Systemic and mucosal immunity induced by attenuated Salmonella enterica serovar Typhimurium expressing ORF7 of porcine reproductive and respiratory syndrome virus

Oral administration of attenuated Salmonella vaccine may provide valuable advantages such as low cost, easy preparation, and safety. Attenuated Salmonella vaccines also serve as carriers of foreign antigens and immunomodulatory cytokines. Presently, an attenuated Salmonella enterica serovar Typhimurium strain was used as a carrier for open reading frame 7 (ORF7) protein of porcine reproductive and respiratory syndrome virus (PRRSV), a swine pathogen of significant global economic importance. Initially, an attenuated S. enterica serovar Typhimurium expressing ORF7 gene derived from PRRSV Korean isolate was constructed. Following oral administration of a single dose of the attenuated Salmonella vaccine expressing PRRSV ORF7, humoral and cell-mediated immune responses specific for ORF7 were induced at both systemic and mucosal sites including spleen, mesenteric lymph node, Peyer's patch, and laminar propria, as evaluated by determining serum ORF7-specific IgG and mucosal IgA responses, as well as Th1- and Th2-type cytokine production from antigen-stimulated T cells. The induced humoral responses were sustained for at least 12 weeks post-immunization. In particular, the immunized mice displayed immune responses to both the foreign ORF7 antigen and Salmonella itself. The results indicate the value of attenuated S. enterica serovar Typhimurium as an oral carrier of PRRSV antigenic proteins to induce effective systemic and mucosal immunity.     

硒在养鸡生产中的研究进展

硒参与动物体内蛋白质、氨基酸、核酸、脂肪、碳水化合物和维生素以及微量元素等营养物质的代谢,在提高动物免疫力、生产性能及改善肉品质方面也有重要的作用。本文综述了硒在鸡营养中的作用效果及机理,为硒在养鸡生产中进一步应用提供参考。     

细菌内毒素对肉鹅生长性能及免疫机能的影响研究

本研究旨在探讨"鹅-鱼"生产体系中水体细菌滋长及所造成的内毒素(LPS)对鹅生长性能和免疫机能的影响.试验1比较了不同水面载鹅密度种鹅血液LPS浓度及所产雏鹅的生长性能.高密度鹅群的血液LPS浓度极显著高于正常密度鹅群(P＜0.01),且所产种蛋受精率和孵化率均低于正常密度鹅群.孵化第25天死胚蛋、弱胚蛋尿囊液中LPS浓度极显著高于活胚蛋(P＜0.01).此外,高密度鹅群所产雏鹅的死亡率较高,早期采食量低且生长性能差,肉鹅胸肌率、腿肌率均显著低于正常密度鹅群(P＜0.05),而腹脂率和皮下脂肪率则显著高于后者(P＜0.05).试验2观察外源LPS对雏鹅采食和生长的影响.对雏鹅腹腔注射外源LPS显著降低了采食量、生长速度和屠宰性能(P＜0.05),并导致肝脏和脾脏肿大.试验3观察了LPS对鹅免疫机能的影响.对生长鹅注射外源LPS使鹅血液中的白细胞数量迅速下降且极显著低于对照组(P＜0.01).LPS还严重降低免疫BSA后抗BSA抗体的效价以上结果说明LPS通过降低鹅的免疫机能影响其健康状况;降低采食量,导致雏鹅生长和屠宰性能下降.     

乳酸杆菌免疫治疗作用研究进展

乳酸杆菌是人体内重要的生理菌群,并在人体内发挥着重要的作用。乳酸杆菌主要通过作为疫苗载体、作为免疫调节剂、用于治疗疾病、抗肿瘤方式发挥免疫作用。就乳酸杆菌的免疫治疗作用进行了阐述。     

酵母多糖对种鸡生产性能和免疫功能的影响

旨在研究日粮中添加不同水平酵母多糖对于种鸡生产性能和免疫功能的影响.试验选用288羽45周龄的良风花种鸡,随机分为4个处理组,每个处理组设3个重复,每个重复24只鸡.第Ⅰ组喂以基础日粮,设为对照组;第Ⅱ组添加0.15%的酵母多糖;第Ⅲ组添加0.20%的酵母多糖;第Ⅳ组添加0.25%的酵母多糖.试验前各组生产性能差异不显著,预饲期1周.试验期7周,共8周.结果表明,日粮中添加不同水平的酵母多糖对种鸡生产性能和免疫功能均有显著影响,添加水平为0.15%时产蛋率提高4.56%,种蛋受精率提高3.27%,入孵蛋孵化率提高了7.45%,种鸡体内白介素-2(IL-2)含量较对照组提高7.54%;添加水平为0.20%时产蛋率提高9.16%,种蛋受精率提高4.22%,入孵蛋孵化率提高了5.69%,种鸡体内白介素-2(IL-2)和干扰素-γ(IFN-γ)的含量较对照组也分别提高了9.17%(IL-2)和11.82%(IFN-γ).综合整个试验来说,在种鸡日粮中添加0.20%的酵母多糖为最适水平.     

γ-氨基丁酸对蛋鸽就巢习性、免疫和抗氧化性能的影响

选用360日龄的蛋鸽96对,随机分为4组,每组3个重复,每个重复8对,分别饲喂基础日粮（对照组）、基础日粮＋20mg/kgγ-氨基丁酸（γ-aminobutyric acid,GABA）（试验Ⅰ组）、基础日粮＋40mg/kg GABA（试验Ⅱ组）和基础日粮＋80mg/kg GABA（试验Ⅲ组）。预饲期10d,试验期30d。结果显示：（1）日粮中添加GABA能提高蛋鸽的月产蛋个数（P〉0.05）,缩短产蛋间隔（P〉0.05）,其中20mg/kg GABA组月产蛋个数增加13.66%（P〉0.05）,40mg/kg GABA组缩短产蛋间隔10.08%（P〉0.05）;（2）与对照组相比,40mg/kg GABA组显著降低血清中催乳素水平（P〈0.05）,提高促卵泡刺激素水平,显著提高血清中IgA、IgG和补体C3水平（P〈0.05）,但对IgM和补体C4水平没有显著影响;（3）3个剂量的GABA对肝组织和肾组织MDA含量无显著影响,但可以显著降低心组织中的MDA含量（P〈0.05）。与对照组相比,40mg/kg GABA组显著提高肝组织与心组织中超氧化物歧化酶活性（P〈0.05）和谷胱甘肽过氧化物酶活性（P〈0.05）。结果表明,日粮中添加GABA可降低血清PRL水平,缩短就巢时间,通过增加机体的免疫性能和抗氧化性能,维持内分泌的稳定,改善蛋鸽的产蛋性能。     

Activated Toll-like receptors participate in chronic renal tubulointerstitial injury induced by cyclosporine A

AIM: To study the role of innate immunity in the pathogenesis of renal tubulointerstitial injury.METHODS: The model of nephrotoxic nephropathy was induced by chronic cyclosporine A (CsA) administration (15 mg·kg^-1·d^-1 for 4 weeks) in Sprague-Dawley rats. The tubulointerstitial injury, characterized by inflammatory cell infiltration and striped fibrosis, was examined by the methods of immunohistochemistry and trichrome staining. The expression of Toll-like receptors (TLR), TLR ligand heat-shock protein 70 (HSP70)and intrarenal complement elements (C3, C4d and C9) was evaluated in rat kidneys by the methods of in situ hybridization and immunohistochemistry.RESULTS: Compared with the normal rats, the rats exposed to CsA showed impaired renal function, ED-1-positive cell infiltration and striped tubulointerstitial fibrosis (all P<0.01). Concomitantly, CsA treatment up-regulated the expression of TLR2 and TLR4 at mRNA and protein levels in renal tubular cells, accompanied by increased putative TLR ligand (HSP70) and the immunoreactivity of intrarenal complements. These up-regulated innate immunity components were located in the areas of severe tubulinterstitial injury.CONCLUSION: CsA-induced renal tubulointerstitial injury is closely associated with the activation of intrarenal innate immunity.     

"促免1号"抗肉鸡免疫应激效果的观察

选择同一批次科宝雏鸡2500只，分在两个专业户家进行试验，随机分为试验组和对照组；试验组卜15日龄日粮中添加0．5％“促免1号”，16—44日龄添加0．2％“促免1号”。试验表明：专业户A：试验组（A。）和对照组（A2）相比平均体重提高4．786％、成活率提高了2％、料肉比降低9．2％；专业户B：试验组（B。）和对照组（B2）相比平均体重提高3．60896、成活率提高2％、料肉比降低14．9％。这说明“促免1号”能缓解免疫应激，提高肉鸡日增重、成活率和降低料肉比的作用。     

高热应激模型下CLA对蛋鸡免疫功能的影响Ⅰ细胞免疫和体液免疫指标的变化

选用ND、IBD常规免疫25周龄的海兰(褐)蛋鸡120只,随机等分为试验组、对照组,分别置于2个人工气候室内二层阶梯式单笼饲养,试验组日粮为基础日粮+20 g/kg共轭亚油酸,对照组为基础日粮,设定热应激模型:22℃5 d(预试期)、30℃5 d、32℃5 d、35℃5 d、22℃5 d(恢复期),进行为期25 d的CLA对高热应激蛋鸡免疫功能的影响试验。结果显示,在30℃119 h、32℃119 h、35℃119 h、22℃119 h(恢复期)时,血液淋巴细胞比率,T、B淋巴细胞转化率,CD 4+、CD 8+T细胞亚群等细胞免疫指标和血清ND、IBD、IgG抗体水平等体液免疫指标试验组均显著高于对照组(P<0.01)。表明CLA有缓解高温环境导致的蛋鸡免疫水平下降,促进热应激解除后机体免疫力恢复等降低热应激负效应的作用。     

雏鸡新城疫免疫后免疫器官组织的免疫学变化

本文主要研究了雏鸡 ND 免疫后免疫中枢器官(法氏囊、胸腺)、外周免疫器官(脾脏)以及消化道和呼吸道相关的局部免疫组织(盲肠扁桃体、丕氏斑、十二指肠粘膜和肺支气管粘膜淋巴组织、哈德尔腺)中浆细胞,TANAE~+,MΦ,淋巴细胞数的变化。结果表明,ND 免疫后免疫器官组织的体液免疫和细胞免疫应答均增强。