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1.
肠道上皮细胞（intestinal epithelial cells,IECs）是动物机体抵御病原微生物的第一道防线,是黏膜机械屏障、免疫屏障和化学屏障的重要组成部分,具有吸收和屏障双层功能。肠道中微生物数量庞大、种类繁多,根据其与宿主的关系,主要分为共生菌、条件致病菌和病原菌3类,在肠道屏障的构建中发挥重要作用。IECs首先通过直接或间接方式对肠道微生物进行识别,区别自身与非自身,对自身物质（即共生菌）免疫耐受,对非自身物质（即病原菌）产生特异性免疫反应。IECs与肠道共生菌共同抵御肠道病原微生物,维持肠道健康,病原微生物侵入肠道,IECs主要通过胞外分泌物和细胞表面黏液层双重屏障发挥作用,其中胞外分泌物主要包括黏蛋白、抗菌分子和抗微生物免疫球蛋白。肠道共生菌可以通过竞争识别位点,分泌抗菌物质,增加黏液分泌,诱导IECs更新、增殖和修复等方式抵御病原微生物,维护正常的肠黏膜屏障功能。在IECs抵御肠道病原微生物入侵过程中,病原微生物通过自身运动、分泌毒素和酶等破坏肠上皮屏障,直接接触IECs,对其进行损伤。因此IECs和肠道菌群间相互作用,共同维持肠道内环境稳态。作者就IECs和肠道微生物结构、功能的适应性变化作一综述,以期阐述肠道微生物-上皮细胞屏障互作的机制。 相似文献
2.
冬春季节猪的病毒性腹泻病主要发生在气候多变、寒冷、潮湿、环境卫生不良的冬春季节,主要病原有猪传染性胃肠炎病毒(TGEV)、流行性腹泻病毒(PEDV)和轮状病毒(RV),它们有时也和其他病原混合感染引起腹泻,因此临床上很难简单区分"冬痢"的病原. 相似文献
3.
正1轮状病毒概况轮状病毒(Rotavirus,RV)是导致婴幼儿腹泻最常见的病原微生物。无论是发达国家还是发展中国家,婴幼儿RV感染率均较高。而发展中国家由于人口数量多且医疗卫生条件落后于发达国家,因此RV腹泻的发生率和死亡率显著高于发达国家,调查结果显示全世界每年因为RV感染导致死亡的人数超过40万~([1]),我国每年因感染RV发生腹泻死亡的儿童约3.5万人~([2])。 相似文献
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《现代畜牧兽医》2017,(6)
轮状病毒(Rotavirus,RV)是一种人兽共患病病原,能够引起幼龄动物和婴幼儿发生腹泻疾病,危害人和动物身体健康。目前尚无特效治疗药治疗该病。RV NSP1是其逃避宿主先天性免疫应答的关键蛋白,具有介导IRFs、RIG-I、β-Tr CP、TRAFs和STATs等宿主免疫应答通路中的重要分子降解的功能,从而逃避宿主免疫。RV在感染宿主细胞过程中,可以破坏微循环,感染导致小肠绒毛细胞死亡脱落;RV NSP4蛋白介导多种离子非正常转运;刺激肠神经系统等多种途径致使机体产生病理损伤,发生腹泻甚至严重可致死亡。了解轮状病毒感染后的免疫逃避机制和病理损伤机制对于研制高效疫苗和靶向药物具有一定的指导意义。 相似文献
6.
《中国预防兽医学报》2021,(9)
正轮状病毒(Rotavirus,RV)是导致儿童、仔猪和许多其它幼年动物严重脱水性胃肠炎的病原之一。尽管在医疗卫生系统和兽医领域已开展了十余年的RV疫苗的免疫工作,但它仍持续威胁低收入国家儿童的健康,同时也给养猪业造成严重的经济损失。因此急需深入了解RV的复制特性,开发有效防控RV感染的策略。RV复制的主要场所为病毒质,它的形成对病毒的有效复制尤为重要。 相似文献
7.
用聚丙烯酰胺凝胶电泳(PAGE)检查了二个猪场的42份仔猪腹泻粪样。轮状病毒(RV)核酸(RNA)检出率分别为11.1%(3/27)和33.3%(5/15)。通过PAGE 法,检出了5株 A 组 RV 和5株 C 组 RV,证实了 A组 RV 和 C 组 RV 可同时感染某一猪场和混合感染同一只猪。 相似文献
8.
轮状病毒(Rotavirus,RV)属呼肠孤病毒科(Reoviridae)轮状病毒属.现已证实RV是婴幼儿和各种幼龄动物病毒性腹泻的主要病原之一.猪RV在无其他病原存在的实验条件下可引起悉生猪和未食初乳的猪发生严重的胃肠炎和绒毛萎缩.RV的基因组由11节段的双股RNA组成.所有的11个节段都有同样的末端结构,具有5'm'GPPPPGm,3'末端无Poly(A)尾,单一长开放阅读框架(open readingframe,ORF'),缺乏聚腺苷酸序列.ORF两端为5'和3'端的非编码区(5'-and 3'-terminal untranslated regions,UTRs). 相似文献
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董齐 《畜牧兽医科技信息》2003,(2)
猪传染性胃肠炎(TGE)和猪轮状病毒(RV)病是两种病毒性肠道传染病。TGE是以发病急、传播快各种年龄的猪只均可感染,以腹泻、呕吐、脱水及10周龄以内仔猪死亡率极高为主要特征。RV是包括猪在内的多种幼龄动物的重要的肠道病原。本病以潜伏期短、厌食、偶有呕吐、随后腹泻为特征的急性肠道感染,特别是断奶仔猪腹泻发病率极高,死亡 相似文献
11.
Mycotoxins are structurally diverse fungal metabolites that can contaminate a variety of dietary components consumed by animals and humans. It is considered that 25% of the world crop production is contaminated by mycotoxins. The clinical toxicological syndromes caused by ingestion of moderate to high amounts of mycotoxins and their effect on the immune system have been well characterized. However, no particular attention has been focused on the effects of mycotoxins on the local intestinal immune response. Because of their location, intestinal epithelial cells (IECs) could be exposed to high doses of mycotoxins. As a component of the innate local immune response, intestinal epithelial cells have developed a variety of mechanisms which act to reduce the risk of infection by microorganisms or intoxication by toxic compounds. This review summarises the innate immune response developed by intestinal epithelial cells and reports the literature concerning the effects of mycotoxins on them. Particularly, the effects of mycotoxins on the maintenance of a physical barrier by epithelial cells will be discussed together with their effect on extrinsic protective components of the innate intestinal immunity: mucus secretion, antimicrobial peptide generation, IgA and pro-inflammatory cytokine release. 相似文献
12.
Chiba E Villena J Hosoya S Takanashi N Shimazu T Aso H Tohno M Suda Y Kawai Y Saito T Miyazawa K He F Kitazawa H 《Research in veterinary science》2012,93(2):688-694
We evaluated whether a bovine intestinal epithelial (BIE) cell line could serve as a useful in vitro model system for studying antiviral immune responses in bovine intestinal epithelial cells (IECs) and for the primary screening of immunobiotic microorganisms with antiviral protective capabilities. Immunofluorescent analyses revealed that toll-like receptor 3 (TLR3) was expressed in BIE cells, and the results of real-time quantitative PCR showed that these cells respond to stimulation with poly(I:C) by up-regulating pro-inflammatory cytokines and type I interferons. In addition, we demonstrated that BIE cells are useful for the primary screening of immunobiotic lactic acid bacteria strains which are able to beneficially modulate antiviral immune responses triggered by TLR3 activation in bovine IECs. The characterization of BIE cells performed in the present study represents an important step towards the establishment of a valuable bovine in vitro system that could be used for the development of immunomodulatory feed for bovine hosts. 相似文献
13.
猪流行性腹泻病毒（porcine epidemic diarrhea virus,PEDV）是一种全球分布的α冠状病毒,能引起仔猪流行性腹泻,猪流行性腹泻一旦暴发会给养殖业带来巨大的经济损失。在病毒感染期间,Ⅰ型干扰素（type Ⅰ interferon,IFN-Ⅰ）是先天性抗病毒反应的关键介质。大多数冠状病毒通过限制IFN的产生和IFN应答的激活而产生一些策略以规避IFN应答。然而,PEDV颉颃IFN抗病毒作用的分子机制尚未完全清楚。猪感染PEDV后,机体的先天免疫不能有效抵抗PEDV的侵害,PEDV通过限制或阻断IFN的功能和隐藏自身的病原体相关分子模式（pathogen-associated molecular patterns,PAMP）两种途径逃逸宿主先天免疫。在此过程中,PEDV的结构蛋白和非结构蛋白及一些蛋白酶起到了关键作用,核衣壳（nucleocapsid,N）蛋白能抑制IFN-Ⅰ的产生,协助病毒逃避机体的抗病毒天然免疫,木瓜样蛋白酶通过去泛素化酶活性阻断天然免疫信号通路,PEDV也可通过阻断双链核糖核酸（double-stranded RNA,dsRNA）诱导IFN-Ⅰ的产生,以逃避宿主的先天免疫。这些研究为深入了解IFN在PEDV致病过程中的作用及PEDV逃避IFN抗病毒的机制提供了理论依据,并有助于深入了解病毒与宿主先天性免疫之间的关系,同时也为PEDV的防治及PEDV疫苗的研发提供参考。 相似文献
14.
Induction of mucosal immune responses and protection against enteric viruses: rotavirus infection of gnotobiotic pigs as a model 总被引：4，自引：0，他引：4
Enteric viruses are a major cause of diarrhea in animals and humans. Among them, rotaviruses are one of the most important causes of diarrhea in young animals and human infants. A lack of understanding of mechanisms to induce intestinal immunity and the correlates of protective immunity in neonates has impaired development of safe and effective vaccines against enteric viruses. Studies of candidate vaccines using an adult mouse model of subclinical enteric viral infections often do not predict vaccine efficacy against disease evaluated in neonatal large animals. A series of studies have been conducted using a neonatal gnotobiotic pig model of rotavirus infection and diarrhea to identify correlates of protective immunity and to evaluate traditional and novel vaccine approaches for the induction of mucosal immune responses and protection to enteric viruses. Gnotobiotic pigs recovered from infection with virulent Wa human rotavirus (HRV) (mimic natural infection) had high numbers of intestinal IgA rotavirus-specific primary antibody-secreting cells (ASCs) and memory B-cells (to recall antigen) measured by ELISPOT assay, which correlated with complete protection against rotavirus challenge. Most short-term IgA memory B-cells were resident in the ileum, the major site of rotavirus replication. Spleen, not the bone marrow, was the major resident site for longer-term IgG memory B-cells. Candidate rotavirus vaccines evaluated in pigs for their ability to induce intestinal or systemic ASC and protection against rotavirus infection and diarrhea included attenuated live virus, inactivated virus, and baculovirus-expressed double-layered rotavirus-like particles (2/6-VLPs). In combination with those candidate vaccines, various adjuvants, delivery systems, and immunization routes were tested, including incomplete Freund's adjuvant for i.m. immunization, and a mutant Escherichia coli heat labile enterotoxin R192G (mLT) for i.n. immunization. It was shown that orally administered replicating vaccines were most effective for priming for intestinal IgA ASC and memory B-cell responses, but i.n. administered non-replicating 2/6-VLPs plus mLT were effective as booster vaccines. We conclude that protective immunity depends on the magnitude, location, viral protein-specificity, and isotype of the antibody responses induced by vaccination. Therefore highly effective enteric viral vaccines should: (i) induce sufficient levels of intestinal IgA antibodies; (ii) include viral antigens that induce neutralizing antibodies; and (iii) require the use of effective mucosal adjuvants or antigen delivery systems for non-replicating oral or i.n. vaccines. 相似文献
15.
《Veterinary immunology and immunopathology》2015,163(3-4):103-114
Bovine leukemia virus (BLV) infection is widespread in the US dairy industry and the majority of producers do not actively try to manage or reduce BLV incidence within their herds. However, BLV is estimated to cost the dairy industry hundreds of millions of dollars annually and this is likely a conservative estimate. BLV is not thought to cause animal distress or serious pathology unless infection progresses to leukemia or lymphoma. However, a wealth of research supports the notion that BLV infection causes widespread abnormal immune function. BLV infection can impact cells of both the innate and adaptive immune system and alter proper functioning of uninfected cells. Despite strong evidence of abnormal immune signaling and functioning, little research has investigated the large-scale effects of BLV infection on host immunity and resistance to other infectious diseases. This review focuses on mechanisms of immune suppression associated with BLV infection, specifically aberrant signaling, proliferation and apoptosis, and the implications of switching from BLV latency to activation. In addition, this review will highlight underdeveloped areas of research relating to BLV infection and how it causes immune suppression. 相似文献
16.
轮状病毒(rotavirus,RV)是引起婴幼儿和多种幼龄动物非细菌性腹泻病的主要病原之一,全世界每年因该病所引起人和动物死亡数量众多,并造成了巨大的经济损失。因此,世界卫生组织呼吁将RV疫苗的研制列为最优先发展的疫苗项目之一。对RV的分子生物学研究进展进行了综述,旨在为更好地开展轮状病毒相关基因的实验室研究提供基础。 相似文献
17.
短链脂肪酸介导的宿主肠道免疫调控机制 总被引：1，自引：0，他引：1
肠道是营养素、微生物群和宿主进行免疫反应的共享场所。肠道稳态失衡、免疫功能失调、环境因素等都可能引发疾病,肠道微生物群是控制机体健康肠道内环境平衡的一个重要因素。短链脂肪酸(SCFAs)主要由细菌发酵产生,是肠道微生物群及宿主肠上皮细胞(IECs)的重要能量来源,能够维持肠道酸碱平衡,抑制有害病原菌生长,调节宿主肠道免疫,降低炎症反应。SCFAs不仅在共生细菌聚居的肠道内起局部作用,而且还影响肠道免疫细胞,调节免疫反应。本文主要概述了SCFAs通过G蛋白偶联受体(GPCRs)激活途径、组蛋白脱乙酰化酶(HDAC)抑制作用改变代谢状态,并将代谢途径与表观遗传修饰联系起来引起宿主免疫应答,降低肠道炎症反应并增强肠道屏障功能。 相似文献
18.
Meyerhoff RR Nighot PK Ali RA Blikslager AT Koci MD 《Comparative immunology, microbiology and infectious diseases》2012,35(1):63-69
The inducible nitric oxide synthase (iNOS) enzyme has long been recognized as a key mediator of innate immune responses to infectious diseases across the phyla. Its role in killing or inactivating bacterial, parasitic, and viral pathogens has been documented in numerous host systems. iNOS, and its innate immune mediator NO has also been described to have negative consequence on host tissues as well; therefore understanding the pathogenesis of any infectious agent which induces iNOS expression requires a better understanding of the role iNOS and NO play in that disease. Previous studies in our laboratory and others have demonstrated evidence for increased levels of iNOS and activity of its innate immune mediator NO in the intestine of turkeys infected with astrovirus. To begin to characterize the role iNOS plays in the innate immune response to astrovirus infection, we identified, characterized, developed tkiNOS specific reagents, and demonstrated that the intestinal epithelial cells induce expression of iNOS following astrovirus infection. These data are the first to our knowledge to describe the tkiNOS gene, and demonstrate that astrovirus infection induces intestinal epithelial cells to express iNOS, suggesting these cells play a key role in the antiviral response to enteric infections. 相似文献
19.
家禽的天然免疫应答在抵抗病毒感染的过程中起着关键性作用，视黄酸诱导基因-Ⅰ（retinoic acid inducible gene-Ⅰ，RIG-Ⅰ）作为细胞质内一类识别病毒双链RNA的模式识别受体，与天然免疫应答密切相关。它可通过RNA配体结合病原相关分子模式监测细胞质中的病毒RNA，此过程激活了RIG-Ⅰ及下游线粒体抗病毒信号蛋白（MAVS），最终导致干扰素调节因子（IRF3/7）和核因子κB （NF-κB）活化，诱导产生Ⅰ型干扰素等免疫细胞因子，进而使细胞做出相应的抗病毒天然免疫反应。但由于鸡体内缺乏RIG-Ⅰ基因，目前大多将鸭源或鹅源RIG-Ⅰ基因转染鸡成纤维母细胞（DF-1）研究RIG-Ⅰ基因在鸡感染禽类病毒时是否具有免疫功能。文章介绍了RIG-Ⅰ在家禽体内的表达及其介导的抗病毒天然免疫信号通路，并简述了RIG-Ⅰ在家禽体内抗病毒作用的研究概况，为抑制家禽病毒的感染和免疫系统研究，以及研制新型抗病毒疫苗或免疫佐剂等提供参考。 相似文献
20.
Yukako Tokutake Marcin Taciak Kan Sato Masaaki Toyomizu Motoi Kikusato 《Animal Science Journal》2021,92(1):e13604
Peptide transporter 1 (PepT1) is a transporter responsible for absorbing dipeptide and tripeptide in enterocytes and is upregulated by dipeptide in mammals. It has not been certain whether intestinal PepT1 expression is responsive to dipeptides in chickens because of the lack of in vitro study using the cultured enterocytes. This study established a primary culture model of chicken intestinal epithelial cells (IECs) in two-dimensional monolayer culture using collagen gel by which the response of chicken PepT1 gene expression to dipeptide stimuli was evaluated. The cultured chicken IECs showed the epithelial-like morphology attached in a patch-manner and exhibited positive expression of cytokeratin and epithelial cadherin, specific marker proteins of epithelial cells. Moreover, the chicken IECs exhibited the gene expression of intestinal cell type-specific marker, villin1, mucin 2, and chromogranin A, suggesting that the cultured IECs were composed of enterocytes as well as goblet and enteroendocrine cells. PepT1 gene expression was significantly upregulated by synthetic dipeptide, glycyl-l-glutamine, in the cultured IECs. From the results, we herein suggested that dipeptide is a factor upregulating PepT1 gene expression in chicken IECs. 相似文献