Identification of a novel HLA-A2-restricted cytotoxic T lymphocyte epitope from cancer-testis antigen PLAC1 in breast cancer

Identification of cytotoxic T lymphocyte (CTL) epitopes from tumor antigens is essential for the development of peptide vaccines against tumor immunotherapy. Among all the tumor antigens, the caner-testis (CT) antigens are the most widely studied and promising targets. PLAC1 (placenta-specific 1, CT92) was considered as a novel member of caner-testis antigen, which expressed in a wide range of human malignancies, most frequently in breast cancer. In this study, three native peptides and their analogues derived from PLAC1 were predicted by T cell epitope prediction programs including SYFPEITHI, BIMAS and NetCTL 1.2. Binding affinity and stability assays in T2 cells showed that two native peptides, p28 and p31, and their analogues (p28-1Y9?V, p31-1Y2L) had more potent binding activity towards HLA-A*0201 molecule. In ELISPOT assay, the CTLs induced by these four peptides could release IFN-γ. The CTLs induced by these four peptides from the peripheral blood mononuclear cells (PBMCs) of HLA-A*02⁺ healthy donor could lyse MCF-7 breast cancer cells (HLA-A*0201⁺, PLAC1⁺) in vitro. When immunized in HLA-A2.1/K^b transgenic mice, the peptide p28 could induce the most potent peptide-specific CTLs among these peptides. Therefore, our results indicated that the peptide p28 (VLCSIDWFM) could serve as a novel candidate epitope for the development of peptide vaccines against PLAC1-positive breast cancer.     

外源亚精胺对盐胁迫下马铃薯幼苗生长和生理生化特征的影响

盐胁迫是影响作物生长的主要非生物胁迫类型,引起离子毒害和渗透胁迫,导致植物生长减弱、失绿、萎蔫甚至死亡。前期研究表明,适宜浓度的外源亚精胺能够缓解盐胁迫条件下植物叶片受损伤程度,提升生物膜抵抗盐离子伤害的能力,促进植物生长。该试验采用营养液培养法,以100mmol·L-1、200mmol·L-1、300 mmol· L-1NaCl溶液模拟不同盐胁迫程度,以中度耐盐品种晋薯16号、轻度耐盐品种冀张薯12号为试材,当马铃薯脱毒幼苗长至 4～5 片真叶时,连续叶面喷施0.9mmol·L-1外援亚精胺 7 d,2次/d。分析叶面喷施外源亚精胺（Spd）对不同盐胁迫程度条件下马铃薯幼苗生长、叶片抗氧化酶活性、渗透调节物质含量的影响。结果表明：（1）叶面喷施Spd缓解了盐胁迫对幼苗生长的抑制作用,提高了叶绿素含量和根系活力,提升超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、抗坏血酸(ASA)和谷胱甘肽(GSH)等抗氧化酶活性,以及脯氨酸、可溶性糖、氨基酸含量;（2）200 mmol· L-1NaCl胁迫条件下,Spd对“晋薯16号”缓解作用最显著。研究表明Spd通过提高马铃薯幼苗根系活力、叶绿素含量、抗氧化酶活性、渗透调节能力,提高马铃薯幼苗对盐胁迫的适应性,促进马铃薯幼苗生长。     

蚯蚓基因组学的研究进展: 基于全基因组及线粒体基因组

蚯蚓被喻为土壤中的“生态系统工程师”, 具有高度的多样性且在全世界都有分布, 被用作土壤健康的指示生物。蚯蚓具有极强的环境适应能力, 在不断适应的过程中促进了自身基因组的进化。本文对近年来蚯蚓全基因组以及线粒体基因组的研究进展进行了综述。蚯蚓全基因组的测序、拼装和分析为研究蚯蚓生态学、污染物对蚯蚓致毒的分子机制、免疫防御的分子机制、蚯蚓再生的分子机制等奠定基础。而线粒体基因组多应用于蚯蚓分子系统发育方面的研究, 目前已有多种蚯蚓通过线粒体基因组测序完成了物种的鉴定。本文建议今后重点开展以下几方面的研究: (1)针对现有的4种蚯蚓全基因组测序结果, 进一步进行比较基因组学、进化基因组学和功能基因组学的研究。(2)完善不同种蚯蚓的基因文库和表达序列标签。(3)建立线粒体基因组、全基因组与蚯蚓物种多样性的关联分析。     

Phosphatidylinositol-3 phosphatase myotubularin-related protein 6 negatively regulates CD4 T cells

Intracellular Ca2+ levels rapidly rise following cross-linking of the T-cell receptor (TCR) and function as a critical intracellular second messenger in T-cell activation. It has been relatively under appreciated that K+ channels play an important role in Ca2+ influx into T lymphocytes by helping to maintain a negative membrane potential which provides an electrochemical gradient to drive Ca2+ influx. Here we show that the Ca2+-activated K+ channel, KCa3.1, which is critical for Ca2+ influx in reactivated naive T cells and central memory T cells, requires phosphatidylinositol-3 phosphatase [PI(3)P] for activation and is inhibited by the PI(3)P phosphatase myotubularin-related protein 6 (MTMR6). Moreover, by inhibiting KCa3.1, MTMR6 functions as a negative regulator of Ca2+ influx and proliferation of reactivated human CD4 T cells. These findings point to a new and unexpected role for PI(3)P and the PI(3)P phosphatase MTMR6 in the regulation of Ca2+ influx in activated CD4 T cells and suggest that MTMR6 plays a critical role in setting a minimum threshold for a stimulus to activate a T cell.     

纤毛虫念珠异列虫射出胞器的超微结构观察

应用扫描电镜术和透射电镜术显示,纤毛虫念珠异列虫(Anteholosticha monilata)的射出胞器早期发生在细胞质深处,附近有不同类型的囊泡结构。成熟后射出胞器向表膜迁移,结构由不同电子密度片层的体部、结晶状的中心轴杆部和多层膜的帽部组成。受外界刺激时胞器冲破皮层射出,形态呈"蘑菇"状。据上述观察结果推测:该射出胞器具有防御作用,它可能起源于高尔基体活动产生的小泡;在亲缘关系较近的纤毛虫中,其射出胞器可能具有相似的分化特征。     

TGF-β promote epithelial-mesenchymal transition via NF‐κB/NOX4/ROS signal pathway in lung cancer cells

Molecular Biology Reports - Epithelial-mesenchymal transition (EMT), transforming growth factor β(TGF-β) and reactive oxygen species(ROS) plays a central role in cancer metastasis....     

A New Orchid Genus,Danxiaorchis, and Phylogenetic Analysis of the Tribe Calypsoeae

Background

Orchids have numerous species, and their speciation rates are presumed to be exceptionally high, suggesting that orchids are continuously and actively evolving. The wide diversity of orchids has attracted the interest of evolutionary biologists. In this study, a new orchid was discovered on Danxia Mountain in Guangdong, China. However, the phylogenetic clarification of this new orchid requires further molecular, morphological, and phytogeographic analyses.

Methodology/Principal Findings

A new orchid possesses a labellum with a large Y-shaped callus and two sacs at the base, and cylindrical, fleshy seeds, which make it distinct from all known orchid genera. Phylogenetic methods were applied to a matrix of morphological and molecular characters based on the fragments of the nuclear internal transcribed spacer, chloroplast matK, and rbcL genes of Orchidaceae (74 genera) and Calypsoeae (13 genera). The strict consensus Bayesian inference phylogram strongly supports the division of the Calypsoeae alliance (not including Dactylostalix and Ephippianthus) into seven clades with 11 genera. The sequence data of each species and the morphological characters of each genus were combined into a single dataset. The inferred Bayesian phylogram supports the division of the 13 genera of Calypsoeae into four clades with 13 subclades (genera). Based on the results of our phylogenetic analyses, Calypsoeae, under which the new orchid is classified, represents an independent lineage in the Epidendroideae subfamily.

Conclusions

Analyses of the combined datasets using Bayesian methods revealed strong evidence that Calypsoeae is a monophyletic tribe consisting of eight well-supported clades with 13 subclades (genera), which are all in agreement with the phytogeography of Calypsoeae. The Danxia orchid represents an independent lineage under the tribe Calypsoeae of the subfamily Epidendroideae. This lineage should be treated as a new genus, which we have named Danxiaorchis, that is parallel to Yoania. Both genera are placed under the subtribe Yoaniinae.