谷氨酰胺二肽对断奶仔猪肠道免疫的影响

采用体外淋巴细胞转化试验研究谷氨酰胺(Gln)及丙氨酰谷氨酰胺(Ala-Gln)对早期断奶仔猪肠系膜淋巴结细胞增殖的影响。摘取28日龄断奶仔猪肠系膜空、回肠淋巴结,分离淋巴细胞,接种于含不同浓度Gln或Ala-Gln的培养液中37℃培养72h后,四甲基偶氮唑盐(MTT)法测定细胞增殖。Gln浓度为2mmol/L时,淋巴细胞刺激指数最大;Ala-Gln浓度为1mmol/L时,淋巴细胞刺激指数最大。增加Gln或Ala-Gln浓度并没有增加其效应。本试验表明Gln和Ala-Gln均可以促进丝裂原植物凝集素(PHA)刺激的淋巴细胞增殖,在一定浓度范围内Ala-Gln与Gln具有相似的作用。     

Overview of the Immune Dynamics of the Digestive System

The digestive tract of the chicken is a major site of pathogen exposure. Although the bird has a multifaceted set of tools to prevent or resist infection, any activation of the immune system can divert nutrients away from production. Therefore, prevention of pathogenic exposure is preferred. However, it is unlikely that the bird can escape exposure to all pathogens during its life, thus the ability to respond to immunologic challenges is essential. The immune system of birds is similar to that of mammals in terms of structure and function, although some differences do exist, particularly in regulatory aspects. The innate immune system responds nonspecifically to foreign molecules and is essential for the induction of the specific (acquired) immune response. Cells of the innate immune system include macrophages, dendritic cells, heterophils, and natural killer cells. The acquired immune response involves recognition of a specific antigen and response by lymphocytes. Cytotoxic T lymphocytes are especially effective at inducing cells infected with intracellular pathogens to undergo apoptosis. Helper T lymphocytes increase the effectiveness of innate immune cells in combating extracellular pathogens and are also essential for activating B lymphocytes, which produce antibodies specific to the invading pathogen. All aspects of the immune system function together, although one aspect will often dominate, depending on the type and severity of the infection. This paper reviews the basics of avian immune function in general and discusses the immune system in the digestive tract in particular in birds. The consequences of activation of the immune system are presented.Currently, growth-promoting antibiotics are not used in poultry in many countries; the North American industry may be moving in that direction as well, either through legislation or consumer pressure. Several nonantibiotic means of manipulating the immune system to prevent the health- and performance-suppressing effects of immune system activation are presented here.     

红细胞在肿瘤免疫中的作用与地位

1981年Siegel提出了红细胞免疫系统（red cellimmunesystem）的新概念，开辟了机体免疫系统的新领域。在肿瘤的发生发展过程中，机体的免疫功能起着非常重要的作用，过去的研究多只涉及白细胞免疫系统，而红细胞在其中所起的作用一直受到忽视，因而对红细胞的作用与地位有必要加以重新认识。     

妊娠母猪采食鸡粪饲料对免疫功能的影响

选用体重、配种期相近的长大二元母猪10头,配种后随机分成二组,分别接受二种日粮(含鸡粪饲料日粮和对照日粮)至妊娠结束。产前20～25d采血进行免疫功能体外测验。试验结果表明:总花环(EtRFC)、活性花环(EaREC)和稳定花环(EsRFC)的形成率两组均无显著差异。说明鸡粪饲料饲喂妊娠母猪对其免疫功能无不良影响。     

不同锌源对肉用仔鸡早期生长及免疫的影响

试验选用 1日龄Avine肉用仔鸡 75羽 ,随机分成 3组 ,每组设 5个重复 ,每重复 5羽。 1组饲喂玉米—豆粕基础日粮作为对照 ;2、 3组日粮中分别加入硫酸锌、蛋氨酸锌 40mg/kg (以锌计 )。测定试验鸡生长性能及部分免疫学指标 ,以研究不同锌源对仔鸡早期生长和免疫的影响。结果表明 ,基础日粮中添加蛋氨酸锌和硫酸锌均能有效提高仔鸡生长和改善饲料效率 ;蛋氨酸锌组效果优于硫酸锌组。添加锌能提高胫骨、胰脏中锌含量 ;蛋氨酸锌组锌增加幅度高于硫酸锌组。血清锌含量及血清AKP活性三组间无显著差异 (P >0 0 5)。添加锌对仔鸡 7日龄ANAE+ 有一定影响 (P >0 0 5) ;不同锌源对仔鸡ND抗体滴度、免疫器官指数、补体C3均无明显差异 (P >0 0 5)。     

黏膜免疫和半胱胺对十二指肠生长抑素mRNA表达的影响

应用鸡新城疫弱毒苗单一口服和分别灌喂两种剂量半胱胺后再口服鸡新城疫弱毒苗,进行消化道黏膜免疫肉鸡,通过RT-PCR方法检测十二指肠中SS基因表达。结果表明,首免第4周后各个试验组SSmRNA的表达无显著差异。首免第5周后两种剂量半胱胺结合新城疫免疫组SSmRNA的表达比对照组显著增加(P<0.05),单一新城疫免疫组SSmRNA的表达虽然比对照组增加,但并不显著。提示黏膜免疫后淋巴细胞产生的细胞因子可刺激十二指肠SSmRNA的表达,半胱胺可增加十二指肠SSmRNA的表达。肠黏膜免疫可影响动物体内收稿日期:2002-06-17课题来源:国家自然科技基金(30070564)作者简介:杨　倩(1962-),女,南京农业大学动物医学院副教授,博士,主要从事动物免疫神经内分泌研究工作。神经内分泌系统中SSmRNA的表达。     

微生态制剂及其在动物生产上的应用

在动物疾病的防治中 ,抗生素发挥了巨大的作用 ,但长期大量使用造成了动物体免疫功能的下降 ,增加了对某些病原菌的易感性等副作用。而微生态制剂具有促动物生长、防治疾病 ,无副作用等特点 ,成为抗生素理想的替代品之一。大量实验已证明微生态制剂在激活动物体免疫功能、改善动物肠道菌群平衡、提高机体抗病能力等方面均发挥着十分重要的作用。虽对其研究刚刚起步 ,但必将成为今后研究的热点之一。文章就微生态制剂的起源、组成及其近年来在动物生产上的应用和对机体免疫功能的影响作了简要综述 ,并就其存在的问题及今后的发展进行了探讨     

肺炎支原体感染对大鼠免疫功能和一些生化指标的影响

采用滴鼻法建立大鼠肺炎支原体感染模型 ,并对其体液免疫和细胞免疫功能进行了检测。与正常对照组相比 ,感染组大鼠血清中IgG、IgM明显降低 ,C3补体增加 ;血清中IL 2、IL 6降低 ,TNF α增高 ;全血中CD+ 8增加 ,CD+ 4/CD+ 8比值降低 ;血浆中NO、MDA含量增加 ,GSH Px活性增加。结果表明 ,细胞因子和免疫球蛋白的紊乱导致机体体液免疫和细胞免疫功能的低下 ,并诱发肺部广泛的炎症反应 ,提示它们在肺炎支原体感染的发病机制及肺外并发症的发生中起重要作用。     

浸泡免疫预防草鱼细菌性烂鳃病效果的研究

用酚灭活的柱状嗜纤维菌和从该菌体提取的菌体脂多糖浸泡接种２０～２５ｇ的草鱼鱼种，共浸泡２次间隔一周。通过检测受免鱼体血清、肠和体表粘液中凝集抗体效价、血液中吞噬细胞的吞噬活性和采用活菌攻毒的方法，探讨了浸泡免疫接种疫苗对预防草鱼细菌性烂鳃病的效果。结果表明，受免鱼体与对照鱼相比，血清、肠和体表粘液中凝集抗体效价和血液中吞噬细胞的吞噬活性都有明显上升。经活菌攻毒后，酚灭活柱状嗜纤维菌疫苗免疫组免疫保护率达３０％，而脂多糖疫苗免疫组免疫保护率为５５％。     

In utero heat stress alters the postnatal innate immune response of pigs

The effects of in utero heat stress (IUHS) range from decreased growth performance to altered behavior, but the long-term impact of IUHS on postnatal innate immune function in pigs is unknown. Therefore, the study objective was to determine the effects of early gestation IUHS on the immune, metabolic, and stress response of pigs subjected to an 8 hr lipopolysaccharide (LPS) challenge during postnatal life. Twenty-four pregnant gilts were exposed to thermoneutral (TN; n = 12; 17.5 ± 2.1 °C) or heat stress (HS; n = 12; cyclic 26 to 36 °C) conditions from days 6 to 59 of gestation, and then TN conditions (20.9 ± 2.3 °C) from day 60 of gestation to farrowing. At 12 wk of age, 16 IUHS and 16 in utero thermoneutral (IUTN) pigs were selected, balanced by sex and given an intravenous injection of LPS (2 µg/kg BW mixed with sterile saline [SAL] and injected at 2 µL/kg BW) or SAL (2 µL/kg BW). Body temperature was monitored every 30 min, and blood was obtained at 0, 1, 2, 3, 4, 6, and 8 hr following the LPS challenge. Blood samples were analyzed for glucose, insulin, non-esterified fatty acids (NEFA), cortisol, and cytokine concentrations. In addition, white blood cell counts were determined at 0 and 4 hr. Hour 0 data were used as covariates. Body temperature was increased (P < 0.01) in LPS (40.88 ± 0.08 °C) vs. SAL (39.83 ± 0.08 °C) pigs. Eosinophils tended to be decreased overall (P = 0.09; 43.9%) in IUHS vs. IUTN pigs. Glucose concentrations were reduced overall (P = 0.05; 5.9%) in IUHS vs. IUTN pigs. The NEFA concentrations tended to be greater (P = 0.07; 143.4%) in IUHS-LPS pigs compared with all other treatments, and IUTN-LPS pigs tended to have greater (127.4%) circulating NEFA concentrations compared with IUTN-SAL and IUHS-SAL pigs. Cortisol was increased (P = 0.04) in IUHS-LPS compared with IUTN-LPS pigs at 3 hr (21.5%) and 4 hr (64.3%). At 1 hr, tumor necrosis factor α was increased (P = 0.01; 115.1%) in IUHS-LPS compared with IUTN-LPS pigs. Overall, interleukin-1β (IL-1β) and interleukin-6 (IL-6) were greater (P < 0.04; 281.3% and 297.8%, respectively) in IUHS-LPS pigs compared with all other treatments, and IUTN-LPS pigs had increased IL-1β and IL-6 concentrations compared with IUTN-SAL and IUHS-SAL pigs. In summary, IUHS altered the postnatal cytokine, metabolic, and physiological stress response of pigs during postnatal life, which may have negative implications toward the innate immune response of IUHS pigs to pathogens.