SARS-CoV S DNA疫苗诱导特异性T细胞及相关细胞因子的特性研究

目的 小鼠经皮下SARS-CoV S DNA疫苗免疫后，研究其特异性T细胞及相关细胞因子的特性。方法SARS-CoV S DNA疫苗免疫BALB／c小鼠后，获取淋巴细胞悬液。经S抗原多肽刺激后，采用ELISA检测细胞培养上清液中IFN-γ／的水平，利用流式细胞仪在单个细胞水平上检测IFN-γ和IL-2的表达及其关系。结果 当S混合多肽刺激后，DNA疫苗免疫小鼠的淋巴细胞产生大量的IFN-γ，与对照鼠相比差异有统计学意义（P〈0．01）。细胞亚群分析的结果表明，IFN-γ^＋和IL-2^＋的CD4^＋T细胞百分率明显高于CD8^＋T细胞。单独产生IL-2的细胞占大多数，其次为IFN-γ和IL-2双阳性细胞，只产生IFN-γ的细胞很少。结论 SARS-CoV S DNA疫苗免疫小鼠后可以诱导抗原特异性CD4^＋和CD8^＋T细胞的产生。     

CD4+T细胞的分裂与表面标志和细胞因子产生相关性的探讨

目的：阐明抗原特异性CD4^ T细胞的分裂、细胞表面分子的表达和细胞因子产生之间的关系。方法：从T细胞受体转基因小鼠(DO11、10)的脾和淋巴结中分离CD4^ T细胞。在抗原提呈细胞存在的情况下，经OVA多肽抗原刺激后，检测细胞的分裂、表型和细胞因子的产生。结果：经抗原刺激3天后，CD4^ T细胞分裂1-5次，细胞膜表面抗原CD25、CD44的表达随着细胞的分裂而增加，相反，CD62L和CD69随着细胞分裂次数的增加而递减。细胞因子IFN-γ、IL-4和IL-10随着细胞分裂次数的增加而递增。IL-12促进细胞的分裂，增加IFN-γ的产生，抑制IL-4和IL-10的产生。结论：当CD4^ T细胞活化后，随着细胞的分裂，其细胞膜表面分子的表达和细胞因子的产生均发生质和量的变化。     

共刺激分子4-1BBL基因免疫对HBsAg核酸疫苗诱导小鼠特异性免疫应答的影响

目的 研究共刺激分子4-1BBL基因免疫对HBsAg核酸疫苗诱导小鼠特异性体液和细胞免疫应答的影响.方法 将HBV表面抗原核酸疫苗pcDS2单独或联合共刺激分子4-1BBL质粒肌肉注射免疫C57BL/6小鼠;ELISA法检测小鼠血清抗-HBs IgG及亚型IgG1和IgG2a;迟发型超敏反应(DTH)反应检测体内细胞反应;流式细胞仪检测CD4+ T淋巴细胞分泌IL-4和IFN-γ及CD8+T淋巴细胞分泌IFN-γ水平;流式细胞仪检测小鼠脾细胞HBsAg特异性体外细胞毒性T淋巴细胞杀伤作用(CTL).结果 与单纯免疫核酸疫苗pcDS2组比较,pcDS2和4-1BBL联合免疫组小鼠的抗-HBs水平显著提高,抗-HBs IgG亚类以IgG2a占优;免疫小鼠经HBsAg脚掌皮下刺激后,联合免疫组小鼠脚掌的厚度显著高于pcDS2组;联合免疫组CD4+T淋巴细胞的IL-4和IFN-γ表达水平及CD8+T淋巴细胞的IFN-γ表达水平显著升高;DNA疫苗免疫的各组小鼠,HBsAg特异性体外CIL杀伤作用高于对照组,其中联合免疫组小鼠的体外CTL杀伤作用最强.结论共刺激分子4-1BBL不仅能增强HBV DNA疫苗诱导特异性体液免疫应答,还能增强特异性型细胞免疫反应,尤其增强体内CIL的杀伤活性.     

HIV gag DNA疫苗诱导小鼠特异性细胞免疫应答的研究

目的 研究小鼠注射HIV gag DNA疫苗后的抗原特异性细胞免疫应答.方法 C57BL/6小鼠以初免/加强的策略经肌肉注射HIV gag DNA疫苗,一周后获取其脾与肺的单个细胞,体外经Gag抗原多肽刺激后,采用ELISA法检测细胞培养上清中IFN-γ的水平,ELISPOT法检测IFN-γ分泌细胞的频率,流式细胞仪分析特异性T细胞的亚群.结果 经Gag多肽刺激后,加强免疫组IFN-γ产生的总体水平和分泌细胞频率均高于对照组及初次免疫组.HIV gag DNA疫苗可同时诱导产生Gag-特异性CD4 和CD8 T细胞.结论 HIV gagDNA疫苗免疫小鼠后可诱导抗原特异性效应性T细胞应答.     

环孢素A对LPS诱导的早期炎症反应的影响

目的研究环孢素A(cyclosporin A,CsA)对脂多糖(lipopolysaccharide,LPS)诱导的小鼠早期炎症反应的影响。方法小鼠腹腔内注射LPS诱导炎症反应,静脉注射不同浓度的CsA。6h后取血清,使用ELISA方法观察炎性因子IFN-γ和IL-6的含量;取脾细胞,使用流式细胞仪观察CD4+和CD8+T细胞表面的活化分子CD69表达;并使用细胞内细胞因子染色的方法,观察CD4+和CD8+T细胞IFN-γ和IL-4的产生水平。结果 CsA可以明显降低LPS诱导的小鼠血清中IFN-γ的水平,抑制CD4+和CD8+T细胞表面CD69分子的表达,抑制T细胞IFN-γ和IL-4的产生,均表现为剂量依赖性抑制关系。结论 CsA剂量依赖性抑制LPS诱导的小鼠早期炎症反应。     

人类巨细胞病毒特异性CD8+ T细胞IFN-γ和穿孔素水平的检测

目的研究人巨细胞病毒(hCMV)结构蛋白pp65衍生抗原肽(pp65495-503, NLV)特异性CD8+ T细胞的功能特性.方法将HLA-A2/NLV四聚体染色与细胞内细胞因子或穿孔素染色相结合,以流式细胞仪直接分析NLV特异性CD8+ T细胞内穿孔素的表达水平,或者在NLV抗原肽刺激6 h后分析γ-干扰素(IFN-γ)的表达水平.结果 NLV抗原肽能诱导hCMV特异性CD8+ T细胞分泌IFN-γ,不同供者特异性CD8+ T细胞产生IFN-γ的比率存在较大差异(55.69±17.64) %,当NLV抗原肽质量浓度为10 μg/mL时IFN-γ阳性细胞百分率最高;未经刺激的特异性CD8+ T细胞内表达较高水平的穿孔素(53.90±16.41)%.结论识别单一表位的hCMV特异性CD8+ T细胞合成IFN-γ和穿孔素的能力存在多样性.     

GPIF对免疫损伤小鼠T淋巴细胞膜表面共刺激分子表达的影响

目的：分析羊胎盘免疫调节因子(GPIF)对BALB/c小鼠T淋巴细胞共刺激表面抗原分子表达及其细胞因子分泌的影响，探讨羊胎盘免疫调节因子免疫促进作用机理。方法: 60Coγ-ray辐射所致免疫抑制小鼠连续7 d腹腔注射GPIF，流式细胞分析术分析BALB/c小鼠脾细胞表达CD28+、CD152+单阳性细胞百分率，表达CD4+CD28+、CD8+CD28+、CD4+CD152+、CD8+CD152+双阳性细胞百分率；ELISA法检测小鼠血清IL-2、IFN-γ分泌水平。结果: 羊胎盘免疫调节因子显著提高免疫损伤小鼠脾淋巴细胞CD28+、CD4+CD28+、CD8+CD28+阳性细胞百分率(P<0.05，P<0.01)，降低CD152+、CD4+CD152+阳性细胞百分率(P<0.05，P<0.01)，提高小鼠血清IL-2、IFN-γ分泌水平(P<0.01)。结论: 羊胎盘免疫调节因子的免疫促进作用与其调节T淋巴细胞CD28、CD152共刺激分子通路的活化信号传递，降低T淋巴细胞的功能抑制，促进T淋巴细胞的活化有关。活化的T淋巴细胞分泌细胞因子IL-2、IFN-γ，参与细胞因子介导的免疫网络调节。     

不同种类乙型肝炎表面抗原诱导小鼠早期细胞免疫应答的比较

目的 比较不同表达系统来源的乙型肝炎(乙肝)表面抗原(HBsAg)免疫小鼠诱导早期脾淋巴细胞抗原特异性细胞免疫应答的特点,探讨影响乙肝疫苗保护效果的因素.方法 3种HBsAg(汉逊酵母、CHO细胞和血源)分别皮下接种不同组小鼠(BALB/c,H-2d),每只3μg,于免疫后4d分离脾单个核细胞(MNC),经细胞分选仪(MACs)分选后,获得纯度高于90％的CD4+和CD8+T细胞,应用ELISPOT测定MNC、CD4+和CD8+T细胞体外刺激后所产生的细胞因子IFN-γ、IL-2斑点数( SFC).结果 细胞分选后,汉逊抗原诱导CD8+T细胞分泌IFN-γ的水平和CD4+T细胞分泌IL-2水平均显著高于CHO抗原组(8/10、2/10,P=0.035;6/10、0/10,P=0.005).汉逊抗原组与血源抗原组CD8+T细胞经体外刺激诱导IFN-y全部阳转(10/10),但分泌水平上汉逊抗原组显著高于血源抗原组(t=2.479,P=0.035);汉逊抗原组诱导CD4+T细胞IFN-γ阳转率及分泌水平均显著高于血源抗原组(10/10、4/10,P=0.005;t=3.967,P=0.003).结论 乙肝抗原免疫小鼠4d即可诱导细胞免疫应答,且汉逊酵母抗原早期诱导抗原特异性IFN-γ、IL-2的能力显著高于CHO和血源抗原,与其临床考核母婴传播阻断HBV保护率显著优于CHO和血源乙肝疫苗相一致,为及时接种乙肝疫苗的必要性和高危新生儿选择接种乙肝疫苗的类型提供依据.     

八肽胆囊收缩素对经钥孔戚血蓝蛋白免疫小鼠T淋巴细胞亚群的影响

目的：探讨八肽胆囊收缩素（CCK-8）对经钥孔戚血蓝蛋白（KLH）免疫小鼠T淋巴细胞亚群的影响。方法：雌性BALB/c小鼠KLH免疫同时分别给予不同剂量CCK-8。流式细胞法检测小鼠外周血及脾细胞中CD4+、CD8+T细胞阳性百分率；RT-PCR法检测脾细胞中Th1型细胞因子IFN-γ、Th2型细胞因子IL-4 mRNA表达；ELISA法检测其培养上清中IFN-γ、IL-4水平；HE染色观察小鼠肺组织病理变化。结果：CCK-8下调KLH免疫小鼠外周血及脾细胞中上升的CD4+、CD8+T细胞阳性百分率，降低CD4+/CD8+比值；进一步提高其IFN-γ mRNA表达和培养上清中IFN-γ分泌量，同时下调上升的IL-4 mRNA表达和培养上清中IL-4分泌量；减轻KLH免疫所致小鼠肺部炎症。结论：CCK-8可调节适应性免疫应答，抑制T细胞尤其是CD4+T细胞活性；抑制Th2功能，提高Th1功能，因此可能在变态反应性疾病的发病和防治中具有一定作用。     

Ag85A DNA疫苗加强免疫显著提高卡介苗初免小鼠的抗结核T细胞免疫应答

目的 构建表达结核分枝杆菌(Mycobacterium tuberculosis,Mtb)免疫优势抗原Ag85A的DNA疫苗,分析其加强免疫后提高卡介苗(BCG)初免小鼠的抗结核T细胞免疫应答.方法 以Mtb毒株H37Rv基因组DNA为模板,PCR扩增Ag85A抗原编码的结构基因并克隆至真核表达载体pVAX1中构建其DNA疫苗;接着,将纯化后的该DNA疫苗加强免疫BCG初免小鼠2针,以BCG和DNA单独免疫小鼠为对照,免疫8周后无菌分离脾淋巴细胞,分别应用IFN-γ ELISPOT和多因子胞内流式细胞术(intracellular staining)分析免疫小鼠的Mtb抗原特异性效应细胞免疫水平与分泌IFN-γ/TNF-α/IL-2的多功能CD4+T细胞频率及其强度以及CD8+T细胞免疫应答.结果 与BCG免疫及DNA单独免疫组相比,Ag85A DNA加强免疫不仅能显著提高小鼠IFN-γ+TNF-α+IL-2+多功能T细胞,IFN-γ+IL-2+、IL-2+TNF-α+双功能T细胞与IL-2+单功能T细胞的频率以及IL-2的分泌能力,还能显著诱导小鼠产生更多分泌IFN-γ和IL-2的CD8+T细胞.结论 本研究成功构建了表达Mtb免疫优势抗原Ag85A的DNA疫苗并分析了其免疫原性,证实了BCG初免-DNA加强的免疫策略可同时显著增强实验小鼠的Mtb抗原特异性CD4+T和CD8+T细胞应答水平,有利于提高BCG的免疫原性,为增强BCG逐渐下降的抗结核保护效果提供新思路.     

Pathogenicity of PMV-3/parakeet/Netherlands/449/75 for chickens

Infection of 1-day-old chicks with PMV-3/parakeet/Netherlands/449/75 (449) by intramuscular, intranasal or contact routes resulted in severe impairment of growth in all groups compared to uninfected control birds. In the group infected intramuscularly with 449 virus 16/22 birds died within 14 days of infection. No clinical signs were seen in 6-week-old chickens infected with 449 by intramuscular, intranasal or contact routes. One-day-old chicks infected with a large dose of NDV-B(1) and one-day-old chicks placed in contact with these birds also showed significant impairment of growth compared to uninfected controls.     

Nucleotide sequence of RNA segment 3 of the avian influenza A/FPV/Rostock/34 and its comparison with the corresponding segment of human strains A/PR/8/34 and A/NT/60/68

The nucleotide sequence of RNA segment 3 of A/FPV/Rostock/34 (H7N1), an avian strain of influenza A virus, has been determined from a cloned DNA copy. Segment 3 codes for the PA polypeptide and the sequence specifies an acidic polypeptide of 716 amino acid residues. Comparison of the sequence with the corresponding segment of two human strains A/PR/8/34 and A/NT/60/68 indicates significant divergence of the avian sequence from the human sequences at the nucleotide level. At the amino acid level there is considerably greater homology between the avian and human strains. This presumably reflects a constraint on divergence of the PA polypeptide imposed by a common functional requirement of PA in all influenza virus strains.     

Determination of the rpoB gene sequences of Bartonella henselae and Bartonella quintana for phylogenic analysis

Using the Genome Walker™ procedure, which allows PCR amplification of genomic DNA using a single gene-specific primer and direct automated sequencing methodology, we obtained the nucleotide sequence of the RNA polymerase β subunit (rpoB) from Bartonella henselae and Bartonella quintana. A phylogenetic tree constructed from these data and other rpoB sequences available in GenBank is, in part, consistent with those previously derived from 16S rRNA gene sequences and confirms the position of Bartonella within the α subdivision of Proteobacteria. In fact, this analysis showed that rpoB data are similar to 16S rRNA data for the α, β and γ subdivisions of Proteobacteria. In contrast, concerning other bacteria included in our study, the topologies of phylogenetic trees were different. Based on the bootstrap values derived from rpoB phylogenic analysis, we believe that this molecule should contribute to better understanding the evolutionary process.     

Evaluation of the A/Seal/Mass/1/80 virus in squirrel monkeys

An influenza A virus isolated from seals [A/Seal/Mass/1/80 (H7N7)] and an isolate of this virus obtained from a human conjunctiva were evaluated for replication and virulence in squirrel monkeys. When the seal virus was administered intratracheally, it replicated in lungs and nasopharynges and induced illness almost to the same extent that a human influenza A virus [A/Udorn/72 (H3N2)] did. In one monkey that died of pneumonia, the seal virus was recovered from spleen, liver, and muscle as well as lung. After conjunctival administration in monkeys, the seal virus replicated to a peak titer in the conjunctivae 30-fold greater than that attained by the human virus, but this difference was not statistically significant. In contrast, the seal virus replicated less well than the human virus in the tracheae and nasopharynges when administered by the conjunctival route. These results indicate that the seal virus can replicate efficiently in primates, that it can spread systemically, and that it might differ from human virus in being able to replicate slightly better in primate conjunctival tissue.     

An evaluation of the genetic stability and pathogenicity of the Russian cold-adapted influenza A donor strains A/Leningrad/134/17/57 and A/Leningrad/134/47/57 in ferrets

The influenza A components of live attenuated vaccines used in Russia have been prepared as reassortants of the cold-adapted (ca) H2N2 viruses, A/Leningrad/134/17/57-ca (Len/17) and A/Leningrad/134/47/57-ca (Len/47), and virulent epidemic strains. The lesions responsible for attenuation within the six internal genes of each donor strain have been sequenced and described, but relatively little is known as to their stability before and after passage in susceptible hosts. In the work reported in this paper, RT-PCR restriction analysis and limited sequencing of individual genes were used to evaluate the stability of lesions in stocks of the both donor strains after passage in ferrets, which have been used widely as susceptible hosts for assessment of the virulence of influenza strains. Len/47 was shown to possess expected lesions by RT-PCR and restriction analysis. Substitution at position 1066 of the NP gene, which has been previously reported to be unique to Len/47 [Klimov et al., Virology 186 (1992) 795], was also shown to be present in all clones of Len/17. This change was confirmed by limited sequence analysis and was shown to be retained in progeny viruses isolated from the lungs and turbinates of inoculated ferrets. Two other changes in the PB2 and PB1 genes that were present in Len/47 were detected by limited sequence analysis alone. Further previously unreported minor changes were shown to be present for Len/17 and Len/47, but not both, and their significance is unknown. Limited replication of each donor strain occurred in ferrets and minimal clinical signs and histopathology were present. By contrast, the parental strain Len/57 and the recent epidemic strain A/Sydney/6/97 induced clinical signs and histopathology that were typical of influenza disease.     

Cold-Adapted Variants of Influenza A Virus: Evaluation in Adult Seronegative Volunteers of A/Scotland/840/74 and A/Victoria/3/75 Cold-Adapted Recombinants Derived from the Cold-Adapted A/Ann Arbor/6/60 Strain

Influenza A/Scotland/74 (H3N2) and A/Victoria/75 (H3N2) cold-adapted (ca) recombinant viruses, prepared by mating the A/Ann Arbor/6/60 (H2N2) ca donor virus and influenza A wild-type virus, were evaluated in adult seronegative volunteers (serum hemagglutination-inhibiting antibody titer, 相似文献   

A comparison of the biochemical properties of the human diaphorase (DIA3) isozymes determined by the common alleles DIA13, DIA23 and DIA33

(1) Various buffer systems for the starch gel electrophoresis of human diaphorase isozymes have been explored. Electrophoresis in a Tris/Borate system at pH 8.6 which includes 70 micron NADH in the gel and cathodal electrode buffers, provides good resolution of the six DIA3 phenotypes previously resolved by isoelectric focusing. (2) The variant genes DIA13, DIA23 and DIA33 occur with frequencies of about 0.76, 0.23 and 0.01 respectively in the English population. (3) The isozymes determined by the least common gene, DIA33, are markedly different from the isozymes determined by DIA13 and DIA23 in their relatively low heat stability, high affinity for Blue Sepharose and slow anodal electrophoretic mobility in buffer systems containing borate. The DIA3 1 and DIA3 2 isozymes are similar to one another in these characteristics.