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YANG Xia ZHANG Dian-qing SONG Jia-wei XIAO Sheng-zhong SHENG Jin-liang YAN Gen-qiang 《中国畜牧兽医》2017,44(9):2739-2746
In order to study the biological function of the main active region of sheep antimicrobial peptide NK-Lysin, three pairs of functional domain peptide fragments were designed and synthesized the antibacterial activity was detected by radial diffusion test and minimal inhibitory concentration. We analyzed the toxic effects of chicken red blood cells and screen the best peptides for treatment chicken challenged by Salmonella pullorum in this study. The rusults showed that synthesized peptides were inhibitory to Escherichia coli and Salmonella pullorum. Fragment length of peptides, C-terminal amidation and peptide inner loop were essential to antibacterial activity. Two of synthesized peptides were used to treat chichen challenged by Salmonella pullorum which obviously decreased the mortality of chicken. The pathological damage of heart,liver,kidney were less than that of control group. This study laid a foundation for the development of the sheep NK-Lysin peptides as candidate antimicrobial agents. 相似文献
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合成绵羊抗菌肽NK-Lysin抗菌活性及其对雏鸡沙门氏菌攻毒的治疗效果研究 总被引：3，自引：0，他引：3
为了研究绵羊抗菌肽NK-Lysin主要活性区的生物学功能,试验设计并合成了3对功能区多肽片段,并利用径向扩散试验和最小抑菌浓度对其抗菌活性进行检测,分析了合成多肽对鸡血红细胞的毒性作用,筛选出抗菌效果最好的多肽对沙门氏菌攻毒的雏鸡进行治疗,检测其治疗效果。结果表明,合成多肽对大肠杆菌、沙门氏菌具有抑制活性,多肽片段长度、多肽C-端有无酰胺化及多肽内的二硫键是否成环对多肽的抗菌活性均有影响;筛选出的2个多肽在治疗雏鸡沙门氏菌攻毒的过程中能够明显降低死亡率,对雏鸡心脏、肝脏、肾脏的病理损伤也明显小于对照组。本研究结果为绵羊抗菌肽NK-Lysin作为候选抗菌药物的开发奠定了基础。 相似文献
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Al-Haddawi M Mitchell GB Clark ME Wood RD Caswell JL 《Veterinary immunology and immunopathology》2007,116(3-4):153-162
Bovine viral diarrhea virus (BVDV) infection is an important risk factor for development of shipping fever pneumonia in feedlot cattle, and infects but does not cause morphologic evidence of damage to airway epithelial cells. We hypothesized that BVDV predisposes to bacterial pneumonia by impairing innate immune responses in airway epithelial cells. Primary cultures of bovine tracheal epithelial cells were infected with BVDV for 48 h, then stimulated with LPS for 16 h. Expression of tracheal antimicrobial peptide (TAP) and lingual antimicrobial peptide (LAP) mRNA was measured by quantitative RT-PCR, and lactoferrin concentrations were measured in culture supernatant by ELISA. BVDV infection had no detectable effect on the constitutive expression of TAP and LAP mRNA or lactoferrin concentration in culture supernatant. LPS treatment provoked a significant increase in TAP mRNA expression and lactoferrin concentration in the culture supernatant (p<0.01), and these effects were significantly (p<0.02, p<0.01) abrogated by prior infection of the tracheal epithelial cells with the type 2 ncp-BVDV isolate. In contrast, infection with the type 1 ncp-BVDV isolate had no effect on TAP mRNA expression or lactoferrin secretion. LPS treatment induced a significant (p<0.001) upregulation of LAP mRNA expression, which was not significantly affected by prior infection with BVDV. These data indicate that infection with a type 2 BVDV isolate inhibits the LPS-induced upregulation of TAP mRNA expression and lactoferrin secretion by tracheal epithelial cells, suggesting a novel mechanism by which this virus abrogates respiratory innate immune responses and predisposes to bacterial pneumonia in cattle. 相似文献
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【目的】 天蚕素抗菌肽是一种商品化的阳离子抗菌肽,在水貂体内的研究较少。试验旨在探究抗菌肽对育成期母貂脏器系数、血清及空肠免疫指标、肠组织形态的影响。【方法】 选取65日龄体重相近的短毛黑母貂60只,随机分为6组,每组10个重复,每个重复1只,单笼饲养。各组饲粮中分别添加0(对照组)、100、200、300、400和500 mg/kg抗菌肽,预试期1周,正试期8周。饲养试验结束后,每组取6只水貂进行心脏采血,采集内脏器官、十二指肠及空肠样品,并测定血清及空肠免疫指标、肠道组织形态。【结果】 与对照组相比,100、300和400 mg/kg抗菌肽组脾脏指数显著升高(P < 0.05);各试验组补体C3(C3)、补体C4(C4)和免疫球蛋白M(IgM)含量均显著升高,除200 mg/kg抗菌肽组外的所有试验组免疫球蛋白A(IgA)和免疫球蛋白G(IgG)含量均显著升高(P < 0.05);各试验组肿瘤坏死因子(TNF-α)含量均显著降低,100、200、300 mg/kg抗菌肽组分泌型免疫球蛋白(sIgA)、γ干扰素(IFN-γ)及白细胞介素-10(IL-10)含量均显著升高(P < 0.05);各试验组十二指肠和空肠绒毛高度均显著升高,且200 mg/kg抗菌肽组十二指肠隐窝深度显著低于400和500 mg/kg抗菌肽组,而绒毛高度/隐窝深度(V/C)显著高于对照组、400和500 mg/kg组(P < 0.05);200、300和400 mg/kg抗菌肽组空肠V/C均显著升高(P < 0.05)。【结论】 饲粮中添加天蚕素抗菌肽可促进育成期母貂免疫器官发育,提高机体免疫力,改善肠组织形态,建议抗菌肽添加水平为100~200 mg/kg。 相似文献
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本试验旨在研究脂肪甘油三酯脂肪酶(ATGL)和长链脂酰辅酶A合成酶1(ACSL1)基因在鹅的不同组织器官中的表达差异,并探索2个基因表达对机体脂肪沉积和血清脂类代谢的调控。选取16周龄五龙鹅30只(公母各占1/2),屠宰后用实时荧光定量PCR检测不同组织器官(肝脏、心脏、皮下脂肪、腹部脂肪、胸肌、腿肌、肌胃、腺胃、小肠、肾脏、大脑、肺、脾脏)中A TG L、A CSL1基因表达量。结果表明:1)在鹅的皮下脂肪、腹部脂肪、肝脏、脾脏、肾脏、心脏、胸肌和腿肌中均检测出ATGL和ACSL1基因的表达;ATGL基因在皮下脂肪和腹部脂肪中表达量最高,其次是肝脏和脾脏,在肾脏、心脏、胸肌和腿肌中只有少量表达;ACSL1基因在皮下脂肪、腹部脂肪、肝脏、脾脏中表达量较高,在肾脏、心脏、胸肌和腿肌中有少量表达,而在肌胃、腺胃和肺中几乎不表达。2)ATGL基因表达量与腿肌肌内脂肪率、胸肌肌内脂肪率、腹部脂肪率、胸肌率和腿肌率呈显著或极显著负相关(P0.05或P0.01),与皮下脂肪率呈显著正相关(P0.05);ACSL1基因表达量与腿肌肌内脂肪率、胸肌肌内脂肪率、胸肌率呈正相关(P0.05),与腿肌率呈显著正相关(P0.05),与皮下脂肪率呈显著负相关(P0.05)。3)ATGL基因表达量与血清甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和葡萄糖含量呈显著或极显著正相关(P0.05或P0.01);ACSL1基因表达量与血清总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和葡萄糖含量呈负相关(P0.05),与甘油三酯含量呈显著负相关(P0.05)。由此可见,ATGL和ACSL1基因在鹅的不同组织器官中的表达具有明显差异性,对机体脂肪沉积和血清脂类代谢具有反向调控作用。 相似文献
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目前鹅的养殖模式仍然以半旱养为主，对水体的依赖形成高温高湿的环境进一步促进细菌的繁殖使体内LPS累积，导致鹅的脾脏免疫功能受损。白术多糖具有调节机体免疫功能的作用，因此本研究旨在进一步探索白术多糖（PAMK）对脂多糖（LPS）处理雏鹅脾脏免疫损伤的保护作用。 本试验选用24只马岗鹅，随机分为四组，每组6个重复。对照组（CON组）和脂多糖组（LPS组）正常饲喂基础日粮，白术多糖组（PAMK组）和白术多糖加脂多糖组（PAMK+LPS组）在饲喂的日粮中添加400 mg/kg的PAMK。在24和26日龄时，CON组和PAMK组的雏鹅腹腔注射0.5 mL生理盐水；LPS组和PAMK+LPS组腹腔注射2 mg/kg?BW LPS溶液，第26日龄注射一小时后采集脾脏。HE结果显示，与CON组相比，LPS组的脾脏细胞排列疏松、细胞萎缩，形态各异，细胞数目减少并伴有凋亡现象 。，动脉周围淋巴鞘面积显著缩小；与LPS组相比，LPS+PAMK组的细胞排列紧密，细胞形态与对照组接近；此外，转录因子（LPS组GATA-3表达水平显著低于CON组和PAMK组，但LPS+PAMK组与LPS组相比，GATA-3表达水平显著升高；LPS组T-bet表达水平显著低于CON组，但LPS+PAMK组与LPS组相比，T-bet表达水平显著升高），在日常饲粮中添加400 mg/kg的PAMK后发现，细胞因子及转录因子的mRNA表达水平都得到了显著恢复（P＜0.05）。结果表明，在雏鹅发生炎症反应时，白术多糖能够通过调节细胞因子和转录因子的表达水平，缓解雏鹅脾脏的炎症反应，起到一定保护作用。 相似文献
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TBK1是IKKs蛋白激酶家族中的一员,也是免疫应答的重要调节因子之一,在Toll样受体通路等多条信号通路中均能发挥作用。Toll受体作为先天免疫中最为重要的一类模式识别受体,能够特异性地识别病原微生物的保守结构。为了探究东北林蛙在LPS和嗜水气单胞菌刺激下TBK1表达量变化的规律,本研究运用荧光定量PCR检测东北林蛙在嗜水气单胞菌和LPS两种不同的刺激源刺激下肾脏、肺脏、脾脏和肝脏中TBK1的表达水平。结果表明:在嗜水气单胞菌和LPS处理下,肾脏、肺脏、脾脏和肝脏中的TBK1表达量变化显著(P <0. 01),但在不同组织中,LPS和嗜水气单胞菌刺激下TBK1的表达量变化趋势并不完全一致。推测在不同的组织中不同的刺激源产生免疫应答的时间不尽相同。和不同物种的实验数据对比分析,发现各物种TBK1分子的表达量变化关系的规律不显著,推测在不同物种的不同器官中,受到外源微生物侵染时会有选择的激活不同的信号转导通路完成免疫应答。 相似文献
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为了探究猪Toll样受体（Toll-like receptor 5,TLR5） 基因表达水平与F18大肠杆菌抗性的关系,试验通过不同血清型产肠毒素大肠杆菌（F18ab和F18ac）侵染猪小肠上皮细胞（IPEC-J2）,同时通过脂多糖（LPS）分别诱导IPEC-J2细胞4和8 h,利用实时荧光定量PCR检测TLR5基因表达水平变化,并利用Western blotting进行蛋白表达分析。结果显示,不同血清型大肠杆菌（F18ab和F18ac）菌体侵染IPEC-J2细胞后,TLR5基因表达水平均极显著上调（P<0.01）;LPS诱导IPEC-J2细胞4和8 h后,TLR5基因表达水平均极显著上调（P<0.01）,且在LPS诱导IPEC-J2细胞8 h后,TLR5基因表达水平明显高于诱导4 h。与对照组相比,细胞中TLR5蛋白的表达水平极显著上调（P<0.01）,与LPS诱导及F18大肠杆菌菌体刺激IPEC-J2细胞后mRNA表达水平结果相一致。本研究在细胞水平上分析了TLR5表达水平和F18大肠杆菌侵染的相关性,进一步证实猪TLR5基因的表达水平在细胞抵抗F18大肠杆菌的侵染过程中发挥了重要的调控作用,为今后关于TLR5基因功能及其在大肠杆菌腹泻遗传育种应用的研究奠定基础。 相似文献
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The objective of this study was to understand the distribution patterns and levels of Salmonella Enteritidis (SE) in the immune organs of ducklings after oral challenge. We conducted serovar-specific real-time polymerase chain reaction (PCR) for SE to detect the genomic DNA of SE in the blood and immune organs, including the bursa of Fabricius, thymus, spleen, and Harderian gland, from ducklings after oral challenge at different time points. The results showed that SE was consistently detected in all the samples. The Harderian gland and spleen tested positive at 8 hr postinoculation (PI). The organism was detected in the blood, bursa of Fabricius, and thymus at 10 hr PI. The copy number of SE DNA in each tissue reached a peak at 24-36 hr PI. The spleen, blood, and Harderian gland contained high concentrations of SE, whereas the thymus and bursa of Fabricius had low concentrations. SE populations began to decrease and were not detectable at 2 days PI, but they were still present up to 9 days PI in the spleen, without producing any apparent symptoms. To validate these results, the indirect immunofluorescent antibody (IFA) technique was used, and the IFA results were similar to those of the fluorescent quantitative-PCR. In conclusion, the results provided insight into the SE life cycle in the immune organs; furthermore, the Harderian gland and spleen were determined to be the primary sites of invasion among the immune organs of normal ducklings after oral SE challenge. This study will help in understanding the pathogenesis of SE infection in vivo and may help in the development of a live Salmonella vaccine in the future. 相似文献