title: [Simulated weightlessness inhibits  antitumor immunity of T lymphocytes in melanoma-bearing   mice].
abstract: OBJECTIVE
  To investigate the effects of simulated weightlessness on antitumor immunity of T lymphocytes in mice.
  
  
  METHODS
  The malignant melanoma was xenografted by subcutaneous injection of B16 cells into the right hind limb of every mouse. The mice suspended by tail at a -15 degree to 20 degree head-down tilt were used as simulated weightlessness models. The effects of simulated weightlessness on tumor volume and survival time were observed. T the numbers of leucocytes, lymphocytes and T lymphocyte subsets in peripheral blood of tumor-bearing mice under simulated weightlessness were monitored by an automatic hemacytometer and a flow cytometer. The effects of simulated weightlessness on the production of IL-2, TNF-α and IFN-γ in T lymphocytes and the cytotoxicities of tumor-specific CTLs to tumor cells were analyzed by ELISA and LDH release.
  
  
  RESULTS
  Compared with control group, the tumors grew faster, the survival times were shorter, the number of lymphocytes, the ratio of lymphocytes, CD3(+);, CD4(+);/CD3(+); and CD8(+);/CD3(+); T lymphocytes in peripheral blood dropped, and the proliferation of splenic T lymphocytes induced by mitogen was reduced (P<0.05 or P<0.01) in the simulated weightlessness group. The production of IL-2, TNF-α and IFN-γ induced by tumor cells and cytotoxicities of tumor-specific CTLs to tumor cells were inhibited in mice under simulated weightlessness (P<0.05 or P<0.01).
  
  
  CONCLUSIONS
  Simulated weightlessness inhibits antitumor immunity of T lymphocytes.
authors: Department of Pathology and Experimental Medicine, 306th Hospital of PLA, Beijing 100101, China. sishy306@sohu.com
authors: Shaoyan
authors: S
authors: Si
authors: Shujun
authors: S
authors: Song
authors: Liang
authors: L
authors: Shi
authors: Junli
authors: J
authors: Liu
authors: Bingxin
authors: B
authors: Xu
authors: Yong
authors: Y
authors: Yi
authors: Xiaoqing
authors: X
authors: Tan
authors: Jianzhong
authors: J
authors: Zhang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000276:immunology* / Q000494:pharmacology; D001835:Body Weight / Q000187:drug effects / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008546:Melanoma, Experimental / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology; D018474:Weightlessness Simulation
chemical_list: D000970:Antineoplastic Agents; D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D007770:L-Lactate Dehydrogenase