New gene-based approaches for an AIDS vaccine

Vaccine approaches against AIDS have focused on inducing cellular immune responses, since many studies revealed the role of T cell responses in the control of human immunodeficiency virus or simian immunodeficiency virus (SIV) infections. The experimental infection of rhesus macaques with SIV or chimeric SHIV is routinely used as a model for AIDS. In such models, DNA immunization is a tool to elicit specific T cell responses and to study their protective efficacy. DNA immunogenicity in primates depends on parameters such as level of antigen expression, choice of the antigen among SIV proteins, use of fusion proteins, route of immunization, and addition of adjuvants. Recent results suggest that priming with DNA and boosting with attenuated recombinant viral vectors, each expressing corresponding SIV antigens, leads to improved specific immunity and, in some cases, affords protection against pathogenic challenge. After preclinical evaluations, DNA has entered clinical trials for a therapeutic or prophylactic gene-based AIDS vaccine.     

梅山与长大母猪下丘脑-垂体-卵巢轴Kiss1和GPR54基因的表达差异

研究早熟与晚熟品种母猪下丘脑-垂体-卵巢轴Kiss1和GPR54基因的表达差异。选用8头梅山母猪与12头长大(LY)母猪为研究对象,梅山母猪于70 d和100 d屠宰,LY母猪于70、100 d和199 d屠宰,收集血清及下丘脑、垂体、卵巢组织样品。ELISA检测血清瘦素(Leptin)和雌二醇(E2)水平,PCR克隆梅山与LY母猪Kiss1基因编码序列,实时荧光定量PCR检测母猪下丘脑、垂体、卵巢组织Kiss1和GPR54基因表达水平。结果表明:梅山与LY母猪Kiss1基因编码序列相似性为100%;梅山与LY母猪初情期下丘脑Kiss1基因表达量极显著高于垂体与卵巢(P<0.01),卵巢GPR54基因表达水平显著高于下丘脑与垂体(P<0.05)。梅山母猪下丘脑-垂体-卵巢轴Kiss1基因表达水平都显著高于相同日龄和初情期LY母猪(P<0.05),梅山母猪血清Leptin水平极显著高于相同日龄LY母猪(P<0.01)。而E2水平显著高于100 d与初情期LY母猪(P<0.01)。Leptin与下丘脑Kiss1和GPR54基因表达呈显著正相关(P<0.05),而E2仅与下丘脑Kiss1基因表达有极显著正相关关系(P<0.01);梅山与LY母猪Kiss1基因编码区序列相似性为100%,梅山母猪下丘脑-垂体-卵巢轴上kiss1基因表达量较LY母猪高,主要原因可能是初情日龄早,下丘脑Kiss1基因表达水平的高低与血清Leptin和E2浓度密切相关。     

蒙古羊Hoxc8基因甲基化与胸椎数量的关系

为了研究蒙古羊Hoxc8基因的甲基化与胸椎数的关系,试验采用亚硫酸氢盐测序PCR方法进行检测。结果表明:蒙古羊的14枚胸椎个体(T14)占26.1%,7枚腰椎个体(L7)占69.5%,其中Hoxc8 exon-1含27个CpG。T13型个体的甲基化CpG分别为6,3,6;T14型个体的甲基化CpG分别为23,20,21。T13和T14的甲基化比例平均值分别为(18.500±0.064)%和(79.030±0.056)%(P=0.002)。T14蒙古羊Hoxc8 exon-1的甲基化功能区(120～142个碱基)的CpG胞嘧啶全部甲基化,而T13则相反。说明蒙古羊Hoxc8 exon-1甲基化CpG的密度和数量影响Hoxc8基因的表达,并且调控胸椎的发育。     

“三三法”快速检测沙门氏菌的研究

将DHL平板上产H_2S和不产H_2S的菌落分别用TSI、LMA、甘露醇或TSI、LMA、ONPG三管判定,辅以肠杆菌科诊断噬菌体0—1、C多价、E多价三滴法快速检测沙门氏菌的方法简称“三三法”。近两年来我们用此法检测了125批、341份样品中236株可疑菌株,检出沙门氏菌27株、11个血清型,经系统生化验证符合率100％。表明该法具有快速、简便、准确、实用的优点。     

紫花苜蓿MsCOL1基因RNAi表达载体的构建及转化

根据紫花苜蓿CONSTANS类似基因MsCOL1基因(登录号:DQ661682)序列,设计含有酶切位点的两对特异性引物,以紫花苜蓿cDNA为模板,分别合成用于构建干扰载体的正反义片段,将正反义片段分别插入表达载体pART27的相应位置,构建含有发夹结构的RNAi载体pART-S-A.利用农杆菌介导方法,将pART-S-A转化到紫花苜蓿中,经PCR检测,获得了7株转基因植株.经RT-PCR检测,证明转基因植株中MsCOL1基因表达量有所下降,其中5株的表达量明显的降低.结果表明,已构建成功具有发夹结构的RNAi载体pART-S-A,它可有效的抑制紫花苜蓿MsCOL1基因.     

Leukocyte differentiation antigens in canine cutaneous and oral plasmacytomas

Seventeen cutaneous and oral tumours with light microscopic features of plasmacytomas from 16 dogs were studied. Clinically, most neoplasms were benign, although three recurred after excision and three were locally invasive. Tumours most often arose on the pinnae, digits, gingiva, and inguinal regions near areas of chronic inflammation and exhibited variable degrees of plasmacytic differentiation microscopically. Diagnosis of plasmacytoma was confirmed in paraffin-embedded tissues with a panel of leukocyte differentiation antigen markers that included cross-reactive antibodies for Mb-1 (CD79a), CD3, and vimentin and canine-specific antibodies for CD45RA and CD18. Immunoreactivity for Mb-1 and CD45RA, including staining of multinucleate cells and cells with karyomegaly, confirmed a B-cell origin of neoplasms, while staining for CD3 and CD18 revealed an extensive network of infiltrative T-cells and dendritic cells in tumours suggestive of a directed immune response. These findings (i) demonstrate the value of using a panel of antibodies for leukocyte antigens to differentiate plasmacytomas from other cutaneous and oral round cell tumours, and (ii) suggest that immune recognition and responsiveness within tumours may play a role in the behaviour of plasmacytomas in dogs by affecting tumour cell growth and differentiation.     

影响棕色脂肪组织产热活性因素的研究进展

全球性肥胖流行问题愈发严峻,而脂肪组织本身可能是解决这个问题的关键。人和哺乳动物体内存在两种脂肪组织,发挥着截然相反的作用。与白色脂肪组织存储机体过剩的能量不同,棕色脂肪组织中存在独特的解偶联蛋白,能将脂肪酸氧化磷酸化,释放热能,增加能量消耗。因此,通过激活棕色脂肪组织产热,加速体内储存的脂质氧化磷酸化,成为了一种新的预防和治疗肥胖的手段。论文阐述影响棕色脂肪产热活性的因素以及相关机制,旨在为肥胖的治疗提供新的思路和方向。     

成都麻羊乳上皮黏蛋白MUC1的遗传多态性研究

采用SDS-PAGE研究成都麻羊乳上皮黏蛋白MUC1的遗传多态性,并以金堂黑山羊、乐至黑山羊、自贡黑山羊、藏山羊作对照进行比较分析。结果表明:成都麻羊与对照山羊乳MUC1的多态性丰富,成都麻羊有7种基因型、5个等位基因优势基因为C、D、E,金堂黑山羊7种基因型、6个等位基因优势基因为B、C、D,乐至黑山羊6种基因型、6个等位基因优势基因为B、C、D,自贡黑山羊5种基因型、5个等位基因优势基因为A、C、D,藏山羊3种基因型、3个等位基因优势基因为C、D。乳MUC1的基因型、等位基因的分布品种间有差异;根据乳MUC1等位基因频率对供试山羊品种进行聚类分析,成都麻羊与金堂黑山羊的遗传距离最小(D=0.2507)先聚为一类,再依次与乐至黑山羊(D=0.2831)、自贡黑山羊(D=0.3721)、藏山羊(D=0.4752)聚为一大类,结果较好的反映了成都麻羊与对照山羊品种间的亲缘关系。     

２，４-二叔丁基苯酚对啤酒花幼苗生长与光合特性的影响

前期对不同植龄啤酒花根系分泌物及根际土壤的化学物质进行了分离鉴定,结果发现有酚类物质的存在且２,４-二叔丁基苯酚含量较高,为了进一步证实啤酒花是否存在自毒作用,采用田间小区栽培试验,研究了不同用量［０（ＣＫ,Ａ０）,７．５（Ａ１）,１５．０（Ａ２）和２２．５ｍｍｏｌ／ｍ２（Ａ３）］２,４-二叔丁基苯酚处理对啤酒花幼苗生长及光合特性的影响。结果表明,２,４-二叔丁基苯酚用量Ａ１ 和Ａ２ 处理,啤酒花生长好,地上部、地下部、总生物量及日均光合速率均比对照高,且达到显著差异（犘＜０．０５）;２,４-二叔丁基苯酚用量Ａ３ 处理,啤酒花地上部、地下部和总生物量及光合特性均较对照降低,差异达到显著水平（犘＜０．０５）。啤酒花幼苗叶片光合速率日变化呈双峰型,最高峰出现在上午９：００左右,次高峰出现在中午１５：００左右,午间有明显的“午休“现象,与对照（Ａ０）相比,Ａ１、Ａ２、Ａ３ 三个处理的次高峰出现的时间均有推迟,且Ａ１ 和Ａ２ 处理的幼苗午休”现象不太明显,气孔因素是导致其“午休”的主要原因。