三倍体湘云鲫2号IFNa3基因的克隆及功能初探

三倍体湘云鲫2号具有不育、生长快、抗病抗逆性强等优良特性。为探究其抗病优势分子机制,实验克隆及鉴定了三倍体湘云鲫2号干扰素a3(3nIFNa3)。3nIFNa3的CDS由552个核苷酸组成,编码184个氨基酸。经预测,3nIFNa3 N端23位氨基酸为信号肽;3nIFNa3成熟肽中存在2个半胱氨酸残基并参与形成二硫键,表明其隶属于Ⅰ型一组干扰素。实时荧光定量PCR (qPCR)结果显示,宿主细胞经poly I∶C刺激后8 h、草鱼呼肠孤病毒(GCRV)或鲤春病毒血症病毒(SVCV)感染后48 h,3nIFNa3的转录水平达到最高。免疫印迹和免疫荧光结果显示,3nIFNa3为分泌型蛋白,分子量约为21.8 ku,其在出胞前主要分布于细胞质中。进一步研究发现,在宿主细胞中过表达3nIFNa3或含3nIFNa3的上清培养基孵育宿主细胞均能诱导内源ISG基因转录水平的显著提高。其中,3nSTAT1及3nVIPERIN在含3nIFNa3的上清培养基孵育后2 h转录水平达到最高,3nPKR则在4 h表达水平最高。此外,病毒滴度测定及结晶紫染色实验表明,EPC细胞经3nIFNa3孵育或过表达3nIFNa3后,其抗GCRV和SVCV的能力均显著增强。研究表明,3nIFNa3为可分泌的细胞因子,在宿主抗病毒天然免疫反应中发挥作用。     

Prospects in Salmonella Control: Competitive Exclusion,Probiotics, and Enhancement of Avian Intestinal Immunity

Salmonella infections are mainly asymptomatic in poultry but are associated with widespread human illness from this source. Therefore, there is continuing interest in finding ways of preventing flock infection and, hence, contamination of poultry products with salmonellas. This review considers aspects of Salmonella carriage in poultry and host interactions that may be exploitable in the future to improve existing control measures. These include factors involved in colonization of the gastrointestinal tract, the role of competitive exclusion and probiotic treatments, and enhancement of intestinal immunity.     

鸡传染性支气管炎（肾型HK株）活疫苗的研究

肾型鸡传染性支气管炎病毒致弱株ＨＫ毒株引自其他研究所，用于制作活疫苗。此苗每剂量含毒价不低于１０＾３．５ＥＩＤ５０，经－１５℃中贮存１８个月，不影响其免疫效力。接种４个月后的鸡中８０％能抵抗强毒攻击，已在野外应用于２５，０００，０００羽上鸡只，未出现不良反应病例，说明此疫苗在实验室及野外应用都很满意。     

Ecosystem Immunity as a Strategy for Controlling Insect Pests in a Biotic Community

Summary

Populations of insect pests sometimes increase beyond the economic threshold to become serious problems in crop production. However, their populations are usually maintained below the economic injury level by natural predator insects and parasites. Living bodies often develop a degree of immunity against pest invasion, such as macrophages in the human body. In this case, macrophages reproduce in the human body at the expense of blood and body fluid, but are suppressed below the level of illness to the human body. This is analogous to crops, which have developed defense mechanism in the biotic community against pests by means of natural enemies and provided immunity in a total system. However, natural enemies, parasites and predators, must be maintained themselves with little compensation or support from the agroecosystem. Some years ago I proposed a model “reproduction curve with two equilibrium points” to describe the fluctuation of insect populations (Takahashi, 1964). The lower equilibrium point in the model can be regarded as a latent period and the higher one as the outbreak level. This model is based on the S-shaped functional response curve of predator to prey density and is applicable in a biotic community where polyphagous predators predominate. To ensure stable populations of natural enemies in the biotic community, it is necessary to maintain their food supply in the field. The populations of monopha-gous predators, such as parasitoids, fluctuate in response to prey or host populations sometimes inducing dramatic increases in pest populations above the economic injury level. On the other hand, polyphagous predators can utilize ordinary organisms as alternate food sources and keep their population stable even when a pest population (i.e., their target food) decreases to low level. This model will be discussed with respect to the diversity of a biotic community.     

口服鸭瘟弱毒苗诱导鸭局部黏膜和系统免疫中IgA、IgM和IgG发生规律研究

为探讨鸭瘟弱毒苗诱导鸭局部黏膜和系统免疫中抗体发生的规律,本研究将鸭瘟病毒Cha株弱毒苗经口免疫20日龄樱桃谷鸭,60 d内定时随机剖杀5只鸭,采集血清、胆汁、气管和消化道(食道、十二指肠、空肠、回肠、盲肠和直肠)分泌液,应用间接ELISA检测抗DPV的IgAI、gM和IgG滴度(以Log10表示)。结果表明:①血清中检测到IgA、IgM和IgG的时间段分别为9-36、3-15和9-60天,滴度由高到低为IgG、IgM和IgA;②胆汁中检测到IgAI、gM和IgG的时间段分别为6-15、9-12和12-36天,滴度由高到低为IgA、IgG和IgM;③气管中检测到IgA、IgM和IgG的时间段分别为6-60、3-12和9-27天,滴度由高到低为IgAI、gM和IgG;④食道中检测到IgAI、gM和IgG的时间段分别为3-60、3-27和9-60天,滴度由高到低为IgA、IgM和IgG;⑤各肠段抗体滴度由高到低及相应检测到的时间段:十二指肠中为IgA(3-60天)I、gM(3-15天)和IgG(9-27天);空肠中为IgA(6-60天)I、gM(6-12天)和IgG(9-36天);回肠中为IgA(9-60天)、IgM(6-9天)和IgG(15-21天);盲肠中为IgA(6-60天)I、gG(12-36天)和IgM(6天);直肠中为IgA(3-60天)I、gG(12-21天)和IgM(6天)。结果显示,鸭瘟弱毒疫苗经口免疫鸭后,IgM和IgG分别是系统免疫中体液免疫的先锋抗体和主要抗体;IgA、IgG和IgM在胆汁中存留时间短;IgA是气管和消化道中的主要抗体。     

鸡新城疫/传染性支气管炎二联油乳剂灭活疫苗试验研究报告(Ⅲ)——二联苗安全性、免疫效力及保存期试验

用同胚培养的含NDV、IBV胚液制备的二联油乳剂灭活苗(简称鸡二联灭活苗),经免疫效力试验表明,用50倍稀释的鸡二联灭活苗,0.5ml/只剂量免疫18日龄鸡,4周后试验免疫鸡分别进行NDV、IBV强毒攻击,攻毒保护率均在50%以上,证明0.5ml剂量含有50个半数保护量(50个PD_(50)),NDHI抗体≥1:16,IBVN抗体≥1:8便可保护.三批疫苗免疫18日龄鸡,0.5ml/只组免疫鸡体内有效抗体可维持16周以上,0.25ml/只组有效抗体可维持到12周.疫苗在20℃保存4个月有效,4~8℃普通冰箱中保存15个月有效.以3倍免疫量免疫18日龄鸡4周内无任何毒副反应.     

猪后海穴接种猪传性胃肠炎疫苗对母乳及仔猪血清中IL—2含量的影响

应用放射免疫分析方法，测定比较了猪后海穴穴位免疫与常规口服、肌肉途径免疫猪传染性胃肠炎疫苗后，母猪初乳、常乳免疫仔猪血清中IL-2的含量。结果表明，初服中IL-2的含量以穴位免疫最高；常乳中IL-2含量各种免疫途径基本一致，处于较低水平。仔猪免疫后3d，血清中IL-2含量，穴位免疫与口服免疫基本一致，但均高于肌肉免疫及对照；免疫后7d，血清中IL-2含量，穴位免疫高于口服、肌肉免疫。从免疫调节因子方面看出，后海穴对动物机体免疫功能具有正向促进作用。     

鸡新城疫La Sota株、传染性支气管炎W_(93)株二联活疫苗研究 Ⅲ.疫苗免疫期试验

分别用3批鸡新城疫、传染性支气管炎二联活疫苗(LaSota+W93),NDLaSota单苗和IBW93单苗免疫SPF鸡,并于免疫后第3、7、14、30、90、150天分别用NDV和NIBV强毒攻击。结果表明,二联活疫苗(LaSota+W93)于免疫后7～150d可获得与相应单苗同样的保护力。     

Cathelicidins类抗菌肽研究进展

论述了动物先天免疫中的重要成分——抗菌肽家族之一的cathelicidins家族的基因结构特点及其表达；生物学活性、作用机理等方面的特点，并对其应用前景做了展望。