益生菌对肠道黏膜免疫的影响

益生菌作为一类以活菌为主的新型菌制剂,能在肠道内定殖,维护肠道菌群平衡,并刺激肠黏膜免疫组织,对肠道黏膜免疫有重要的影响。益生菌可直接作用于宿主的免疫系统,刺激胸腺、脾脏和法氏囊等免疫器官的发育,促进巨噬细胞活力或发挥佐剂作用,活化肠黏膜内相关淋巴组织,使免疫球蛋白A分泌增加,使免疫球蛋白A生物合成增加,提高消化道黏膜免疫功能。     

疫佳灵对鸡小肠T淋巴细胞数量的影响

家禽黏膜系统由家禽胃肠道、呼吸道及某些外分泌腺(哈德氏腺、盲肠扁桃体等)黏膜相关淋巴组织构成.消化道淋巴组织是动物体内免疫系统的第一道防线.消化道中的淋巴组织可产生大量的免疫细胞-分泌型免疫球蛋白A细胞(sIgA),通过上皮分泌到消化道黏膜表面形成一层免疫保护层.小肠黏膜层中分泌型免疫球蛋白A(sIgA)细胞是消化道黏膜免疫的物质基础,是黏膜免疫的主要效应因子.     

黏膜免疫在禽病防治中的作用

黏膜特异性免疫系统(mucosal immune system，MIS)是由黏膜相关淋巴组织(MALT)，包括肠相关淋巴组织(GALT)和支气管相关淋巴组织(BALT)组成的免疫系统。包括肠道黏膜集合淋巴结、消化道、呼吸道和泌尿生殖道黏膜下层的淋巴小结和弥散淋巴组织，含有丰富的B细胞、T细胞和巨噬细胞等。     

浅析黏膜免疫在禽疾病中的重要性

黏膜免疫系统是有肠相关淋巴组织、支气管相关淋巴组织及其他黏膜相关淋巴组织组成的免疫系统。包括肠道黏膜集合淋巴结、呼吸道和泌尿生殖道黏膜下层的淋巴小结和弥散型淋巴组织,含有丰富的B细胞、T细胞和巨噬细胞。黏膜相关淋巴组织不同于其他免疫系统,它是受黏膜表面的抗原物质刺激而形成的免疫系统,即是机体整个免疫系统的重要组成部分,同时具有独特功能的独立免疫系统。黏膜免疫重要成分是免疫球蛋白IgA,以单体和二聚体两种分子形式存在,单体存在于学清中,二聚体由呼吸道、消化道和生殖道等部位黏膜固有层的浆细胞产生,是有两个单体…     

贝氏莫尼茨绦虫感染绵羊对小肠局部黏膜淋巴组织的影响

为了研究贝氏莫尼茨绦虫自然感染绵羊对小肠黏膜免疫组织的影响,分别从宏观、微观及亚微观水平对自然感染贝氏莫尼茨绦虫的成年绵羊(感染组)肠道进行了细致地观察,并与正常成年绵羊(正常组)进行了比较.结果显示,感染组肠道所见虫体平均长度为1.5m,头节主要吸附在空肠淋巴集结分布丰富的部位,一般寄生数量为1～2条.眼观,虫体寄生部位黏膜增厚,表面有大量灰白色黏液附着,其间可见点状出血.镜下,局部黏膜上皮脱落,而在完整的黏膜上皮处,其上皮细胞、上皮内淋巴细胞、杯状细胞的数量都明显增多;固有层内毛细血管充血,淋巴细胞、浆细胞、弥散淋巴组织以及肠腺杯状细胞均有不同程度的增生,头节寄生处部分肠腺坏死;黏膜下层淋巴小结、淋巴集结显著增生,部分增生凸入固有层形成新的圆顶区;固有层与黏膜下层以及黏膜肌层可见大量嗜酸性粒细胞浸润.扫描电镜下,感染组肠黏膜上皮脱落;贝氏莫尼茨绦虫头节呈椭球状,有4个吸盘,无顶突,小沟,表面覆盖一层致密的微绒毛.研究结果表明,肠黏膜增厚,主要是局部黏膜免疫相关细胞在寄生虫虫体表面覆盖的微绒毛的不断刺激下,机体抗感染自身组织增生所致.成年绵羊对抗贝氏莫尼茨绦虫的感染可能是通过黏膜免疫相关组织增生来加强局部免疫力而实现的.     

家禽的黏膜免疫研究及功能

家禽机体的呼吸道、消化道和泌尿生殖道黏膜在家禽机体占有很大的表面积,是机体与外界环境相隔的最大屏障,是病原微生物感染家禽的主要入侵部位和定居场所,同样此处的淋巴组织是抵御病原入侵的第一道防线,是免疫的主要屏障.而诱导黏膜免疫,特别是局部易感染部位的黏膜免疫,对黏膜感染有很好的保护作用,因此,黏膜免疫近年来越来越受到重视,许多免疫途径也是通过黏膜免疫进行的.     

肥大细胞在动物肠道黏膜免疫屏障中的作用

肠道黏膜屏障包括机械屏障和免疫屏障等,后者主要由肠黏膜吸收上皮细胞和肠道相关淋巴组织构成。肠道黏膜免疫细胞包括淋巴细胞、杯状细胞、肥大细胞等。其中肥大细胞是天然免疫的效应细胞之一,其不仅在天然免疫中发挥重要作用,且能通过所分泌的细胞因子参与获得性免疫。笔者综述了肥大细胞的生物学特性及其在肠道免疫屏障中的作用。     

家禽黏膜免疫研究

一、家禽黏膜免疫反应概述黏膜免疫系统由家禽胃肠道、呼吸道及某些外分泌腺哈氏腺、盲肠扁桃体等黏膜相关淋巴组织构成。在家禽的黏膜免疫系统中，尤其是肠相关淋巴组织ＧＡＬＴ和眼结膜相关淋巴组织ＣＡＣＴ在抗病毒免疫反应中起着非常重要的作用。据报道，ＧＡＬＴ是作为家禽机体第一层抵抗病原的免疫屏障。鸡肠上皮淋巴细胞ＩＥＬ主要存在于家禽肠道中的盲肠扁桃体和十二指肠的部位，在空肠中存在很少，在回肠中存在更少。ＩＥＬ的数量与肠道淋巴细胞的数量成正比，同时，ＩＥＬ的细胞数量受到肠道内抗原类型和数量的影…     

藏羊消化道黏膜免疫系统特性的研究

试验采用形态学方法对藏羊消化道黏膜免疫相关特性进行观察,并对肠段中肉眼可见的组织性淋巴样组织结(PPs)大小数量等进行数据统计。HE染色观察研究消化道肠相关淋巴组织(GALT)的特点及相关数据,免疫组化技术检测肠段中免疫球蛋白G(IgG)的分布特征及相对表达量。结果表明:小肠中PPs组织分布集中,总体呈中央突起边界清晰的腺状,其面积在0.68～10.8 cm2之间,回肠部分最为发达。大肠中PPs总体数量大小均低于小肠,其多位于肠袋中,外观呈蜂窝状,结肠中分布较多,直肠中未发现。空肠与回肠中淋巴小结发达且集中,其他肠段仅有数量不等的孤立淋巴滤泡存在。IgG在结肠与回肠中大量表达,直肠中仅有微量表达。说明藏羊肠道中PPs的形态学特征具有一定的规律,IgG的表达也具有特征性,总体与各个肠段功能相对应,这可能与藏羊的消化道黏膜免疫系统的进化有关。     

不耐热性肠毒素的黏膜免疫佐剂效应及其应用

黏膜免疫和黏膜免疫佐剂是近年来发展起来的新的免疫理论和新型技术，已成为医学界和免疫学界的研究热点。人们发现，虽然绝大多数病原微生物的感染始发于黏膜部位(呼吸道、消化道、尿道和生殖道)，但是在动物和人群中暴发传染病的数量都相对较低，部分原因就在于感染局部和全身免疫系统会产生多种免疫球蛋白来抵抗感染。不耐热性肠毒     

黄鳝消化道的组织学与组织化学研究

用肠卷石蜡法 ,对幼鳝和成鳝的消化道全长作纵切片 ,HE染色显示消化器官组织结构 ,嗜银法显示消化道内分泌细胞。结果显示 ,黄鳝消化道为一直形管道 ,主要由食管、胃、前肠和后肠组成。消化道的组织结构与哺乳类有许多相似之处 ,基本上由 4层组成。但食管上皮为含有大量杯状细胞的复层上皮 ,除胃体部外 ,其余器官内均缺腺体。本研究还显示了各器官连接部的结构变化。上述器官内均有散在分布的消化道内分泌细胞 ,表明黄鳝消化道还是一个主要的内分泌器官     

鸡生殖道相关淋巴组织研究进展

It is of great importance to learn about the changes of reproductive tract mucosal immune status by studying the normal development of hens, especially during the immediate post-hatch and laying period, because the chicken reproductive tract associated lymphoid tissue （RTALT） is the first immune barrier of the genitourinary tract against the invasion of external pathogenic microorganisms. This study can serve as a theoretical basis of the reproductive tract disease prevention (especially salmonellosis) for laying hens, and ultimately achieve the goal of providing pollution-free eggs for people to consume. Therefore, this article on chicken reproductive tract associated lymphoid tissue structural basis for development as well as their immune function were reviewed.     

Histological and immunohistochemical studies of the proximal caecum and caecal tonsils of quail (Coturnix coturnix japonica)

The proximal caecum in quails consists of lymphoid and non‐lymphoid structures. The caecal tonsils in the proximal part of the caecum are units of gut‐associated lymphoid tissue in poultry. This study aimed to examine the histological characteristics of the proximal caecum, as well as compositions of dendritic cells (DCs) and antigen‐presenting cells (APCs) in the caecal tonsil of quails. Tissue sections were stained with Crossman's triple, periodic acid–Schiff, Gordon and Sweet's silver, Congo red and methyl green‐pyronin dyes, as well as immunohistochemically by the streptavidin–biotin–peroxidase complex method. Caecal lymphoid tissue was located in the lamina propria and submucosa. Germinative centres were observed within the lymphoid tissue. Reticular fibres were mainly distributed in the border area of the germinal centre with only a few fibres scattered in the centre. Plasma cells were observed in the subepithelial region and germinal centres. Eosinophil granulocytes were prevalent in the lymphoid tissue. Additionally, CD83‐immunoreactive DCs and MHC class II immunoreactive APCs were present in the subepithelial area and diffuse lymphoid tissue. While DCs were seen in the germinal centres of tonsillar units, APCs were rarely present in the germinal centres, but they were noticed around the germinal centres. In conclusion, the histological structure of the proximal caecum in quails and the distributions of some immunological cells in the caecal tonsils were revealed. Therefore, the defensive role of the caecal tonsils in the digestive system may be better understood, and comparative studies may be carried out.     

Digestive Physiology and the Role of Microorganisms

The gastrointestinal tract contains within it a microenvironment of bacteria that influences the host animal in many ways. The microflora can metabolize several nutrients that the host cannot digest and converts these to end products (such as short-chain fatty acids), a process that has a direct impact on digestive physiology. The microbiota directs the assembly of the gut-associated lymphoid tissue, helps educate the immune system, affects the integrity of the intestinal mucosal barrier, modulates proliferation and differentiation of its epithelial lineages, regulates angiogenesis, modifies the activity of the enteric nervous system, and plays a key role in extracting and processing nutrients consumed in the diet. Despite these important effects, the mechanisms by which the gut microbial community influences host biology remain almost entirely unknown. Recent molecular-based investigations have confirmed the species diversity and metabolic complexity of gut microflora, although there is much work to be done to understand how they relate to each other as well as the host animal. It is almost a century ago that Eli Metchnikoff proposed the revolutionary idea to consume viable bacteria to promote health. Since that time, the area known as probiotics has made dramatic progress, particularly during the past 2 decades. The last 20 yr have also seen the emergence of a new, related area of study—prebiotics. Use of these 2 ideas—providing live nonpathogenic bacteria as well as substrates for their growth—have potential to help optimize the health of animals by manipulating the gastrointestinal tract in positive ways.     

饲用益生菌对动物肠道免疫调节的作用机理

益生菌即一类以活菌为主的新型饲料添加剂,其活菌能在动物肠道内定植,维护肠道菌群平衡,并刺激肠黏膜免疫系统,引起体液免疫和细胞免疫应答,从而增强机体抗病力.本文对益生菌的免疫刺激及其作用机理进行综述.     

Morphologic studies of intrapulmonary airway mucosa-associated lymphoid tissues in swine

Morphologic structures of the lymphoid tissues associated with the mucosa of the respiratory tract in swine aged 11 to 13 weeks were studied by dissecting, light, and transmission electron microscopy. Tissues along the respiratory tract were collected for further examination. Light microscopic examination showed that the lymphoid tissues were associated with bronchi (8.38%), bronchioles (81.63%), and respiratory bronchioles (9.98%). The lymphoid tissues were identified at different levels of the airways and were designated intrapulmonary airway mucosa-associated lymphoid tissues. Anatomically, the lymphoid tissues were found mostly in the bronchiolar bifurcations, with an arteriole frequently nearby. Histologically, the lymphoid tissues contained a single dome-shaped lymphoid follicle, which bulged out from the mucosal surface into the airway, where it was covered along the mucosal side by a layer of specialized epithelium. Ultrastructurally, the mucosal surface of the specialized epithelial cells was equipped with microfolds or cytoplasmic projections instead of cilia. The cytoplasm was elongated, and therefore much thinner than that of ordinary epithelial cells. Many lymphocytes were found scattered in the mucosal epithelium between or beneath the specialized epithelial cells. This structure was similar to that seen in the Peyer's patches of the small intestine in swine and other animals.     

黄牛呼吸道CD3+淋巴细胞分布的研究

CD3⁺是T细胞群的重要表面标志,呼吸道黏膜下分布的CD3⁺淋巴细胞作为抗感染黏膜免疫的基础,在保护机体抵抗呼吸道感染中发挥重要作用。为了解黄牛呼吸道CD3⁺淋巴细胞和淋巴组织的分布,本研究运用HE染色法和免疫组织学方法对5头7岁健康婆罗门黄牛的鼻黏膜、气管、肺内支气管及肺脏组织的CD3⁺淋巴细胞和淋巴组织的分布进行了研究。结果显示,黄牛的鼻黏膜、气管、肺内支气管和肺脏组织中均分布有CD3⁺淋巴细胞,且主要分布于黏膜上皮间及其下方固有层中及腺体周围;在鼻黏膜和肺脏组织中分布有CD3⁺淋巴细胞形成的弥散淋巴组织。牛呼吸道中CD3⁺淋巴细胞数量在鼻黏膜和肺脏组织中分布最多,气管黏膜、肺内支气管黏膜次之。本试验结果明确了CD3⁺淋巴细胞在黄牛呼吸道中的分布谱,表明黄牛呼吸道具备引发局部黏膜免疫的基础条件,为牛呼吸道黏膜免疫及呼吸道疾病防治研究提供了数据支撑。     

猪呼吸道淋巴组织发育的亚显微结构变化

应用组织学和电镜技术研究猪呼吸道发育过程中淋巴组织的变化。结果表明：扁桃体和咽部是呼吸道进入机体的第一个淋巴组织集中的部位，弥散淋巴组织在出生时就存在，淋巴小结不明显；20日龄时扁桃体中淋巴组织增生，淋巴小结清晰可见；120日龄淋巴小结数量增加，紧靠鳞状上皮密集排列，淋巴小结发育很好，并出现生发中心。扁桃体复层鳞状上皮中含有大量的上皮内淋巴细胞。气管叉是呼吸道进入机体的第二个淋巴组织集中的部位，出生时气管叉外膜中淋巴组织直接与气管支气管淋巴结相连，淋巴组织明显可见。20日龄时气管叉外膜中淋巴组织已分开，形成气管叉外膜密集的淋巴组织和气管支气管淋巴结两个部分。120日龄时气管叉处淋巴组织特别发达，黏膜上皮中上皮内淋巴细胞数量也显著增加。肺内气管和细支气管固有膜中均有较多的淋巴细胞，其中浆细胞数量增加，上皮中仍存在少量的上皮内淋巴细胞。本试验结果提示猪呼吸道是黏膜免疫较理想的诱导位点和效应位点，新生仔猪通过鼻腔免疫可提高呼吸道局部黏膜免疫力。     

植物提取物对家禽肠道健康的调控及其作用机制

植物提取物中的活性物质有黄酮类、植物精油、生物碱、茶多酚、皂苷和多糖等,这些活性物质在动物机体内具有抗菌、抗氧化、增强肠道免疫、促进消化酶分泌及改善肠道健康等多种生理功能,且具有无残留和无耐药性等特点,是抗生素的理想替代品之一。本文借鉴国内外学者近年来的植物提取物在家禽肠道健康调控方面的研究成果,对植物提取物的抑菌活性成分及抗菌机制进行了概括和阐述,重点综述了植物提取物对家禽肠道消化生理、肠道发育及黏膜形态、肠道菌群、肠道免疫和肠道有害代谢产物的影响及其作用机制,以期为今后在家禽生产中合理使用植物提取物提供科学依据。