Increase in the ability of human cancer cells to induce cytotoxic T lymphocytes by ultraviolet irradiation

The roles of ultraviolet-B (UV) radiation in the immunogenicity of human cancer cells have not been fully studied. We have investigated the effects of UV radiation on metastatic melanoma and renal cell carcinoma cells with regard to MHC antigen expression and the ability to induce cytotoxic T lymphocyte (CTL) activity in peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocytes (TIL) against untreated autologous tumor cells. UV radiation respectively decreased or increased MHC class I expression of freshly isolated tumor cells or cultured tumor cells, and also decreased MHC class I expression of starved cultured tumor cells. It increased the ability of both freshly isolated and cultured tumor cells to induce CTL activity from PBMC against untreated autologous tumor cells. UV-irradiated subclones that were more susceptible to CTL lysis were more potent for CTL induction from TIL than either an untreated parental clone or a UV-irradiated subclone that was resistant to CTL lysis. In summary, UV radiation increased the ability of tumor cells to induce CTL activity without a corresponding effect on MHC antigen expression.This work was supported in part by a grant CA47891 from the National Cancer Institute, USA, a grant-in-aid of the comprehensive 10-years strategy for cancer control from ministry of a Health and Welfare, Japan, and the Ishibashi Research Fund, Japan     

Intein-mediated rapid purification of recombinant human pituitary adenylate cyclase activating polypeptide

In order to obtain the recombinant human PACAP efficiently by intein-mediated single column purification, a gene encoding human PACAP was synthesized and cloned into Escherichia coli expression vector pKYB. The recombinant vector pKY-PAC was transferred into E. coli ER2566 cells and the target protein was over-expressed as     

扁蓄总黄酮含量的测定

以35％乙醇为提取溶剂,聚酰胺吸附提纯,芦丁为标准品,用分光光度法于510nm处测定了扁蓄各部位的总黄酮含量。结果表明：扁蓄全草总黄酮含量为4．349％,根为7．115％,茎为5．454％,叶为3．544％。     

稻根象甲种群空间格局及其受耕法的影响

本文根据36块田的调查,用种群空间格局参数I、C_A、I_δ、m~*/m和α、β值进行分析,稻根象甲幼虫和(?)≥0.6头/样方(每样方为0.5m~2)的成虫种群,在稻田均属具公共k值的负二项分布;(?)<0.6头/样方的成虫种群则为随机分布。成虫聚块的大小和面积与平均密度有关。低密度时种群的聚集主要由于环境的异质性;高密度时种群的聚集则由本身的行为习性所致。随着耕作强度的增加,幼虫种群的聚集度和越冬死亡率增大。     

High-level expression and purification of recombinant huGM-CSF (9-127)/IL-6 (29-184) fusion protein in Escherichia coil

As HuGM-CSF and huIL-6 seem to have synergistic and complementary actions, researchers have proposed that fusion proteins incorporating these two cytokines could show increased biological activity, especially in terms of hematopoietic function. Here, we sought to obtain a functional GM-CSF/IL-6 fusion protein and to investigate its biological activities in vitro. A novel construct encoding a fusion protein of huGM-CSF (9-127) and IL-6 (29-184) was generated in the pBV220 expression vector by step-by-step cloning. Amino acids 1-8 of huGM-CSF and amino acids 1-28 of huIL-6 were deleted by PCR. The mutant huGM-CSF (9-127) and huIL-6 (29-184) cDNAs were linked via a linker sequence encoding 15 amino acid residues (G-G-S-G-S)3. Direct sequencing was used to confirm the validity of the desired construct, and the fusion protein was expressed in Escherichia coli host strain BL21 (DE3) in the form of inclusion bodies (IBs). The expression level was more than 25% of the total cell lysate, and a novel purification and refolding strategy was used to isolate the fusion protein product. Inclusion bodies were purified by Q Sepharose H.P. ion exchange in 8 mol/L urea, followed by in situ refolding by Sephacryl S-200. The renatured fusion proteins were obtained at a purity of >95%, and the strategy of refolding on the gel filtration column was found to be efficient, with a relative refolding rate of 80%. This entire refolding and purification procedure could be performed within one day and may prove applicable to large-scale purification and refolding of recombinant proteins from IBs in E. coli. This new method was used to obtain huGM-CSF (9-127)/IL-6 (29-184) fusion protein with high purity and biological activity. MTT assays in TF-1 and B9 cell lines showed that the specific biological activity of huGM-CSF was 1.14+/-0.10 x 10(8) U/mg, and that for huIL-6 was 1.89+/-0.11 x 10(7) U/mg. The fusion protein exhibited enhanced huGM-CSF, but similar huIL-6 biological activities compared with those of either GM-CSF or IL-6 alone. This suggests that our novel huGM-CSF (9-127)/IL-6 (29-184) fusion protein may hold future promise as a therapeutic agent.     

抗体库的起源、发展及应用前景

抗体是高等动物特异性免疫应答反应所产生的免疫球蛋白,负责特异抗原的识别和清除。抗体不仅是机体抵抗病原体入侵的强大武器,也是基础科学研究中用于特异性分子识别的专用工具。抗体分子的多样性导致了抗体库概念的产生,让我们认识到每个高等生物个体都是一个天然的抗体库。在后基因组时代,为了适应各种“组学”研究,特别是为了蛋白质组学研究的高通量技术需求,在噬菌体展示技术平台的基础上,构建了各种基因工程抗体库和抗体替代物库。但现在越来越多的其他展示技术如核糖体展示、mRNA展示等体外展示技术也被用于抗体库的研究,而且表现出了相比于噬菌体展示更多的优势。以下根据目前最新发表的有关综述文章和研究论文,对抗体库的起源、发展及应用前景给予粗略的描述,为读者提供最新的参考文献,通过分析目前存在的问题,论述了抗体库技术的应用前景和发展趋势。     

Injection of duck recombinant follistatin fusion protein into duck muscle tissues stimulates satellite cell proliferation and muscle fiber hypertrophy

Follistatin (FST) can inhibit the expression of myostatin, which is a predominant inhibitor of muscle development. The potential application of myostatin-based technology has been prompted in different ways in agriculture. We previously constructed an expression vector of duck FST and isolated the FST fusion protein. After the protein was purified and refolded, it was added to the medium of duck myoblasts cultured in vitro. The results show that the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide value of the myoblasts in the duck FST treatment group is higher than that in the control group, which indicates that the duck FST fusion protein exhibits the biological activities that can accelerate myoblast proliferation. To further investigate the roles of duck FST on muscle development, we injected the protein into the duck muscle tissues in vivo. The results show that both the duck muscle fiber cross-sectional area and the satellite cell activation frequency are influenced more in the FST treatment group than they are in the control group. In addition to these phenomena, expression of MyoD and Myf5 were increased, and the expression of myostatin was decreased. Together, these results suggest the potential for using duck FST fusion protein to inhibit myostatin activity and subsequently to enhance muscle growth in vivo. The mechanism by which FST regulates muscle development in the duck is similar to that in mammals and fishes.     

辽宁和江苏两省杂草稻植物性状多样性

辽宁和江苏两省是我国杂草稻(Oryza sativa f. spontanea)发生最为严重的地区之一, 为明确两省杂草稻识别特征和类型, 我们在两省14个市29个样点采集样品, 与当地栽培水稻品种一并在南京种植, 观测了营养生长期和生殖生长期的23个植物性状。结果表明, 两省杂草稻在营养生长期的1月株高、1月和2月分蘖数, 在生殖生长期的果皮色、谷粒长/宽比、百粒重、落粒性、秆硬度、剑叶宽、剑叶长、有效穗数、50%黄熟、50%黄熟–50%抽穗和全黄熟等性状与相应的当地栽培稻存在差异;主成分1和主成分2组成的二维散点图(累计贡献率达43.24%)也显示出两省杂草稻间以及与栽培稻间的差异性。采用欧氏距离对两省杂草稻进行系统聚类可以将杂草稻分为籼型和粳型。其中辽宁省杂草稻全部聚在粳型类群中, 它们又可细分为两类; 江苏省杂草稻既有粳型, 又有籼型, 其中粳型与辽宁省杂草稻聚在粳型类群中, 籼型又可分为3类。这6个类群分别具有如下突出特点: 第1类为强落粒、粒轻、秆矮、早熟、偏粳等; 第2类为无芒、穗多、强休眠、剑叶窄、偏粳等; 第3类为长芒、弱分蘖、穗少、弱落粒、偏粳等; 第4类为硬秆、剑叶宽、迟熟、强休眠、偏籼等; 第5类为红果皮、粒长、软秆、粒重、偏籼等; 第6类为无芒、株高、穗长、剑叶长、偏籼等。上述杂草稻的形态学指标和类型的研究将为两省开展杂草稻危害防治工作提供理论依据。