严重创伤对淋巴细胞的激活作用:一个曾经被忽视的问题

传统的观点认为,严重创伤可致机体非特异性免疫功能以及由T、B淋巴细胞介导的细胞免疫和体液免疫功能受抑,从而使机体的抗感染能力减弱[1,2].但近来大量的研究表明,创伤可致中性粒细胞、单核-巨噬细胞激活并分泌炎症介质,该变化在创伤后系统性炎症反应综合征(SIRS)及多器官功能障碍综合征(MODS)的发生发展过程中,扮演着极为重要的角色.然而有关创伤对淋巴细胞激活作用的研究曾一度被忽视.本文就该领域近十几年来为数不多的相关文献作一综合介绍.     

创伤后IL-2表达受抑与核转录NFAT和AP-1变化的关系

目的探讨创伤后脾细胞活化T细胞核因子(nuclear factor of activated T cells,NFAT)和激活蛋白-1(activator protein-1,AP-1)的DNA结合活性、部分家族成员c-Fos,c-Jun,JunB蛋白的表达和白细胞介素2(IL-2)表达的动态变化及它们间的关系.方法采用小鼠双后肢闭合性砸伤+骨折模型,于创伤后6、12h,1、4、7、10、14d处死动物,分离脾细胞,经ConA刺激细胞后收集培养上清以测定IL-2活性;提取脾细胞RNA以测定IL-2 mRNA;提取脾细胞核蛋白,用电泳迁移率改变试验(electrophoretic mobility shift assay,EMSA)检测NFAT、AP-1的DNA结合活性,用免疫蛋白印迹法(Western blot assay)检测c-Fos,c-Jun,JunB蛋白的表达.结果和正常对照组相比,创伤后IL-2活性均有不同程度的降低,其受抑的程度在创伤后4d更为明显.创伤后脾细胞NFAT和AP-1的DNA结合活性亦逐渐下降,至伤后4d时下降最明显,为正常对照组的41%和49%.这与创伤后脾细胞IL-2的活性和IL-2 mRNA的降低相一致.c-Fos蛋白水平在伤后1、4d明显降低;c-Fos蛋白表达无明显变化;JunB蛋白水平仅在伤后1d明显表达.结论上述结果提示,创伤后脾细胞IL-2表达受抑至少部分是由于核转录因子NFAT和AP-1的DNA结合活性降低所导致;而NFAT和AP-1的DNA结合活性降低可能部分由于创伤影响c-Fos蛋白的生成所致.     

超抗原和核转录因子

在超抗原对真核生物免疫识别的过程中,核转录因子在细胞因子基因调控方面起着重要作用.当不同的细胞在受到不同的超抗原刺激时,众多核转录因子的激活途径和调控细胞因子的表达也具有多样性.     

大鼠细胞因子信号转导抑制因子-1基因的多态性及其结构分析

目的 扩增大鼠细胞因子信号转导抑制因子-1(SOCS-1)基因,利用生物信息学方法预测其结构和功能特征,为进一步的实验研究提供理论指导.方法 扩增并测序大鼠的SOCS-1编码区序列,利用生物信息学网站的在线分析工具和Vector NTI suite软件包,识别大鼠SOCS-1基因并预测其编码蛋白质的各种结构特征,根据该基因构建其分子进化树.结果 聚合酶链反应(PCR)扩增获得2个序列不同的SOCS-1基因,BLASTx分析该基因为全长基因,该基因全长639 bp,编码212个氨基酸(aa),具有1个SOCS盒(aa172～aa208),1个Scr同源区2(SH2)结构域(aa80～aa155)和1个核定位序列(aa160～aa174),一级结构含有2个线性B细胞抗原表位,全部位于蛋白的表面,并在空间结构上相距较远.结论 SOCS-1基因具有基因多态性,其保守的SH2区域及SOCS盒与其对信号转导通路抑制作用有关,而其核定位序列可能影响其他核转导因子,B细胞线性表位则在免疫诊断方面有较好的应用前景.     

慢性血吸虫感染对脓毒症小鼠保护作用的研究

目的 初步探讨慢性血吸虫(SJ)感染对脓毒症小鼠的保护作用及其机制.方法 选择BALB/c雄性小鼠,按随机数字表法分组进行三部分实验.实验1:经腹部皮肤接种SJ尾蚴感染8周建立慢性SJ感染模型,分为正常组和SJ组,每组10只;用酶联免疫吸附法(ELISA)检测血清白细胞介素(IL-4和IL-10)、肿瘤坏死因子-α(TNF-α)、γ-干扰素(IFN-γ)水平,实时荧光定量聚合酶链反应(PCR)检测腹腔巨噬细胞IL-10和TNF-α的mRNA表达,了解慢性SJ感染小鼠免疫状态.实验2:以脂多糖(LPS)腹腔注射诱导小鼠脓毒症模型,分为LPS组和SJ-LPS组,每组15只;用ELISA法动态观察注射LPS后0、24、48和72 h细胞因子的变化,0 h的水平相当于正常小鼠和SJ感染8周水平,观察慢性SJ感染对脓毒症过程的影响.实验3:分别以盲肠结扎穿孔术(CLP)和LPS诱导两种不同的脓毒症模型,评价慢性SJ感染对脓毒症小鼠72 h存活率的影响.结果 实验1:SJ组血清抗炎因子IL-4[(151.35±12.24)ng/L]和IL-10[(133.22±11.09)ng/L]水平较正常组[IL-4(56.32±8.66)ng/L,IL-10(48.17±7.23)ng/L]显著升高(均P＜0.05),并可使巨噬细胞向替代活化性巨噬细胞分化,慢性SJ感染使腹腔巨噬细胞高表达IL-10 mRNA(SJ组4.46±1.82,正常组1.52±0.60),抑制TNF-α mRNA表达(SJ组1.61±0.93,正常组2.32±1.03,均P＜0.05).实验2、3:慢性SJ感染小鼠血清IL-4、IL-10于注射LPS后0 h即显著升高,随后下降,至72 h仍明显高于LPS组[IL-4(ng/L):92.2±7.6比41.5±4.5;IL-10(ng/L):92.1±7.8比35.6±4.0,均P＜0.05];TNF-α、IFN-γ均于24 h达峰值后逐渐下降,至72 h SJ-LPS组仍显著低于LPS组[TNF-α(ng/L):82.9±5.6比91.5±5.2;IFN-γ(ng/L):44.1±4.8比52.6±4.0,均P＜0.05].慢性SJ感染可明显改善CLP或LPS所致脓毒症小鼠的存活率(CLP:80%比20%,LPS:70%比30%,均P＜0.05).结论 慢性SJ感染可使脓毒症小鼠血清抗炎因子升高,存活率上升,从而起到保护作用.

Abstract：

Objective To preliminarily study the protective effect of chronic schistosoma japonica (SJ)infestation against sepsis in mice and its mechanism. Methods BALB/c male mice were used, and the experiment was divided into three parts. Experiment 1: chronic SJ infestation model was reproduced by SJ cercaria inoculation through abdominal skin for 8 weeks. Twenty mice were randomly grouped into normal group (n=10) and SJ group (n=10). The levels of interleukins (IL-4, IL-10), tumor necrosis factor-α(TNF-α) and interferon-γ (IFN-γ) in serum were detected by enzyme linked immunosorbent assay (ELISA).Real-time polymerase chain reaction (PCR) was employed to detect the levels of IL-10 mRNA and TNF-αmRNA in abdominal macrophages. This experiment was meant to evaluate immune state in mice with chronic SJ infestation. Experiment 2: lipopolysaccharide (LPS) was intraperitoneally injected to reproduce sepsis model. Thirty mice were randomly grouped into LPS group (n=15) and SJ-LPS group (n=15). The levels of cytokines were determined by ELISA at 0, 24, 48 and 72 hours after LPS injection. This experiment was meant to detect the effect of chronic SJ infestation in mice during the septic process. Experiment 3 : two types of sepsis model were reproduced by cecal ligation and puncture (CLP) and LPS injection, respectively. The survival rate of mice with chronic SJ infestation in 72 hours in either type of sepsis was evaluated. Results Experiment 1, compared with normal group [IL-4 (56.32±8.66) ng/L, IL-10 (48.17±7.23) ng/L],chronic SJ infestation showed an increase in serum IL-4 [(151. 35 ± 12. 24) ng/L] and IL-10 [(133. 22 ±11. 09) ng/L, both P＜0. 05]. Chronic SJ infestation also resulted in an increase in IL-10 mRNA expression (SJ group 4. 46±1. 82, normal group 1. 52±0. 60) and inhibited TNF-α mRNA expression (SJ group 1. 61±0.93, normal group 2. 32±1.03) in abdominal macrophages (both P＜0. 05), indicating that macrophages could be differentiated into alternative activated macrophages. Experiments 2 and 3 showed that the levels of serum IL-4 and IL-10 were increased at 0 hour after LPS injection, and then gradually decreased in SJ-LPS group, but the levels were still higher than those in LPS group at 72 hours [IL-4 (ng/L): 92. 2±7. 6 vs.41.5±4. 5; IL-10 (ng/L): 92. 1±7. 8 vs. 35. 6±4. 0, both P＜0. 05]; the levels of TNF-α and IFN-γ were increased at 24 hours, and then decreased in SJ-LPS group, and the levels were lower than those in LPSgroup at 72 hours [TNF-α (ng/L): 82. 9±5. 6 vs. 91. 5±5. 2; IFN-γ (ng/L): 44.1±4. 8 vs. 52. 6±4. 0,both P＜0. 05]. Therefore, chronic SJ infestation could improve the survival rate of mice with sepsis induced by CLP or LPS (CLP: 80% vs. 20%, LPS: 70% vs. 30%, both P＜0.05). Conclusion Chronic SJ infestation could elevate anti-inflammatory factors in septic mice, thus ameliorating the survival rate, so it has protective effect on mice with sepsis.     

创伤后抗菌药物预防性使用策略

由各种事故或暴力所导致的创伤已成为当今社会死亡和致残的主要因素。感染是创伤后公认的并发症,预防性使用抗菌药物能够减少创伤后感染及其并发症的发病率。笔者就创伤后预防性使用抗菌药物的时间、种类、剂量、疗程及给药途径进行阐述。     

Criculating fibrocytes: a potent cell population in antigen-presenting and wound healing

Fibrocytes are bone marrow-derived mesenchymal progenitors that co-express hematopoietic cell antigens and markers of monocytic lineage as well as fibroblast products. During wound healing, fibrocytes have been found to possess the ability of antigen-presentation to naive T cells in the inflammatory phase. Moreover, they can promote the endothelial cell proliferation, migration and angiogenesis by secreting several proteins. Fibrocytes can further differentiate into mature mesenchymocyte lineage, such as fibroblasts, myofibroblasts and adipocytes, and they may represent the systemic source of myofibroblasts that exert a contractile force required to close tissue wounds. A deep understanding of the mechanism involved in fibrocyte migration and differentiation may lead to the development of a novel theory of normal physiology and pathology.     

创伤及手术对瘦素的影响

瘦素（Leptin）是一种由167个氨基酸组成的蛋白质，主要由脂肪组织合成、分泌入血循环，通过与下丘脑的特异性受体结合能调节摄食、体重、生殖及其他内分泌和代谢过程，也能结合周围组织受体而影响免疫、造血、骨代谢、伤口愈合及血管再生等生理功能。关于创伤及手术对瘦素的影响，近来有很多研究报道，现综述如下。     

创伤后瘦素及其受体的变化及临床意义研究

目的观察创伤后瘦素（leptin）及其受体（oh-R）的变化，初步探讨二者在创伤恢复过程中的临床意义。方法2007年7月-2008年3月收治的52位创伤患者依据AIS-ISS评分分为3组：①轻伤组（ISS〈16或AIS≤2，n=21）；②重伤组（16≤ISS〈25或AIS=3，n=17）；③严重伤组（Iss≥25或AIS〉3，n=14）。以1个月来无感染病史的7位健康人作为对照。采集患者人院第1天（D1）、第3天（D2）、第6天（ID3）以及对照组成员（D0）血清，酶联免疫吸附法（ELISA）测定血清瘦素及ob-R水平。结果严重伤组SIRS、MODS、脓毒症发生率均高于重伤组及轻伤组（P〈0．05）。随创伤程度的加重，各时相点瘦素与ob-R水平也随之增高。D1时，重伤组、轻伤组、对照组间瘦素水平无显著差异（P〉0.05），但3组均显著低于严重伤组（P〈0．05）。D2时，重伤组和轻伤组瘦素水平均显著高于对照组（P〈0．05），且3组均显著低于严重伤组（P〈0．05）。D3时各组间比较结果与D1相同。ob-R水平D1、D2、D3时4组间比较均有显著性差异（P〈0．05）。结论创伤后瘦素及ob-R水平均随创伤程度的加重而增加，测定创伤后瘦素水平的变化在一定程度上可判断创伤程度及预后。与瘦素相比，ob-R的变化持续时间更长，对损伤更为敏感。     

核因子-κB"圈套"策略对创伤性炎症大鼠肝脏炎症介质IL-6的作用研究

目的探讨核因子-κB（NF-κB）靶向性寡核苷酸（oligodeoxynucleotides,ODN）“圈套”策略对创伤性炎症大鼠肝脏炎症介质IL-6的影响.方法Wistar大鼠96只,随机分成生理盐水对照组、创伤性炎症组、“圈套”ODN组和变异“圈套”ODN组.运用凝胶阻滞实验检测创伤性炎症术后肝脏组织NF-κB的活性及合成“圈套”ODN的体外竞争抑制,用RT-PCR和ELISA法检测大鼠肝脏组织IL-6的mRNA水平和蛋白水平.结果大鼠创伤性炎症术后3 h肝脏NF-κB的活性开始升高,在术后12 h达高峰.肝脏组织IL-6 mRNA水平和蛋白水平也明显上升,与肝脏NF-κB的活性改变一致,“圈套”ODN在体外能有效地抑制NF-κB活性.“圈套”ODN治疗后大鼠肝脏组织IL-6的mRNA水平和蛋白水平均明显下降,肝脏功能明显好转,而变异“圈套”ODN却没有效果.结论NF-κB“圈套”策略通过特异性抑制NF-κB活性,可以有效地抑制创伤性炎症大鼠肝脏炎症介质IL-6的释放.