subsets / Q000378:metabolism / Q000528:radiation effects
chemical_list: D016207:Cytokines