体外分化的人体巨噬细胞抑制天然杀伤(NK)细胞的研究

本文继先前工作后,进一步应用正常健康人外周血单个核细胞(PBMNC)经塑料培皿粘附技术把单核细胞分离出来,经培养进一步纯化,随后动态观察培养0,2,4,6和8天的单核-巨噬细胞的形态变化和对新鲜分离同种异基因个体PBMNC中NK活性的影响。实验表明,体外分化6天和8天的巨噬细胞质/核比例和胞浆内空泡显著增加,细胞直径约为0天时的2倍。这些细胞和PBMNC之比为0.5:1时,引起了NK细胞活性的50%以上抑制(4小时~(51)Cr标记K 562肿瘤的同位素释放试验)。这种抑制效应不为过氧化氢酶(Catalase 4000单位/毫升)和前列腺素合成酶的抑制剂(Indom 1×10~(-5)M)所阻断。实验证明,同种异基因个体的NK细胞不能识别巨噬细胞表面抗原,从而排除了巨噬细胞和K562肿瘤抗原竞争的可能性。实验还表明,巨噬细胞对NK活性的抑制是不受HLA约束的。应用高频超声振荡破碎巨噬细胞膜方法和免疫调变技术进一步提示,人体巨噬细胞对NK活性的抑制与巨噬细胞体积无关,而与体外分化所赋有的固有特性和它们分泌的免疫调节分子有关。     

中国盲走螨属一新种和二新纪录：蜱螨亚纲：植绥螨科

本文记述我国植绥螨科盲走螨属Ｔｙｐｈｌｏｄｒｏｍｕｓ一新种和中国二新纪录：鲁盲走螨Ｔ．ｌｕｅｎｓｉｓ ｓｐ．ｎｏｖ．,甲胄盲走螨Ｔ．ｌｏｒｃａｔｕｓ,肥厚盲走螨Ｔ．ｈｉｇｏｅｎｓｉｓ。标本保存于上海复旦大学环境和资源生物系。     

密码结构域及其功能表现

能组织成超级结构的各种序列组块,因其具有特定一级序列、或者具有某种卷曲的螺旋构象和某种非β螺旋结构,可以作为有特异功能的结构域、被特异的结合蛋白质识别和结合,因而可称为密码结构域,密码结构域作为特异的分子相互作用和过程的遗传指令,参与细胞周期的各种事件乃至发育和分化过程中基因有区别的表达.     

Positive selection is a general phenomenon in the evolution of abalone sperm lysin

Lysin is a 16kDa acrosomal protein used by abalone sperm to create a hole in the egg vitelline envelope (VE). The interaction of lysin with the VE is species-selective and is one step in the multistep fertilization process that restricts heterospecific (cross-species) fertilization. For this reason, the evolution of lysin could play a role in establishing prezygotic reproductive isolation between species. Previously, we sequenced sperm lysin cDNAs from seven California abalone species and showed that positive Darwinian selection promotes their divergence. In this paper an additional 13 lysin sequences are presented representing species from Japan, Taiwan, Australia, New Zealand, South Africa, and Europe. The total of 20 sequences represents the most extensive analysis of a fertilization protein to date. The phylogenetic analysis divides the sequences into two major clades, one composed of species from the northern Pacific (California and Japan) and the other composed of species from other parts of the world. Analysis of nucleotide substitution demonstrates that positive selection is a general process in the evolution of this fertilization protein. Analysis of nucleotide and codon usage bias shows that neither parameter can account for the robust data supporting positive selection. The selection pressure responsible for the positive selection on lysin remains unknown.      

Development of a serum-free medium using computer-assisted factorial design and analysis

Stepwise screening of media supplements using factorial design and analysis was employed in the development of serum-free medium for a recombinant Chinese hamster ovary cell line. The effects (growth and target protein production) of different combinations were measured at two time points to ensure adequate response. The results were analysed by a computer program specialized in factorial analysis. The formulation deduced from the previous experiment was used as the new basal medium for the next screening. Certain significant nutrients were studied again in a more advanced formulation in order to analyse the potential synergistic effects with new media components. Compared to cells grown in serum-containing medium, cells adapted to the final formulation of the serum-free medium had a comparable growth rate but a four fold increase in the active protein production.Abbreviations ANOVA Analysis of variance - BSA bovine serum albumin - CHO Chinese hamster ovary - FBS fetal bovine serum - MTT 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide - PBS phosphate buffered saline - SFM serum-free medium     

The plant glycosyltransferase clone collection for functional genomics

The glycosyltransferases (GTs) are an important and functionally diverse family of enzymes involved in glycan and glycoside biosynthesis. Plants have evolved large families of GTs which undertake the array of glycosylation reactions that occur during plant development and growth. Based on the Carbohydrate‐Active enZymes (CAZy) database, the genome of the reference plant Arabidopsis thaliana codes for over 450 GTs, while the rice genome (Oryza sativa) contains over 600 members. Collectively, GTs from these reference plants can be classified into over 40 distinct GT families. Although these enzymes are involved in many important plant specific processes such as cell‐wall and secondary metabolite biosynthesis, few have been functionally characterized. We have sought to develop a plant GTs clone resource that will enable functional genomic approaches to be undertaken by the plant research community. In total, 403 (88%) of CAZy defined Arabidopsis GTs have been cloned, while 96 (15%) of the GTs coded by rice have been cloned. The collection resulted in the update of a number of Arabidopsis GT gene models. The clones represent full‐length coding sequences without termination codons and are Gateway^® compatible. To demonstrate the utility of this JBEI GT Collection, a set of efficient particle bombardment plasmids (pBullet) was also constructed with markers for the endomembrane. The utility of the pBullet collection was demonstrated by localizing all members of the Arabidopsis GT14 family to the Golgi apparatus or the endoplasmic reticulum (ER). Updates to these resources are available at the JBEI GT Collection website http://www.addgene.org/ .