title: Space-relevant radiation modifies cytokine profiles, signaling proteins and Foxp3+ T cells.
abstract: OBJECTIVE
  The major goal was to evaluate effects of various radiation regimens on leukocyte populations relatively long-term after whole-body irradiation.
  
  
  METHODS
  C57BL/6 mice were exposed to-low-dose/low-dose rate (LDR) (57)Co γ-rays (0.01 Gy, 0.03 cGy/h), with and without acute 2 Gy proton (1 Gy/min) or γ-ray (0.9 Gy/min) irradiation; analyses were done on days 21 and 56 post-exposure.
  
  
  RESULTS
  Numerous radiation-induced changes were noted at one or both time points. Among the most striking differences (P < 0.05) were: (i) High percentage of CD4(+)CD25(+)Foxp3(+) T cells in spleens from the Proton vs. LDR, Gamma and LDR + Proton groups (day 56); (ii) high interleukin-2 (IL-2) in spleen supernatants from the LDR and LDR + Proton groups vs. 0 Gy (day 56), whereas IL-10 was high in the LDR + Gamma group vs. 0 Gy (day 56); (iii) difference in transforming growth factor-β1 (TGF-β1) in spleen supernatants from Proton and LDR + Proton groups vs. Gamma and LDR + Gamma groups (both days); (iv) low TGF-β1 in blood from LDR + Proton vs. LDR + Gamma group (day 21); and (v) high level of activated cJun N-terminal kinase (JNK) in CD4(+) T cells from LDR + Proton vs. LDR + Gamma group (day 21).
  
  
  CONCLUSIONS
  The findings demonstrate that at least some immune responses to acute 2 Gy radiation were dependent on radiation quality time of assessment, and pre-exposure to LDR γ-rays.
authors.affiliation: Department of Radiation Medicine, Radiation Research Laboratories, Loma Linda University and Medical Center, Loma Linda, CA, USA. dgridley@dominion.llumc.edu
authors.forename: Daila S
authors.initials: DS
authors.lastname: Gridley
authors.forename: Asma
authors.initials: A
authors.lastname: Rizvi
authors.forename: Adeola Y
authors.initials: AY
authors.lastname: Makinde
authors.forename: Xian
authors.initials: X
authors.lastname: Luo-Owen
authors.forename: Xiao Wen
authors.initials: XW
authors.lastname: Mao
authors.forename: Jian
authors.initials: J
authors.lastname: Tian
authors.forename: Jason M
authors.initials: JM
authors.lastname: Slater
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Pecaut
mesh_terms: D000818:Animals; D001835:Body Weight / Q000528:radiation effects; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism*; D005118:Extraterrestrial Environment; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D007962:Leukocytes / Q000166:cytology / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D015398:Signal Transduction / Q000528:radiation effects; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D053773:Transforming Growth Factor beta1 / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000097:blood; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D016207:Cytokines; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases