Moderate hypothermia delays proinflammatory cytokine production of human peripheral blood mononuclear cells.
OBJECTIVE
To clarify the influence of moderate hypothermia on the production of proinflammatory cytokines.


METHODS
Controlled in vitro study.


METHODS
Research laboratory.


METHODS
Peripheral blood mononuclear cells from healthy adult human subjects.


METHODS
Stimulation with 1 microg/mL lipopolysaccharide at 33 degrees C and 37 degrees C.


METHODS
Concentrations of released tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 were measured chronologically by enzyme immunoassay. The number of mRNA copies of these cytokines was determined by competitive reverse transcriptase-polymerase chain reaction analysis, and nuclear factor-kappaB activations were assessed by electrophoretic mobility shift assay.


RESULTS
Significant reduction of the released-tumor necrosis factor-alpha concentration was observed 1 and 2 hrs after the stimulation with lipopolysaccharide at 33 degrees C compared with 37 degrees C. The peak release of interleukin-1beta at 33 degrees C was delayed 12 hrs later than that at 37 degrees C. A delayed peak in the release of interleukin-6 also was observed at 33 degrees C. The peaks of cytokines were confirmed at the mRNA expression level by competitive reverse transcriptase-polymerase chain reaction analysis at both temperatures. The peak of the tumor necrosis factor-alpha mRNA expression level was observed at 1 hr after the stimulation at 37 degrees C and 2 hrs after the stimulation at 33 degrees C. In the interleukin-1beta mRNA expression, at 37 degrees C the first peak appeared 1 hr and the second 6 hrs after the stimulation. In contrast, at 33 degrees C, the first peak appeared 2 hrs and the second 12 hrs after the stimulation. Whereas interleukin-6 mRNA expression at 37 degrees C peaked 6 hrs after the stimulation, no definite peak was observed at 33 degrees C and the expression level was approximately half of that at 37 degrees C. The maximum intensity of nuclear factor-kappaB activation at 33 degrees C was delayed by 1.5 hrs compared with that at 37 degrees C.


CONCLUSIONS
Moderate hypothermia delays the induction of proinflammatory cytokines in human peripheral blood mononuclear cells.
Department of Emergency Medicine, Traumatology and Toxicology, International Medical Center of Japan, Tokyo, Japan.
Akio
A
Kimura
Shinsaku
S
Sakurada
Hisashi
H
Ohkuni
Yuko
Y
Todome
Kiyoshi
K
Kurata
D000328:Adult; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D007375:Interleukin-1; D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha