New insights of Helicobacter pylori host-pathogen interactions: The triangle of virulence factors, epigenetic modifications and non-coding RNAs

Helicobacter pylori(H. pylori) is a model organism for understanding host-pathogen interactions and infection-mediated carcinogenesis. Gastric cancer and H. pylori colonization indicates the strong correlation. The progression and exacerbation of H. pylori infection are influenced by some factors of pathogen and host. Several virulence factors involved in the proper adherence and attenuation of immune defense to contribute the risk of emerging gastric cancer, therefore analysis of them is very important. H. pylori also modulates inflammatory and autophagy process to intensify its pathogenicity. From the host regard, different genetic factors particularly affect the development of gastric cancer. Indeed, epigenetic modifications, Micro RNA and long non-coding RNA received more attention. Generally, various factors related to pathogen and host that modulate gastric cancer development in response to H. pylori need more attention due to develop an efficacious therapeutic intervention. Therefore, this paper will present a brief overview of host-pathogen interaction especially emphases on bacterial virulence factors, interruption of host cellular signaling, the role of epigenetic modifications and non-coding RNAs.

Golden Promise barley(Hordeum vulgare) is a suitable candidate model host for investigation interaction with Heterodera avenae

Heterodera avenae （cereal cyst nematode, CCN） infects many cereal crops and causes serious yield losses worldwide. Interaction studies investigating H. avenae and its hosts are still in their infancy. In this study, a barley model plant, the Hordeum vulgare cultivar Golden Promise, was investigated for its potential as a candidate model host to study its inter- action with H. avenae. CCN-infective juveniles were attracted by the root tips and gathered around the root elongation zones of Golden Promise on 0.7% water agar plates. The juveniles invaded the roots and developed successfully until maturation at 40 days after inoculation in sterile sand soil. The cryotomy and syncytium measurements indicated that the syncytia enlarged gradually throughout the development of the nematodes and caused the corresponding root regions to swell obviously. Quantitative real-time PCR analysis showed that the down-regulation of defence-related barley genes and up-regulation Of development-related barley ger^es contribute to the understanding of compatible interaction between H. avenae and Golden Promise. Barley stripe mosaic virus （BSMV） virus-induced gene silencing （VIGS） can be used in the roots of Golden Promise. In conclusion, the Hordeum vulgare cultivar Golden Promise is a suitable candidate model host for interaction studies with Heterodera avenae. The studies presented above document the first CCN host that no.t only has published genome context but also be compatible to BSMV VIGS.

Proteomics: A Successful Approach to Understand the Molecular Mechanism of Plant-Pathogen Interaction

In recent years, proteomics has played a key role in identifying changes in protein levels in plant hosts upon infection by pathogenic organisms and in characterizing cellular and extracellular virulence and pathogenicity factors produced by pathogens. Proteomics offers a constantly evolving set of novel techniques to study all aspects of protein structure and function. Proteomics aims to find out the identity and amount of each and every protein present in a cell and actual function mediating specific cellular processes. Structural proteomics elucidates the development and application of experimental approaches to define the primary, secondary and tertiary structures of proteins, while functional proteomics refers to the development and application of global (proteome wide or system-wide) experimental approaches to assess protein function. A detail understanding of plant defense response using successful combination of proteomic techniques and other high throughput techniques of cell biology, biochemistry as well as genomics is needed for practical application to secure and stabilize yield of many crop plants. This review starts with a brief introduction to gel- and non gel-based proteomic techniques followed by the basics of plant-pathogen interaction, the use of proteomics in recent pasts to decipher the mysteries of plant-pathogen interaction, and ends with the future prospects of this technology.

Understanding host-microbial interactions in rumen：searching the best opportunity for microbiota manipulation

Ruminants utilize a wide variety of dietary substrates that are not digestible by the mammals, through microbial fermentation taking place in the rumen. Recent advanced molecular based approaches have allowed the characterization of rumen microbiota and its compositional changes under various treatment conditions.However, the knowledge is still limited on the impacts of variations in the rumen microbiota on host biology and function. This review summarizes the information to date on host-microbial interactions in the rumen and how we can apply such information to seek the opportunities to enhance the animal performance through manipulating the rumen function.

MicroRNA-mediated interactions between host andhepatitis C virus

Micro RNAs(mi RNAs) are small noncoding RNAs. More than 2500 mature mi RNAs are detected in plants, animals and several types of viruses. Hepatitis C virus(HCV), which is a positive-sense, singlestranded RNA virus, does not encode viral mi RNA. However, HCV infection alters the expression of host mi RNAs, either in cell culture or in patients with liver disease progression, such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. In turn, host mi RNAs regulate HCV life cycle through directly binding to HCV RNAs or indirectly targeting cellular m RNAs. Increasing evidence demonstrates that mi RNAs are one of the centered factors in the interaction network between virus and host. The competitive viral and host RNA hypothesis proposes a latent cross-regulation pattern between host m RNAs and HCV RNAs. High loads of HCV RNA sequester and de-repress host mi RNAs from their normal host targets and thus disturb host gene expression, indicating a means of adaptation for HCV to establish a persistent infection. Some special mi RNAs are closely correlated with liver-specific disease progression and the changed levels of mi RNAs are even higher sensitivity and specificity than those of traditional proteins. Therefore, some of them can serve as novel diagnostic/prognostic biomarkers in HCVinfected patients with liver diseases. They are also attractive therapeutic targets for development of new anti-HCV agents.

Disruption of non-classically secreted protein(MoMtp)compromised conidiation,stress homeostasis,and pathogenesis of Magnaporthe oryzae

Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.

Host-guest interaction of β-cyclodextrin with isomeric ursolic acid and oleanolic acid:physicochemical characterization and molecular modeling study

Ursolic acid(UA) and oleanolic acid(OA) are insoluble drugs. The objective of this study was to encapsulate them into β-cyclodextrin(β-CD) and compare the solubility and intermolecular force of β-CD with the two isomeric triterpenic acids. The host-guest interaction was explored in liquid and solid state by ultraviolet-visible absorption,1H NMR, phase solubility analysis, and differential scanning calorimetry, X-ray powder diffractometry, and molecular modeling studies. Both experimental and theoretical studies revealed that β-CD formed 1: 1 water soluble inclusion complexes and the complexation process was naturally favorable. In addition, the overall results suggested that ring E with a carboxyl group of the drug was encapsulated into the hydrophobic CD nanocavity. Therefore, a clear different inclusion behavior was observed, and UA exhibited better affinity to β-CD compared with OA in various media due to little steric interference, which was beneficial to form stable inclusion complex with β-CD and increase its water solubility effectively.

Interaction between Hosts and Guests of Rural Tourism in Northeast China Based on Symbolic Interaction Theory

With constant economic development and continuous improvement of living standards in Northeast China,rural tourism,as a new type of tourism,is increasingly favored. From the perspective of symbolic interaction theory,taking the current situation of rural tourism in Northeast China as an example,this paper explained the semiotic significance between hosts and guests in rural tourism. It established the evaluation indicators for authentic symbolic perception of rural tourism. Also,combined with the theories of sociology and anthropology,it studied the interaction between hosts and tourists of rural tourism in Northeast China.

Advances on the Molecular Mechanism of the Interaction between Ralstonia solanacearum and Hosts

Ralstonia solanacearum is an important model phytopathogenic bacterium that causes bacterial wilt disease on many plant species and leads to serious economic losses. The interactions between R. solanacearum and host plants have become a model system for the study of plants and pathogens interactions. This paper reviews the advances on the molecular mechanisms between R. solanacearum and hosts interaction including the formation of plant innate immunity, the suppression of plant innate immunity by this pathogen and the activation of effector-triggered immunity. Furthermore, we made a prospect on how to utilize the interaction mechanism between R. solanacearum and hosts to control the disease.

Virus-Encoded MicroRNAs Reveal How Ranavirus Interacts with Amphibian Immune Defense

Ranaviruses are harmful viruses that infect amphibians, fish, and reptiles, and have caused particularly devastating declines in amphibian populations. One particular type of ranavirus, called Frog Virus 3 (FV3), has been extensively studied due to its prevalence and impact on amphibians. Previous research has primarily focused on the virus’s genes, but little attention has been given to the non-coding regions of its genome. This article reviews recent studies that reveal the ability of ranaviruses, including FV3, to encode microRNA (miRNA), a type of regulatory RNA. These viral miRNAs play a crucial role in suppressing frog immune genes, modulating the virus-host interaction, and promoting viral infection. Understanding how ranaviruses use miRNAs to control disease progression is essential for addressing the health threat they pose to wildlife and ecosystems.

Quantitative prediction of the bitterness of atomoxetine hydrochloride and taste-masked using hydroxypropyl-β-cyclodextrin:A biosensor evaluation and interaction study

The bitterness of a drug is a major challenge for patient acceptability and compliance,especially for children.Due to the toxicity of medication,a human taste panel test has certain limitations.Atomoxetine hydrochloride(HCl),which is used for the treatment of attention deficit/hyperactivity disorder(ADHD),has an extremely bitter taste.The aim of this work is to quantitatively predict the bitterness of atomoxetine HCl by a biosensor system.Based on the mechanism of detection of the electronic tongue(Etongue),the bitterness of atomoxetine HCl was evaluated,and it was found that its bitterness was similar to that of quinine HCl.The bitterness threshold of atomoxetine HCl was 8.61μg/ml based on the Change of membrane Potential caused by Adsorption(CPA)value of the BT0 sensor.In this study,the taste-masking efficiency of 2-hydroxypropyl-β-cyclodextrin(HP-β-CyD)was assessed by Euclidean distances on a principle component analysis(PCA)map with the SA402B Taste Sensing System,and the host–guest interactions were investigated by differential scanning calorimetry(DSC),powder X-ray diffraction(XRD),nuclear magnetic resonance(NMR)spectroscopy and scanning electron microscopy(SEM).Biosensor evaluation and characterization of the inclusion complex indicated that atomoxetine HCl could actively react with 2-hydroxypropyl-β-cyclodextrin.

Vaccine by Chicken Line Interaction Alters the Protective Efficacy against Challenge with a Very Virulent plus Strain of Marek’s Disease Virus in White Leghorn Chickens

Marek’s disease (MD) is a lymphoproliferative disease of domestic chickens caused by Marek’s disease virus (MDV), an oncogenic and highly contagious α-herpesvirus. MD has been controlled by vaccination but sporadic outbreaks of MD still occur in some parts of the world. Efforts to improve vaccine efficacy have continued in both research communities and vaccine industries. We reported the host genetic variation affecting Marek’s disease vaccine-induced immunity in chickens earlier. In this study, we evaluated chicken lines, vaccines, and line by vaccine interaction on the protective efficacy of vaccination against MD. Specific pathogen free chickens from the relatively resistant line 63 and the highly susceptible line 72 were primarily used to evaluate the protection by three kinds of vaccines (rMd5ΔMeq, CVI988/Rispens, and HVT) upon challenge with a very virulent plus strain of MDV, vv+648A. Our data confirmed that both the chicken line and the vaccine significantly affected the protective efficacy of vaccination and showed that a chicken line by vaccine interaction, in most of the trials, also altered vaccine protective efficacy. More interestingly, although the protective index of all vaccine strains was higher in resistant than in susceptible line of chickens, the difference for HVT protection was striking and warrants further study. The findings may have important implications for vaccine development as well as for selective use of particular vaccines in specific lines of chickens to achieve maximum protection at minimized costs.

Ecological Study on Bacteria-Zooplankton Interaction in Domat AI-Gandal Lake, AL-Jouf Area, Kingdom of Saudi Arabia

A year-long survey of some physical parameters （water temperature, dissolved oxygen, pH, turbidity）, chemical parameters （Biological Oxygen Demand ＂BOD＂, Chemical Oxygen Demand ＂COD＂, nitrate, ammonia, orthophosphate） and some biological （zooplankton） and microbiological （total bacteria, indicator bacteria, pathogenic bacteria） components in Domat AI-Gandal Lake was conducted. Water samples were collected seasonally from spring 2004 to winter 2005. Four locations on the Lake were sampled in order to evaluate the condition of the Lake. To investigate the possible effect of zooplankton in controlling the presence of faecal indicator bacteria, a 24 hour experiment was carried out to examine this hypothesis as well as the grazing pressure of zooplankton on the bacterial community of the Lake. The results showed that variations in season temperature affected the zooplankton and density of bacteria in the Lake. Zooplankton was composed by Protozoa 75%, Rotifera 20.6%, Cladocera 3% and Copepoda 2%. The reduction rates for the tested faecal pollution indicators in presence of zooplankton predators were remarkable （up to 99%）. In conclusion zooplankton, especially protozoa, was found to play an important role as biological control against bacterial indicators of faecal pollution.

Host niche, genotype, and field location shape the diversity and composition of the soybean microbiome

Plant-associated microbes represent a key determinant of plant fitness through acquiring nutrients,promoting growth,and resisting to abiotic and biotic stresses.However,an extensive characterization of the bacterial and fungal microbiomes present in different plant compartments of soybean in field conditions has remained elusive.In this study,we investigated the effects of four niches(roots,stems,leaves,and pods),four genotypes(Andou 203,Hedou 12,Sanning 16,and Zhonghuang 13),and three field locations(Jining,Suzhou,and Xuzhou)on the diversity and composition of bacterial and fungal communities in soybean using 16S and internal transcribed spacer rRNA amplicon sequencing,respectively.The soybean microbiome significantly differed across organs.Host genotypes explained more variation in stem bacterial community composition and leaf fungal community composition.Field location significantly affected the composition of bacterial communities in all compartments and the effects were stronger in the root and stem than in the leaf and pod,whereas field location explained more variation in stem and leaf fungal community composition than in the root and pod.The relative abundances of potential soybean fungal pathogens also differed among host organs and genotypes,reflecting the niches of these microbes in the host and probably their compatibility to the host genotypes.Systematic profiling of the microbiome composition and diversity will aid the development of plant protection technologies to benefit soybean health.

猪肺炎支原体通过抑制SPLUNC1功能破坏呼吸道炎性反应平衡

【背景】猪肺炎支原体(Mycoplasmahyopneumoniae,Mhp)通过定植猪呼吸道黏膜层,破坏呼吸道炎性反应平衡,引起炎性损伤和持续性感染。短的上腭、肺及鼻咽上皮克隆1蛋白(short palate lung and nasal epithelial clone1,SPLUNC1)是呼吸道黏膜分泌的具有重要抗菌和抗炎功能的蛋白,被认为是呼吸道黏膜面对危险信号时的“信号传感器”。【目的】从Mhp和SPLUNC1相互作用入手,分析Mhp感染对SPLUNC1表达的影响以及SPLUNC1对Mhp引起的炎性反应的调控作用,揭示Mhp引起炎性损伤的新机制,为解决Mhp持续性感染问题提供参考。【方法】利用猪肺炎支原体对猪支气管上皮细胞(porcine bronchial epithelial cells,PBECs)感染模型和猪体感染模型,通过荧光定量PCR、间接免疫荧光和Western-blotting等方法,分别检测Mhp感染后对肺脏中SPLUNC1以及体外PBECs中SPLUNC1转录和表达的影响。克隆并扩增猪源SPLUNC1基因通过酶切鉴定,构建成功SPLUNC1真核和原核表达重组质粒pCDNA3.1-SPLUNC1以及pET28a-SPLUNC1。与此同时,设计靶向SPLUNC1的siRNA干扰片段。利用体外SPLUNC1蛋白孵育、体内呼吸道黏膜SPLUNC1抗体封闭,通过Mhp CCU50检测明确SPLUNC1对Mhp体内外生长的影响。在猪支气管上皮细胞中,通过过表达或siRNA干扰SPLUNC1基因,后感染Mhp,利用Western-blotting、间接免疫荧光以及酶联免疫吸附方法,明确SPLUNC1对Mhp的黏附作用、诱导炎性因子表达以及MAPK信号通路活化的影响。【结果】Mhp感染猪后可引起肺脏实变,主要组织病理表现为肺脏炎性损伤,同时显著上调肺泡灌洗液中趋化因子CXCL8和炎性因子TNFα和IL-1β分泌。Mhp体内外感染后,体内肺脏和体外猪支气管上皮细胞中SPLUNC1的转录和表达均显著下调。以上研究表明,Mhp可诱导肺脏炎性反应,抑制SPLUNC1表达。另一方面,体外PBECs中过表达SPLUNC1后,Mhp感染引起的CXCL8表达显著减少;siRNA干扰SPLUNC1后,Mhp感染引起的CXCL8表达显著增加,表明SPLUNC1负调控Mhp感染引起的CXCL8表达。基于Mhp感染入侵呼吸道过程,本研究进一步解析SPLUNC1负调控CXCL8表达的机制。结果表明:无论是SPLUNC1和Mhp体外孵育,还是SPLUNC1抗体体内封闭,Mhp的体内外生长均未受影响;SPLUNC1的过表达或siRNA干扰对Mhp体外黏附PBECs的能力也无显著影响;过表达SPLUNC1可抑制pERK和IκBα的激活,相反SPLUNC1 siRNA干扰后,可促进pERK和IκBα的激活。以上研究证明SPLUNC1不是通过调控Mhp的生长和黏附,而是通过负调控MAPK-ERK通路的活化来调控CXCL8的表达。【结论】SPLUNC1可通过MAPK-ERK信号通路来调控炎性因子的过度表达,维护宿主炎性平衡;与此同时,Mhp感染后可通过抑制SPLUNC1的表达来破坏宿主炎性反应的平衡调控,进而引起炎性损伤。本研究为解析Mhp感染损伤机制提供依据。

民宿促进各民族交往交流交融的价值协同路径研究——以新疆伊宁市六星街和喀赞其民宿为例

民宿是旅游促进各民族交往交流交融(简称旅游促“三交”)的重要载体,民宿主客互动过程也是各民族交往交流交融过程。研究以价值协同论与符号互动论为理论基础,选择伊宁市六星街和喀赞其历史街区周边民宿为研究对象,通过网络文本分析与扎根理论方法,探究民宿主客互动促进各民族交往交流交融的价值协同路径。研究表明:(1)民宿主与游客之间除传统的信息、物质、情感等互动形式外,学习互动是推进旅游促“三交”的重要基础;(2)民宿主客互动受到非言语、言语、技术、情境、政策制度、公平感知及过往经历等因素的综合影响;(3)民宿主客互动促进了主客价值协同,强化了文化和国家认同,夯实了中华民族共同体构建的心理基础。研究有助于厘清民宿场域旅游促“三交”的机理,也可为民族地区民宿业高质量发展提供参考。

近十年国外旅游地主客互动研究进展与启示——基于CiteSpace计量分析

主客互动涉及的是游客与居民在特定旅游目的地的人际互动以及一系列的后续影响。作为一种与游客体验密切相关的现象,主客互动出现了新的研究趋势和发展动向,亟待归纳。文章以2012-2023年国外文献为研究对象,应用CiteSpace软件中的关键词“时区分析”“突发检测分析”等功能,深入考察主客互动的研究态势,并针对以往研究进展中的一些热点和前沿话题展开分析,从而全面揭示主客互动的研究概貌。结果表明:研究热点主要有居民情感态度、游客的心理与行为反应、直接的主客互动过程研究(情感团结、价值共创)等3个方面;研究视角聚焦居民,致力于通过居民主体来改善主客关系、促进旅游高质量发展;研究历程大致划分为关注居民福祉、关注互动质量两大阶段;研究前沿主要在于主客互动微观情感过程与行为研究。

镰刀菌属真菌毒素在植物和病原菌互作中的研究进展

镰刀菌是世界上最重要的植物病原菌之一,可影响植物的生长发育,严重威胁全球粮食安全和生物多样性。几乎所有的镰刀菌都会产生真菌毒素,其毒素种类多、毒性强,一方面可以作为致病因子之一参与镰刀菌的致病过程,另一方面可污染粮食和饲料,进而引起人类和动物的相关病症。已有研究表明,镰刀菌侵染植物后产生的不同种类真菌毒素不仅毒害植物细胞,引起植物组织的坏死,还会加速病原菌的侵染;同时,针对病原菌产生的毒素,植物会激活防御酶并启动防御相关基因的表达,或将致病毒素转化为无毒或低毒物质并转运到胞外,或通过分泌次生代谢物直接抑制病原菌毒素的生物合成。为全面解析镰刀菌毒素在病原菌侵染植物中的作用,提高植物对病原菌的抗性,该文综述了镰刀菌属真菌毒素的种类、毒性机理以及毒素在植物和病原菌互作中的作用,并讨论了植物对真菌毒素的防御反应策略,以期为镰刀菌毒素致病机制和病原菌防治策略研究提供参考。

发酵食品中噬菌体多样性、辅助代谢功能及宿主互作研究进展

噬菌体是地球上多样性最高和最丰富的生物实体。近年来,随着高通量测序技术的不断发展,人们对各种生境中噬菌体组成和功能的研究日渐增多,发酵食品中噬菌体组的研究也越来越受到关注。发酵食品中的噬菌体通过裂解循环和溶原循环两个生命周期与细菌宿主之间发生相互作用、扮演重要生态角色,影响微生物群落结构演替。噬菌体也具有潜在辅助代谢功能,并在一定程度上影响发酵食品风味物质形成。本文对发酵食品噬菌体研究现状和热点进行了综述,重点介绍了发酵食品中噬菌体组成及多样性、噬菌体基因组DNA提取方法、辅助代谢功能以及噬菌体与宿主相互作用及机制(如规律间隔成簇短回文重复序列、结合受体),最后对发酵食品领域噬菌体研究未来发展方向作出了展望,以期为噬菌体在发酵食品领域的进一步研究和应用提供参考。

水稻和拟禾本科根结线虫互作分子机制研究进展

拟禾本科根结线虫(Meloidogyne graminicola)是水稻(Oryza sativa L)的重要病原物之一,在世界各地的危害严重,极大地影响了水稻的安全生产。解析拟禾本科根结线虫致病和水稻的抗病机制是近年来主要的研究热点,同时也是制定水稻根结线虫防控新策略的主要依据。随着分子生物学和基因组学技术的发展,拟禾本科根结线虫的基因组被破译,多个与线虫致病性相关的基因功能得到解析。同时,在水稻染色体中定位到多个与拟禾本科根结线虫抗性相关的数量性状位点(QTLs),克隆出首个水稻抗根结线虫的基因MG1。此外,水稻为了应对根结线虫的侵染,还能通过调控茉莉酸和乙烯等激素信号通路,激活本身抗病基因的表达调控,从而抑制线虫的致病和寄生。上述研究成果为深入理解拟禾本科根结线虫致病机理及水稻抗根结线虫的作用机制提供了重要依据。本文综述了近年来拟禾本科根结线虫致病机制和水稻应答机制的研究进展,并展望未来拟禾本科根结线虫与寄主互作机制的新方向。