ZE515对CP5型金黄色葡萄球菌疫苗的佐剂作用

前期研究表明一种含人参皂甙的植物油佐剂ZE515对口蹄疫疫苗具有佐剂作用,本研究探讨该佐剂对荚膜多糖CP5型金黄色葡萄球菌(S.aureus)疫苗的佐剂作用。将ZE515和灭活的金黄色葡萄球菌抗原乳化制备成疫苗,ICR小鼠皮下注射疫苗免疫2次,二免后3周采血制备血清,检测血清抗体及其亚类、细胞因子IL-5和IFN-γ,取脾脏检测淋巴细胞增殖指数(SI),并对免疫鼠腹腔注射S.aureus活菌进行攻毒保护性试验。结果显示,ZE515能显著增强抗体及其亚类的免疫应答(P0.05),提高淋巴细胞增殖指数(P0.05),提升血清IL-5和IFN-γ表达水平(P0.05)。ZE515对S.aureus疫苗的佐剂作用显著强于常规铝胶佐剂,含ZE515的疫苗对S.aureus强毒攻毒的保护率为75%,而含铝胶佐剂的疫苗保护率只有50%,表明ZE515对S.aureus疫苗具佐剂作用,值得进一步研究。     

布鲁氏菌外膜囊泡生物信息学分析及免疫原性评价

【目的】探索布鲁氏菌外膜囊泡(OMVs)在亚单位疫苗上的应用前景,制备布鲁氏菌OMVs亚单位疫苗,评估布鲁氏菌OMVs的免疫原性。【方法】利用高速离心法制备羊种布鲁氏菌OMVs,通过透射电镜、SDS-PAGE和生物信息学分析对制备的OMVs进行形态和组分分析;使用纳米佐剂(LDH)和弗氏佐剂乳化OMVs后免疫小鼠,通过间接ELISA方法检测免疫后7、14、21、28和35 d小鼠血清中的特异性抗体,利用小鼠IgG ELISA检测试剂盒检测免疫后小鼠血清中IgG抗体水平,评估OMVs诱导产生的体液免疫水平;通过小鼠脾脏淋巴细胞分离与细胞因子白细胞介素4(IL-4)和γ-干扰素(IFN-γ)测定及小鼠外周血T淋巴细胞亚群的流式细胞术测定评估OMVs免疫小鼠的细胞免疫水平。【结果】成功提取并纯化了布鲁氏菌OMVs,其直径大小为20～160 nm。生物信息学分析结果显示,OMVs主要组成蛋白OMP25、OMP31、OMP16、OMP19、BP26及SOD均属于亲水性蛋白和抗原性蛋白,且存在多个B细胞和T细胞优势抗原表位。与PBS组相比,OMVs免疫小鼠后,不同佐剂组均可诱导小鼠产生高水平的特异...     

布鲁菌转录调节因子HFQ诱导机体免疫反应的分析

旨在分析布鲁菌(Brucella)转录调节因子HFQ诱导机体产生的免疫反应。以热灭活牛种布鲁菌S2308为模板,根据GenBank登录的S2308 hfq基因序列(BAB1_1134)设计引物,PCR扩增hfq基因片段后,将其克隆至原核表达载体pET-32a,转化大肠杆菌BL21(DE3)感受态细胞,诱导HFQ蛋白表达;利用SDS-PAGE电泳以及Western blot对重组HFQ蛋白(rHFQ)进行分析;pET-32a空载体、rHFQ和疫苗株M5-90刺激小鼠巨噬细胞RAW 264.7,利用ELISA试剂盒检测细胞因子IFN-γ和IL-4的表达水平;将pET-32a、rHFQ和M5-90免疫小鼠后,检测小鼠脾细胞中IFN-γ和IL-4的水平,以及小鼠血清中IgG抗体水平。结果显示,hfq基因大小为237 bp,编码79个氨基酸,rHFQ大约在25.8 ku处出现蛋白条带,纯化后为单一条带。Western blot结果显示,rHFQ具有较好的反应原性。rHFQ刺激RAW 264.7后,诱导IFN-γ和IL-4的水平与M5-90组相似,显著高于PBS组和pET-32a空载体组,且随着刺激时间的延长而升高。rHFQ免疫小鼠后,诱导脾细胞产生IFN-γ和IL-4的水平,小鼠血清中IgG的水平与M5-90组相似,显著高于PBS组和pET-32a空载体组。布鲁菌HFQ蛋白具有较好的反应原性,并能诱导机体产生较高的细胞免疫和体液免疫水平,是布鲁菌亚单位疫苗研制较理想的候选抗原。     

盘尾丝虫ASP1蛋白佐剂活性区不同标签融合表达与佐剂活性比较

为了探明纯化标签对盘尾丝虫活化相关分泌蛋白1(activation-associated secreted protein 1,ASP1)佐剂活性的影响,将其佐剂活性区PR-1编码序列分别与类弹性蛋白多肽(elastin-like polypeptide,ELP)、ELK16自聚肽或His标签进行融合表达,用相变循环、离心洗涤和镍亲和层析进行融合蛋白纯化;将ELP与传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)VP2基因片段进行融合表达,用蛋白酶切除ELP标签后与不同标签融合PR-1免疫小鼠,两次免疫后不同时间采血分离血清,采用ELISA检测VP2特异IgG、IgG1和IgG2c滴度,用试剂盒检测免疫小鼠血清的IFN-γ、TNF-α、IL-6、IL-10浓度。结果显示,ELP-PR1、ELK-PR1、His-PR1和ELP-VP2融合蛋白在重组大肠杆菌中均获得正确表达,纯化蛋白纯度大于90%;3种标签融合PR-1均能增强免疫小鼠的抗原特异IgG、IgG1和IgG2应答,并能刺激小鼠产生IFN-γ、TNF-α、IL-6或IL-10细胞因子。在3种PR-1融合蛋白中,ELP-PR1的佐剂活性最强,ELK-PR1与不完全弗氏佐剂相当。本研究探索了不同纯化标签对PR-1免疫佐剂活性的影响,为传染性法氏囊病新型亚单位疫苗佐剂研制提供思路。     

绵羊肺炎支原体Y98标准株P30外膜蛋白与IFN-γ的融合表达及其免疫原性

以绵羊肺炎支原体(Mycoplasma oumvipneonia,MO)标准株Y98的P30外膜蛋白为抗原,同时以细胞因子IFN-γ为佐剂,将两者串联融合表达.小鼠免疫保护试验结果显示,P30重组蛋白的免疫保护率为60％,IFN-γ重组蛋白的免疫保护率为20％,P30-IFN-γ重组蛋白的免疫保护率达到80％.间接ELISA试验证实,经100 μL与200 μL P30-IFN-γ重组蛋白免疫小鼠的血清中,P30抗体效价分别为1:32 000与1:64 000.以上结果证实,所制备的重组蛋白对小鼠实验个体基本安全,且P30-IFN-γ重组蛋白中的细胞因子IFN γ组分可以调节机体免疫机能,增强P30蛋白的免疫保护效果.     

粗糙型布鲁菌M111菌壳的安全性和免疫原性

以粗糙型布鲁菌M111株和重组裂解质粒制备出布鲁菌菌壳,利用小鼠模型对布鲁菌菌壳、布鲁菌M111活菌和福尔马林灭活菌的安全性和免疫原性进行比较研究。结果显示,与布鲁菌弱毒菌株M111比较而言,布鲁菌菌壳具有更好的安全性,免疫小鼠后能产生与弱毒菌株相似的血清抗体水平、脾CD3+和CD4+T淋巴细胞反应,甚至产生更高水平的IFN-γ。这些结果表明,布鲁菌菌壳具有与弱毒菌株相似的体液免疫和细胞免疫能力,将来可能作为预防布鲁菌感染的新型候选疫苗,但布鲁菌菌壳疫苗的有效性和特异性免疫机制还有待深入研究。     

铜绿假单胞菌flgE基因菊粉季铵盐纳米DNA的制备与免疫效果研究

为提高铜绿假单胞菌flgE基因DNA疫苗的免疫效果,本实验对菊粉进行阳离子化后获得带正电荷的菊粉季铵盐,以其包裹裸DNA疫苗后制备成菊粉季铵盐纳米DNA疫苗,结果显示,flgE基因壳菊粉季铵盐纳米DNA疫苗在扫描电镜下呈现较为规则的圆球型,粒径100 nm～200 nm。以裸DNA疫苗和菊粉季铵盐纳米DNA疫苗免疫BALB/c小鼠,同时设置灭活疫苗、pcDNA3.1(+)空载体和PBS对照组。免疫1周时经断尾采血并分离血清,采用间接ELISA检测免疫后血清特异性抗体水平,结果显示小鼠免疫后菊粉季铵盐纳米DNA疫苗诱导的血清抗体水平虽低于灭活疫苗,但明显高于裸DNA疫苗(p0.05)。同时每次免疫2周后,每组各随机取5只小鼠分离制备脾淋巴细胞悬液,采用MTT法检测免疫小鼠脾淋巴细胞增殖情况,双抗夹心ELISA测定脾淋巴细胞分泌的IFN-γ和IL-2的水平,结果显示,纳米DNA疫苗组小鼠的刺激指数(SI)及脾淋巴细胞分泌的IFN-γ和IL-2含量与灭活疫苗组相当,显著高于裸DNA疫苗组(p0.05)。三免2周后以1.8×1010cfu/只铜绿假单胞菌CAU0792菌液攻击各组小鼠,且计算存活数及保护率,结果显示灭活疫苗组、菊粉季铵盐纳米DNA疫苗组和裸DNA疫苗组的保护率分别为90%、75%和55%,表明菊粉季铵盐可增强裸DNA疫苗诱导的免疫应答水平和保护效果。本实验首次将菊粉进行季铵盐化后使其带有正电荷,有利于结合DNA分子形成纳米颗粒,从而增强了DNA疫苗的免疫原性,为铜绿假单胞菌DNA疫苗的研制及新型DNA疫苗佐剂的开发奠定了基础。     

新孢子虫NcSRS2和NcSAG1重组蛋白免疫小鼠诱导的免疫应答

为了研究新孢子虫NcSRS2和NcSAG1重组蛋白对动物的免疫效果,利用重组表达的NcSRS2和NcSAG1蛋白与弗氏佐剂混匀后免疫BALB/c小鼠,检测小鼠抗新孢子虫抗体水平和血清中IL-4和IFN-γ含量。结果表明,免疫后的BALB/c小鼠IgG、IgG2a和IFN-γ抗体表达水平升高,IgG1抗体和IL-4表达水平也升高,表明NcSRS2和NcSAG1重组蛋白可激发机体产生Th1型和Th2型免疫反应,且NcSRS2重组蛋白的免疫增强效果与NcSAG1重组蛋白免疫组的差异具有显著统计学意义(P0.05)。本研究结果为研制高效安全的抗新孢子虫的新型疫苗提供了参考。     

鉴别布鲁菌病自然感染动物与疫苗免疫动物胶体金检测试纸条的研制

用金黄色葡萄球菌A蛋白（SPA）标记胶体金技术制作金标垫,以亲和层析法纯化的BP26蛋白作为检测抗原（T线）,研制胶体金快速检测试纸条。用建立的试纸条检测小鼠布鲁菌感染血清,可成功鉴别牛布鲁菌S19感染和BP26缺失疫苗株YZ-2免疫的小鼠。试纸条检测与布鲁菌属同源性较近的几株细菌的阳性血清,结果无交叉反应;试纸条敏感性高于虎红平板凝集试验检测方法,近似于ELISA方法;准确性同于ELISA法,且更为简便快捷。该试纸条具有鉴别布鲁菌病自然感染和疫苗免疫的应用前景。     

CpG ODN联合重组乳酸乳球菌鼻内免疫BALB/c小鼠的佐剂效应

本试验初次建立了CpG ODN联合重组乳酸乳球菌滴鼻免疫BALB/c小鼠模型。结果得出CpG ODN佐剂协同重组菌抗原组血清中抗PRRSV特异性抗体IgG和呼吸道黏膜抗体s-Ig A均高于单独重组菌组(P>0.05)和单独佐剂组(P<0.01),佐剂CpG ODN协同重组菌抗原组的Th1型细胞因子IL-2、IFN-γ及黏膜淋巴因子IL-5的活性高于单独抗原组(P>0.05)及单独佐剂组(P<0.01)。试验结果说明CpG ODN作为佐剂与重组菌鼻腔免疫小鼠后,可以提高重组菌诱导的黏膜免疫反应和Th1细胞参与的系统免疫反应,为研究安全有效的重组菌黏膜疫苗奠定了基础。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein