Vaccines against Major Poultry Viral Diseases: Strategies to Improve the Breadth and Protective Efficacy

The poultry industry is the largest source of meat and eggs for human consumption worldwide. However, viral outbreaks in farmed stock are a common occurrence and a major source of concern for the industry. Mortality and morbidity resulting from an outbreak can cause significant economic losses with subsequent detrimental impacts on the global food supply chain. Mass vaccination is one of the main strategies for controlling and preventing viral infection in poultry. The development of broadly protective vaccines against avian viral diseases will alleviate selection pressure on field virus strains and simplify vaccination regimens for commercial farms with overall savings in husbandry costs. With the increasing number of emerging and re-emerging viral infectious diseases in the poultry industry, there is an urgent need to understand the strategies for broadening the protective efficacy of the vaccines against distinct viral strains. The current review provides an overview of viral vaccines and vaccination regimens available for common avian viral infections, and strategies for developing safer and more efficacious viral vaccines for poultry.     

邻近标记技术在膜蛋白相互作用中的研究进展

膜蛋白是细胞多种生命活动的主要承担者,膜蛋白之间的相互作用参与调控细胞间的接触与信号传递,并与细胞的分化、成熟息息相关。因此,开发多种深入解析膜蛋白之间相互作用的方法具有重要的理论与现实意义。除了传统的免疫共沉淀方法之外,新开发的邻近标记技术已经逐渐成为了研究膜蛋白相互作用的重要手段。邻近标记技术主要利用生物工具酶标记与诱饵蛋白相互作用的邻近蛋白,并通过流式细胞术、质谱以及共聚焦显微成像技术等方法检测膜蛋白之间的相互作用。本文着重介绍了近些年来新开发的用于研究膜蛋白相互作用的多种邻近标记技术,并展望了该类技术在膜蛋白相互作用领域未来的发展前景。

     

Shkbp1缺失对小鼠T淋巴细胞系亚群的影响

目的探讨Shkbp1缺失小鼠(Shkbp-1~(-/-))的血液、骨髓、脾脏中血液细胞分类和T细胞亚群的变化。方法采用Shkbp-1~(-/-)转基因小鼠,经PCR鉴定基因型;利用全自动血液检测仪测定血液细胞分类;采用流式细胞仪检测Shkbp-1~(-/-)和对照组小鼠血液、骨髓、和脾脏中T淋巴细胞亚群。结果血常规结果:中性粒细胞和嗜酸性粒细胞有增高趋势,且有显著差异。淋巴细胞未见显著差异。流式结果显示:对照组血液中CD4~+CD8~+双阳性细胞降低,骨髓中CD3~+、CD4~+升高。但脾脏组织中,其CD3~+、CD4~+、CD8~+、CD4~+CD8~+双阳性细胞均呈下降趋势。结论 Shkbp1参与血液细胞的成熟分化,影响了免疫细胞数量,本研究为探索Shkbp1如何参与血液细胞的分化奠定了研究基础。     

脾内注射法免疫小鼠制备抗—HBc单克隆抗体的研究

用基因工程菌产乙型肝炎核心抗原(HBcAg)对 Balb/c 小鼠脾内多点注射法免疫,将该鼠的脾淋巴细胞与鼠骨髓瘤细胞在 PEG 作用下融合,用固相放射免疫分析法(SPRIA)筛选,成功地获得了2株抗-HBc 阳性的杂交瘤细胞株。通过中和试验和交叉鉴定,2株抗-HBc 单克隆抗体只能与 HBcAg 起反应,而不能与 HBsAg 和 HBeAg 反应。经多次亚克隆后,所得腹水中的抗-HBc 滴度达1:64000～1:28000。这2株单克隆抗体做包被抗体检测 HBcAg 和(125)~Ⅰ标记查患者血清标本时,所测得的结果与人抗-HBc 多克隆抗体做包被或(125)~Ⅰ标记所测得的结果相一致。2株杂交瘤细胞连续传代3个多月,冻存复苏后仍能稳定地分泌特异的抗-HBc 单克隆抗体。     

骨相关生长因子对兔骨髓基质干细胞生长及分化的量效作用

目的研究地塞米松、重组人成纤维细胞生长因子（recombinant human fibroblast growth factor，rhFGF）及重组人骨形成蛋白2（recombinant human bone morphogenetic protein 2，rhBMP-2）对兔骨髓基质干细胞（marrow slromal stem cells，MSCs）生长及分化的量效作用，为其在骨组织上程中的应用提供实验基础。方法体外分离培养免MSCs，分为1个空白对照组及9个实验组。实验组分别与终浓度为10^-8、10^-7、10^-6mol／L地塞米松；终浓度为50、200、500ngng/ml FGF；终浓度为50、500、1000ng／ml rhBMP-2培养。于4、7d终止培养并测定细胞总蛋白及碱性磷酸酶（alkaline phosphatase。ALP）活性。结果与空白对照组比较，10mol／L地塞米松显著抑制细胞蛋白合成（P〈0．05），而10^-8、10^-7mol／L地塞米松对细胞蛋白合成无明显影响；10^-6,10^-7mol／L地塞米松刺激MSCs高度表达ALP（P〈0．05）。rhFGF各浓度组显著促进细胞蛋白合成量差异有统计学意义（P〈0．05），表现ALP活性抑制。rhBMP-2符浓度组对细胞蛋白合成九明显影响；50ng／ml rhBMP2不影响MSCs的ALP活性；当浓度增至500ng／ml与1000ng／ml时，ALP活性显苦增加（P〈0．05）。结论10^-7mol／L地塞米松及500、1000ng／ml rhBMP-2在不影响MSCs增殖的前提下，适当浓度能显著促进MSCs向成骨细胞转化，在骨组织工程的研究中有重要的应用价值。     

"双相"组织工程软骨修复兔关节骨软骨缺损

目的探讨“双相”异体骨基质明胶（bonematrixgelatin,BMG）作为组织工程软骨载体,与同体骨髓间充质干细胞（marrowmesenchymalstemcells,MSCs）结合,构建组织工程软骨修复兔关节骨软骨缺损的效果。方法4月龄新西兰兔32只,雌雄不限,体重2～3kg。①体外实验：取5只新西兰兔,处死后取髂骨和四肢骨,制备一侧松质骨,一侧皮质骨的“双相”异体BMG载体,扫描电镜观察。另取新西兰兔18只,抽取骨髓,分离MSCs并诱导成软骨分化;将诱导而来的软骨前体细胞与“双相”BMG载体复合构建组织工程软骨,分别于1、3和5周取材行Masson、PAS染色和扫描电镜观察。②体内实验：将抽取骨髓的18只及余下的9只新西兰兔制成双侧股骨内髁骨软骨缺损模型,将前期制备的组织工程软骨同体植入18只兔的右股骨内髁骨软骨缺损（A组）,左侧缺损移植异体BMG（B组）,其余9只双侧软骨缺损未予处理作为空白对照（C组）,分别于术后1、3和6个月取材,行大体、组织学和Ⅱ型胶原mRNA原位杂交观察,改良Wakitani法评分,比较各组修复效果差异。结果①体外实验：“双相”BMG松质骨面孔隙大小100-800μm,细胞于其中增生,形成富含细胞的软骨层;皮质骨面孔隙大小10～40pm,细胞层状覆盖于其表面,可作为起支撑作用的软骨下骨。②体内实验：A组术后1个月即可重建关节骨软骨缺损;修复软骨在观察期内逐渐变薄,但在6个月内始终保持关节面及软骨下骨结构完整。B、C组未能修复缺损,缺损周边软骨磨损加剧。改良Wakitani评分显示A组在3个时间点的各项评分结果,除6个月软骨厚度外,其它指标均优于B、C组,且差异有统计学意义（P〈0．01）。Ⅱ型胶原mRNA原位杂交显示,A组缺损区修复组织中细胞阳性染色率明显高于B、C组,且差异有统计学意义（P〈0．01）。结论“双相”异体BMG可作为组织工程软骨载体材料,其结合自体MSCs诱导的软骨前体细胞制备的组织工程软骨,可修复兔关节软骨和软骨下骨。     

Immobilization of decellularized valve scaffolds with Arg-Gly-Asp-containing peptide to promote myofibroblast adhesion

The cell adhesive properties of decellularized valve scaffolds were promoted by immobilization of valve scaffold with arginine-glycine-aspartic acid （RGD）-containing peptides. Porcine aortic valves were decellularized with trypsin/EDTA, and detergent Triton X-100. With the help of a coupling reagent Sulfo-LC-SPDP, the valve scaffolds were immobilized with glycine-arginine-glycine-aspartic acid-serine-proline-cysteine （GRGDSPC） peptide. X-ray photoelectron spectroscopy （XPS） was used for surface structure analysis. Myofibroblasts harvested from rats were seeded onto the valve scaffolds. Cell count by using microscopy and modified MTT assay were performed to assess cell adhesion. Based on the spectra of XPS, the conjugation of GRGDSPC peptide with decellularized valve scaffolds was confirmed. Both cell count and MTT assay showed that myofibroblasts were much easier to adhere to the modified valve scaffolds, which was also confirmed histologically. Our findings suggest that it is feasible to immobilize RGD-containing peptides onto decellularized valve scaffolds. And the technique can effectively promote cell adhesion, which is beneficial for in vitro tissue engineering of heart valves.     

Engineering bacteria to modulate host metabolism

The microbial community of the gut, collectively termed the gut microbiota, modulates both host metabolism and disease development in a variety of clinical contexts. The microbiota can have detrimental effects and be involved in disease development and progression, but it can also offer benefits to the host. This has led in the last years to the development of different therapeutic strategies targeting the microbiota. In this review, we will focus on one of these strategies that involve the use of engineered bacteria to modulate gut microbiota in the treatment of metabolic disorders. We will discuss the recent developments and challenges in the use of these bacterial strains with an emphasis on their use for the treatment of metabolic diseases.