中文摘要：

目的研究急性冠状动脉综合征（ACS）患者外周血中CD4^＋T细胞及CD28^null／CD28^＋亚型活化前后Kv1．3钾通道数目的变化以及Kv1.3钾通道阻滞剂对CD4^＋T细胞活化表达的影响，探讨Kv1.3钾通道在不稳定斑块中的意义。方法用免疫磁珠法分离出27例ACS患者外周血中的CD4^＋T细胞，其中12例进一步分出亚型CIM‘CD28^null和CD4^＋CD28^＋T细胞，采用全细胞膜片钳技术记录细胞活化前及经CD3抗体活化72h后的Kv1.3钾电流。CD4^＋T细胞活化时分别加入终浓度为0．1、1、10nmol／L特异性Kv1.3钾通道阻滞剂rMargatoxin（rMgTX），共同培养72h后用反转录-PCR法检测干扰素-γ、肿瘤坏死因子（TNF）-α及颗粒酶B mRNA的表达。结果活化后CD4^＋、CD4^＋CD28^null、CD4^＋CD28^＋T细胞的Kv1.3钾通道的峰电流均明显增加，细胞平均通道数分别增加约90％、60％、80％[活化前后每个细胞的通道数分别为（402±88）个比（752±275）个、（553±328）个比（874±400）个、（392±133）个比（716±251）个，均P〈0．05]。活化前CD4^＋CD28^nullT细胞Kv1.3钾通道的平均数目比CD4^＋CD28^＋T细胞多约40％（P〈0．05），活化后两者差异无统计学意义（P=0．102）。不同浓度的rMgTX均下调CD4^＋T细胞活化后干扰素-γ、TNF-α、颗粒酶B mRNA的表达，各浓度组间干扰素-γ、TNF-α、颗粒酶B mRNA的表达差异均有统计学意义（均P〈0．01），浓度越高，各mRNA表达越低。结论ACS患者外周血CD4^＋T细胞及CD28^null／CD28^＋亚型活化后Kv1.3钾通道表达增加，特异性Kv1.3通道阻滞剂rMgTX呈浓度依赖性地抑制CD4^＋T细胞活化时干扰素-γ、TNF-α及颗粒酶B mRNA的表达，提示CD4^＋T细胞特别是CD4^＋CD28^nullT细胞的Kv1.3钾通道可作为预防动脉粥样斑块不稳定的潜在治疗靶点。

英文摘要：

Objective To study the Kv1.3 channel expression changes after CD4^＋ and subsets CD28^null/CD28^＋T cells activation in peripheral blood of patients with acute coronary syndrome （ACS）. Methods CD4^＋ T cell in 27 ACS patients and CD4^＋ CD28^null/CD4^＋ CD28^＋ T cells in 12 out of these 27 ACS patients were isolated from peripheral blood with magnetic cell sorting. The whole-cell Kv1.3 currents for three T cells were recorded with patch-clamp technique before and 72 hours after activation by purified anti-human CD3 Interferon gamma, tumor necrosis factor alpha （TNF-α）, granzyme B mRNA expression were determined by reverse transcription-PCR before and 7：2 hours after activation by purified anti-human CD3 in the presence or absence of recombinant Margatoxin （rMgTX, 0. 1, 1, 10 nmol/L）, a specific Kv1.3 channel blocker. Results Peak Kv1.3 channel currents of CD4^＋ , CD4^＋ CD28^null, CD4^＋ CD28^＋ T cells were significantly increased and the mean Kv1.3 channel numbers per cell of these cells were increased by about 90%, 60%, 80% （402 ±88 vs. 752±275, 553 ±328 vs. 874 ±400, 392 ± 133 vs. 716 ±251, all P 〈0. 05） after activation compared to baseline values. Baseline CD4^＋ CD28^null T cell numbers were about 40% more than those of CD4 ^＋ CD28 ^＋ T cell （P 〈0. 05） and were similar after activation （P =0. 102）. The mRNA expression of interferon gamma, TNF-α and granzyme B were dose-dependently down-regulated by rMgTX. Conclusions Kv1.3 channels of peripheral CD4 ^＋ T cell and CD28^null/CD28^＋＋ T cells from ACS patients significantly increased after activation and Kv1.3-specific channel blocker rMgTX could effectively abolish this effect suggesting a potential role of Kv1.3 channel blocker on plaque stabilization in ACS patients.