Radiation and primary immune response to lipopolysaccharide: lymphocyte distribution and function.
BACKGROUND
Lipopolysaccharide (LPS) is a major cause of septic shock and death due to infection with Gram-negative bacteria. The purpose of this study was to quantify the effects of whole-body irradiation on lymphocyte populations during response to challenge with LPS.


METHODS
C57BL/6 mice (n = 10/group) were irradiated whole-body with 3 gray (Gy) gamma-rays in a single fraction at 0.8 Gy/min. LPS (E. coli serotype 0111:B4) at 1 mg/kg was injected intraperitoneally 10 days later and mice were euthanized at 60 min and days 1, 7, and 14 post-inoculation for analyses.


RESULTS
Significant interactions between radiation and LPS were noted in circulating and splenic lymphocyte subpopulations, including T-, B-, and NK-cells, particularly at the early time points. There were significant interactions on circulating, but not splenic, CD62L+ T-cell populations. However, there were no interactions on CD62L+ B-cells. Finally, there were significant interactions in both early and late blastogenic responses.


CONCLUSIONS
The data support that response to infection with Gram-negative bacteria may be significantly compromised by exposure to ionizing radiation.
Pecaut
Michael J
MJ
Department of Radiation Medicine, Molecular Radiation Biology Laboratories, Loma Linda University and Medical Center, Loma Linda, CA 92354, USA. mpecaut@dominion.llumc.edu
Dutta-Roy
Radha
R
Miller
Glen M
GM
Gridley
Daila S
DS
D000818:Animals; D004926:Escherichia coli / Q000276:immunology; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects; D007107:Immune System / Q000187:drug effects* / Q000528:radiation effects*; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects* / Q000528:radiation effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D012772:Shock, Septic / Q000209:etiology; D013154:Spleen / Q000187:drug effects / Q000528:radiation effects; D014916:Whole-Body Irradiation
D008070:Lipopolysaccharides