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1.
干扰素是一组具有多种功能的活性蛋白(主要是糖蛋白),是一种由单核细胞和淋巴细胞产生的细胞因子。根据干扰素产生的来源和结构不同可分为α干扰素、β干扰素和γ干扰素三类。研究发现干扰素通过细胞表面受体作用使细胞产生抗病毒蛋白,从而抑制病毒的复制,同时它还可增强自然杀伤细胞(NK细胞)、巨噬细胞和T淋巴细胞的活力,从而起到免疫调节作用,并增强抗病毒能力。由于干扰素几乎能抵抗所有病毒引起的感染,加  相似文献   

2.
微生物多糖对水产动物免疫作用的研究进展   总被引:1,自引:0,他引:1  
1 水产动物的非特异性免疫系统 非特异性防御机制是脊椎动物抵抗微生物侵袭的第一道防线,指机体组织和体液中的大量细胞和抗菌的蛋白质、糖蛋白、肽类。鱼类的抗菌蛋白包括粘液胰岛素、金属离子螫合剂(铁传递蛋白、血浆铜蓝蛋白、金属硫蛋白)、蛋白酶抑制因子(α2-巨球蛋白、α1-蛋白酶抑制因子及其他)、溶菌酶(溶解酵素、几丁质酶、非特异性细胞溶素)、补体和外源凝集素。抗菌肽在昆虫、两栖类及哺乳动物的非特异性防御中具有非常重要的作用,在鱼类中的研究发展也极其迅速。干扰素系统是非特异性细胞防御机制的重要组成部分。所谓干扰素(IFN),是指通过细胞代谢过程(包括RNA和蛋白质的合成)产生的非特异性抗病毒感染的蛋白质(Anonymous,1980)。I型IFN(IFN-α和IFN  相似文献   

3.
<正>干扰素诱导蛋白(Interferon-induced protein with tetratricopeptide repeats, IFITs)是机体先天免疫系统中,当病原体、肿瘤细胞等微生物刺激相关受体,促使机体免疫细胞诱导表达干扰素后,产生的干扰素刺激因子之一,起抑制病毒复制增殖、抵抗病毒感染的作用。1 IFIT的产生机体的先天免疫,主要包括机体产生的干扰素触发和干扰素的抗病毒效应,建立极其有效的抗病毒状态,有效地在宿主体  相似文献   

4.
Mx蛋白研究进展   总被引:8,自引:2,他引:6  
Mx蛋白是干扰素诱导表达的抗病毒蛋白家族中的成员之一。人、哺乳动物、鱼类、家禽体内都有Mx蛋白。Mx蛋白具有GTP酶活性 ,在其肽链氨基端均包含一个氨基酸序列高度保守的的三联GTP结合区域 ,羧基端存在有亮氨酸拉链区域。人和鼠的Mx蛋白有抗病毒活性。家禽中鸭的Mx蛋白无抗病毒活性 ;鸡的Mx蛋白的抗病毒活性受 6 31位氨基酸的影响 ,当 6 31位氨基酸为天冬酰胺时有抗病毒活性 ,为丝氨酸时则无抗病毒活性。文章最后对禽类Mx蛋白的应用和展望进行了探讨  相似文献   

5.
<正>1957年,英国病毒学家A.Isaacs和瑞士微生物学家J.Lindenmann利用鸡胚绒毛尿囊膜研究流感病毒感染现象时发现,病毒感染的细胞能产生一种因子,这种因子作用于其他细胞能干扰病毒的复制,因而命名为干扰素(IFN)[1]。干扰素是一类能诱导人及动物细胞产生多种广谱抗病毒蛋白的类激素蛋白,具有抗病毒、抗肿瘤及免疫调节等生物学活性,以及广谱、高效和非特异性等特点。目前,在医学领域干  相似文献   

6.
中国科学院水生生物研究所最近在鱼类抗病毒和免疫的分子研究上取得突破,分离、鉴定了一批参与鱼类抗病毒和免疫反应的基因,尤其是鱼类干扰素系统基因。中国科学网站报道称,该研究成果对进一步阐明鱼类抗病毒免疫的分子机制,以至推动鱼类抗病毒药物的研制和抗病毒育种技术的建立都具有重要的理论指导意义。鱼类病毒性疾病是至今无法解决的世界性难题。干扰素系统是脊椎动物非特异性免疫系统中抵抗病毒入侵最重要的效应系统,在人类临床医学已经得到广泛研究和应用。中国科学院水生生物研究所水生所的博士研究生张义兵在鱼类发育和遗传学家桂…  相似文献   

7.
干扰素诱导跨膜转运蛋白是细胞内具有广谱抗病毒作用的抑制因子.其属于dispanin蛋白家族中的一个亚族并具有多种功能,其中其抗病毒功能是主要的研究热点.由于IFITMs,尤其IFITM3,能抑制禽流感等病毒的早期复制因而近年来得到了广泛的关注.目前研究发现,IFITMS主要通过核内体途径阻止病毒的入侵,从而影响病毒的复制.然而,其具体的抗病毒机制还未完全阐释清楚.本文就近年来IFITMs蛋白抗病毒功能的研究进展对其结构特征、细胞亚定位及其抗病毒机制等方面作一一综述.  相似文献   

8.
Mx(myxovirus resistance)蛋白是由Ⅰ型干扰素(IFN)诱导表达的众多抗病毒蛋白中的一员,是一种具有GTP酶活性的肌动蛋白,在人、其他哺乳动物、家禽、鱼类等多种物种体内都广泛存在。Mx蛋白可抑制RNA病毒的复制,如水疱性口炎病毒(VSV)、狂犬病毒等,对某些DNA病毒也有效果,如乙型肝炎病毒。由于其具有广谱的抗病毒作用,所以也是目前国内外研究最广泛的几种抗病毒蛋白之一。文章对多种物种的Mx基因编码蛋白的结构、多态性、功能多样性及抗病毒作用等方面进行了综述,最后对Mx蛋白的应用和前景进行了探讨。  相似文献   

9.
禽类干扰素分子生物学研究进展   总被引:6,自引:0,他引:6  
1 简介自 1 892年 Ivanowsky发现病毒后不久 ,病毒学家们就发现了一种与抗体无关的病毒之间的干扰现象 (Interference)。干扰素 (Interferon,IFN)就是在1 93 5年 Isaccs和 Lindenmann[1] 研究禽流感病毒的干扰现象时在鸡胚绒毛尿囊膜中发现的一种具有干扰病毒繁殖作用的因子。 1 96 3年 Lampson等纯化了这种因子 ,证明其分子量为 2 0~ 3 4 KD的蛋白质。之后研究者对人类及哺乳类动物的干扰素进行了大量的研究 ,取得了突破性的进展。研究表明干扰素是一类能诱导人及动物细胞产生多种广谱抗病毒蛋白的类激素蛋白 ,具有抗病毒、抗肿瘤和…  相似文献   

10.
<正>干扰素(IFN)是一种广谱抗病毒剂,并不直接杀伤或抑制病毒,而主要是通过细胞表面受体作用使细胞产生抗病毒蛋白,从而抑制乙肝病毒的复制;同时还可增强自然杀伤细胞(NK细胞)、巨噬细胞和T淋巴细胞的活力,从而起到免疫调节作用,并增强抗病毒能力。干扰素是一组具有多种功能的活性蛋白质(主要是糖蛋白),是一种由单核细胞和淋巴细胞产生的细胞因子。它们在同种细胞上具有广谱的抗病毒、影响细胞生长,以及分化、调节免疫功能等多种生物活性。  相似文献   

11.
干扰素研究进展   总被引:8,自引:0,他引:8  
干扰素是一类具有广泛生物学活性的蛋白质,具有调节机体免疫功能、抗病毒、抗肿瘤等多种作用,是机体防御系统的重要组成部分。该文主要叙述了干扰素的分类基本特性,作用机理及其在人医和兽医上的应用,并指出了当前干扰素研究中存在的问题。  相似文献   

12.
Viperin is an anti-viral protein, induced by viral infection. In this study, we examined whether over-expression of viperin in fish muscle could inhibit bacterial growth. We first obtained the cDNA sequence of tilapia viperin, through RT-PCR-mediated cloning and sequencing. The cDNA sequence was similar to those of several fish viperins in GenBank, and it was predicted to encode the conserved domain of radical S-adenosylmethionine superfamily proteins. Phylogenetic analysis revealed that tilapia viperin was most closely related to viperin of Sciaenops ocellatus, Coreoperca kawamebari, and C. whiteheadi. Expression of tilapia viperin was significantly up-regulated in the kidney, liver, spleen, and gills upon challenge with lipopolysaccharide (LPS) and poly(I:C) in a time- and dose-dependent manner. Injection of Vibrio vulnificus (204) and Streptococcus agalactiae (SA47) bacteria into tilapia resulted in significant induction of viperin expression in the whole body, kidney, liver, and spleen. Electrotransfer of a viperin-expressing plasmid into zebrafish muscles decreased bacterial numbers and altered expression of immune-related genes. These data indicate that such altered expression may account for the improvement in bacterial clearance following electroporation of viperin, suggesting that fish viperin has antiviral and antibacterial activities.  相似文献   

13.
The control of viral infections is of critical importance to livestock industries worldwide and is highlighted by costly infection outbreaks, such as that seen with foot and mouth disease virus. To ameliorate the impact of increasing problems with viral infections, new vaccine and anti-viral strategies are required and a greater understanding of the anti-viral response is essential. Furthermore, in pigs, evidence is still being gathered on the components of a defined anti-viral immune response. However, this has been greatly improved by the recent cloning and expression of critical cytokines involved in the anti-viral response. To assess the use of recombinant porcine interleukin-12 (rPoIL-12) as an immunotherapeutic and immunomodulator of swine, we have cloned and expressed rPoIL-12 as a single-chain fusion protein from Esherichia coli (E. coli). The fusion encodes the p40 and p35 subunits, linked by a glycine-serine linker and expressed as a C-terminal 6xHis tagged protein. rPoIL-12 stimulated the proliferation of human lymphoblasts and its activity on porcine cells was demonstrated by the ability of rPoIL-12 to increase the mRNA expression of porcine interleukin-18 receptor-alpha (poIL-18Ralpha) from porcine peripheral blood mononuclear cells (PoPMBCs). This data supports the inclusion of E. coli produced rPoIL-12 in immunomodulation strategies in the pig.  相似文献   

14.
Based on the nutrient requirement of Trichogaster trichopterus, a fish meal–based basal diet with 350 g/kg diet crude protein and 16.7 MJ/kg energy was formulated, in which the fish meal protein was replaced by surimi by‐product protein at 0.0 (control), 12.5, 25, 50, 75 and 100% levels. The formulated diets were fed ad libitum to T. trichopterus fingerlings (4.80 ± 0.03 g) in triplicate groups for 45 days in a closed water system. Eighteen fibre‐reinforced plastic tanks with 200 l of water were used for rearing the fish. Weight gain, specific growth rate, feed/gain ratio, protein efficiency ratio, nutrient retention and digestibility (protein and energy) of fish were not affected (p > 0.05) up to 50% fish meal protein replacement level by surimi by‐product protein. While whole‐body protein content of fish was marginally decreased, the lipid content was increased with increase in surumi by‐product incorporation level in the diet. The study results suggest that the fish meal protein, which is scarce and costly nowadays, could be replaced up to 50% by surimi by‐product protein in the diet of blue gourami without hampering the growth and nutrient utilization of fish.  相似文献   

15.
谷氨酰胺可提高鱼类肠上皮细胞蛋白质合成能力,增强肠上皮细胞的抗氧化能力,改善肠道黏膜形态结构,促进鱼类消化道和消化腺生长发育.本文就谷氨酰胺对鱼类消化道生长发育、肠上皮细胞蛋白质合成及抗氧化能力的影响及机理做一综述.  相似文献   

16.
Zoonotic viruses, such as H5N1 Avian Influenza, pose major threats to both animals and humans, and with this in mind there is a need for the development of new anti-viral strategies. The cytokine interleukin-12 (IL-12) is known to play a pivotal regulatory role in the anti-viral response due to its role in the induction of the key anti-viral cytokine IFN-gamma. Therefore, strategies which provide a means for the production of therapeutic quantities of IL-12 may be of major benefit. Here we describe the development of biologically active Escherichia coli (E. coli) derived chicken IL-12 (ChIL-12). The single chain ChIL-12 gene was cloned into the pET32b expression vector, transformed into the BL-21 E. coli strain and expression induced with IPTG. Over expressed protein was solubilised with zwittergent detergent and isolated utilising Nickel ion affinity chromatography. Biological activity was determined as ChIL-12 stimulated proliferation of pre-treated T-cells in vitro. This study is the first example of a biologically active E. coli derived IL-12 from a non-mammalian vertebrate subsequently providing a means for testing the anti-viral therapeutic potential of ChIL-12 in an in vivo model.  相似文献   

17.
中药羊踯躅有杀虫作用,用羊踯躅进行钉螺浸杀试验,研究其杀螺效果。将水提取物和乙醇提取物配制成不同浓度的羊踯躅溶液作浸杀钉螺试验,观察钉螺死亡率及羊踯躅对钉螺软组织中总蛋白和糖原含量的影响,并检测羊踯躅提取液对鱼类的毒性。结果表明,羊踯躅有较强的杀螺作用,而且对鱼类的毒性不明显。  相似文献   

18.
Trout fry were experimentally infected with endoparasites (Anisakis sp.) and/or ectoparasites (Gyrodactylus derjavini). During the following 3 weeks the infection level of G. derjavini was significantly lowered in fish infected with live anisakids compared to fish injected with physiological saline, a corresponding amount of Anisakis protein sonicate or to untreated fish. Subsequent scanning electron microscopy (SEM) of recovered nematodes from the trout showed an extensive colonization of the worms with host macrophages. It is indicated that the activation of the fish immune system by infection with live anisakids influences the skin response of the host with a subsequent negative effect on the ectoparasites G. derjavini.  相似文献   

19.
Only recently Aeromonas salmonicida has been recognized as a significant bacterial pathogen in ulcerative disease of cyprinid fish. Our attempts to formulate a vaccine based on bacterial surface antigens were unsuccessful in conferring reliable protection against lethal challenge. This lead us to study pathological changes in the humoral defense system during ulcerative A. salmonicida infection in carp. High numbers of opportunist pathogens such as A. hydrophila and Pseudomonas sp. were frequently recovered from the internal organs of moribund fish, in addition to A. salmonicida. These findings together with leucopenia in moribund fish suggest that pathogenesis is characterized by a state of immune suppression. In addition, fish which had sustained a sublethal infection were not protected against a subsequent lethal challenge. However, fish previously injected with a concentrated and inactivated culture supernatant showed protection. Differential blood cell counts did not differ between experimental and control groups during sublethal infection in contrast to serum proteins. Furthermore infected non-immune carp showed a progressive decrease of immunoglobulin and total serum protein levels before the day of peak mortality whereas protected carp maintained the immunoglobulin concentration despite a decrease in protein. Our observations suggest the involvement of multiple pathogenic events, affecting different parts of the humoral defense system during ulcerative A. salmonicida infection. The immunosuppressive effects can be minimized by prior vaccination with culture supernatant.  相似文献   

20.
This study was performed to assess the effects of potato protein and fish protein on concentrations of lipids in plasma and lipoproteins and the expression of genes involved in lipid metabolism in pigs used as an animal model. Therefore, 27 young male pigs with an average body weight of 22 kg were fed diets supplemented with protein extracted from potatoes (containing 849 g protein/kg dry matter), Alaska Pollack fillet as a source of fish protein (containing 926 g crude protein/kg dry matter) or casein which was used as control, for 3 weeks. Diets were formulated to supply identical amounts of each protein to the pigs by the three protein sources, namely 116 g/day in first week and 150 g/day in the second and third week. Pigs fed potato protein had lower concentrations of cholesterol in plasma and LDL than pigs fed casein (p < 0.05); no effect was observed on concentrations of HDL cholesterol and triglycerides. Pigs fed fish protein had lower cholesterol concentrations in plasma, LDL and HDL, and lower triglyceride concentrations in triglyceride-rich lipoproteins than pigs fed casein (p < 0.05). mRNA concentrations of genes involved in bile acid synthesis and cholesterol uptake were higher in pigs fed fish protein than in pigs fed casein (p < 0.05); no effect on these genes was observed in pigs fed potato protein. Expression of genes involved in lipogenesis and fatty acid oxidation was not altered by fish protein. In conclusion, this study shows that fish protein and potato protein lower plasma cholesterol concentrations in pigs. The hypocholesterolaemic effect of fish protein might be in part caused by a stimulation of bile acid synthesis; the reason for the hypocholesterolaemic effect of potato protein requires further elucidation.  相似文献   

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