牦牛小肠黏膜的免疫形态学特征及其抗莫尼茨绦虫感染能力的研究

发布时间：2019-01-07 21:46

【摘要】：淋巴集结主要分布于人和动物的回肠，是黏膜免疫反应的主要诱导部位，不同物种之间淋巴集结的分布、数量、形态都不相同，为了揭示牦牛小肠黏膜的免疫形态学特征及其与年龄的关系本研究运用大体解剖学、组织学、组织化学、显微测量的方法对不同年龄牦牛小肠淋巴结节的形态进行了观察，将20头牦牛分为4个年龄组，分别为幼年牦牛（0.5岁、1岁、1.5岁）、青年牦牛（2岁、2.5岁、3岁）、壮年牦牛（4岁、5岁、6岁）、老年牦牛（8岁、9岁、10岁），对淋巴集结的形态、分布部位、数量进行了观察和统计，并对不同年龄牦牛小肠黏膜免疫相关细胞的数量进行了计数。结果：（1）大体解剖学观察显示牦牛小肠分布有2种不同形态的淋巴集结，即结节状和蜂窝状，结节状淋巴集结分布于十二指肠膨大部，蜂窝状淋巴集结分布于空肠、回肠，空肠和回肠的淋巴集结形状都是长条形，淋巴集结长度在0.4cm～17cm之间，宽度在0.2cm～3.7cm之间。淋巴集结的数量与年龄有关，在青年时期达到最大，以后逐渐减少，淋巴集结的外观形态并未随年龄发生变化，淋巴集结在10岁时仍有大量分布；（2）组织学显示牦牛小肠淋巴集结的发达程度与年龄密切相关，青年时期牦牛小肠淋巴组织最发达，显微测量发现青年牦牛回肠中段淋巴集结的厚度达903.20μm，回肠黏膜下层完全被大量淋巴集结所占据，淋巴集结由2～3层淋巴小结排列而成，淋巴组织分布密集，固有层中常见孤立淋巴小结和从黏膜下层突进来的淋巴小结的圆顶区，在圆顶区的滤泡相关上皮内有大量上皮内淋巴细胞，青年牦牛圆顶区的数量最多，随年龄增长淋巴集结的厚度逐渐减小，壮年、老年牦牛回肠淋巴小结和淋巴集结的数量明显减少；（3）细胞计数结果显示牦牛小肠黏膜免疫相关细胞在小肠中的分布趋势是：从十二指肠到回肠上皮内淋巴细胞、杯状细胞、肥大细胞的数量逐渐减少，而嗜酸性粒细胞、浆细胞的数量从前往后呈增多趋势。随着年龄增长，以上各种免疫相关细胞的数量均逐步增多，青年时期达到最多，，之后随着年龄的增加小肠黏膜免疫相关细胞的数量又逐渐减少，老年牦牛小肠黏膜免疫相关细胞的数量较青年、壮年牦牛明显减少（P0.05)。以上研究结果表明青年期牦牛的小肠黏膜免疫功能是最强的。莫尼茨绦虫是寄生于绵羊、山羊、牛等反刍动物小肠的一种大型绦虫，也是最具破坏性的体内寄生虫之一，导致动物死亡率升高、经济价值降低以及许多病理变化。不同于羊、黄牛等其他反刍动物，莫尼茨绦虫对成年牦牛的致病性很弱，成年牦牛感染后几乎没有临床症状。我们推测这可能与牦牛消化道黏膜免疫功能有关，为了分析消化道局部黏膜免疫相关细胞在抗莫尼茨绦虫感染中的作用，本研究采用组织学、组织化学、细胞计数以及统计分析的方法对感染牦牛小肠黏膜免疫相关细胞（上皮内淋巴细胞、杯状细胞、嗜酸性粒细胞、浆细胞、肥大细胞）的水平进行了分析并同正常组做了比较，并运用扫描电镜技术对小肠M细胞进行了观察。结果显示（1）感染组小肠各段上皮内淋巴细胞较对照组明显增多，差异极显著(P0.01)，感染组小肠杯状细胞、嗜酸性粒细胞、浆细胞、肥大细胞的分布数量也均较正常组高，之间差异极显著(P0.01)；（2）几种黏膜免疫相关细胞在小肠的分布趋势是：从十二指肠到回肠上皮内淋巴细胞、杯状细胞、肥大细胞的数量逐渐减少，而嗜酸性粒细胞、浆细胞的数量从前往后呈增多趋势，除空肠和回肠浆细胞数量差异不显著（P＞0.05），其余几种黏膜免疫相关细胞在小肠各段的分布数量均差异显著（P0.05）；（3）扫描电镜结果显示感染组部分肠绒毛断裂或脱落，圆顶区的数量较对照组多，圆顶区滤泡相关上皮中M细胞的数量也较对照组多。研究结果表明莫尼茨绦虫感染可引起成年牦牛感染部位黏膜免疫相关细胞的大量增生，这几种细胞分别参与特异性和非特异性免疫应答，通过强烈的免疫应答反应来抵抗虫体对机体的侵害，这可能是莫尼茨绦虫对成年牦牛致病力弱的主要原因。
[Abstract]:Lymphatic staging is mainly distributed in the ileum of human and animal, is the main inducing part of mucosal immune response, and the distribution, quantity and form of the lymph node assembly between different species are not the same, In order to reveal the characteristics of the immune morphology of the small intestinal mucosa of yak and its relationship with age, the morphology of the small intestinal lymph node was observed by the method of general anatomy, histology, histochemistry and micro-measurement. The 20-head yak was divided into 4 age groups. The morphology, distribution and number of young yak (0. 5, 1, 1. 5), young yak (2, 2, 5, 3), old yak (4, 5, 6), and old yak (8, 9, 10) were observed and counted. The number of immune-related cells in the small intestine of yak was counted. Results: (1) The general anatomical observation showed that the distribution of the small intestine in the yak was 2 different forms of the lymphoid build-up, that is, the nodular and cellular, the nodular-like lymph node was distributed in the enlargement of the duodenum, and the cell-like lymph node was distributed in the jejunum and the ileum. The shape of the lymph node in the jejunum and the ileum was long and the length of the lymph node was between 0. 4cm and 17cm, and the width was between 0.2cm and 3.7cm. The number of lymph nodes was related to the age, reached the maximum during the period of the youth, gradually decreased, the appearance of the lymphoid assembly did not change with age, and the lymph node assembly still had a large number of distribution at the age of 10; (2) Histologically, the developed degree and age of the lymph node in the small intestine of the yak were closely related to the age. The most developed and microscopic measurement of the small intestinal lymphoid tissue in the young yak was found to be 903.20. m u.m in the middle of the ileum of the young yak, and the lower layer of the ileal mucosa was completely occupied by a large number of lymph nodes. The lymph node assembly consists of 2-3 layers of lymphoid nodules, the lymphoid tissue is densely distributed, the common isolated lymphoid nodules in the intrinsic layer and the dome region of the lymph node protruding from the submucosal layer, and a large amount of intraepithelial lymphocytes in the follicular-related epithelium of the dome region, The number of yaks in the young yak was the most, the thickness of the lymph node was gradually decreased with the age, and the number of the lymphoid nodules and the lymph nodes in the old yak was significantly reduced. (3) The cell count showed that the distribution of the immune-related cells in the small intestine was the following: The number of lymphocytes, cup-like cells and mast cells from the duodenum to the ileal epithelium is gradually reduced, while the number of eosinophils and plasma cells is increasing from the front to the back. With the increase of age, the number of the above-mentioned various kinds of immune-related cells increased gradually, the number of young people reached the maximum, and the number of immune-related cells of the small intestinal mucosa gradually decreased with age, and the number of immune-related cells in the small intestinal mucosa of the old yak was smaller. In the middle-aged and middle-aged yak, the yak was significantly reduced (P0.05). The above results show that the immune function of the small intestinal mucosa of the green yak is the strongest. Monitinib is a large parasitic worm that is parasitic in the small intestine of the ruminants such as sheep, goats, cattle and the like, and is one of the most destructive in-vivo parasites, resulting in an increase in animal mortality, a reduction in economic value, and a number of pathological changes. It is different from other ruminants such as sheep, yellow cattle and other ruminants. It may be related to the immune function of the digestive tract of yak. In order to analyze the effect of the local mucosal immune-related cells of the digestive tract in the infection of the anti-monniac, this study is made of histological and texturizing. The level of immune-related cells (intraepithelial lymphocytes, cup-like cells, eosinophils, plasma cells, mast cells) of the small intestinal mucosa of the infected yak was analyzed and compared with the normal group. The small intestine M cells were treated with scanning electron microscope (SEM). The results showed that (1) The number of lymphocytes in the small intestine of the infected group was significantly higher than that in the control group (P0.01). The distribution of small intestinal cup-like cells, eosinophils, plasma cells and mast cells in the infected group was also higher than that in the normal group (P0.01). (2) The distribution of several mucosal immune-related cells in the small intestine is that the number of lymphocytes, cup-like cells and mast cells from the duodenum to the ileal epithelium is gradually reduced, while the number of eosinophils and plasma cells is increasing from the front to the back. There was no significant difference in the number of plasma cells in the jejunum and the ileum (P> 0.05). The distribution of the other mucosal immune-related cells in the small intestine was significant (P0.05). (3) The scanning electron microscope showed that some of the intestinal villi in the infected group were broken or shed, and the number of the dome areas was higher than that of the control group. In addition, the number of M cells in the follicular-related epithelium of the dome was also higher than that in the control group. The results of the study show that the infection of Monitinib can cause a lot of proliferation of the immune-related cells in the infected part of the adult yak, which are involved in the specific and non-specific immune responses, respectively, and are resistant to the invasion of the body by the strong immune response. It may be the main source of the weak pathogenic force of the monniac worm to the adult yaks.
【学位授予单位】：甘肃农业大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R392

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