[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to estimate the acute effects of low dose 12C6+ ions or X-ray radiation on human immune function. The human peripheral blood lymphocytes (HPBL) of seven healthy donors were exposed to 0.05 Gy 12C6+ ions or X-ray radiation and cell responses were measured at 24 h after exposure. The cytotoxic activities of HPBL were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT); the percentages of T and NK cells subsets were detected by flow cytometry; mRNA expression of interleukin (IL)-2, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were examined by real time quantitative RT-PCR (qRT-PCR); and these cytokines protein levels in supernatant of cultured cells were assayed by enzyme-linked immunosorbent assays (ELISA). The results showed that the cytotoxic activity of HPBL, mRNA expression of IL-2, IFN-γ and TNF-α in HPBL and their protein levels in supernatant were significantly increased at 24 h after exposure to 0.05 Gy 12C6+ ions radiation and the effects were stronger than observed for X-ray exposure. However, there was no significant change in the percentage of T and NK cells subsets of HPBL. These results suggested that 0.05 Gy high linear energy transfer (LET) 12C6+ radiation was a more effective approach to host immune enhancement than that of low LET X-ray. We conclude that cytokines production might be used as sensitive indicators of acute response to LDI.
Advances in Space Research 04/2010; 45(7-45):832-838. DOI:10.1016/j.asr.2009.09.024 · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to examine the early effects of low dose (12)C(6+) irradiation or X-ray on peripheral blood lymphocytes (PBL) of patients with alimentary tract cancer and to explore mechanisms that may be involved in an antitumor immune response. We found that the percentage of T lymphocyte subsets, the mRNA expression levels of IL-2 and IFN-γ in PBL, and their protein levels in supernatant were significantly increased 24 hours after exposure to low dose radiation. The effects were more pronounced in the group receiving 0.05Gy (12)C(6+) ion irradiation than the group receiving X-ray irradiation. There was no significant change in the percentage of NK cell subsets and TNF-α production of PBL. Our study suggests that low dose irradiation could alleviate immune suppression caused by tumor burden and that the effect was more pronounced for 0.05Gy high linear energy transfer (LET) (12)C(6+) irradiation.