口蹄疫病毒利用自身蛋白逃逸宿主天然免疫应答的研究进展

口蹄疫（foot-and-mouth disease,FMD）是由口蹄疫病毒（foot-and-mouth disease virus,FMDV）感染偶蹄兽所引起的一种急性、热性、高度接触性传染病,FMDV有7个血清型,加之病毒传播迅速,严重影响畜牧业的发展。FMDV为小RNA病毒科、口蹄疫病毒属的唯一成员,其基因组编码4种结构蛋白和10种非结构蛋白。FMDV感染宿主后利用自身蛋白通过多种途径和方式来影响宿主天然免疫应答,从而有利于FMDV复制的微环境。这些策略包括FMDV参与细胞自噬、内质网应激和应激颗粒形成的细胞过程,破坏多种宿主蛋白的功能,如劫持、裂解宿主蛋白或干扰宿主蛋白的表达、去除宿主蛋白的泛素化以及抑制宿主蛋白的磷酸化。这些逃避天然免疫的策略也是目前研究的热点。基于现有的研究结果,作者总结了近几年FMDV蛋白在抑制宿主天然免疫方面的研究进展,以期为FMDV的研究与防控提供参考。     

禽网状内皮组织增生病病毒感染对SPF雏鸡血液和局部淋巴组织CD4+/CD8+细胞及相关细胞因子表达的影响

旨在探讨禽网状内皮组织增生病病毒（reticuloendotheliosis virus,REV）对SPF雏鸡血液和局部淋巴组织中T淋巴细胞数量以及相关细胞因子表达的影响。将96只1日龄SPF雏鸡随机分为REV感染组和对照组,应用流式细胞术、酸性α-醋酸萘酯酶染色（acid α-naphthyl acetate esterase,ANAE）、荧光定量PCR等方法对上述指标进行检测。试验数据表明,与对照组相比,感染组雏鸡血液CD4⁺T淋巴细胞数量在第7~35天显著降低、CD8⁺T淋巴细胞数量在第7~28天显著升高,CD4⁺/CD8⁺比值在第7~28天显著降低（均P<0.05或P<0.01）;局部淋巴组织哈德尔腺（Hader’s gland,HG）、派伊尔结（Peyer’s patch,PP）和盲肠扁桃体（caecal tonsil,CT）中ANAE⁺T淋巴细胞数量均显著降低（均P<0.05或P<0.01）;GH、PP和CT中细胞因子IL-2、IFN-γ和TNF-α 转录量都有不同程度升高。本研究表明,REV感染引起雏鸡血液中CD4⁺ T淋巴细胞数量降低、CD4⁺/CD8⁺T淋巴细胞比例失衡、局部淋巴组织中T淋巴细胞数量相对减少及细胞因子TNF-α转录持续升高与REV造成感染雏鸡细胞免疫功能显著降低密切相关。     

影响奶牛早期胚胎丢失的因素

早期胚胎丢失,即胚胎着床之前的胚胎死亡,是影响奶牛妊娠率的主要因素。奶牛妊娠早期的胚胎死亡率较高,给牧场造成了严重的经济损失。目前,对于早期胚胎丢失的研究主要集中在染色体异常、生殖激素紊乱、热应激、免疫因素、双胎妊娠、疾病、B族维生素缺乏等方面。本文综述了早期胚胎丢失发生的原因,为预防早期胚胎丢失提供依据。     

Dietary supplementation of potassium sorbate,hydrated sodium calcium almuniosilicate and methionine enhances growth,antioxidant status and immunity in growing rabbits exposed to aflatoxin B1 in the diet

The present experiment was conducted to evaluate the effect of dietary supplementation with some feed additives (potassium sorbate; Sor, hydrated sodium calcium almuniosilicate; Hsc and L-methionine; L-M) against aflatoxin B1 (AF) toxicity in rabbits. A total of 72 growing rabbits (5-week-old) were distributed into six equal groups (4 replicates with 3 rabbits each). The experimental groups are as follows: control group, AF group (supplemented with AF 0.3 mg/kg diet), AF + Sor group (AF 0.3 mg/kg diet + Sor 2 g/kg diet), AF + Hsc group (AF 0.3 mg/kg diet + Hsc 5 g/kg diet), AF + L-M group (AF 0.3 mg/kg diet + L-M 8 g/kg diet) and AF + Mix group (AF 0.3 mg/kg diet + 2 Sor + 5 Hsc + 8 L-M g/kg diet). Live body weight and weight gain at 13 weeks of age were significantly reduced by AF. Feed intake at 13 weeks of age was decreased in AF, AF + Hsc and AF + Mix compared to the control. AF, AF + Hsc and AF + Mix showed the lowest total antioxidant capacity compared to the control. The highest level of reactive oxygen species and 8-Hydroxy-2-desoxyguanosine was observed in AF group. Using of other supplements with AF increased immunoglobulinM than AF alone. In conclusion, dietary supplementation of Sor, L-M, Hsc or their mixture was effective in reducing the adverse effects of AF on performance, antioxidant and immune status of rabbits with more better improvement obtained by Sor or L-M separately.     

Seasonal variations in the concentration of antimicrobial components in milk of dairy cows

The incidence of bovine mastitis and the bulk milk somatic cell count (BMSCC) are influenced by season, which may be associated with innate immune functions, including antimicrobial components in mammary glands. Therefore, the present study was conducted to examine the effect of season on antimicrobial components in milk. Rectal temperature and plasma cortisol, thyroxine, and derivatives of reactive oxygen metabolites (d‐ROMs) were measured as stress parameters. Concentrations of lactoferrin (LF), lingual antimicrobial peptide (LAP), psoriasin (S100A7), and Immunoglobulin A (IgA) in milk were measured as indicators of innate immune function. LF and LAP concentrations were significantly lower in summer than in winter and spring, respectively, whereas the concentration of S100A7 was significantly lower in winter than in spring and autumn. The rectal temperature was significantly higher in summer than in other seasons, whereas plasma cortisol, thyroxine, and d‐ROMs did not exhibit any seasonal variation. In conclusion, even though stress parameters were not changed, the concentration of antimicrobial components, such as LF and LAP, decreased in summer, which may explain the frequent occurrence of mastitis during this season.     

浅谈猪繁殖与呼吸综合征的防控措施

猪繁殖与呼吸综合征(Porcine reproductive and respiratory syndrome,PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)引起的猪的一种高度传染性疾病,又称"猪蓝耳病"。笔者通过引种管理、生物安全、生产流程、疫苗免疫以及实验室监测这五项措施帮助不同的猪场实现对猪蓝耳病的有效防控。     

角鲨烯对1~21日龄白羽肉鸡生长性能、抗氧化能力 和免疫功能的影响

为了研究SQ对1～21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能的影响,选取体重为（38.38±0.25） g的 1日龄雄性AA⁺白羽肉鸡360只,将雏鸡随机分为3组,每组6个重复,每个重复20只,分别饲喂基础日粮,基础日粮+175 mg·kg^-1角鲨烯（squalene,SQ）和基础日粮+350 mg·kg^-1 SQ,试验期为21 d。结果表明：（1）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡平均日增重,并显著降低料重比（P＜0.05）,同时提高肉鸡血清中超氧化物歧化酶（superoxide dismutase,SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）、过氧化氢酶（catalase,CAT）活性及总抗氧化力（total antioxidant capacity,T-AOC）（P＜0.05）,显著降低血清丙二醛（malonyldialdehyde,MDA）含量（P＜0.05）,且350 mg·kg^-1SQ 添加量在改善肉鸡血清过氧化氢酶活性和总抗氧化力方面,效果显著优于175 mg·kg^-1（P＜0.05）。（2）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡血清中高密度脂蛋白、补体C3和C4水平（P＜0.05）,显著降低血清中低密度脂蛋白水平（P＜0.05）,且350 mg·kg^-1 SQ 添加量在降低血清低密度脂蛋白和提高补体C3和C4水平方面效果显著优于175 mg·kg^-1（P＜0.05）。（3）饲粮中添加175和350 mg·kg^-1 SQ均能显著提高肉鸡免疫器官指数（P＜0.05）。综上所述,饲粮中添加 SQ能有效改善1~21日龄白羽肉鸡生长性能、抗氧化能力和免疫功能,其中350 mg·kg^-1 SQ在改善肉鸡血清过氧化氢酶、总抗氧化力、补体C3和C4方面更具优势。     

水稻病毒与植物寄主互作研究新进展

水稻是维持世界一半以上人口生存的主要粮食作物,其产量和品质关系到社会稳定。近年来,水稻病毒引起的病毒病严重影响作物的产量及品质。植物在与病毒长期的互作过程中进化出了多种有效的防御机制来抑制病毒侵染。本文围绕近年来国内外关于水稻抗病毒的研究进展,对植物激素、自噬与水稻病毒的互作关系进行总结,并提出了水稻病毒研究过程中所涉及到的一些问题,以期为开展水稻抗病育种相关研究提供参考。