表达PRRSV M蛋白重组腺病毒的构建及其免疫特性研究

本研究通过RT-PCR方法扩增猪繁殖与呼吸综合征病毒(PRRSV)S1株的M蛋白基因,将其克隆重组到人 血清5型腺病毒载体中,转染293细胞,制备重组腺病毒rAd-M。RT-PCR和IFA方法鉴定,结果表明rAd-M可表 达M基因的mRNA和M蛋白。纯化的rAd-M重组腺病毒经293细胞连续传25代,滴度稳定为107.8 TCID50／ mL。动物免疫试验结果表明,该重组腺病毒rAd-M能够刺激机体产生PRRSV的特异性抗体免疫和细胞免疫应 答反应,从而为PRRSV结构蛋白功能及其基因工程疫苗研究奠定了基础。     

黄鳍鲷弧菌病病原特性及其全菌苗的研究*

自湛江市发病养殖黄鳍鲷分离一株致病菌。对该菌的基本特征、药物筛选、灭活全菌苗等进行了研究。结果表明该病原菌为溶藻弧菌,且对四环素、土霉素、氯霉素、氟哌酸、氧氟沙星等药物敏感,pH6．0比pH8．4时灭活效果好,加入福尔马林可以提高灭活效果;全菌苗能够提高鱼体的免疫能力,减少攻毒时的死亡率。     

灵芝多糖对荷瘤小鼠肿瘤免疫系统的影响

目的:观察灵芝多糖对荷瘤小鼠免疫系统的影响.方法:纯系BALB/c小鼠30只,用U14瘤细胞荷瘤建立动物模型,随机平均分为三组:灵芝多糖治疗组、环磷酰胺治疗组、生理盐水对照组.观察灵芝多糖对荷瘤小鼠NK细胞活性、淋巴细胞转化率、TNF-α等免疫指标的影响.结果:灵芝多糖能够显著提高治疗组小鼠的NK细胞活性、淋巴细胞转化率和血清中TNF-α、IL-2的含量.结论:灵芝多糖能够显著提荷瘤小鼠免疫系统的活性.     

Interleukin-6 is required for parasite specific response and host resistance to Trypanosoma cruzi.

Infection with Trypanosoma cruzi, the agent of Chagas' disease, results in elevated levels of interleukin-6 (IL-6) in serum and infected tissues. However, it remains unknown whether IL-6 plays a role in host defence against T. cruzi. To determine whether IL-6 underlies disease progression, we followed the time course of T. cruzi-infected mice bearing IL-6 +/+ and minus sign/minus sign genotypes, respectively. We found that IL-6 minus sign/minus sign mice were more susceptible to T. cruzi infection as they exhibited about 3-fold higher parasitaemia and died earlier than wild-type animals. Unlike what might be expected, T. cruzi-infected IL-6 minus sign/minus sign mice did not show at peak infection a decrease in the secretion of IFN-gamma, a Th1 cytokine crucial for controlling the parasite. Instead, they exhibited a much reduced splenocyte recall response to T. cruzi antigens. Our results suggest that IL-6 mediates anti-parasite protective responses against T. cruzi.     

肺炎克雷伯菌表面成分对小鼠细菌感染的保护作用

观察肺炎克雷伯菌 (Klebsiellapneumoniae,Kp)表面成分在小鼠体内对细菌感染的保护作用。经肺炎克雷伯菌培养液经溶菌酶、NP40溶菌后 ,再经去脂、去蛋白和有机溶剂沉淀 ,干燥获取Kp表面成分干粉。用不同剂量的Kp表面成分免疫小鼠 ,分别用大肠埃希菌和金黄色葡萄球菌攻击小鼠 ,记录小鼠死亡情况 ,并测定循环抗体效价。结果 :Kp表面成分低剂量组 (30 μg/g体重 )和高剂量组 (40 μg/g体重 )对大肠埃希菌和金黄色葡萄球菌感染有显著保护作用 ,能降低感染小鼠的死亡率。免疫后小鼠的抗体效价明显高于对照组小鼠 (P <0 0 1 )。应用Kp表面成分的小鼠对细菌感染有一定的保护作用。     

Smad3基因剔除小鼠特异性免疫功能的研究

目的　研究Smad3基因剔除小鼠的体液免疫和细胞免疫。方法　采用流式细胞仪对其细胞免疫和体液免疫进行检测 ;并且应用ELISA方法对IgG抗体的吸光度进行测定。结果　纯合型 (- - )小鼠CD8 、CD4 CD8 、IgG雌雄之间差异有显著性 ;CD4 、CD8 、CD3 、CD19 、IgG的值低于野生型 ;结论　CD4 CD8 的比值同野生型比较属于异常 (与人的范围比较 )。因此 ,为在人类免疫疾病研究方面选用该动物提供一定的参考价值     

记忆T细胞平行分化模型的理论研究

为了从理论上讨论T细胞记忆维持机制的问题,基于T细胞的平行分化假说建立了非线性理论模型,利用此模型,在不同的抗原初值下得到了三种不同类型的应答。用优化剂量的抗原免疫生物体并且抗原存在时记忆能持续很长的时间,而失去抗原的同时将失去记忆,得出记忆T细胞平行分化模型确有记忆机制;并发现记忆强度与剩余抗原量有直接的关系,还进一步讨论了记忆细胞寿命的问题,并对体外情况作了预言。     

The Design and Characterization of Receptor-selective APRIL Variants

A proliferation-inducing ligand (APRIL), a member of the TNF ligand superfamily with an important role in humoral immunity, is also implicated in several cancers as a prosurvival factor. APRIL binds two different TNF receptors, B cell maturation antigen (BCMA) and transmembrane activator and cylclophilin ligand interactor (TACI), and also interacts independently with heparan sulfate proteoglycans. Because APRIL shares binding of the TNF receptors with B cell activation factor, separating the precise signaling pathways activated by either ligand in a given context has proven quite difficult. In this study, we have used the protein design algorithm FoldX to successfully generate a BCMA-specific variant of APRIL, APRIL-R206E, and two TACI-selective variants, D132F and D132Y. These APRIL variants show selective activity toward their receptors in several in vitro assays. Moreover, we have used these ligands to show that BCMA and TACI have a distinct role in APRIL-induced B cell stimulation. We conclude that these ligands are useful tools for studying APRIL biology in the context of individual receptor activation.     

Orthogonal test design for optimization of the extraction of polysaccharides from Phascolosoma esulenta and evaluation of its immunity activity

Yield of polysaccharides from Phascolosoma esulenta obtained by phosphate buffer extraction through an orthogonal experiment (L₉(3)⁴) were investigated to get the best extraction conditions. The results showed that extraction temperature, ratio of phosphate buffer to raw material, extraction time, and ratio of trypsinase to raw material were the main four variables that influenced the yields of extracts. The highest yield was obtained when extraction temperature, ratio of phosphate buffer to raw material, extraction time and ratio of trypsinase to raw material were 40 °C, 2, 5.5 h and 1.6, respectively. The immunity-stimulating method showed that polysaccharides from P. esulenta could significantly raise liver, spleen and thymus index of mice and enhance Con A-stimulated mouse spleen cells proliferation. These results indicate that polysaccharides from P. esulenta had significantly higher immunity-stimulating activities.