传染性法氏囊病病毒超强毒GZ株VP2基因的克隆和序列分析

根据已发表的传染性法氏囊病病毒 ( IBDV) 5 2 /70株基因组序列 ,设计并合成了 1对特异扩增 IBDVVP2基因的引物。以 IBDV超强毒 ( vv IBDV) GZ株基因组为模板 ,利用 RT-PCR技术扩增出了 1 .5 kb的c DNA产物 ,将 VP2基因克隆于 p UC1 1 9质粒上 ,得到重组 p UC1 1 9质粒。对 VP2基因全序列进行了测定。序列分析和聚类分析表明 ,GZ株与欧洲超强毒株 UK6 6 1非常相似 ,而与经典强毒株。

新城疫与传染性法氏囊病疫苗对雏鸡联合免疫的研究

将１１４只１１日龄海赛克斯褐公鸡随机分成５组：Ⅰ组为空白对照，Ⅱ组用新城疫（ＮＤ）弱毒苗和ＮＤ油佐剂灭活苗同时免疫，Ⅲ组用传染性法氏囊病（ＩＢＤ）地方毒株油佐剂灭活苗免疫，Ⅳ组用ＮＤ弱毒苗、ＮＤ油佐剂灭活苗、ＩＢＤ地方毒株油佐剂灭活苗同时免疫，Ⅴ组在Ⅳ组的基础上增加ＩＢＤ弱毒苗免疫。５组鸡分别隔离饲养，定期测定血清ＮＤＨＩ效价与ＩＢＤ琼扩效价。选择时机用强毒攻击，观察各组鸡的保护情况。结果：（１）Ⅱ、Ⅳ、Ⅴ组鸡均能很好地抵抗ＮＤＶ强毒的攻击，Ⅲ、Ⅳ、Ⅴ组鸡无论对ＩＢＤＶ人工感染，还是自然感染，均有坚强的保护力；（２）ＩＢＤ地方毒株油佐剂灭活疫苗不干扰ＮＤ疫苗的免疫应答；（３）ＩＢＤ弱毒苗对ＮＤ疫苗的免疫应答有一定影响，在免疫初期能促进机体尽快对ＮＤ疫苗产生应答，但后期ＮＤ疫苗的ＨＩ抗体降低较快；（４）ＮＤ疫苗对ＩＢＤ疫苗的免疫效果无显著影响。作者提出，对雏鸡首免（无论有、无母源抗体）可采用ＮＤ弱毒苗＋ＮＤ油佐剂灭活苗＋ＩＢＤ（地方毒株）油佐剂灭活苗同时进行免疫，至少可以保护到上笼后或开产前免受ＮＤＶ和ＩＢＤＶ的感染，既简化了免疫程序，又可减少对鸡群的应激，值得推广应用。

传染性法氏囊病病毒VP5基因的克隆及表达

利用PCR技术扩增编码IBDVVP5基因的DNA片段 ,进而构建了T7启动子控制下的N端His_Tag融合表达质粒pRSESTA_VP5 ,通过测序证明序列正确后 ,转化进大肠杆菌BL2 1(DE3) ,用IPTG进行诱导表达 ,SDS_PAGE分析结果表明 ,融合蛋白 (约 2 8kDa)在BL2 1中得到高效表达 ,表达产物约占菌体蛋白的 35 %。主要以包涵体形式存在 ,通过金属离子 (Ni2 +)螯合亲和层析纯化 ,得到纯度在 90 %以上的电泳纯表达产物VP5。这些结果为进一步研究IBDVVP5的结构与功能、其在IBD中的作用机理奠定了良好的基础。

家鸡发生传染性囊病的诊治

梨丰乡于某家散放饲养的家鸡500只,60日龄时突然发病,2日内死亡40多只,还有50多只病鸡,感染率达20%,确诊为鸡传染性囊病。1 临床症状病鸡精神不振、昏睡、羽毛松乱、不食,有的只少饮些水,怕冷打堆,精神萎顿,不愿走动。病鸡排浅白色或水样稀便。

Genomic Sequencing and Molecular Characteristics of A Very Virulent Strain of Infectious Bursal Disease Virus Isolated in China

[Objective] The paper was to determine the genomic sequence of a very virulent strain of infectious bursal disease virus（IBDV）,and study its molecular characteristics.[Method] A very virulent strain（vvIBDV）（HLJ-0504） of infectious bursal disease virus（IBDV） with special characters was isolated in China and its genome was sequenced.[Result] Sequence analysis showed that segment A of HLJ-0504 was derived from vvIBDV,while segment B was from a distinct ancestor.The morbidity and mortality of HLJ-0504 was 100% and 86.7%to SPF chickens,respectively.[Conclusion] vvIBDV with distinct segment B were still circulating and the evolution of IBDV was diversified in China.Besides,it is hard to imagine that the virulence of IBDV is determined solely by segment A or B.

Study on the Knockout and the Soluble Prokaryotic Expression of VP5 Protein Transmembrane Region of IBDV

[Objective] The research aimed to construct the prokaryotic expression vector of VP5 protein of IBDV.The transmembrane region sequence of VP5 protein was knocked out.Moreover,the expression,separation and purification of objective protein were carried out.[Method] PCR technology was used to respectively amplify the extracellular and intracellular fragments of VP5 gene of IBDV.Then,the two fragments were simultaneously linked to pET-28b（＋）,and it was the vector-intracellular fragment-extracellular fragment-vector.The recombinant expression plasmid pET-VP5-FC and the improved pET-VP5-SC of VP5 whose transmembrane region gene fragment was knocked out were constructed.Then,the expression plasmid was transformed into BL21（DE3）.After IPTG induction,the recombinant protein was purified by Ni affinity chromatography and the gel filtration chromatography.[Result] The soluble expressed VP5 of IBDV was obtained.[Conclusion] The research laid the foundation for further studying the structure and function of VP5 protein.

Genetic Analysis of the VP2 Hypervariable Region of Thirty-six Infectious Bursal Disease Virus Isolates in China during 2009-2012

[Objective] Infectious bursal disease （IBD） is a highly contagious immuno- suppressive disease caused by infectious bursal disease virus （IBDV）. IBDV is ge- netically prone to mutation, which results in challenges to the disease prevention and control. Thus, it is necessary to continuously monitor the prevalence of IBDV. [Method] 36 IBDVs were identified from ten provinces in China from 2009 to 2012. Partial fragments of VP2, including the hypervariable region （HVR）, from new iso- lates were sequenced and analyzed through comparisons with published sequences of IBDV, including 18 strains isolated previously by our lab and 24 reference strains from China and around the world. [Result] Phylogenetic analysis showed a co-exis- tence of IBDV strains belonging to classic, variant, attenuated, and very virulent IB- DV （wlBDV） in China. wlBDVs remain the predominant strains in China and the new subgroup was emerging. Alignment analysis revealed several distinct amino acid mutations that might be involved in virulence or antigenicity variation. [Conclu- sion] The results offered evolutionary clues showing the emerging trend of obvious variations and diversity of IBDV in major poultry-producing regions of China particu- larly in recent years. These findings will contribute to a better understanding of the genetic evolution of IBDV.

Immune Effect of Combination of Universal Molecular Adjuvant and IBDV Subunit

In order to evaluate the immune effect of the protein expressed by the universal vector pET-mLTA-CTLA-4 plus IBDV subunit, the fusion protein mLTA-CTLA-4 was expressed and purified. Protein toxicity tests were carried out on rabbits.The VP2 gene of infectious bursal virus was amplified by RT-PCR, and lately used for pET-VP2 construction. Ten-day-old free healthy chickens were chosen for a grouped test, including the mLTA-CTLA-4（at different doses） plus VP2 groups, IBDV living vaccine group and control group. Serum and mucosal samples were collected regularly and the neutralization titers of IgG and IgA were assayed, while an animal protection test was conducted to determine the protection rate. The results showed that the protein m LTA-CTLA-4 was non-toxic and its protection rate was100%. IgG or IgA levels in the IBDV vaccine group were slightly higher than those in recombinant protein groups. These results indicated that the recombinant protein mLTA-CTLA-4 could be applied with IBDV subunit vaccine to protect chickens from infection.

Comparative Studies on Detection of Antibodies against Infectious Bursal Disease Virus with Test Strips and Agar Gel Immunodiffusion Method

[Objective] This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method. [Method] Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory, and the results were comparad^with that using traditional agar diffusion method. [Result] The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion; test strips showed higher detection rate in the deter- mination test of 216 clinical samples, with high specificity, easy preservation, and simple and rapid operation, thereby being more suitable for the monitoring of clinical antibodies. [Conclusion] Test strips could replace the existing serological methods, having great promotion and application value in antibody monitoring.

Nutritional status and nutritional therapy in inflammatory bowel diseases

Underweight and specific nutrient deficiencies are frequent in adult patients with inflammatory bowel disease(IBD).In addition,a significant number of children with IBD,especially Crohn's disease(CD) have impaired linear growth.Nutrition has an important role in the management of IBD.In adults with CD,enteral nutrition(EN) is effective in inducing clinical remission of IBD,although it is less efficient than corticosteroids.Exclusive EN is an established primary therapy for pediatric CD.Limited data suggests that EN is as efficient as corticosteroids for induction of remission.Additional advantages of nutritional therapy are control of inflammation,mucosal healing,positive benefits to growth and overall nutritional status with minimal adverse effects.The available evidence suggests that supplementary EN may be effective also for maintenance of remission in CD.More studies are needed to confirm these findings.However,EN supplementation could be considered as an alternative or as an adjunct to maintenance drug therapy in CD.EN does not have a primary therapeutic role in ulcerative colitis.Specific compositions of enteral dietselemental diets or diets containing specific components-were not shown to have any advantage over standard polymeric diets and their place in the treatment of CD or UC need further evaluation.Recent theories suggest that diet may be implicated in the etiology of IBD,however there are no proven dietary approaches to reduce the risk of developing IBD.

Haemostatic system in inflammatory bowel diseases:New players in gut inflammation

Inflammation and coagulation constantly influence each other and are constantly in balance.Emerging evidence supports this statement in acute inflammatory diseases,such as sepsis,but it also seems to be very important in chronic inflammatory settings,such as inflammatory bowel disease(IBD).Patients with Crohn's disease and ulcerative colitis have an increased risk of thromboembolic events,and several abnormalities concerning coagulation components occur in the endothelial cells of intestinal vessels,where most severe inflammatory abnormalities occur.The aims of this review are to update and classify the type of coagulation system abnormalities in IBD,and analyze the strict and delicate balance between coagulation and inflammation at the mucosal level.Recent studies on possible therapeutic applications arising from investigations on coagulation abnormalities associated with IBD pathogenesis will also be briefly presented and critically reviewed.

Potential role of Th17 cells in the pathogenesis of inflammatory bowel disease

The etiopathology of inflammatory bowel disease （IBD） remains elusive. Accumulating evidence suggests that the abnormality of innate and adaptive immunity responses plays an important role in intestinal inflam- mation. IBD including Crohn＇s disease （CD） and ulcerative colitis （UC） is a chronic inflammatory disease of the gastrointestinal tract, which is implicated in an inappropriate and overactive mucosal immune response to luminal flora. Traditionally, CD is regarded as a Thl- mediated inflammatory disorder while UC is regarded as a Th2-1ike disease. Recently, Th17 cells were identified as a new subset of T helper cells unrelated to Thl or Th2 cells, and several cytokines [e.g. interleukin （IL）-21, IL-23] are involved in regulating their activation and differentiation. They not only play an important role in host defense against extracellular pathogens, but are also associated with the development of autoimmunity and inflammatory response such as IBD. The identification of Th17 cells helps us to explain some of the anomalies seen in the Thl/Th2 axis and has broadened our understanding of the immunopathological effects of Th17 cells in the development of IBD.

Potential prospects of nanomedicine for targeted therapeutics in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) such as Crohn's disease are highly debilitating. There are inconsistencies in response to and side effects in the current conventional medications, failures in adequate drug delivery, and the lack of therapeutics to offer complete remission in the presently available treatments of IBD. This suggests the need to explore beyond the horizons of conventional approaches in IBD therapeutics. This review examines the arena of the evolving IBD nanomedicine, studied so far in animal and in vitro models, before comprehensive clinical testing in humans. The investigations carried out so far in IBD models have provided substantial evidence of the nanotherapeutic approach as having the potential to overcome some of the current drawbacks to conventional IBD therapy. We analyze the pros and cons of nanotechnology in IBD therapies studied in different models, aimed at different targets and mechanisms of IBD pathogenesis, in an attempt to predict its possible impact in humans.

Intestinal microbiota in inflammatory bowel disease:Friend of foe?

Inflammatory bowel disease （IBD） arises from disruption of immune tolerance to the gut commensal microbiota, leading to chronic intestinal inflammation and mucosal damage in genetically predisposed hosts. In healthy individuals the intestinal microbiota have a symbiotic relationship with the host organism and possess important and unique functions, including a metabolic function （i.e. digestion of dietary compounds and xenobiotics, fermentation of undigestible carbohydrates with production of short chain fatty acids）, a mucosal barrier function （i.e. by inhibiting pathogen invasion and strengthening epithelial barrier integrity）, and an immune modula- tory function （i.e. mucosal immune system priming and maintenance of intestinal epithelium homeostasis）. A fine balance regulates the mechanism that allows co- existence of mammals with their commensal bacteria. In IBD this mechanism of immune tolerance is impaired because of several potential causative factors. The gut microbiota composition and activity of IBD patients are abnormal, with a decreased prevalence of dominant members of the human commensal microbiota （i.e. Clostridium IXa and IV groups, Bacteroides, bifldobacteria） and a concomitant increase in detrimental bacteria （i.e. sulphate-reducing bacteria, Escherichia coll. The observed dysbiosis is concomitant with defectiveinnate immunity and bacterial killing （i.e. reduced mucosal defensins and IgA, malfunctioning phagocytosis） and overaggressive adaptive immune response （due to ineffective regulatory T cells and antigen presenting cells）, which are considered the basis of IBD pathogen- esis. However, we still do not know how the interplay between these parameters causes the disease. Studies looking at gut microbial composition, epithelial integrity and mucosal immune markers in genotyped IBD populations are therefore warranted to shed light on this obscure pathogenesis.

Etiology of inflammatory bowel disease:A unified hypothesis

Inflammatory bowel disease(IBD),including both ulcerative colitis(UC) and Crohn's disease(CD),emerged and dramatically increased for about a century.Despite extensive research,its cause remains regarded as unknown.About a decade ago,a series of findings made me suspect that saccharin may be a key causative factor for IBD,through its inhibition on gut bacteria and the resultant impaired inactivation of digestive proteases and over digestion of the mucus layer and gut barrier(the Bacteria-Protease-Mucus-Barrier hypothesis).It explained many puzzles in IBD such as its emergence and temporal changes in last century.Recently I further found evidence suggesting sucralose may be also linked to IBD through a similar mechanism as saccharin and have contributed to the recent worldwide increase of IBD.This new hypothesis suggests that UC and CD are just two symptoms of the same morbidity,rather than two different diseases.They are both caused by a weakening in gut barrier and only differ in that UC is mainly due to increased infiltration of gut bacteria and the resultant recruitment of neutrophils and formation of crypt abscess,while CD is mainly due to increased infiltration of antigens and particles from gut lumen and the resultant recruitment of macrophages and formation of granulomas.It explained the delayed appearance but accelerated increase of CD over UC and many other phenomena.This paper aims to provide a detailed description of a unified hypothesis regardingthe etiology of IBD,including the cause and mechanism of IBD,as well as the relationship between UC and CD.

Recent advances in cytokines:Therapeutic implications for inflammatory bowel diseases

Inflammatory bowel diseases （IBDs） are complex and chronic disabling conditions resulting from a dysregulated dialogue between intestinal microbiota and components of both the innate and adaptive immune systems. Cytokines are essential mediators between activated immune and non-immune cells, including epithelial and mes- enchymal cells. They are immunomodulatory peptides released by numerous cells and these have significant effects on immune function leading to the differentiation and survival of T cells. The physiology of IBD is becom- ing a very attractive field of research for development of new therapeutic agents. These include cytokines involved in intestinal immune inflammation. This review will focus on mechanisms of action of oytokines involved in IBD and new therapeutic opportunities for these diseases.

From intestinal stem cells to inflammatory bowel diseases

The pathogenesis of both entities of inflammatory bowel disease (IBD), namely Crohn's disease (CD) and ulcerative colitis (UC), is still complex and under investigation. The importance of the microbial flora in developing IBD is beyond debate. In the last few years, the focus has changed from adaptive towards innate immunity. Crohn's ileitis is associated with a deficiency of the antimicrobial shield, as shown by a reduced expression and secretion of the Paneth cell defensin HD5 and HD6, which is related to a Paneth cell differentiation defect mediated by a diminished expression of the Wnt transcription factor TCF4. In UC, the protective mucus layer, acting as a physical and chemical barrier between the gut epithelium and the luminal microbes, is thin- ner and in part denuded as compared to controls. This could be caused by a missing induction of the goblet cell differentiation factors Hath1 and KLF4 leading to immature goblet cells. This defective Paneth and goblet cell differentiation in Crohn's ileitis and UC may enablethe luminal microbes to invade the mucosa and trigger the inflammation. The exact molecular mechanisms behind ileal CD and also UC must be further clarified, but these observations could give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.

Risk factors and gene polymorphisms of inflammatory bowel disease in population of Zhejiang,China

AIM:To identify the risk factors and three single nucleotide polymorphisms(SNPs) of NOD2/CARD15 gene in inflammatory bowel disease(IBD) of the population in Zhejiang,China.METHODS:A case-control study was conducted using recall questionnaire to collect data on demographic,socioeconomic,lifestyle characteristics and dietary behaviors from 136 determined IBD patients and 136 paired healthy controls.COX regression method was used to screen the statistically significant risk factors for IBD.The polymorphisms of NOD2/CARD15 gene Arg702Trp,Gly908Arg and Leu1007fsinsC were genotyped and further compared between 60 patients with IBD and 60 healthy controls by polymerase chain reaction and restriction fragment length polymorphism.RESULTS:IBD occurred primarily in young and middle-aged people.The mean age for IBD patients was 42.6 years.The ratio of males to females was 1.23:1.COX regression indicated a higher statistical significance in milk,fried food and stress compared with the other postulated risk factors for IBD.None of the patients with IBD and healthy controls had heterozygous or homozygous SNPs variants.CONCLUSION:Milk,fried food and stress are associated with increased risk of IBD.The common variants in NOD2/CARD15 gene are not associated with IBD in China's Zhejiang population.

Importance of nutrition in inflammatory bowel disease

Inflammatory bowel disease （IBD） results from the interaction between an individual＇s immune response and precipitant environmental factors, which generatean anomalous chronic inflammatory response in thosewho are genetically predisposed. Various feeding practices have been implicated in the origin of IBD based on epidemiological observations in developed countries, but we do not have solid evidence for the etiological role played by specific food types. IBD is associated with frequent nutritional deficiencies, thepattern and severity of which depends on the extent,duration and activity of the inflammation. Nutritional support allows these deficiencies in calories, macro and micronutrients to be rectified. Enteral nutrition is also aprimary therapy for IBD, especially for Crohn＇s disease,as it allows the inflammatory activity to be controlled,kept in remission, and Drevents or delays the need forsurgery. Nutritional support is especially important in childhood IBD as an alternative to pharmacological treatment. This report discusses the complex relationship between diet and IBD.