title: Analysis of immune cell populations and cytokine profiles in murine splenocytes exposed to whole-body low-dose irradiation.
abstract: OBJECTIVE
  In contrast to high-dose therapeutic irradiation, definitive research detailing the physiological effects of low-dose irradiation is limited. Notably, the immunological response elicited after low-dose irradiation remains controversial.
  
  
  METHODS
  Female C57BL/6 mice were whole- body-irradiated with a single or three daily fractions up to a total dose of 0.1, 1, or 10 cGy. Blood and spleen were harvested 2, 7 and 14 days after irradiation.
  
  
  RESULTS
  The splenic CD4(+) T cell subpopulations were temporarily increased at 2 days after single or fractionated irradiation, whereas the percentage of dendritic cells (DC) and macrophages was decreased. Whereas CD8(+) T cell populations were decreased in single-dose irradiated mice at day 7, early and sustained reduction of CD8(+) T cell numbers was observed in fractionated- dose-irradiated mice from day 2 until day 14. In addition, single-dose irradiation resulted in a Th1 cytokine expression profile, whereas fractionated-dose irradiation drove a Th2 shift. Additionally, increased expression of immune-related factors was observed at early time-points with single-dose irradiation, in contrast to the dose-independent induction following fractionated-dose irradiation.
  
  
  CONCLUSIONS
  Our results demonstrate that low-dose irradiation modulates the immune response in mice, where the sensitivity and kinetics of the induced response vary according to the dosing method.
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Song
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.|b Laboratory of Immunology, College of Veterinary Medicine, Seoul National University , Seoul , Republic of Korea.
authors.forename: Mi-Hyoung
authors.initials: MH
authors.lastname: Kim
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Seong-Mook
authors.initials: SM
authors.lastname: Kang
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Seung-Youn
authors.initials: SY
authors.lastname: Jung
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Jiyeon
authors.initials: J
authors.lastname: Ahn
authors.affiliation: b Laboratory of Immunology, College of Veterinary Medicine, Seoul National University , Seoul , Republic of Korea.
authors.forename: Hee-Jong
authors.initials: HJ
authors.lastname: Woo
authors.affiliation: c Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro & Nuclear Power Co., Ltd , Seoul , Republic of Korea.
authors.forename: Seon Young
authors.initials: SY
authors.lastname: Nam
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Sang-Gu
authors.initials: SG
authors.lastname: Hwang
authors.affiliation: d Department of Obstetrics and Gynecology , Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Sang-Young
authors.initials: SY
authors.lastname: Ryu
authors.affiliation: a Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences , Seoul , Republic of Korea.
authors.forename: Jie-Young
authors.initials: JY
authors.lastname: Song
mesh_terms: D000818:Animals; D002452:Cell Count; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D005786:Gene Expression Regulation / Q000528:radiation effects; D007107:Immune System / Q000166:cytology* / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D011829:Radiation Dosage; D017382:Reactive Oxygen Species / Q000378:metabolism; D013154:Spleen / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D013997:Time Factors; D014916:Whole-Body Irradiation
chemical_list: D016207:Cytokines; D017382:Reactive Oxygen Species
keywords: Low-dose irradiation; cytokine expression; immune response; reactive oxygen species; whole-body irradiation