CpG ODN的最新研究进展

CpG C9DN是指含有CpG基序(以非甲基化胞嘧啶鸟嘌呤为基元构成的特定核苷酸序列结构)的C3DN。近期研究显示,CpG ODN作为佐剂,可明显促进Th1型免疫应答的产生。其与不完全弗氏佐剂(IFA)联合应用时,其效应甚至强于完全弗氏佐剂(CFA)。即使与Th2型佐剂如氢氧化铝合用亦可明显促进免疫应答的产生,且Th1型应答明显强于Th2型应答。CpG ODN能直接激活B细胞、树突状细胞、     

免疫佐剂 CpG—DNA的研究进展

特异性免疫即是含有PAMP的反应物与天然免疫细胞上的PRR相结合,激活天然免疫应答,从而活化抗感染途径,并最终发挥获得性免疫应答的一系列反应过程。CpG—DNA作为一种在进化中高度保守的PAMP,它可以模拟感染过程,克服新型疫苗PAMP不足的缺陷,从而诱导强烈的免疫应答。CpG—DNA可以直接激活B淋巴细胞、单核／巨噬细胞和树突状细胞,上调免疫刺激分子的表达,调节免疫反应,诱导IL-12、IL-1和TNF-等多种细胞因子的分泌,此外,它还能间接刺激NK细胞、T淋巴细胞。由于其独特的优点,CpG—DNA在畜牧兽医临床中显示其极强的使用价值和广阔的应用前景。     

CpG ODN对鸡新城疫LaSota活疫苗的免疫增强效应

将3种不同的未甲基化CpGODN分别与新城疫LaSota活疫苗混合后，经滴鼻和点眼免疫鸡，通过检测鸡血清中HI抗体、外周血T淋巴细胞增殖活性、诱导巨噬细胞分泌NO含量，以及刺激外周血淋巴细胞表达IFN-γ、IL-6与IL-1β mRNA量，分析各CpGODN对新城疫LaSota活疫苗免疫效果的影响。结果表明，经2次免疫后，含GTCGTT核心基序的CpG ODN1组，鸡血清平均HI抗体效价最高达8．2log2、淋巴细胞刺激指数达9．836、NO分泌量达35．833μmol／L，分别比疫苗单独免疫组高出2个滴度（P〈0．05）、4．4（P〈0．01）、27．6μmol／L（P〈0．01）；含GACGTT核心基序的CpG ODN2组增强作用不明显．与疫苗单独免疫组无差异；而CpGODN3的免疫刺激活性由于受其侧翼序列的影响，作用明显减弱甚至丧失。对细胞因子的影响，CpGODN3组IFN-γ mRNA表达量稍高于CpG ODN1组，而其余细胞因子均以CpG ODN1组表达水平最高（P〈0．05）。由此证明CpG ODN1能显著增强鸡对新城疫LaSota活疫苗的体液和细胞免疫反应，可以作为高效的免疫增强剂。     

免疫刺激剂CpG ODN在家禽疾病防控中的研究进展

CpG ODN是含一个或多个非甲基化CpG基序的寡聚脱氧核苷酸,根据其结构及生物学活性的不同,分为A、B、C、P四种类型,目前在家禽疾病防控方面的研究主要以B型CpG ODN为主,CpG ODN通过与鸡TLR-21受体结合发挥其免疫刺激活性,可用于防控鸡常见细菌性感染、病毒性感染以及球虫感染等。文章从CpG ODN的分类、作用机制、家禽疾病防控等方面进行阐述,为CpG ODN在家禽生产中的应用提供参考。     

免疫佐剂研究进展

佐剂的主要作用是提高抗原(免疫原)的免疫原性和免疫反应的可持续性,它能引导机体的免疫系统对抗原产生体液免疫或细胞免疫反应.对佐剂的选择取决于免疫的目的,从用途上分,佐剂可分为试验用佐剂和疫苗用佐剂.前者主要用于特异性抗体的制备,而后者则作为疫苗的必要成分.文章主要介绍目前常用的几种佐剂包括铝盐佐剂、弗氏佐剂、免疫刺激复合物(ISCOM)、脂质体和CpG及其在科研和疫苗中的应用.     

免疫佐剂研究进展

佐剂的主要作用是提高抗原（免疫原）的免疫原性和免疫反应的可持续性，它能引导机体的免疫系统对抗原产生体液免疫或细胞免疫反应。对佐剂的选择取决于免疫的目的，从用途上分，佐剂可分为试验用佐剂和疫苗用佐剂。前者主要用于特异性抗体的制备，而后者则作为疫苗的必要成分。文章主要介绍目前常用的几种佐剂包括铝盐佐剂、弗氏佐剂、免疫刺激复合物（ISCOM）、脂质体和CpG及其在科研和疫苗中的应用。     

桦褐孔菌发酵产物增强CpG ODN佐剂效应的研究

为了减少CpG ODN佐剂的用量,降低疫苗的生产成本,在日粮中添加桦褐孔菌发酵产物(Inonotus obliquus fermentation products,IOFP),以确定其对CpG ODN佐剂效应的增强效果。试验设立CpG ODN、IOFP的单独和联合应用组(CV、V+IOFP、CV+IOFP组),以及不添加佐剂的疫苗组(V组)和对照组(PBS组),所有动物于14日龄进行新城疫病毒(Newcastle disease virus,NDV)灭活疫苗首免,21 d后加强免疫。分别于首免后0、7、14、21、28、35和42 d分离各组外周血血清,进行NDV HI抗体滴度和中和抗体滴度的测定,同时分离淋巴细胞进行增殖指数(Stimulation index,SI)的测定;随后分离各组首免后0、21和42 d外周血淋巴细胞和血清,对CD4+、CD8+T细胞含量和IL-4、IFN-γ表达量进行测定。结果显示,相比于两者的单独使用,CpG ODN和IOFP的联合应用并未表现出进一步增强机体HI抗体滴度、淋巴细胞增殖指数、CD4+/CD8+T细胞含量和Th1/Th2细胞因子表达量的作用,但对中和抗体滴度的提升作用显著。结果表明,IOFP能够在一定程度上增强CpG ODN的佐剂效应。     

免疫佐剂研究进展

免疫佐剂是指先于抗原或与抗原同时应用,能非特异地改变或增强机体对抗原的特异性免疫应答,以及增强相应抗原的免疫原性或改变免疫反应类型,而本身无抗原性的物质。佐剂近年来发展较快,多种新型佐剂层出不穷,本文就对近年来一些常规的佐剂和新型佐剂的研究进展做一综述。     

CpG ODN对水貂免疫增强效果的研究

为获得对水貂具有免疫刺激活性的CpG ODN序列,设计合成了45种含不同CpG基序的DNA序列,应用MTS比色法测定合成CpG ODNs刺激水貂PBMC增殖的能力,结果有11条CpG ODN对水貂PBMC有刺激活性（SI＞2）;应用SI值大于5的6种CpG ODN分别与水貂伪狂犬灭活疫苗联合免疫水貂,免疫后经水貂血清抗伪狂犬中和抗体效价测定和水貂PBMC非特异性增殖效应检测,结果有3个CpG ODN序列对水貂具有较好免疫增强作用,分别是CpG-21(ATCGATTTGTCGTTATCGAT)、CpG-23(ATCGATGAACGTTAACGTTTC)和CpG-24(AACGTTCATCGATATCGATGT)。本研究获得3条对水貂具有较好免疫刺激活性的CpG ODN序列,可为水貂新型CpG佐剂的研究提供参考。     

CpG ODN--一类潜在的新型免疫佐剂

随着对CpG基序的DNA和寡核苷酸免疫学特性的深入了解，CpG DNA和CpG ODN在未来疫苗研究开发中的佐剂特性日益受到重视，本文对CpG ODN的结构特征、免疫活性、作用机制、佐剂效应及应用前景作了综述。     

疫苗佐剂胞嘧啶-鸟嘌呤寡脱氧核苷酸的研究进展

胞嘧啶-鸟嘌呤寡脱氧核苷酸(cytosine phosphate guanidine oligodeoxynucleotide,CpG ODN)是指含有非甲基化的胞嘧啶和鸟嘌呤二核苷酸为核心序列的核苷酸序列,近年来,CpG ODN作为一种新型免疫佐剂的研究越来越多,可诱发机体产生多种免疫学效应,提高系统免疫和黏膜免疫水平,具有安全性高,耐受性强等特点。     

新型免疫佐剂研究进展

随着免疫学研究的不断深入,研究开发高效、低毒、副反应小的免疫佐剂具有重要的理论和实际意义。本文对不同类型的新型免疫佐剂的研究现状进行了综述,以期为免疫佐剂的研制提供参考。     

CpG ODN重组质粒对猪外周血淋巴细胞免疫刺激作用的研究

为获得对猪具有免疫刺激活性的含CpG序列的重组质粒,设计合成了11条CpG序列,应用MTS比色法测定合成CpG ODNs刺激猪PBMC增殖的能力,结果有10条CpG ODN对猪PBMC具有刺激活性(SI>2);以对猪PBMC具有较高刺激活性的CpG06和CpG08为核心,分别合成含6次重复序列的重组质粒pCpG06和pCpG08,并检测其对猪PBMC的刺激活性,结果重组质粒pCpG06和pCpG08对猪PBMC的刺激指数分别可达4.97和5.32,并可刺激猪PBMC产生较高水平的IL-4。研究获得的重组质粒pCpG06和pCpG08对猪PBMC具有较好的刺激活性,可为猪用CpG佐剂的研究提供参考。     

Formulation with CpG ODN enhances antibody responses to an equine influenza virus vaccine

Previous studies have shown that protection against equine influenza virus (EIV) is partially mediated by virus-specific IgGa and IgGb. In this study we tested whether addition of a CpG ODN formulation to a commercial killed virus vaccine would enhance EIV-specific IgGa and IgGb antibody responses, and improve protection against an experimental EIV challenge. Thirty na?ve horses were assigned to one of three groups and vaccinated as follows: 10 were given vaccine (Encevac TC4, Intervet Inc.) alone, 10 were given vaccine plus 0.25 mg CpG ODN 2007 formulated with 30% Emulsigen (CpG/Em), and 10 controls were given saline. All horses were challenged with live virus 12 weeks after the final vaccination. Antibody responses were tested by single radial hemolysis (SRH) and ELISA, and protection was evaluated by determination of temperature, coughing, and clinical scores. Killed virus vaccine combined with CpG/Em induced significantly greater serologic responses than did the vaccine alone. All antibody isotypes tested increased after the addition of CpG/Em, although no shift in relative antibody isotypes concentrations was detected. Vaccination significantly improved protection against challenge but the differences between the two vaccine groups were not statistically significant. This study is the first demonstration that CpG/Em enhances antigen-specific antibody responses in horses and supports its potential to be used as an adjuvant for vaccines against equine infections.     

CpG寡核苷酸对IBDV VP2基因真核表达质粒免疫增效作用

以传染性法氏囊病病毒(IBDV)VP2蛋白基因表达质粒DNA为免疫原，以CpG的寡核苷酸(CpG-0DN)为免疫佐剂，肌肉注射于14日龄SPF鸡，1周后加强免疫1次，2次免疫后15d和21d分别测定血清ELISA抗体效价，并于免疫后21d用IBDV99儿强毒株攻毒和进行病理学观察。结果显示，(1)VP2基因重组质粒DNA与CpG共同免疫组的ELISA抗体水平明显高于VP2重组质粒免疫组；(2)IBD弱毒苗与VP2重组质粒免疫组抗体水平明显高于VP2重组质粒免疫组，且比VP2基因重组质粒DNA与CpG共同免疫组略高；(3)VP2基因重组质粒DNA与CpG共同免疫组及IBD弱毒苗与VP2重组质粒免疫组可明显降低IBDV强毒攻击后引起的急性发病率和死亡率。由此表明，CpG寡核苷酸对IBDV VP2蛋白基因真核表达质粒免疫具有明显增强作用，有很大的应用前景。     

Efficacy of QCDCR formulated CpG ODN 2007 in Nile tilapia against Streptococcus iniae and identification of upregulated genes

The potential of using a QCDCR (quilA:cholesterol:dimethyl dioctadecyl ammonium bromide:carbopol:R1005 glycolipid) formulated CpG oligodeoxynucleotide (ODN), ODN 2007, to confer protection in Nile tilapia against Streptococcus iniae infection was evaluated in this study. At two days post treatment, QCDCR formulated ODN 2007 elicited significant (P<0.05) protection to Nile tilapia, with relative percent survival of 63% compared to fish treated by QCDCR alone. To understand the molecular mechanisms involved in the protective immunity elicited by ODN 2007, suppression subtractive cDNA hybridization technique was used to identify upregulated genes induced by ODN 2007. A total of 69 expressed sequence tags (ESTs) were identified from the subtractive cDNA library. Quantitative PCR revealed that 44 ESTs were significantly (P<0.05) upregulated by ODN 2007, including 29 highly (>10-fold) and 15 moderately (<10-fold) upregulated ESTs. Of all ESTs, putative peroxisomal sarcosine oxidase was upregulated the highest. The 69 ESTs only included six genes that had putative functions related to immunity, of which only two (putative glutaredoxin-1 and carboxypeptidase N catalytic chain) were confirmed to be significantly upregulated. Our results suggest that the protection elicited by ODN 2007 is mainly through innate immune responses directly or indirectly related to immunity.     

Immunoadjuvant effects of bacterial genomic DNA and CpG oligodeoxynucleotides on avian influenza virus subtype H5N1 inactivated oil emulsion vaccine in chicken

This study investigated the immunoadjuvant effects of three types of bacterial genomic DNA and CpG oligonucleotides (CpG ODN) on the avian influenza virus (AIV) subtype H5N1 inactivated oil emulsion vaccine under two immunization strategies. The genomic DNA extracted from Escherichia coli O₂, Staphylococcus aureus, Streptococcus faecalis FQ68, and synthetic CpG ODN were used as adjuvants, and their effects on the AIV oil emulsion vaccine were examined in chickens. The results indicated that when administered separately from the vaccine, adjuvants induced lower haemagglutination inhibition (HI) titres and serum IgG titres but resulted in higher concentrations of IFN-γ and IL-10. In contrast, when combined with the oil emulsion vaccine prior to inoculation, CpG ODN induced higher HI, IgG titres and IFN-γ concentration but resulted in lower IL-10 concentration. These data suggest that, depending on the immunization approaches, adjuvants may exert distinct immune effects in chickens receiving AIV H5N1 oil emulsion vaccine: the prior incorporation of CpG ODN into the vaccine may augment both the humoral and Th1 type immune responses, while separate inoculation of adjuvants has not shown better adjuvanticity.     

CpG ODN对仔猪淋巴细胞增殖和细胞因子诱生的影响:在体和离体试验

将CpGODN、non CpG ODN分别接种初生仔猪，同时分离仔猪的外周血单核细胞，以CpGODN、non CpG ODN对外周血单核细胞体外培养，分别检测仔猪Th1型细胞因子分泌情况。结果表明，与non CpG ODN和对照组相比，CpG ODN能在体内显著提高仔猪的淋巴细胞白介素-2诱生活性、淋巴细胞增殖、血清中IFN-γ和IL-12水平（P〈0．05），亦能在体外刺激仔猪的外周血单核细胞分泌IFN-γ和IL-12（P〈0．01）。这显示CpG—ODN能显著增强动物的免疫应答能力。