靶向M细胞的抗原递送¾¾增强黏膜免疫应答的关键策略

黏膜是阻止病原入侵的第一道防线,黏膜免疫系统在抵抗感染方面起着至关重要的作用。通过黏膜途径接种疫苗可以同时诱导黏膜和全身免疫反应,因此,理论上针对黏膜的免疫策略是最合理和有效的。但黏膜免疫系统的复杂性和屏障作用造成抗原诱导的免疫应答水平低下,制约了黏膜疫苗的发展。M细胞(Microfoldcells)是黏膜免疫系统所独有的,其具有捕获腔内抗原和启动抗原特异性免疫应答的功能。M细胞摄取抗原的多少直接关系到黏膜疫苗的免疫效力,而利用M细胞配体可将抗原靶向递呈给M细胞,从而实现高效的黏膜免疫应答。靶向M细胞的抗原递送策略及其应用可以提高黏膜免疫应答水平,促进黏膜疫苗的研制。尽管如此,要成功研制安全高效的黏膜疫苗,今后依然有漫长的路要走,这可能有赖于进一步探究M细胞的特性和功能及黏膜免疫机制。     

EBV编码miRNAs在病毒感染和肿瘤发生中的功能和意义

EB病毒(Epstein-Barr virus,EBV)是一种172 kb大小的线性双链DNA病毒,与鼻咽癌、淋巴瘤、胃癌等恶性肿瘤的发生密切相关. EBV编码的微小RNAs (miRNAs)可以调节病毒和宿主细胞基因的表达,并且在癌症发生发展中起着多种作用.本文综述了EBV编码的miRNAs (EBV-encoded miRNA,EBV miRNAs)在病毒感染和肿瘤发生、侵袭转移、抗凋亡、信号通路等方面的生物学功能,以及对于EBV相关肿瘤诊断标志物的潜在意义. EB病毒编码的miRNAs也可能成为进一步研究EBV相关肿瘤治疗的一个候选靶点.     

鸡源暹罗芽孢杆菌CML548的益生特性及全基因组分析

【背景】芽孢杆菌是用于动物微生态制剂的重要菌株之一。暹罗芽孢杆菌因具有较强的抑菌活性,近年来受到广泛关注。【目的】对实验室前期分离的鸡源暹罗芽孢杆菌CML548的益生特性进行评价,通过全基因组测序及生物信息学分析,探究其抑菌及潜在的益生机制。【方法】通过牛津杯法、稀释涂布平板法分别对菌株CML548的抑菌和产酶特性、酸和胆盐的耐受性进行研究。使用IlluminaHiSeq2500测序平台进行全基因组测序,并通过多种生物信息学工具和数据库对基因组进行注释和分析。【结果】体外实验表明该菌株具有优良的益生性状：能够有效抑制致病性大肠杆菌、鼠伤寒沙门氏菌、产气荚膜梭菌的生长;能够同时产生蛋白酶、淀粉酶和纤维素酶;具有较高的酸和胆盐耐受性。全基因组测序分析表明菌株CML548的基因组大小为4061741bp,GC含量为46.07%,预测到3 961个编码基因。分别有1 693、2 704、3 413、186、67、1、5个基因被GO、KEGG、COG、CAZy、DBAASP、CARD、VFDB数据库注释;通过antiSMASH预测到16个与次级代谢产物合成相关的基因簇。此外,还发现其含有抗菌活性...     

基于成果导向教育理念的“发酵工程实验”课程内容设计及实践

"发酵工程实验"是生物工程专业的工程类重要主干课之一,是培养学生工程设计、工程实践和创新思维的重要课程。基于构思—设计—实现—运行(conceive—design—implement—operate,CDIO)理念,"发酵工程实验"通过构建模块化课程内容,以构思、设计、实现、运作的项目导向模块开展课程设计,进行目标导向的教学模式改革。以"发酵工程实验"课程为载体,将工程基础知识、发酵工程系统实践能力、团队合作能力、创新能力培养等融为一体。建立基于成果导向教育(outcome-based education,OBE)理念的学生学习效果评价体系,完成"发酵工程实验"课程教学任务。学生对改革后的"发酵工程实验"课程满意度明显提高,教学效果显著。     

Multi-Shell Copper Catalysts for Selective Electroreduction of CO2 to Multicarbon Chemicals

Electrocatalytic CO₂ reduction (CO₂R) coupled with renewable electricity has been considered as a promising route for the sustainability transition of energy and chemical industries. However, the unsatisfactory yield of desired products, particularly multicarbon (C₂₊) products, has hindered the implementation of this technology. This work describes a strategy to enhance the yield of C₂₊ product formation in CO₂R by utilizing spatial confinement effects. The finite element simulation results suggest that increasing the number of shells in the catalyst wil lead to a high local concentration of *CO and promotes the formation of C₂₊ products. Inspired by this, Cu nanoparticles are synthesized with desired hollow multi-shell structures. The CO₂ reduction results confirm that as the number of shells increase, the hollow multi-shell copper catalysts exhibit improved selectivity toward C₂₊ products. Specifically, the Cu catalyst with 4.4-shell achieved a high selectivity of over 80% toward C₂₊ at a current density of 900 mA cm⁻². Evidence from in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy unveils that the multi-shell Cu catalyst exhibits an enhanced *CO_atop coverage and the stronger interaction with *CO_atop compared to commercial Cu, confirming the simulation results. Overall, the work promises an effective approach for boosting CO₂R selectivity toward value-added chemicals.     

Gut microbiome in gastrointestinal cancer: a friend or foe?

The impact of the gut microbiome on host health is becoming increasingly recognized. To date, there is growing evidence that the complex characteristics of the microbial community play key roles as potential biomarkers and predictors of responses in cancer therapy. Many studies have shown that altered commensal bacteria lead to cancer susceptibility and progression in diverse pathways. In this review, we critically assess the data for gut microbiota related to gastrointestinal cancer, including esophageal, gastric, pancreatic, colorectal cancer, hepatocellular carcinoma and cholangiocarcinoma. Importantly, the underlying mechanisms of gut microbiota involved in cancer occurrence, prevention and treatment are elucidated. The purpose of this review is to provide novel insights for applying this understanding to the development of new therapeutic strategies in gastrointestinal cancer by targeting the microbial community.     

The small nonstructural protein NP1 of human bocavirus 1 directly interacts with Ku70 and RPA70 and facilitates viral DNA replication

Human bocavirus 1 (HBoV1), a member of the genus Bocaparvovirus of the family Parvoviridae, causes acute respiratory tract infections in young children. Well-differentiated pseudostratified human airway epithelium cultured at an air-liquid interface (HAE-ALI) is an ideal in vitro culture model to study HBoV1 infection. Unique to other parvoviruses, bocaparvoviruses express a small nonstructured protein NP1 of ~25 kDa from an open reading frame (ORF) in the center of the viral genome. NP1 plays an important role in viral DNA replication and pre-mRNA processing. In this study, we performed an affinity purification assay to identify HBoV1 NP1-inteacting proteins. We identified that Ku70 and RPA70 directly interact with the NP1 at a high binding affinity, characterized with an equilibrium dissociation constant (K_D) of 95 nM and 122 nM, respectively. Furthermore, we mapped the key NP1-interacting domains of Ku70 at aa266-439 and of RPA70 at aa181-422. Following a dominant negative strategy, we revealed that the interactions of Ku70 and RPA70 with NP1 play a significant role in HBoV1 DNA replication not only in an in vitro viral DNA replication assay but also in HBoV1-infected HAE-ALI cultures. Collectively, our study revealed a novel mechanism by which HBoV1 NP1 enhances viral DNA replication through its direct interactions with Ku70 and RPA70.