Repeated gamma irradiation attenuates collagen-induced arthritis via up-regulation of regulatory T cells but not by damaging lymphocytes directly

Hiroko Nakatsukasa, Mitsutoshi Tsukimoto, Akihiro Tokunaga, Shuji Kojima

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31 Citations (Scopus)


We recently reported that repeated 0.5-Gy irradiation attenuates the pathology of collagen-induced arthritis. In this study, to investigate the mechanism further, we focused on changes in Treg/Th17 cells and changes in the production of antibody against an external antigen in response to irradiation as well as on the radiosensitivity of Treg cells. DBA/1J mice were immunized with type II collagen to induce arthritis and exposed to low-dose rays (0.5 Gy/week for 5 weeks). Production of IL6 and IL17 as well as autoantibody was suppressed by irradiation in the early phase of collagen-induced arthritis. The percentage of Treg cells was significantly increased by irradiation at 4, 6 and 8 weeks after the immunization. We also investigated the effect of repeated radiation on the production of antibodies against an external antigen in ovalbumin-immunized BALB/c mice. We found that repeated 0.5-Gy irradiation enhanced antibody production, accompanied by an increase of the antibody-producing plasma cell population and increased Th2-type cytokine secretion. We also found that the radiosensitivity of Treg cells did not differ from that of other T cells. These results suggest that a major mechanism of attenuation of the pathology of collagen-induced arthritis by repeated 0.5-Gy irradiation is up-regulation of Treg cells concomitantly with suppression of IL6 and IL17 production.

Original languageEnglish
Pages (from-to)313-324
Number of pages12
JournalRadiation Research
Issue number3
Publication statusPublished - 2010 Jan 1
Externally publishedYes


ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Biophysics
  • Radiation
  • Medicine(all)

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