Department of Cell Biology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Epilepsia. 2011 Sep;52(9):1627-34. doi: 10.1111/j.1528-1167.2011.03080.x. Epub 2011 May 31.
A link between seizure susceptibility, blood-brain barrier (BBB) failure, and the activation of peripheral white blood cells has been recently proposed. However, the molecular players involved in this cascade of events are unknown. We tested the hypothesis that immunosupression by splenectomy or lack of perforin, a downstream factor of natural killer (NK) and cytotoxic T cells, could reduce seizure onset.
Pilocarpine was used to induce seizures in adult rats wild-type and perforin-deficient mice. Splenectomy was performed prior to pilocarpine injection. Seizure onset was evaluated by electroencephalography (EEG) and joint time-frequency analysis. Spleens from control and pilocarpine-treated groups were analyzed for anatomical changes and CD3+ cell content. BBB damage was assessed by measuring albumin parenchymal extravasation. Fluorescence-activated cell sorting (FACS) analysis was performed on spleen and brain tissue of wild-type and perforin-deficient mice treated, or not, with pilocarpine.
Splenectomy significantly reduced seizure-associated mortality. Histologic analysis of the spleens exposed to pilocarpine revealed altered white and red pulp anatomy and an increase in CD3+ T cells. Onset of status epilepticus (SE) and mortality were significantly decreased in perforin-deficient mice. Pilocarpine significantly increased spleen NK 1.1 and CD8+ cell percentage; in contrast, the brain inflammatory cell profile remained unchanged at the time of pilocarpine SE. BBB damage was reduced in the perforin-deficient pilocarpine-treated mice.
Immunosuppressant maneuvers such as splenectomy or lack of perforin decrease the onset or the severity of pilocarpine SE. Our results suggest that cytotoxic lymphocytes, and specifically the cytolytic factor perforin, may be key molecular players involved in the axis between peripheral intravascular inflammation and seizures.
最近有人提出，癫痫易感性、血脑屏障（BBB）衰竭和外周白细胞激活之间存在联系。然而，该级联事件中涉及的分子参与者尚不清楚。我们检验了这样一个假设，即脾切除术或缺乏穿孔素（NK 和细胞毒性 T 细胞的下游因子）的免疫抑制作用可以降低癫痫发作的起始。
使用匹罗卡品诱导成年大鼠和穿孔素缺陷小鼠癫痫发作。在注射匹罗卡品前进行脾切除术。通过脑电图（EEG）和联合时频分析评估癫痫发作的起始。分析对照和匹罗卡品处理组的脾脏，以评估解剖学变化和 CD3+细胞含量。通过测量白蛋白实质外渗来评估 BBB 损伤。对未用或用匹罗卡品处理的野生型和穿孔素缺陷型小鼠的脾脏和脑组织进行荧光激活细胞分选（FACS）分析。
脾切除术显著降低了癫痫发作相关的死亡率。暴露于匹罗卡品的脾脏的组织学分析显示，白髓和红髓解剖结构发生改变，CD3+T 细胞增加。穿孔素缺陷型小鼠的癫痫持续状态（SE）起始和死亡率显著降低。匹罗卡品显著增加了脾脏 NK1.1 和 CD8+细胞的百分比；相比之下，在匹罗卡品 SE 时，大脑炎症细胞谱保持不变。穿孔素缺陷型匹罗卡品处理小鼠的 BBB 损伤减少。
免疫抑制手段，如脾切除术或缺乏穿孔素，可降低匹罗卡品 SE 的起始或严重程度。我们的结果表明，细胞毒性淋巴细胞，特别是细胞溶解因子穿孔素，可能是涉及外周血管内炎症和癫痫发作之间轴的关键分子参与者。
