大鼠IL-6受体基因的克隆及在大肠杆菌中的表达

目的：获取大鼠IL－6受体（IL－6R）的基因并高效表达。方法：用PCR技术，从正常成年大鼠脑的cDNA文库中，获得编码IL－6R基因的序列。测序后，通过PCR扩增和基因重组，分别构建IL－6R基因全长和羧基端部分编码序列的表达载体，并导入大肠杆菌DH5α中，通过IPTG诱导表达重组融合蛋白。对表达的羧基端序列编码的融合蛋白过谷胱甘肽琼脂糖柱进行纯化。结果：获得正常成年大鼠I-6R(98-1493位）的基因，测序结果与已发表的基因序列相一致。重组蛋白以包涵体的形式进行表达。经SDS－PAGE分析，在相对分子质量（Mr)为74000和43000处，各有1条特异的蛋白带。对羧基端基因表达的包涵体形式的蛋白进行变性、重折叠及纯化后，得到了庙纯度融合蛋白。结论：成功地克隆正常成年大鼠IL－6R基因，并在E.coli DH5α中高效表达，为进一步制备抗IL－6R抗体和进行原位分子杂交研究创造了条件。     

大鼠缺血心肌中NF-κB活性改变及其对iNOS表达的影响

观察心肌梗死大鼠不同时期缺血心肌中NF—κB的活性变化，评价其是否参与调控缺血心肌中iNOS的表达。将雄性Wistar大鼠36只复制心肌梗死模型，检测心肌梗死后1、2、3及4W缺血心肌中NF—κB活性和iNOS的表达；另腹腔每日注射NF—κB抑制剂NAC(160mg／kg)及注射盐水作对照，2周后检测缺血心肌中iNOS的表达。共6组，每组6只，另取6只假手术对照。用EMSA检测NF—κB，RT—PCR及免疫组化测iNOS。结果显示：(1)心肌梗死后，缺血心肌中NF—κB活性明显增高，1-2W活性最强，3W后开始下降，4W接近正常水平。(2)心肌梗死1W后缺血心肌中iNOSmRNA及蛋白质表达明显增加，其变化趋势同NF—κB。(3)加用NAC干预后的大鼠缺血心肌中iNOSmRNA及蛋白质的表达显著下降。实验说明缺血可刺激心肌中iNOS的表达增加及NF—κB的活化；NF—κB参与调控缺血心肌中iNOS的表达。     

TRAIL受体在肿瘤细胞系上的表达及意义

目的 检测TNF相关凋亡诱导配体（TRAIL）的受体，在来源于血液系统、肝脏、肺脏和大肠的8个肿瘤细胞系中的表达，并探讨其意义。方法 采用半定量RT－PCR，对TRAIL受体的表达进行半定量检测。结果 TRAIL凋亡通路中，能够诱导凋亡反应的死亡受体DR4和DR5，在所检测的肿瘤细胞系中都有表达，其中DR5在所有肿瘤细胞系中的表达水平均显著高于DR4（P＜0．05）。而能够竞争性与TRAIL诱导的凋亡反应的诱骗受体DcR1和DcR2，在所有的肿瘤细胞中都呈低水平表达或不表达。结论 DR5可能在TRAIL诱导凋亡的通路中发挥最重要的作用。TRAIL死亡受体和诱骗受体在肿瘤细胞系中的表达具有差异性，这种差异性可在一定程度上解释不同细胞对TRAIL诱导凋亡的敏感度。     

小鼠白细胞介素6的cDNA克隆及其在昆虫细胞中的表达

本文采用ＲＴ－ＰＣＲ技术从ＬＰＳ刺激后的小鼠腹腔巨噬细胞，扩增小鼠ＩＬ－６ｃＤＮＡ，并克隆构建ｐＧＥＭ－３Ｚｆ（＋）ＩＬ－６质粒，继将小鼠所得ｃＤＮＡ克隆到ｐＶＬ１３９２载体上，利用杆状病毒ＡｃＮＰＶ表达系统在Ｓｆ９中进行瞬间表达，用ＩＬ－６依赖细胞株ＭＨ６０·ＢＳＦ２检测其表达活性，结果表明，感染后４８ｈ后就具有明显ＩＬ－６表达，由此可见，利用该系统可成功地表达小鼠ＩＬ－６基因。     

TNF-α、IL-8在脂多糖致大鼠脑水肿中的表达

目的　探讨脂多糖 (lipopolysaccharide ,LPS)致大鼠脑水肿发生过程中 ,地塞米松作用下TNF α、IL 8表达水平的变化及相互关系。方法　利用LPS诱导大鼠脑水肿发生 ,测定脑组织含水量及伊文私蓝 (Evansblue,EB)含量 ,制备脑组织匀浆 ,ELISA法测IL 8含量 ,放射免疫法测TNF α含量。结果　LPS注入后LPS组和DXM组脑组织含水量和伊文思蓝含量均较NS组增高 (P <0 .0 5) ;LPS组TNF α和IL 8含量较NS组显著增高 (P <0 .0 1 ) ,但DXM组较LPS组显著降低 (P <0 .0 5) ;DXM组TNF α和IL 8含量在早期 (≤ 2 4h)较NS组增高 (P <0 .0 5) ,48h时则无显著差异 (P >0 .0 5)。LPS组脑组织含水量与EB含量 ,TNF α与脑组织含水量 ,IL 8与脑组织含水量 ,IL 8与EB含量均呈正相关 (r值分别为 0 .537,0 .42 3 ,0 .473 ,0 .831 ,P <0 .0 5)。结论　TNF α、IL 8参与了脂多糖诱导的脑水肿的发生、发展过程 ,早期应用糖皮质激素可以抑制炎性细胞因子的生成 ,减轻炎症反应与组织损伤。     

神经营养素受体在人外周血T细胞中表达的研究

目的 研究人外周血CD4^ /CD8^ T细胞4种神经营养素受体基因的转录。方法 应用尼龙手法分离出T细胞，磁式细胞分离法（MACS）分离CD4^ /CD8^ T细胞亚群，再以RT－PCR法研究4种神经营养素受体在两种T细胞亚群上的表达。结果 未经刺激的CD4^ /CD8^ T细胞亚群不表达任何神经营养素受体。经PHA或PPD刺激后，CD4^ /CD8^ T细胞亚群表达trkA,CD8^ T细胞亚群表达trkC；而在各种状态下的T细胞上均未见表达trkB及p75^NGFR。结论神经营养素受体在两种T细胞亚群中有不同的表达格局，提示不同T细胞亚群受神经营养素调节的模式可能各不相同。     

OPG与MBP融合蛋白在大肠杆菌中的表达

目的 克隆人骨保护素（OPG）成熟肽段编码区基因，并在大肠杆菌中表达。方法 采用RT－PCR法，扩增人OPG成熟肽段编码区cDNA，并克隆入原核表达载体pMAL-c2x中，转化BL21（DE3）PlysS大肠杆菌感受态细胞，经0.1mmol/L IPTG诱导后，收集菌体蛋白，进行SDS－PAGE及Western blot鉴定。结果 获得人OPG成熟肽段编码区cDNA，以构建的原核表达载体pMAL-OPG转化菌株后，可表达人OPG和麦芽糖结合蛋白（MBP）的融合蛋白，相对分子质量（M）为85000。表达产物的蛋白量约为菌体总蛋白的13％。Western blot表明，融合蛋白能与抗人OPG多克隆抗体特异性结合。结论 获得人OPG成熟肽全长cDNA，并在大肠杆菌中以OPC－MBP融合蛋白的形式表达。     

5-HT受体亚型在原代培养大鼠脊髓背角神经元的表达

为探讨脊髓背角内 5 -HT发挥作用的受体类型及其胞内信号转导机制 ,本研究首先利用免疫荧光技术对胎鼠脊髓背角神经元的产率进行了观察 ,再利用反转录 PCR方法观察了 5 -HT受体 14种亚型 m RNAs在原代培养神经元中的表达。原代培养的背角神经元生长状态良好 ,存活时间达到 14～ 2 1d。对培养的背角细胞用神经元特异性标志物—神经细胞核蛋白 (Neu N)进行免疫荧光检测的结果表明 ,神经元的产率超过 90 % ;用 PCR方法在培养的背角神经元中检测到了 5 -HT1 A、5 -HT1 B、5 -HT1 D、5 -HT1 F、5 -HT2 A、5 -HT2 C、5 -HT3、5 -HT4 、5 -HT5A、5 -HT5B、5 -HT6 和 5 -HT7等受体亚型 m RNAs的表达。但上述各受体亚型的表达水平存在差异 ,未检测到 5 -HT1 E和 5 -HT2 B受体亚型 m RNAs的表达。结果表明 ,本研究建立的实验方法可满意地获得原代培养脊髓背角神经元 ;这些神经元不但表达多种受体亚型 ,而且表达类型与以往在成年大鼠脊髓背角观察到的表达状况基本一致。上述结果为进一步开展 5 -HT作用机制的体外研究奠定了基础。     

人白细胞介素18 cDNA的克隆和在大肠杆菌中的表达

白细胞介素１８（ＩＬ－１８）是１９９５年克隆的一种新型细胞因子，又称ＩＦＮ－γ诱导因子，主要由活化的巨噬细胞产生，其相对分子质量（Ｍｒ）为１８　３００［１、２］。ＩＬ－１８可诱导ＴＨ１细胞产生ＩＦＮ－γ和ＧＭ－ＣＳＦ等细胞因子，增强ＮＫ细胞和ＣＴＬ的活性［１、２］，促进ＩＬ－２介导的Ｔ细胞增殖；增强ＴＨ１等细胞产生ＴＨ１类细胞因子［３、４］；促进免疫细胞表达ＦａｓＬ，增强Ｆａｓ介导的细胞毒作用等多种生物学功能［５］，在抗病原微生物感染﹑抗肿瘤及抗超敏反应等方面具有潜在的应用前景。因此，我们采用Ｒ…     

肺癌患者红细胞免疫分子CR1和IL-8受体的变化

肺癌是危害人类健康的最常见恶性肿瘤之一。肺癌患者免疫功能失衡 ,机体免疫状态往往低下与紊乱 :Ｔ淋巴细胞免疫功能下降而血循环中免疫球蛋白和细胞因子异常上升 ,肺肿瘤局部炎症反应差。肺癌患者免疫监护能力下降的机制相当复杂 ,至今还不甚了解。随着现代免疫学理论与技术的发展 ,人们已认识到红细胞是一种天然免疫刺激剂和免疫调节剂 ,在机体免疫防御系统中占有重要地位[1] 。我们对肺癌患者的红细胞ＣＲ1受体活性的变化做了研究[2 ] ,但红细胞上还有趋化因子受体 ,在调控炎症反应中占有很重要的地位 ,已引起我们的重视。我们分别对 31…     

pcDNA3.1/hIL-18真核表达载体的构建及表达

目的 :构建重组真核表达质粒pcDNA3.1/IL 18,并在哺乳动物细胞COS 7和Rlc310中进行瞬时和稳定性表达。方法 :从含hIL 18基因的中介载体 pGEM TEasy( pGEM T/hIL 18)中 ,以限制性内切酶酶切方法获得目的片段 ,克隆入真核表达质粒 pcDNA3.1( )中。以脂质体法转染COS 7和Rlc310细胞 ,用RT PCR检测IL 18mRNA的水平 ,免疫组化染色法检测蛋白表达。结果 :构建了hIL 18基因的重组真核表达质粒pcDNA3.1/IL 18,并可在哺乳动物细胞中瞬时、稳定表达 ,获得了可稳定表达hIL 18基因的Rlc310细胞株。结论 :pcDNA3.1/IL 18的构建及表达 ,为IL 18抗肿瘤作用的研究奠定了基础     

Glucocorticoid receptor expression in nontumorous human pituitaries and pituitary adenomas

Glucocorticoids have multiple actions, including a suppressive feedback effect on pituitary corticotrophs via the glucocorticoid receptor (GR). By immunocytochemistry, we studied GR expression in 86 surgically removed various pituitary adenoma types. Ten cases contained nontumorous pituitary fragments, which were suitable for immunocytochemical investigation. In addition, 30 autopsy-obtained pituitaries, 10 of them containing incidental microadenomas, were examined as well. Using a polyclonal GR antibody, the streptavidin-biotin-peroxidase complex method revealed nuclear and/or cytoplasmic GR immunoreactivity in many nontumorous corticotrophs and other adenohypophysial cell types and in S-100 protein immunopositive stellate cells. Cellular localization was confirmed by double immunostaining. Pars intermedia corticotrophs, posterior lobe axons, Herring bodies, and pituicytes as well as several endothelial cells lining the capillaries were also immunopositive. GR immunoreactivity was also demonstrated in many GH, PRL, ACTH, TSH, FSH, LH α-subunit producing adenomas, null cell adenomas, and oncocytomas. The extent and degree of immunostaining varied considerably from case to case. Suppressed corticotrophs showing the Crooke’s hyaline change due to glucocorticoid excess were present in the nontumorous pituitaries of patients with Cushing’s disease and in those treated with pharmacologic doses of glucocorticoids. Many suppressed nontumorous corticotrophs exhibited only weak or no GR immunopositivity, indicating GR downregulation accompanied by cellular injury. Study of autopsy obtained pituitaries for GR yielded inconclusive results indicating that autopsy obtained adenohypophyses are not suitable for the immunocytochemical investigation of GR.     

Skewed B cell receptor repertoire and reduced antibody avidity in patients with DOCK8 deficiency

DOCK8 immunodeficiency syndrome (DIDS) is a combined immunodeficiency characterized by recurrent viral infections, severe atopy and early onset malignancy. Immunological abnormalities include lymphopenia, CD8⁺ T‐cell cytoskeleton dysfunction, defective B cell memory and variable serum immunoglobulin levels. Here, we analyse the B cell receptor repertoire (BCR) characteristics and antibody avidity of four DIDS patients, attempt to understand the dysregulated humoral immunity in DIDS patients with a normal antibody titre and suggest a scientific basis for intravenous immunoglobulin (IVIG) replacement therapy for these patients. We analysed BCR characteristics, including somatic hypermutation (SHM) frequency, using deep sequencing of multiplex PCR products derived from BCR heavy chain CDR3 regions from DIDS patients and controls. The antibody avidity of human tetanus and hemophilus influenza B antibodies was determined by ELISA using thiocyanate elution. IVIG replacement treatment and infection conditions were investigated retrospectively. We found skewing of the BCR repertoire and decreased antibody avidity in patients with DIDS. DIDS patients had fewer negatively charged amino acids than healthy controls. The SHM frequency of the IGHV3 gene was lower in patients with DIDS. Patients received regular IVIG therapy, resulting in fewer and less severe infections. We conclude that although IgG levels are normal in most DIDS patients, IVIG replacement therapy is still necessary.     

RB tumor suppressor gene expression in hepatocellular carcinomas from patients infected with the hepatitis B virus

Hepatitis B virus (HBV) infection is closely associated with the development of hepatocellular carcinoma (HCC), but definite mechanisms by which it could play an etiologic role have not yet been identified. Modifications of the function of the RB tumor suppressor gene, which regulates the cell cycle, could provide such a mechanism. In the present study, the expression of the protein product of RB, pRB, was evaluated by immunohistochemical staining in HCC tissues from 25 patients from China and the United States, adjacent nontumorous liver from 19 of those patients, five human HCC cell lines, three human hepatoblastoma cell lines, and five specimens of normal human liver. Representative samples were also evaluated by western blot. Altered expression of RB was detected in eight HCC tissues (pRB undetectable in five HCCs and detected in <1% of nuclei of HCC cells in three others); all eight had detectable hepatitis B surface or core antigen in the adjacent nontumorous liver, indicating active HBV infection. pRB was detected in 10--95% of nuclei (normal expression) in the remaining 17 HCCs, and in many nuclei in all 19 nontumorous livers, and in the 5 normal livers. No pRB staining was detected in the nuclei of three HCC cell lines, but pRB was detected in > 90% of nuclei of the other HCC and hepatoblastoma cell lines. The relationship of pRB expression to mutations of the p53 tumor suppressor gene was also examined. The absence of detectable nuclear pRB by immunohistochemical staining was associated with the presence of presumed mutant p53 detected by immunohistochemical staining in four out of five HCC cases. In addition, all three HCC cell lines lacking detectable pRB also had a p53 mutation or a p53 deletion. HCCs with altered pRB expression included more grade III and IV tumors (8/8,100%) than did HCCs with normal pRB expression (7/17, 41%) (P < 0.02), suggesting that abnormal pRB expression may be associated with more advanced histologic grades of HCC. These data indicate that interference with the normal function of the tumor suppressor gene RB or its product pRB, often with concomitant p53 mutation, may be one of several mechanisms that contribute to the development or progression of HCC in humans infected with HBV. © 1994Wiley-Liss, Inc.     

The interleukin-8 receptor B and CXC chemokines can mediate transendothelial migration of human skin homing T cells

We studied the involvement of chemokines that bind to G protein-coupled receptors in the migration of skin homing T cells across a bilayer vascular construct (BVC) consisting of a fibroblast matrix underneath an activated endothelial (EC) monolayer. Based on the expression of the cutaneous lymphocyte-associated antigen (CLA), a skin homing receptor, CD45R0⁺ T cells freshly isolated from blood or HUT-78 cutaneous T lymphoma cells were separated into CLA⁺ and CLA⁻ subpopulations. These T cells were incubated on interleukin (IL)-1β and tumor necrosis factor-α-activated EC, and the number of transmigrated cells was determined. The chemokine IL-8 was selectively involved in the enhanced migration of CLA⁺ T cells across activated EC as demonstrated by blocking antibody to IL-8 but not to GRO-α, MCP-1 and RANTES. Identical results were obtained with both human umbilical vein EC (HUVEC) and microvascular skin EC (HDMEC). Pertussis toxin selectively inhibited the enhanced transendothelial migration (TEM) of CLA⁺ T cells, suggesting that CLA-dependent TEM depends on G_i protein-transmitted signals. Moreover, the IL-8 receptor B (IL-8RB) appeared to be functionally involved in TEM, as demonstrated by receptor desensitization with the CXC chemokines IL-8 and GRO-α and by blocking the IL-8RB with specific monoclonal antibodies. Although only the IL-8RB was involved in CLA-dependent TEM, mRNA encoding IL-8RA and IL-8RB was expressed by both CLA⁺ and CLA⁻ T cells. This correlated with IL-8RA and IL-8RB surface expression on these cells. Thus, the IL-8RB is selectively functional in TEM of T cells expressing the skin homing receptor CLA. Our results demonstrate a critical role for IL-8 and possibly other IL-8RB ligands in addition to the IL-8RB in TEM and suggest the involvement of these molecules in the homing of specific T cells to inflamed skin.     

T细胞受体库及细胞因子表达与胃癌进展及转移的关系

目的　了解在胃癌的发展过程中 ,肿瘤细胞与机体免疫系统间相互作用的特征。方法采用高敏感的放射性标记半定量RT PCR技术检测胃癌病人癌组织、非癌性粘膜组织及外周血各细胞亚群中细胞因子及T细胞受体亚家族mRNA的表达。结果　进展期胃癌外周血CD8+ T细胞中的增殖性T细胞克隆数低于早期胃癌 (P =0 .0 5 )。有淋巴结转移病例外周血CD8+ T细胞和CD4 + T细胞中的增殖性T细胞克隆数较无转移组明显减少 (P =0 .0 0 0 17、P =0 .0 16 )。有淋巴结转移病例的癌组织 ,其CD8+ T细胞中IL 6、IL 8、TNF α和CD4 + T细胞中IL 4mRNA的水平 (0 .4 3± 0 .17、0 .4 2± 0 .11、0 .18± 0 .0 5、0 .0 8± 0 .0 3)均较非癌性粘膜组织中的 (0 .0 8± 0 .0 2、0 .17± 0 .0 5、0 .0 8± 0 .0 3、0 .0 1± 0 .0 0 )增高 (P =0 .0 4 0、P =0 .0 2 0、P =0 .0 17、P =0 .0 34) ;而无淋巴结转移病例的癌组织与非癌性粘膜组织中各细胞因子的表达均未发现统计学差异。结论　胃癌病人T细胞受体库及细胞因子表达与胃癌进展及转移相关 ,进展期胃癌及发生转移的病例免疫系统受到抑制。     

人CD38抗原胞外段基因克隆及表达

目的 克隆并表达人CD38抗原分子的胞外估基因。方法 采用RT－PCR法，从高表达CD38抗原的Daudi细胞系中，扩增CD38全长cDNA，并将其插入pGEM-T载体中。重新设计引物，从重组pGEMT载体中，扩增CD38抗体分子的胞外段基因，再亚克隆到表达载体pET28a( )，转化大肠杆菌BL21，用IPTG诱导表达。结果 经酶切鉴定及序列分析表明，克隆的CD38外段基因的序列与文献^[1,2]的报道完全一致。将该片段亚克隆到表达载体pET28a( ) ,经IPTG诱导在大肠杆菌BL21中获得表达。结论 获得了人CD38抗原分子胞外段基因及其原核表达产物，对进一步制备单克隆抗体，研究CD38分子的功能具有重要的意义。