牛肝提取物提高仔鸡免疫力的研究

将牛肝提取物注射到第13日龄和第15日龄鸡胚中能显著提高孵出后仔鸡的抗SRBC血清抗体的效价,促进脾和法氏囊淋巴细胞增殖、分化。同时,牛肝提取物与雏鸡法氏囊粗提取液,抗鸡法氏囊病毒抗体均有增强仔鸡抵抗传染性法氏囊病的能力。实验结果表明牛肝提取物中可能含有类似法氏囊素的物质。     

胸腺对法氏囊滤泡及脾脏B淋巴细胞区发育的影响

Siskind 等(1979)发现胸腺或胸腺细胞对B细胞接触抗原前的发育有影响;未成熟B细胞对胸腺依赖性抗原反应而产生异质性抗体的能力受胸腺的控制。Bhogal 等(1984)进一步指出,鸡法氏囊 B细胞的发育存在一个胸腺依赖的阶段,胸腺对法氏囊的发育可能存在体液性影响。本文通过手术去除胸腺、注射胸腺提取液等实验,观察法氏囊和脾脏淋巴细胞的显微和亚显微结构的变化,探讨胸腺对法氏囊滤泡及脾脏 B细胞区发育的影响。 材料和方法:实验用初生雏鸡是从山东省农科院购买的莱杭雏鸡,常规饲养。实验每组 10只雏鸡,分以下几组进行:1.手术切除胸腺组,取刚孵出的雏鸡,手术去除胸腺;2.手术切除胸腺并注射同龄鸡     

牛肝提取物提高鸡免疫力的研究

将牛肝提取物注射到第１３日龄第１５日龄鸡胚中能显著提高孵出后３仔鸡的抗ＳＲＢＣ血清抗体的效价,促进脾和法氏囊淋巴细胞增殖、分化。同时,牛肝提取物与雏鸡法氏囊粗提取液,抗鸡法氏囊病毒抗体均有增强仔鸡抵抗传染性法氏囊病的能力。实验结果表明牛肝提取物中可能含有类似法氏囊素的物质。     

蛇胸腺胚胎发育的组织学研究

该文应用光镜、电镜和细胞计数技术对胚胎发育期虎斑颈槽蛇胸腺的发育分化进行了研究。在胚胎发育１１期,胸腺原基内出现前淋巴细胞。从胚胎发育１２期至出生前（１６期）,淋巴细胞不断增殖分化,小淋巴细胞逐渐增多,而淋巴母细胞和中淋巴细胞逐渐减少。胸腺皮质和髓质形成于１６期。巨噬细胞以及肌样细胞和胸腺ＡＰＵＤ细胞分别形成于胚胎发育１４期和１５期,随后数量有所增加,分别分布于胸腺皮质和髓质。     

丙酸睾酮对鸡的法氏囊表面上皮内吞作用(Endocytosis)的影响

在莱杭雏鸡和仔鸡的肛唇上进行胶质碳处理,证明法氏囊附着滤泡上皮具有内吞作用。被内吞的碳粒24小时以后,主要存在于淋巴滤泡髓部的星状细胞及胞间隙中。在法氏囊发育的不同时期,用丙酸睾酮处理,均可损害附着滤泡上皮细胞。它们的亚微结构发生了变化,同时正常的内吞作用也受到明显地抑制。特别是用高剂量的丙酸睾酮处理以后,附着滤泡上皮细胞的内吞作用受到完全抑制。此外也揭示了丙酸睾酮处理以后,法氏囊淋巴滤泡表面的形态变化与法氏囊自然退化的情形大致相似。进一步证明法氏囊的自然退化与体内性激素浓度升高有关。     

鸟类法氏囊的结构与功能

法氏囊（bursaofFabricius或bursaFabricii）又叫腔上囊,是位于幼鸟泄殖腔背部并以短的囊管与其相连的卵圆形囊。此结构由意大利著名解剖学家、外科医生希罗尼马斯．法布里修斯（HieronvmusFabricius,1537～1619）首先发现并作了描述,故名。现被认为是鸟类特有的一个中枢淋巴器官。法勇的位置和结构从组织学角度看,法氏囊是一种类似胸腺的结构,其囊壁向囊内呈放射状突出形成许多柱状上皮构成的盲突,淋巴小结呈袋状广泛分布于盲突中。每个淋巴小结由疏松的胶质及致密的皮质所构成,髓质位于袋的内部,含有大的分枝的上皮细胞、巨噬细…     

关于法氏囊内T细胞及腔淋巴细胞的研究

本实验表明,法氏囊内存在一个T淋巴细胞弥散渗透区(DIA),在初生雏鸡中开始形成,一月半发育完善,同样在ISE(滤泡间上皮)上皮层内亦存在少量的弥散T淋巴细胞,上述淋巴细胞与腔淋巴细胞,形态结构极为相似。酯酶活性反应均显示T细胞型。 另外初生雏鸡切除胸腺,不仅影响DIA的发育而且影响滤泡的发育。     

E.tenella感染鸡CD4+、CD8+T细胞的动态变化研究

用免疫组化ABC法检测了柔嫩艾美耳球虫(E.tenella)感染雏鸡后各免疫器官和盲肠局部的T淋巴细胞亚群CD4 淋巴细胞和CD8 T淋巴细胞数的动态变化。结果表明:(1)雏鸡初次感染E.tenella后,免疫器官盲肠扁桃体、脾脏、胸腺和盲肠黏膜中的CD4 T淋巴细胞均于第2天开始增殖,第6天~8天达到峰值;二次感染后第2天有短暂的下降,第5天开始缓慢回升,第8天二次达到峰值,但第二个峰值比第一个峰值低,说明CD4 T淋巴细胞积极参与启动免疫应答和抵抗初次感染。(2)雏鸡初次感染E.tenella后,免疫器官法氏囊、盲肠扁桃体、脾脏、胸腺和盲肠黏膜中的CD8 T淋巴细胞都于第2天开始增殖,第8天达到峰值;二次感染后立即回升,第5天达到峰值,然后缓慢下降,且第二个峰值比第一个峰值高,表明CD8 T淋巴细胞是抵抗再感染的主力。     

骨髓间充质干细胞对器官移植中记忆性T细胞的影响

探讨骨髓间充质干细胞在器官移植中记忆性T淋巴细胞功能的影响。通过同种异基因皮肤移植的方法诱导CD8~+记忆性T淋巴细胞的产生,在体外应用混合淋巴增殖实验观察骨髓间充质干细胞对经过刺激后的T细胞增殖情况的影响;另一方面,通过同种异基因小鼠心脏移植模型的建立,在体内验证和观察骨髓间充质干细胞对小鼠移植器官生存寿命的影响。骨髓间充质干细胞在混合淋巴增殖实验中,可以有效抑制CD8~+记忆性T淋巴细胞的增殖能力,实验组淋巴细胞增殖指数明显低于对照组(t=4.575,p0.05);在小鼠心脏移植模型中,输注骨髓间充质干细胞后移植心脏的生存寿命明显增加,差异有统计学意义(p0.05)。骨髓间充质干细胞能够有效抑制器官移植中CD8~+记忆性T淋巴细胞的增殖,诱导免疫耐受,延长异体器官存活时间。     

抗体形成细胞发育的免疫组织化学研究

本文采用辣根过氧化物酶(HRP)作为抗原,与福氏佐剂一起对雄性豚鼠进行二次免疫,追踪腘淋巴结中抗体形成细胞的发育和分化。在二次免疫后的早期(2—3天),淋巴结的皮质区(特别是淋巴滤泡间区)和髓质区几乎同时出现阳性反应的细胞,主要是淡棕色的小淋巴细胞和中淋巴细胞。至6—9天,这二个区域的阳性细胞数明显增加达到高峰,主要是棕色和棕褐色的前浆细胞和浆细胞,皮质区与髓质区的阳性细胞在某些区域相连接。从12天起这二个区域的阳性细胞开始下降,在27—49天,淋巴结中只存在少数分散的阳性细胞,部分细胞萎缩变形成残留的浆细胞。在同一切片视野中除了看到棕褐色浆细胞和淡棕色小淋巴细胞外,还可以看到包括中淋巴细胞和前浆细胞等过渡型细胞。因此,我们认为浆细胞是分别在皮质区和髓质区由淋巴细胞发育而成。     

Immune complexes of E. coli antigens and maternal IgG in the bursa of Fabricius

The bursa of Fabricius of the chicken is known to be both a primary lymphoid organ and a secondary lymphoid tissue. Bursal follicles are equipped with antigen-trapping follicle-associated epithelium. However, bioactive antigens such as protein and bacteria have not been detected in the bursal parenchyma. By immunoperoxidase staining with a polyspecific antibody (Ab) against Escherichia coli, we detected aggregated E. coli antigens in the medulla of bursal follicles after hatching. The distribution of aggregated E. coli antigens is restricted to the medulla of bursal follicles. The antigens are not found in the spleen or the parenchyma of the caecal tonsil. The bursa is thus a trapping site for E. coli antigens from the external environment. Furthermore, two-color immunostaining clarified that these antigens form immune complexes with maternal IgG (MIgG) and are retained by reticular cells. Additionally, immune complexes in the bursa were shown to induce the rapid development of serum IgM Ab for indigenous E. coli. Our results suggest that immune complexes of MIgG and environmental antigens in the medulla of bursal follicles exert positive effects on B-cell differentiation in the bursa in situ.     

ELECTRON MICROSCOPY OF THE BURSA OF FABRICIUS OF THE EMBRYONIC CHICK WITH PARTICULAR REFERENCE TO THE LYMPHO-EPITHELIAL NODULES

Electron microscopic studies of the bursa of Fabricius during the 15th and 16th day of embryonic development in the chick have shown the following findings in the submicroscopic structure of the cellular elements of the lympho-epithelial follicles. In the medulla, basal endodermal epithelial cells undergo mitosis and differentiation into lymphoblasts. During this transformation, there is a reduction in the amount of rough endoplasmic reticulum, an increase in the number or ribosomes, and frequently an enlargement of the Golgi complex. As lymphoblasts differentiate into medium lymphocytes there is a loss of endoplasmic reticulum, a reduction in the number of ribosomes and in the size of the Golgi complex, as well as a decrease in the number and size of mitochondria and in the size of the cell and nucleus. Cytoplasmic processes of reticular-epithelial cells extend between proliferating lymphocytic cells. Desmosomes connect stellate reticular-epithelial and basal epithelial cells but are not present in lymphocytic cells. Nuclear blebbing and vesiculation are frequently observed in the various cell forms of the developing lympho-epithelial nodules. Although lymphocytes and lymphocytopoietic activities in the cortex are sparse during this stage of embryonic development of the bursa, transitional forms between mesenchymal cells and lymphoblasts have been encountered. In addition, lymphoblasts and/or undifferentiated epithelial cells occasionally may pass through the basement membrane from the medulla into the cortical region of the developing nodule. That lymphocytes in the bursa of Fabricius originate from both endodermal and mesodermal derivatives during embryonic development appears to be consistent with both light and electron microscopic observations.     

The origin of IgG-containing cells in the bursa of Fabricius

The bursa of Fabricius of the chicken is known as a primary lymphoid organ for B-cell development. Morphologically, the origin of IgG-containing cells in the bursa has not been clear until now, because abundant maternal IgG (MIgG) is transported to the chick embryo and distributed to the bursal tissue around hatching. Thus, it has been difficult to find out whether these cells themselves biosynthesize IgG or if they acquire MIgG via attachment to their surface. Our present study employing in situ hybridization clarified that IgG-containing cells in the medulla of bursal follicles did not biosynthesize IgG. To study the role of MIgG in the development of those IgG-containing cells, MIgG-free chicks were established from surgically bursectomized hen (SBx-hen). We found that, on the one hand, deprivation of MIgG from chicks completely inhibited the development of IgG-containing cells in the medulla after hatching. On the other hand, administration of MIgG to MIgG-free chicks recovered the emergence of those cells. In addition, we observed that those cells did not bear a B-cell marker and possessed dendrites with aggregated IgG. These results demonstrate that IgG-containing cells in the medulla are reticular cells that capture aggregated MIgG. Moreover, we show that the isolation of the bursa from environmental stimuli by bursal duct ligation (BDL) suppressed the development of IgG-containing cells after hatching. Thus, it is implied that environmental stimulations play a key role in MIgG aggregations and dendritic distributions of aggregated MIgG in the medulla after hatching.     

山羊羔淋巴集结的研究

对不同发育时期山羊羔淋巴集结、简称ＰＰ的显微和亚显微结构的观察显示羊ＰＰ的发生和组织学特征与鸟类法氏囊极为相似。同时,羊羔ＰＰ提取液可提高仔兔和仔鸡血清抗体的滴度,促进淋巴组织的发育。实验结果表明山羊ＰＰ是Ｂ淋巴细胞发生的重要部位,山羊ＰＰ中含有类似法氏囊素的物质。     

Vasculogenesis of the bursa cloacalis (bursa of Fabricius) of the chick embryo

Vasculogenesis of the bursa cloacalis (bursa of Fabricius) was examined in 10- to 21-day chick embryos and in chicks during the first 5 days post-hatching. The entire circulatory system was injected with India ink, and the bursae were then removed and either cleared for examination in toto or sectioned serially. The bursa was supplied by three pairs of extrinsic blood vessels. At 10 and 11 days of incubation, most intrinsic vessels were arranged in a superficial, hexagonal network. In regions of developing plicae, the hexagonal plexus extended into the core of each plica, forming middle plical vessels. The latter were interconnected across interplical areas by cross-connecting vessels. The middle plical vessels gave rise to small capillary offshoots, which soon increased in complexity, forming delicate loops. Branches extended from these loops through the subepithelial lamina propria to incipient epithelial buds by 12 days of incubation. All epithelial buds were supplied by at least one such branch, and similar branches extended to the basal aspect of the epithelium in areas where epithelial buds had not yet formed. This observation is consistent with the hypothesis that blood vessels induce formation of epithelial buds. At about 15 days of incubation, the cortex and medulla of each developing lymphatic follicle were defined clearly, and an intricate, web-like, capillary network coursed throughout the follicular cortex. The medulla appeared to be devoid of capillaries. The diameters of all intrinsic and extrinsic bursal blood vessels gradually increased throughout development. During post-hatching stages, the diameters of the extrinsic vessels continued to increase, whereas those of the intrinsic vessels were markedly decreased from late pre-hatching stages.     

The effect of alterations in myc gene expression on B cell development in the bursa of Fabricius

Infection of 18-day embryonic bursal lymphocytes with a v-myc-containing retrovirus leads directly to a polyclonal proliferation of surface immunoglobulin-positive (slg+) cells in the bursa of Fabricius detected four weeks after hatching. These v-myc-expressing bursal cells repopulate the follicles of chemically ablated bursae more efficiently than total normal 18-day embryonic bursal cells. In contrast, comparable normal bursal cells lose the ability to repopulate follicles by four weeks. Bursal lymphocytes expressing either a retroviral v-myc or a c-myc gene deregulated by adjacent retroviral integration retain the ability of embryonic bursal lymphocytes to diversify their immunoglobulin light chain genes. These results suggest that retroviral deregulation of myc expression during avian B cell development induces outgrowth of a population of cells with the cardinal phenotypic characteristics of bursal stem cells.     

Identification of B-L antigens on reticular epithelial cells of the bursa of Fabricius

We have established two monoclonal antibodies against B-L antigens (chicken Ia-like antigens). The specificity of the antibodies for B-L antigens was determined by two criteria, the cellular expression and the molecular structure of antigens with which they reacted. They reacted with antigens expressed on bursacytes, Con A-blast thymocytes, macrophages, and MDCC MSB1, but not with thymocytes and erythrocytes. In molecular basis, they recognized 64,000 dalton glycoprotein consisting of two polypeptides, 35,000 and 32,000 dalton, which bound non-covalently. To investigate the distribution of B-L antigens on non-lymphoid cells of the bursa of Fabricius, which were thought to play important roles in the differentiation of B cells, anti-B-L antigen and anti-chicken immunoglobulin (Ig) monoclonal antibodies were used. B-L antigen-positive cells were detected in both cortical and medullary areas, whereas Ig-positive lymphoid cells were confined to the medullary areas of normal chicken bursal follicles. In the bursal follicles of cyclophosphamide (CY)-treated chickens, lymphoid cells were depleted but epithelial cells remained intact. And B-L antigen-positive but Ig-negative cells were easily detected in the medullary areas of almost all follicles. These cells were identified to be reticular epithelial cells (REp cells) from the result of their keratin expression.     

Cell lineage segregation during bursa of Fabricius ontogeny

The population dynamics of myeloid and lymphoid lineages during bursa of Fabricius ontogeny were analyzed by immunofluorescence by using two monoclonal antibodies (mAb). CL-1 mAb reacts with all chicken hemopoietic cells, except mature erythrocytes. L22 mAb reacts with bursa and bursa-derived lymphocytes, with a minor subset of macrophages and with some cells of the thymic medulla. The staining of embryonic bursas by these antibodies helps to distinguish between two different lineages of hemopoietic cells: CL-1+/L22+ cells represent B lymphocytes and a minor subset of macrophages, while CL-1+/L22- cells correspond to most of the macrophages and to the granulocytes, which disappear at the end of the embryonic life. CL-1+/L22- as well as CL-1+/L22+ cells were first observed outside the bursal rudiment. This indicates that there is a pre-bursal segregation between these two hemopoietic lineages and that two different kinds of precursors colonize the bursal rudiment at about the same time (day 9 for CL-1+/L22- cells and days 9 or 10 for CL-1+/L22+ cells). Moreover our data show that the colonization of the bursal epithelium by hemopoietic precursors is a two-step phenomenon. The first cells which enter belong to the CL-1+/L22- lineage, express Ia-like antigens at a high level, are dendritic in morphology, and represent cells of the macrophage/dendritic cell lineage. They are responsible for the formation of the epithelial bud which are then colonized by a small number of lymphoid precursors which belong to the CL-1+/L22+ lineage. Quail-chick bursa grafting experiments were also performed and the grafts were examined for CL-1 (restricted to chicken hemopoietic cells) and L22 reactivity. These observations confirmed our previous findings about the kinetics of the colonization of bursal rudiment by hemopoietic precursors and give support for a pre-bursal segregation between two hemopoietic pathways.     

Effect of environmental antigens on the Ig diversification and the selection of productive V-J joints in the bursa

In chickens, a single set of unique functional segments of both Ig H and L chain genes is rearranged during early embryogenesis to generate a pool of B cell progenitors that will be diversified in the bursa by gene conversion, forming the preimmune repertoire. After hatching, bursal cells are exposed to environmental Ags in the bursal lumen. We prepared B cells from each single bursal follicle and used PCR-directed Ig L chain gene analysis to study the differentiation of B cells and the effect of antigenic stimulation from the bursal lumen on the neonatal chicken B cell repertoire formation. Selective amplification of B cell clones with a productive V-J joint was observed during the late embryonic stage, possibly by the interaction with ligands expressed on the bursal stroma and further accelerated in the neonatal chicken. Administration of the artificial Ags into the bursal lumen before the isolation of bursa by bursal duct ligation in the embryo caused a significant increase in lymphocytes with a productive V-J joint in the neonatal chicken bursa compared with the isolated bursa. Intra- and interclonal diversity of a complementarity-determining region measured by an evolutionary distance increased during bursal development. Clonal diversification did not require stimulation by artificial Ags from the bursal lumen. Thus, the preimmune repertoire in the bursa is generated by gene conversion during Ag-independent B cell proliferation, and antigenic stimulation from the bursal epithelium to bursal B cells plays roles in the selection of clones with a productive V-J joint.     

豚鼠卵巢囊淋巴孔的发现及卵巢囊超微结构研究

本实验通过扫描电镜等方法研究豚鼠卵巢囊及卵巢囊淋巴孔的结构,并探讨了卵巢囊及其淋巴孔的种属差异.实验结果首次报道豚鼠卵巢囊内、外层上皮均存在淋巴孔;豚鼠卵巢囊结构在输卵管走行、囊闭合程度及囊表面超微结构等方面与金仓鼠存在差异.结果提示豚鼠卵巢囊内、外层淋巴孔是沟通卵巢囊腔、卵巢囊淋巴系及腹膜腔的形态基础,可能是三者间物质转运的重要途径.卵巢囊淋巴孔可能影响物种的繁殖并参与囊腔内局部免疫反应.卵巢囊结构和发育程度与对应的输卵管伞端等结构及其他生殖特点相适应,研究结果丰富了生殖形态学和比较解剖学资料.