Polysaccharide Nucleic Acid of Bacillus Calmette Guerin Modulates Th1/Th2 Cytokine Gene Expression in Lipopolysaccharide-Induced Mastitis in Rats

The aim of this study was to evaluate, in rats, the changes in the T helper type 1 (Th 1)/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide (LPS) and to characterize the moderating effects of the polysaecharide nucleic acid of Bacillus Calraette Guerin (BCG-PSN) on the mammary gland. In the control group, the levels of IL-2 and INF-γ, mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion (PI) compared to the control value (O h; P<0.01).BCG-PSN increased mRNA expression of both INF-γ' and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 eytokine ratio due to Th1 cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction ofN-acety1-β-D-glucosaminidase (NAGase) was observed at 24 h PI in the BCG-PSN treatment group compared to the control group (P<0.05). Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.     

卡介菌多糖核酸体外抗病毒活性试验

为探讨卡介菌多糖核酸(BCG-PSN)的抗病毒效果,对离体培养的鸡胚成纤维(CEF)细胞进行水疱口炎病毒(VSV)感染,用四甲基偶氮唑盐(MTT)比色法检测BCG-PSN对CEF细胞活性的影响;用细胞病变法(CPE)检测BCG-PSN对VSV的抑制作用,并在安全浓度范围内筛选BCG-PSN抑制VSV的最佳作用时间和作用剂量。试验结果表明:BCG-PSN能显著抑制VSV在CEF细胞上的生长,但抑制作用并非随着其剂量的增加和作用时间的延长而增强,质量浓度为144.0μg/mL的BCG-PSN在CEF细胞上作用24 h后,产生的抗病毒活性最强;当BCG-PSN质量浓度大于800μg/mL时则对CEF细胞具有明显的毒性作用。BCG-PSN可诱导CEF细胞产生IFN-α和IFN-β,研究结果显示:BCG-PSN的抗病毒作用与其诱导的干扰素有关。     

卡介菌多糖核酸缓解内毒素诱发大鼠乳腺炎的机制研究

【目的】为探讨卡介菌多糖核酸(polysaccharide nucleic acid fraction of Bacillus Calmette Guerin,BCG-PSN)对内毒素(endotoxin or lipopolysaccharide,LPS)诱发实验性动物乳腺炎的保护机制,【方法】72只清洁级SD大鼠被随机分成实验组和对照组(n=36)。确定怀孕14d起,隔日左后腿胫骨前肌肌内注射BCG-PSN(实验组)或灭菌生理盐水(对照组)0.33mL/只,连续5次;产后72h经乳头管灌注LPS10μg/侧到第4对乳腺(两侧)内。分别于灌注前(定义为0h)及灌注后3、6、9、12和24h(n=6)颈静脉放血处死动物,采集样品。【结果】组织病理学观察显示,BCG-PSN加快了LPS诱发炎症的组织修复进程,促进了炎症后期泌乳量的恢复。定量RT-PCR结果显示,BCG-PSN能降低乳腺组织中Toll样受体-4(toll-like receptor-4,TLR-4)mRNA表达水平,实验组与对照组相比,第6、9、24h差异显著。酶活性检测结果显示,诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOs)活性在乳腺组织中和血清中变化规律相反;组织中酶活性,实验组和对照组分别在6、9h达到最高,血清中活性分别在6、3h最低。放射免疫检测结果显示,同对照组相比,BCG-PSN使乳腺组织中炎症相关细胞因子肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的分泌极值降低,极值出现时间提前,而血清中未表现出明显的变化。【结论】BCG-PSN可能通过降低TLR-4的表达,抑制炎性细胞因子及酶的过度分泌,缓解LPS及相关因子(TNF-α、iNOs)对乳腺组织的损伤。     

卡介菌多糖核酸对新城疫疫苗免疫雏鸡抗氧化及免疫活性的影响

本试验将卡介菌多糖核酸应用于新城疫疫苗免疫雏鸡,观察其抗氧化和对鸡体免疫功能的影响。将200只1日龄AA肉鸡随机分为5组,每组40只,分别为卡介菌多糖核酸高（0.12 mg/只）、中（0.06 mg/只）、低（0.03 mg/只）剂量组,黄芪多糖组（阳性对照,0.06 mg/只）和空白对照组。每组鸡7日龄时免疫新城疫疫苗并同时按分组要求注射药物,连续7 d,空白对照组以生理盐水代替。分别于用药后5、10、15和20 d分批剖杀鸡,采取胸腺、脾脏、法氏囊和颈静脉血,测定免疫器官系数,鸡新城疫病毒（NDV）抗体滴度,血浆IgG、IgM、超氧化物歧化酶（SOD）、脂质过氧化物（LPO）和谷胱甘肽过氧化物酶（GSH-Px）的含量。结果表明,卡介菌多糖核酸能显著提高鸡血清中SOD和GSH-Px含量,降低LPO含量（P＜0.05）,具有良好的抗氧化功能;能显著提高受试鸡的免疫器官系数、NDV抗体滴度、血清中IgG和IgM含量（P＜0.05）,具有良好的免疫佐剂效应。     

卡介菌多糖核酸对内毒素诱发的实验性山羊乳腺炎乳腺组织的保护研究

【目的】本试验通过卡介菌多糖核酸对内毒素诱发的实验性山羊乳腺炎乳腺组织的保护研究，探讨灌注免疫增强剂BCG-PSN对乳腺组织的影响，研究调动乳腺自身的防御功能，以防治乳腺炎的发生。【方法】选取泌乳初期健康睢宁白山羊6只，左乳区经过乳头管灌注卡介菌多糖核酸5 ml，右乳区灌入5 ml注射用生理盐水作为对照，连灌6 d。第7天按50 µg•kg-1体重分别向左、右乳区灌注大肠杆菌内毒素。灌注前及灌注后0、1、2、3、4、5、6、7、8、9、24 h观察山羊整体及乳房局部变化。灌注24 h后，处死动物，取乳腺组织，部分Bouin氏液固定、部分液氮保存。【结果】临床症状及病理切片观察均显示，山羊表现典型的急性乳腺炎症状。与灌注生理盐水对照相比，乳腺灌注卡介菌多糖核酸能显著降低乳腺组织中部分炎症相关因子的含量及其基因表达水平。其中N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）、髓过氧化物酶（MPO）、碱性磷酸酶（AKP）、诱导型一氧化氮合成酶（iNOS）活性显著降低（P<0.05）；IL-1β、TNF-α的含量及其mRNA表达水平均显著降低（P<0.05），IL-6的含量显著降低（P<0.05），其mRNA表达水平有所降低但差异不显著（P>0.05）。【结论】灌注卡介菌多糖核酸可以抑制乳腺组织内IL-1β、TNF-α等炎性细胞因子及和炎症相关酶的过度释放、减轻炎症因子对乳腺上皮细胞的损伤，对内毒素诱发的山羊实验性乳腺炎有较强的保护作用。     

卡介菌多糖核酸对IBDV感染鸡的免疫活性研究

为了评价卡介菌多糖核酸(BCG-PSN)在畜禽病毒性疾病中的作用及其诱导机体免疫的能力,建立了人工感染传染性法氏囊病(IBD)动物模型,通过检测免疫器官指数、IBDV抗体、外周淋巴细胞亚群、诱导干扰素和白介素水平等特异性和非特异性免疫指标,评估不同剂量BCG-PSN对IBDV感染鸡免疫功能的影响。结果显示:免疫器官脾脏指数和胸腺指数在注射BCG-PSN的初期出现上升趋势,而在注射BCG-PSN后期(15d)受试鸡外周血液CD4+/CD8+值显著提升;各BCG-PSN注射组的IBDV抗体滴度在试验初期明显提高;从注射开始,BCG-PSN就显示出其对IFN-γ、IFN-α和IL-2的显著提升效果。上述结果说明:BCG-PSN既能调节IBDV感染鸡的细胞免疫功能,又能调节机体的体液免疫功能,激活组织细胞释放包括IFN-γ、IFN-α和IL-2等多种细胞因子,以0.3mg·kg-1的注射剂量可获得良好的免疫效果。     

Polysaccharide Nucleic Acid of Bacillus Calmette Guerin Modulates Th1/ Th2 Cytokine Gene Expression in Lipopolysaccharide-lnduced Mastitis in Rats

The aim of this study was to evaluate, in rats, the changes in the T helper type 1（Th1）/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide （LPS） and to characterize the moderating effects of the polysaccharide nucleic acid of Bacillus Calmette Guerin （BCG-PSN） on the mammary gland. In the control group, the levels of IL-2 and INF-7 mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion （PI） compared to the control value （0 h; P〈0.01）. BCG-PSN increased mRNA expression of both INF-γ and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 cytokine ratio due to Thl cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction of N-acetyl-β-D-glucosaminidase （NAGase） was observed at 24 h PI in the BCG-PSN treatment group compared to the control group （P〈 0.05）. Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.