Tomohiro Matsui1, Natsumi Kawahara, Arisa Kimoto, Yusuke Yoshida. 1. Department of Laboratory Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-kogushi, Ube, Yamaguchi, 755-8505, Japan, giants@yamaguchi-u.ac.jp.
Abstract
BACKGROUND: T cells infiltrate into the infarcted brain within days after cerebral ischemia and play essential roles in exacerbating the delayed phase of the brain injury by producing pro-inflammatory factors. However, the involvement of these factors in brain damage is also demonstrated systemically. Such periphery-brain abnormalities are interesting because they may constitute a pathway to the central nervous system (CNS), which may be a target of therapeutic hypothermia. Although this therapy protects neurons after severe brain damage, the underlying mechanisms are partly understood. We examined the effects of hypothermic and hyperthermic cultures on peripheral T cell-derived release of interleukin (IL)-17 and granzyme B (GrB) and evaluated whether and how these factors induced neurotoxicity and activated brain endothelial cells. METHODS: We determined levels of IL-17 and GrB produced by several activated, IL-1β/IL-23-treated activated T cells (naïve CD4(+), CD4(+), CD8(+), and γδ T cells obtained from healthy humans) under hypothermia, normothermia, and hyperthermia. The viability of neuronal SH-SY5Y cells treated with IL-17 or GrB and mRNA expression of adhesion molecules/chemokines by brain endothelial bEND.3 cells treated with IL-17 were also measured. RESULTS: Compared with normothermia, IL-17 and GrB release in these T cells was reduced by hypothermia but augmented by hyperthermia. IL-17 and GrB caused the death of neuronal SH-SY5Y cells, and IL-17 upregulated mRNA expression of several adhesion molecules/chemokines in bEND.3 cells; both effects were concentration-dependent. CONCLUSION: Hypothermia reduced but hyperthermia augmented T cell-derived release of IL-17 and GrB that mediate neuronal cell death, suggesting that the attenuation of T cell-derived release of these factors by therapeutic hypothermia leads to the inhibition of neuronal cell death in the delayed phase of brain injury. Moreover, hypothermia may suppress but hyperthermia may promote the recruitment of inflammatory cells to CNS by regulating brain endothelial activation of IL-17.
BACKGROUND: T cells infiltrate into the infarcted brain within days after cerebral ischemia and play essential roles in exacerbating the delayed phase of the brain injury by producing pro-inflammatory factors. However, the involvement of these factors in brain damage is also demonstrated systemically. Such periphery-brain abnormalities are interesting because they may constitute a pathway to the central nervous system (CNS), which may be a target of therapeutic hypothermia. Although this therapy protects neurons after severe brain damage, the underlying mechanisms are partly understood. We examined the effects of hypothermic and hyperthermic cultures on peripheral T cell-derived release of interleukin (IL)-17 and granzyme B (GrB) and evaluated whether and how these factors induced neurotoxicity and activated brain endothelial cells. METHODS: We determined levels of IL-17 and GrB produced by several activated, IL-1β/IL-23-treated activated T cells (naïve CD4(+), CD4(+), CD8(+), and γδ T cells obtained from healthy humans) under hypothermia, normothermia, and hyperthermia. The viability of neuronal SH-SY5Y cells treated with IL-17 or GrB and mRNA expression of adhesion molecules/chemokines by brain endothelial bEND.3 cells treated with IL-17 were also measured. RESULTS: Compared with normothermia, IL-17 and GrB release in these T cells was reduced by hypothermia but augmented by hyperthermia. IL-17 and GrB caused the death of neuronal SH-SY5Y cells, and IL-17 upregulated mRNA expression of several adhesion molecules/chemokines in bEND.3 cells; both effects were concentration-dependent. CONCLUSION:Hypothermia reduced but hyperthermia augmented T cell-derived release of IL-17 and GrB that mediate neuronal cell death, suggesting that the attenuation of T cell-derived release of these factors by therapeutic hypothermia leads to the inhibition of neuronal cell death in the delayed phase of brain injury. Moreover, hypothermia may suppress but hyperthermia may promote the recruitment of inflammatory cells to CNS by regulating brain endothelial activation of IL-17.
Authors: Arthur Liesz; Wei Zhou; Éva Mracskó; Simone Karcher; Henrike Bauer; Sönke Schwarting; Li Sun; Dunja Bruder; Sabine Stegemann; Adelheid Cerwenka; Clemens Sommer; Alexander H Dalpke; Roland Veltkamp Journal: Brain Date: 2011-03 Impact factor: 13.501
Authors: Lucie Roussel; François Houle; Carlos Chan; Yu Yao; Julie Bérubé; Ron Olivenstein; James G Martin; Jacques Huot; Qutayba Hamid; Lorenzo Ferri; Simon Rousseau Journal: J Immunol Date: 2010-03-12 Impact factor: 5.422