鸡毒支原体F弱毒疫苗株细胞免疫特性研究

为了解鸡毒支原体（Mycoplasma gallisepticum,MG）F弱毒疫苗株的细胞免疫特性,分别以活菌浓度为109（A组）、106（B组）ccu/mL的MG F株及生理盐水（C组）点眼接种SPF鸡,采用流式细胞技术及T淋巴细胞增殖试验对免疫前后淋巴细胞亚类Th/T、Tc/T、Th/Tc及刺激指数（SI）的动态变化规律进行研究。结果显示免疫后A、B组的Th/T、Tc/T、SI明显升高,其中Th/T于d5、d7,Tc/T、SI于d7、d14,A组显著高于B组（P〈0.05）。研究结果表明,免疫MG F株可较好的提高鸡的细胞免疫,且MG F株活菌浓度与接种鸡外周血Th/T、Tc/T、SI呈正相关。     

Effects of Mancozeb and Metribuzin on in vitro proliferative responses and oxidative stress of human and rat spleen lymphocytes stimulated by mitogens

Pesticides have been shown to possess marked immunotropic activity. The aim of this work was to study the in vitro effects of different concentrations (1–100 μM) of Mancozeb (fungicide) and Metribuzin (herbicide), on the proliferative responses of human and rat spleen lymphocytes stimulated by concanavalin A (ConA, mitogen), the Th1- (IL-2, INFγ) and Th2- (IL-4) cytokine secretion and on the intracellular oxidative status. The results showed that Mancozeb significantly reduced ConA lymphocyte proliferation in a dose-dependent manner in both humans and rats. It also decreased IL-2, INFγ and IL-4 secretion with a a shift away to Th1 phenotype. Metribuzin at low concentrations (1–10 μM) resulted in activation of ConA stimulated lymphocyte proliferation and cytokine production in both human and rat spleen cells. However, at high concentrations (25–100 μM), Metribuzin induced a dose-dependent inhibition of lymphocyte proliferation and cytokines. Changes in intracellular levels of reduced Glutathione, hydroperoxides and carbonyl proteins and in the activities of catalase and SOD were observed after Mancozeb and Metribuzin exposure reflecting oxidative stress and DNA damage specially at high concentrations.In conclusion, Mancozeb and Metribuzin had significant immunomodulatory properties with oxidative stress induction at high concentrations.     

苜蓿多糖对猪瘟兔化弱毒疫苗免疫效果的影响

用苜蓿多糖作为猪瘟兔化弱毒疫苗的强化剂对60日龄体重18～20 kg的仔猪进行免疫试验研究.B淋巴细胞和抗体水平监测结果表明,苜蓿多糖可使猪外周血液的B淋巴细胞增多,血清抗体水平提高.攻毒试验表明,参试的2批猪,试验组潜伏期（34～72 h和36～68 h）,明显长于对照组（12～48 h和14～48 h）,发热温度试验组为（40.5～40.9℃和40.6～40.8℃）低于对照组（41.4～42.0℃和41.2～41.7℃）,高热期试验组为（30～96 h和46～98 h）低于对照组（72～148 h和72～146h）.说明苜蓿多糖对猪瘟疫苗免疫效果具有明显的强化作用.     

树舌发酵浸膏多糖对肉鸡肠黏膜组织结构及肠道免疫细胞的影响

为研究肉鸡日粮中添加树舌发酵浸膏多糖(Polysaccharides from the fermentation concentrate of Ganoderma applanatum(Pers.ex Gray.),GAP)对肉鸡肠黏膜结构及上皮内淋巴细胞和杯状细胞数量的影响,选用1日龄健康AA肉鸡225只,随机分成5个处理组,每组3次重复,每次重复15只。5个处理组分别为空白对照组(基础日粮)、抗生素阳性对照组(基础日粮+5mg/kg黄霉素)和3个GAP组(基础日粮中分别添加0.05%、0.10%和0.20%GAP),试验期42d。结果表明:1)与对照组相比,日粮中添加0.10%和0.20%的GAP可显著增加肉鸡肠绒毛高度(P0.05),降低隐窝深度(P0.05),提高肠绒毛高度和隐窝深度的比值(V/C)(P0.05);2)与对照组相比,日粮中添加0.10%和0.20%GAP显著升高小肠各段的上皮内淋巴细胞和杯状细胞数量(P0.05);3)小肠各段上皮内淋巴细胞和杯状细胞数量随年龄增长而逐渐增多;4)同一日龄各试验组的上皮内淋巴细胞数量从十二指肠到回肠递减,而杯状细胞则呈递增趋势。以上结果提示:在肉鸡日粮中添加GAP可显著改善肉鸡小肠黏膜结构,维持肠道黏膜的正常屏障结构,促进肉鸡健康生长。其中以0.10%GAP添加量效果最好。     

番鸭神经肽S的基因克隆及其对番鸭脾淋巴细胞增殖的影响

分别采用基因克隆技术、细胞分离培养技术和四甲基偶氮唑蓝(MTT)法首次克隆了番鸭神经肽S(NPS)的基因,并探讨NPS对番鸭脾淋巴细胞体外增殖能力的影响.基因测序结果显示,所克隆的番鸭NPS c DNA序列为181 bp,与其他物种NPS的同源性极高,其中与鸡NPS的亲缘关系最近.MTT法研究结果显示:0.01-1000 nmol·L-1NPS可促进番鸭脾淋巴细胞体外的增殖,其中以10 nmol·L-1NPS的促进效果最优;10 nmol·L-1NPS协同脂多糖(LPS)及1 nmol·L-1NPS协同植物血凝素(PHA)对促进脾淋巴细胞增殖的效果最好.上述结果表明,番鸭NPS基因在进化上是高度保守的,NPS可协同LPS或PHA共同促进番鸭脾淋巴细胞的体外增殖.     

银杏叶复方对肉兔小肠黏膜形态及上皮内淋巴细胞 和杯状细胞数量的影响

为研究银杏叶复方对肉兔小肠黏膜形态及上皮内淋巴细胞和杯状细胞数量的影响,试验选择40只30日龄统一断奶的雌性健康新西兰兔,随机分为4组,每组5个重复,每个重复2只。基础日粮为玉米-豆粕-草粉型, 其中对照组Ⅰ组饲喂基础日粮, 试验Ⅱ、Ⅲ、IV组饲喂分别在基础日粮中添加0.50%、1.00%和1.50%的银杏叶复方,试验期30 d。结果表明,1.00%和1.50%银杏叶复方组的空肠绒毛高度和绒毛高度/隐窝深度(V/C)显著高于对照组（P<0.05）,0.50%和1.00%组回肠V/C比值也显著高于对照组（P<0.05）;1.00%和1.50%银杏叶复方组的空肠淋巴细胞数量显著高于对照组（P<0.05）,0.50%银杏叶复方组的十二指肠杯状细胞数量显著高于对照组（P<0.05）。基于试验结果推断：饲粮中添加1.00%的银杏叶复方制剂,可维持和养护断奶肉兔的小肠黏膜组织。     

沙门菌感染对小鼠白细胞总数及其亚群动态变化的影响

为研究沙门菌感染对小鼠白细胞总数及其亚群动态变化的影响,采取腹腔注射的方法给小鼠接种6.5×10⁹ CFU/mL浓度的沙门菌0.1 mL/只,分别在4、6、8、12、16和24 h采集小鼠血液,应用全自动动物血液细胞分析仪检测感染小鼠的白细胞总数、淋巴细胞数、单核细胞数和粒细胞数,记录并分析小鼠24 h内白细胞总数及其亚群的动态变化。结果表明：模型组小鼠白细胞总数及其亚群均呈先升高后降低的趋势,且白细胞总数和粒细胞数的变化幅度最明显,与空白对照组比较差异极显著（P<0.01）。说明感染沙门菌能够刺激小鼠机体产生免疫应答,影响血液中白细胞总数及其亚群的动态变化。     

猪圆环病毒2型对仔猪淋巴细胞内cAMP和cGMP的影响

为探讨猪圆环病毒2型(PCV2)作用下淋巴细胞的免疫活性,本研究通过体外培养仔猪脾脏淋巴细胞及巨噬细胞(Mφ),分别以PCV2和PCV2+Mφ与淋巴细胞相互作用,同时设Mφ和空白对照组.培养0h、6h、12h、24 h后收取各组淋巴细胞,放射免疫法检测胞内cAMP和cGMP浓度.另外,选取15头PCV2阴性仔猪,每头滴鼻PCV2病毒悬液,分别于14d、21 d、35 d迫杀,每次5头,并设立阴性对照组4头.放射免疫法检测脾脏cAMP和cGMP浓度,并计算cAMP/cGMP比值.体外检测结果显示:PCV2对体外培养淋巴细胞内cAMP和cGMP浓度影响不大;而在Mφ存在时PCV2在6h时能显著降低cAMP和cGMP浓度和cAMP/cGMP比例(p＜0.05); 12 h时cGMP浓度下降(p＜0.05),cAMP和cGMP比例上升(p＜0.05); 24 h时cGMP浓度上升(p＜0.05),但cAMP/cGMP比例降低(p＜0.05).体内检测结果表明,PCV2能显著降低仔猪脾脏细胞内cAMP浓度(p＜0.05)及cAMP/cGMP比值(p＜0.05).该研究结果表明,在巨噬细胞存在时PCV2能够降低淋巴细胞内cAMP/cGMP的比值,从而影响淋巴细胞的功能.     

Effect of dietary boron on immune function in growing beef steers*

Thirty‐six Angus and Angus × Simmental cross steers (initial BW 269.5 ± 22.3 kg) were used to determine the effects of dietary boron (B) on performance and immune function. Steers were fed on one of the three dietary treatments: (i) control (no supplemental B; 7.2 mg B/kg DM), (ii) 5 mg supplemental B/kg DM and (iii) 50 mg supplemental B/kg DM, from sodium borate for 78 days. Supplementation of dietary B had no effect on body weight (BW) gain, feed intake or gain:feed during the study. Jugular blood samples were collected prior to feeding on days 28, 63 and 77 for plasma‐B analysis. Supplementation of dietary B increased (p < 0.001) plasma B‐concentration in a dose‐responsive manner. Furthermore, plasma B‐concentration was correlated (p < 0.001; R² = 0. 95) to daily B‐intake (mg B/day). Jugular blood was also collected, from an equal number of steers from each treatment, on day 42 or 44 for determination of in vitro production of interferon‐γ and tumour necrosis factor‐α from isolated monocytes and assessment of lymphocyte proliferation. Dietary B did not affect T‐ or B‐lymphocyte proliferation or in vitro cytokine production from monocytes. On day 49 of the study, the humoral immune response was assessed by i.m. injection of a 25% pig red blood cell (PRBC) solution for determination of anti‐PRBC IgG and IgM titre responses. Boron‐supplemented steers had greater (p = 0.035) anti‐PRBC IgG titres than controls on day 7 but not on day 14 or 21 post‐injection. Anti‐PRBC IgM titres did not differ throughout the sampling period. Results from this study indicate that supplemental B had minimal effects on immune function and did not affect performance of growing steers.