Evidence for in vivo reaction of antibody and complement to surface antigens of human cancer cells

The immune adherence test was used to determine whether antibody and complement in cancer patients are fixed in vivo to tumor cells. Human erythrocytes adhered in vitro to the surface of human cancer cells obtained from autopsy and biopsy. Adherence was enhanced by further addition of the C2 and C3 components of complement, and was diminished by preliminary treatment with antibody to C3 (that is, to beta1C-globulin). The results suggest that tumor associated membrane antigens form complexes in vivo with antibodies and complement.     

A crystal structure of the complex between human complement receptor 2 and its ligand C3d

The interaction of complement receptor 2 (CR2)--which is present on B cells and follicular dendritic cells--with its antigen-bound ligand C3d results in an enhanced antibody response, thus providing an important link between the innate and adaptive immune systems. Although a cocrystal structure of a complex between C3d and the ligand-binding domains of CR2 has been published, several aspects of this structure, including the position in C3d of the binding interface, remained controversial because of disagreement with biochemical data. We now report a cocrystal structure of a CR2(SCR1-2):C3d complex at 3.2 angstrom resolution in which the interaction interfaces differ markedly from the previously published structure and are consistent with the biochemical data. It is likely that, in the previous structure, the interaction was influenced by the presence of zinc acetate additive in the crystallization buffer, leading to a nonphysiological complex. Detailed knowledge of the binding interface now at hand gives the potential to exploit the interaction in vaccine design or in therapeutics directed against autoreactive B cells.     

中毒性表皮坏死松解症患者皮疹疱液和血清中 sIL-2R、IL-1 α的检测与意义

目的 :探讨T淋巴细胞在中毒性表皮坏死松解症 (TEN)早期角质形成细胞坏死中的作用。方法 :采用ELISA方法检测 9例TEN、5例Ⅱ度烧伤患者疱液和血清中可溶性IL 2受体 (sIL 2R)、IL 1α水平。结果 :TEN患者疱液中sIL 2R水平显著高于烧伤患者 (P <0 .0 0 1)及TEN患者血清 (P <0 .0 0 1) ,而烧伤患者疱液中IL 1α水平显著高于TEN患者(P <0 .0 5 )及烧伤患者血清 (P <0 .0 5 )。结论 :TEN患者疱液中高水平sIL 2R可能与局部免疫介导的细胞毒反应下调有关 ,进一步支持活化的T淋巴细胞在TEN早期水疱形成中的作用     

Regulation of alloreactivity in vivo by a soluble form of the interleukin-1 receptor

In vitro studies have shown that cytokines are involved in the regulation of the immune response, but their role in vivo is less well defined. Specific cytokine antagonists enable the identification of particular cytokines involved in the response and offer a means for modifying it. Systemic administration of a soluble, extracellular portion of the receptor for interleukin-1 (sIL-1R) had profound inhibitory effects on the development of in vivo alloreactivity. Survival of heterotopic heart allografts was prolonged from 12 days in controls to 17 days in mice treated with sIL-1R. Lymph node hyperplasia in response to a localized injection of allogeneic cells was completely blocked by sIL-1R treatment. The inhibition was overcome by simultaneous administration of interleukin-1 (IL-1); thus, sIL-1R acts by neutralizing IL-1. These results implicate IL-1 as a regulator of allograft rejection and demonstrate the in vivo biological efficacy of a soluble cytokine receptor.     

A parathyroid hormone inhibitor in vivo: design and biological evaluation of a hormone analog

A synthetic analog of bovine parathyroid hormone (bPTH), [tyrosine-34] bPTH-(7-34)NH2, was found to inhibit parathyroid hormone action in vivo. When the analog and parathyroid hormone were infused simultaneously to rats at a molar ratio of 200 to 1, the analog inhibited the excretion of urinary phosphate and adenosine 3',5'-monophosphate. When infused alone at the same dose rate, the analog was devoid of agonist activity. The compound was prepared by following design principles developed for inhibitors of parathyroid hormone, and is believed to be the first antagonist of parathyroid hormone that is effective in vivo.     

Soluble HL-A7 antigen: localization in the beta-lipoprotein fraction of human serum

The HL-A7 antigen of human leukocytes occurs as a soluble, low-density lipoprotein in the serum of HL-A7-positive individuals. Its presence in high concentration may inhibit direct leukocyte grouping, leading to erroneous results. This finding affords an easy method for the preparation of monospecific cytotoxic antiserums by absorption with serum fractions rather than leukocytes.     

Clonal gene therapy: transplanted mouse fibroblast clones express human alpha 1-antitrypsin gene in vivo

A retroviral vector was used to insert human alpha 1-antitrypsin (alpha 1AT) complementary DNA into the genome of mouse fibroblasts to create a clonal population of mouse fibroblasts secreting human alpha 1AT. After demonstrating that this clone of fibroblasts produced alpha 1AT after more than 100 population doublings in the absence of selection pressure, the clone was transplanted into the peritoneal cavities of nude mice. When the animals were evaluated 4 weeks later, human alpha 1AT was detected in both sera and the epithelial surface of the lungs. The transplanted clone of fibroblasts could be recovered from the peritoneal cavities of those mice and demonstrated to still be producing human alpha 1AT. Thus, even after removal of selective pressure, a single clone of retroviral vector-infected cells that expressed an exogenous gene in vitro, continued to do so in vivo, and when recovered, continued to produce the product of the exogenous gene.     

Human monocytes: distinct receptor sites for the third component of complement and for immunoglobulin G

Human monocytes contain two distinct receptor sites, one specific for the third component of complement (C'3), the other for immunoglobulin G(gammaG). The two receptors may function either independently or cooperatively in the induction of phagocytosis. Ingestion of erythrocytes coated with immunoglobulin M antibody requires a relatively large number of bound C'3 molecules per cell. Ingestion of erythrocytes sensitized with gammaG antibody is independent of complement; however, the reaction is inhibited by concentrations of gammaG far below those in normal serum. Inhibition by gammaG-globulin is overcome by a relatively small number of bound C'3 molecules per cell. The two monocyte receptors exert a cooperative effect on ingestion by monocytes of erythrocytes coated with gammaG antibody in the presence of inhibitory amounts of free gammaG.     

香蕉BBI 型蛋白酶抑制剂（MaBBI1）的诱导、变性和复性

BBI(Bowman-Birk protease inhibitor)是一种富含半胱氨酸的植物蛋白酶抑制剂,其抑制的蛋白酶主要包括胰蛋白酶、糜蛋白酶和弹性蛋白酶等丝氨酸蛋白酶。以从香蕉(Musa acuminata L.cv.Brazilian)根中提取的总RNA逆转录成的c DNA为模板,根据NCBI公布的野生型马来西亚蕉(Musa acuminata subsp.Malaccensis)BBI基因(收录号:XM_009415512)的序列设计引物,克隆了1个BBI型蛋白酶抑制剂基因(MaBBI1)。MaBBI1基因大小为381 bp,编码126个氨基酸,包括12个半胱氨酸(9.5%),将该基因构建到载体p GEX-6P-1上转化大肠杆菌Rossetta菌株进行重组蛋白GST-MaBBI1的诱导表达。在IPTG诱导3 h后,一个预测分子量为40.8953 ku的GST-MaBBI1融合蛋白被大量表达。IPTG诱导后的GST-MaBBI1融合蛋白是不溶的并累积成包涵体,通过对包涵体进行变性和复性的方法得到可溶的GST-MaBBI1融合蛋白,为进一步在体外研究该蛋白的功能奠定基础。     

Recombinant human tumor necrosis factor-alpha: effects on proliferation of normal and transformed cells in vitro

Modulation of the growth of human and murine cell lines in vitro by recombinant human tumor necrosis factor-alpha (rTNF-alpha) and recombinant human interferon-gamma (rIFN-gamma) was investigated. rTNF-alpha had cytostatic or cytolytic effects on only some tumor cell lines. When administered together with rIFN-gamma, rTNF-alpha showed enhanced antiproliferative effects on a subset of the cell lines tested. In contrast to its effects on sensitive tumor cells, rTNF-alpha augmented the growth of normal diploid fibroblasts. Variations in the proliferative response induced by rTNF-alpha were apparently not due to differences in either the number of binding sites per cell or their affinity for rTNF-alpha. These observations indicate that the effects of rTNF-alpha on cell growth are not limited to tumor cells, but rather that this protein may have a broad spectrum of activities in vivo.     

半胱胺对羊毛生长及皮肤中GH受体、IGF-1和IGF-1型受体基因表达的影响

罗米丽×中国美利奴 (新疆军垦型) 杂交一代断奶母羔 214只, 随机分成两组, 在日粮中分别添加 3 5 (试验组) 和 0g·kg-1 (对照组) 生长调节剂CT2000 (半胱胺盐酸盐), 实验期为 120d。于试验前和试验结束时称重, 采毛和皮肤样品, 测定母羔生长速度, 羊毛长度、细度、强度、弯曲度和羊毛油汗颜色, 并用反转录多聚酶链式反应 (RT PCR) 方法, 定量分析绵羊皮肤中生长激素受体 (GHR)、胰岛素样生长因子 1 (IGF 1) 和胰岛素样生长因子 1型受体(IGF 1R)mRNA的相对丰度。实验结果显示, 与对照组相比较, 试验组平均日增重提高 12 77% (P<0 01), 羊毛平均日增长提高 24 01% (P<0 01), 羊毛纤维直径平均日增长提高 217 31% (P<0 01), 羊毛纤维强度没有显著的差异(P>0 05), 羊毛油汗颜色和羊毛弯曲度的正常百分率显著提高 (P<0 05); 皮肤中GHRmRNA表达量增加 110 57%(P<0 01), IGF 1、IGF 1RmRNA表达量无明显变化。结果表明, 半胱胺 (CT2000 ) 能够显著提高羔羊生长性能, 促进羊毛生长, 其机制可能与提高皮肤中GHR水平有关。     

The role of magma overpressure in suppressing earthquakes and topography: worldwide examples

In an extending terrane basaltic magma supplied at a pressure greater than the least principal stress (overpressure) may be capable of suppressing normal faulting and the earthquakes and topographic relief that commonly accompany normal faulting. As vertical dikes intrude, they press against their walls in the direction opposite the least principal stress and increase its magnitude. The emplacement of tabular intrusions causes the internal magma pressure to act selectively in opposition to tectonic stresses. This process tends to equalize the stresses and thus diminishes the deviatoric stress (difference between maximum and minimum stresses) that creates faults and causes earthquakes. Observations of the pattern of seismicity and magmatism worldwide indicate that magmatism commonly supplants large earthquakes as the primary mechanism for accommodating tectonic extension. Recognizing the extent of magmatic stress accommodation is important in assessing seismic and volcanic risks.     

拟南芥LRR-RLK家族蛋白CLV1胞外域的可溶性表达与纯化

大肠杆菌NusA蛋白与拟南芥LRR-RLK家族蛋白CLAVATA1(CLV1)胞外结构域(Ectodomain,ECD)融合表达,实现了蛋白CLV1-ECD的可溶性表达;CLV1-ECD与其配体蛋白CLAVATA3(CLV3)共表达,可以明显提高它的水溶性。该实验方法快速简易地获得了大量纯化的CLV1-ECD蛋白,避免了包涵体变性与复性的复杂过程,为植物CLAVATA信号系统的进一步研究奠定了基础。     

The tat gene of human T-lymphotropic virus type 1 induces mesenchymal tumors in transgenic mice

Human T-lymphotropic virus type 1 (HTLV-1) is a suspected causative agent of adult T-cell leukemia. One of the viral genes encodes a protein (tat) that not only results in transactivation of viral gene expression but may also regulate the expression of certain cellular genes that are important for cell growth. Transgenic mice that expressed the authentic tat protein under the control of the HTLV-1 long terminal repeat were generated, and cell types that are permissive for the viral promoter and the effects of the tat gene on these cells were studied. Three of eight founder mice with high levels of expression of the transgene in muscle were bred and then analyzed. All developed soft tissue tumors at multiple sites between 13 to 17 weeks of age. This phenotype was transmitted to nine of nine offspring that inherited the tat gene and were available for analysis. The remaining five founders expressed the transgene in the thymus, as well as in muscle. This second group of mice all exhibited extensive thymic depletion and growth retardation; in all of these mice, death occurred between 3 to 6 weeks of age before tumors became macroscopically visible. The tat gene under the control of the HTLV-1 regulatory region showed tissue-specific expression and the tat protein efficiently induced mesenchymal tumors. The data establish tat as an oncogenic protein and HTLV-1 as a transforming virus.     

人乳头瘤病毒16L1蛋白的原核表达及免疫原性研究

采用聚合酶链反应技术从宫颈癌组织中获得人乳头瘤病毒(HPV)16L1基因,克隆到pGEM—TEasy载体中,再连接到原核表达载体pGEX-6p-1谷胱甘肽-S-转移酶基因的下游,重组质粒转化大肠杆菌BL21,经IPTG诱导、SDS—PAGE分析,用表达产物免疫小鼠,获得的血清进行间接免疫荧光检测。结果表明：获得的pGEX-6p-1-L1基因在大肠杆菌中能以谷胱甘肽-S-转移酶融合蛋白的形式得到高效表达,表达产物免疫小鼠,间接免疫荧光显示免疫血清能与peDNA—L1转染的B16细胞呈现特异反应,说明体外表达的HPV16L1蛋白保留了天然蛋白的抗原性,可作为HPV的诊断抗原、免疫学分析和疫苗研制的原料。     

小峰熊蜂可溶型海藻糖酶基因的克隆及表达分析

【目的】克隆小峰熊蜂（Bombus hypocrita）可溶型海藻糖酶基因（soluble trehalase,Tre-1）全长cDNA序列,预测该基因及其编码蛋白的理化性质,明确该基因在小峰熊蜂不同组织及不同发育时期的表达特性,为研究该基因在小峰熊蜂生长发育中的生物学功能奠定基础。【方法】根据地熊蜂（B. terrestris）和B. impatiens可溶型海藻糖酶基因Tre-1编码蛋白的保守区序列,利用Primer Premier 5.0设计简并引物扩增得到小峰熊蜂保守区片段;随后根据该片段设计基因特异性引物,用RACE方法获得5'端和3'端片段。在此基础上,根据RACE扩增所得片段和保守序列,预测开放阅读框（ORF）序列,分别在起始密码子近5'端和终止密码子的近3'端设计ORF区特异性引物扩增得到ORF,最后采用BioEdit软件比对、拼接获得小峰熊蜂Tre-1 cDNA全长序列。运用ExPASy、SignalP 4.1、NetOGlyc 1.0 sever、ClustalW和MEGA 5.0等软件对该基因进行生物信息学分析,并利用实时荧光定量PCR技术,采用2^-ΔΔCt方法检测不同组织及不同发育时期可溶型海藻糖酶基因的相对表达量。【结果】克隆所得基因cDNA全长为3 129 bp,命名为BhTre-1（GenBank登录号：KJ025078）,其中包含5'端441 bp非编码区和3'端945 bp非编码区,ORF为1 743 bp,共编码580个氨基酸。其编码的蛋白预测分子质量为67.16 kD,等电点为5.95;有1个信号肽结构（1-21位）,1个甘氨酸富集区（GGGGEY）,2个特色“标签序列”（PGGRFKEFYYWDSY和QWDFPNAWPP）,6个Asn-Xaa-Ser/Thr（N-X-S/T）序列,无跨膜区。序列分析发现BhTre-1氨基酸序列与地熊蜂BtTre-1和B. impatiens BiTre-1的一致性很高,分别为99%和98%,与西方蜜蜂（Apis mellifera）和云南小蜜蜂（A. florea）的Tre-1一致性也达到78%;系统发育分析也表明BhTre-1与BtTre-1、BiTre-1的亲缘关系最近,与AmTre-1、AfTre-1之间的亲缘关系次之。基因定量分析结果显示BhTre-1在成虫被检测的各组织中均有表达,在中肠的表达量最高,其次是马氏管,其他各组织表达量较低。成年工蜂的BhTre-1表达量高于幼虫和蛹,工蜂出房后随着龄期的增加表达量呈现先升高后降低的规律,在第15天表达量最高。【结论】克隆得到了BhTre-1全长cDNA序列,其分子生物学特性与其他昆虫Tre-1相似,该基因在小峰熊蜂中肠表达量最高,此外,幼虫和蛹的表达量低于成年工蜂,工蜂出房后表达量呈现先升高后降低的趋势,为进一步研究该基因在小峰熊蜂体内的生物学功能奠定了基础。     

Aflatoxin B1: binding to DNA in vitro and alteration of RNA metabolism in vivo

Aflatoxin B(1) binds to both native and denatured DNA, as shown by spectroscopy and equilibrium dialysis. It also strongly inhibits incorporation of cytidine into rat liver nuclear RNA and lowers the RNA content of the nucleus. The extremle toxicity and carcinogenicity of aflatoxin B(1) may be direct results of the affinity of this agent for DNA.     

L-glutamic acid decarboxylase: a new type in glial cells and human brain gliomas

Human glial cells grown in culture and gliomas and white matter contain an l-glutamic acid decarboxylase which is stimulated markedly by carbonyl-trapping agents. In contrast, L-glutamic acid decarboxylase activity of human cerebral gray matter is strongly inhibited by carbonyl-trapping agents. These results suggest a glial localization of the new type of l-glutamic acid decarboxylase.     

广东汉人血管紧张素Ⅱ 1型受体基因A-C 1166多态性与原发性高血压、冠心病的关系

目的：了解血管紧张素Ⅱ受体1(AT1R)基因3’端非翻译区(3’—UTR)A—C 1166多态性在广东人群中的分布特点及其与该人群患原发性高血压(EH)和冠心病(CAD)的关系。方法：用PCR和限制性内切酶酶切技术分析了186例广东汉族大学生、68例EH患者和72例CAD患者AT。R基因A—C 1166多态性的基因型和等位基因频率。结果：该人群A—C1166基因多态性明显不同于白人，与中国北方汉人相似。健康组中没发现CC型纯合子，疾病组中仅1例EH患者和1例CAD的患者为CC基因型。C1166等位基因频率0．04，A 1166等位基因频率为0．96。疾病组与健康组之间差异无显著性。结论：AT1R基因A—C 1166多态性与广东汉族人患EH和CAD无关。