HBV转基因小鼠T细胞免疫状态

以正常非转基因 ICR小鼠为对照 ,用 3H-Td R掺入法和 ELISA分别测定了 HBV转基因 ICR小鼠脾淋巴细胞针对 HBe Ag的特异性增殖功能及其培养液上清中 Th1、Th2相关细胞因子 m IFN-γ、m IL-2、m IL-6、m IL-1 0含量。结果 ,HBV转基因小鼠脾淋巴细胞对 HBe Ag刺激引起的增殖反应、HBe Ag与 Con A共同刺激引起的增殖反应及其培养液上清中 4种细胞因子含量均明显低于对照组。以上结果表明 ,HBV转基因小鼠 Th1、Th2淋巴细胞所介导的特异性免疫功能均受到抑制     

旋毛虫排泄/分泌(ES)抗原致鼠胸腺淋巴细胞凋亡的研究

本试验首次以体外培养的小鼠胸腺淋巴细胞为实验对象,加入旋毛虫（Trichinella spiralis）肌幼虫ES抗原做刺激物,通过对鼠胸腺淋巴细胞DNA损伤、凋亡水平的检测,进而证明旋毛虫肌幼虫ES抗原能够诱导鼠胸腺淋巴细胞发生调亡。掌握这种免疫细胞凋亡（apoptosis）发生的过程,对分析免疫应答的特点和调控,以及探索旋毛虫病（Trichinosis）的发病机制和提供防治对策都具有重要意义。     

Flow cytometric and immunophenotypic evaluation of acute lymphocytic leukemia in dog bone marrow

Monoclonal antibodies provide powerful tools for detection of lineage-specific markers on hematopoietic cells. We used the combination of cell morphology, cytochemistry, flow cytometric scatter plot analysis, and labeling of cells with 6 monoclonal antibodies to detect and subclassify lymphocytic leukemia in bone marrow from 5 dogs. Antibodies included anti-CD18 (a panleukocyte marker), anti-MHC class II (detects most B and T lymphocytes and monocyte/macrophages), anti-Thy-1 (a pan-T-lymphocyte and monocyte/macrophage marker), anti-CD3 (a pan-T-lymphocyte marker), anti-CD21 (a B-lymphocyte marker), and anti-CD14 (a monocyte/macrophage marker). Of the 5 dogs evaluated, 2 were categorized as acute T-cell prolymphocytic leukemia, 2 as acute non-T, non-B lymphoblastic leukemia, and 1 as acute B-cell lymphoblastic leukemia. Results of this study indicate marked variation in the morphology and immunophenotype of canine lymphocytic leukemia.     

Influence of Dexamethasone on Some Cellular Aspects of the Immune System in Cats

In view of the frequent use of glucocorticoids in the treatment of cats, we studied the effect of dexamethasone on their immunological system. The phagocytic activity and oxidative burst of neutrophils and monocytes were evaluated by cytometric analysis using commercial kits and the subpopulations of lymphocytes were assessed. Neutrophilia and monocytosis reduced phagocytic activity, as shown from the number of phagocytized bacteria, and variations in the intensity of the oxidative burst in activated neutrophils and monocytes were observed. Dexamethasone also caused an increase in the number of B lymphocytes.     

Orientation of bovine CTL responses towards PIM, an antibody-inducing surface molecule of Theileria parva, by DNA subunit immunization

East Coast fever, an acute lymphoproliferative disease of cattle, is caused by the apicomplexan parasite Theileria parva. Protective immunity is mediated by CD8(+) cytotoxic T lymphocytes directed against schizont-infected cells. The polymorphic immunodominant molecule, although an antibody-inducing surface molecule of the schizont, has been hypothesized to play a role in protective immunity. In order to evaluate the immunogenicity of PIM for inducing CTL, cattle were immunized with PIM in isolation from other T. parva antigens, forcing the presentation of PIM-derived epitopes on the MHC class I molecules. Although parasite-specific cytotoxicity was induced in both vaccinated animals, their immune response was clearly different. One animal generated MHC-restricted parasite-specific CTL against PIM while the other calf exhibited a strong PIM-specific proliferative response but non-MHC-restricted parasite-specific cytotoxicity. Only calf 1 survived a lethal sporozoite challenge. This DNA immunization technique with an antigen in isolation of CTL-immunodominant antigens might open possibilities for directing CTL responses against predefined antigens, such as strain cross-reacting CTL antigens.     

The innate immune response against Brucella in humans

Pathogens have developed different strategies to survive and multiply within their host. Among them is the ability to control phagocyte apoptosis while another is to affect the expression of cytokines which is necessary for a normal protective function of the immune response. To establish themselves and cause chronic disease in humans and animals, Brucella spp. invade and proliferate within monocytic phagocytes. We have established that in humans, Brucella suis impairs the apoptosis of monocytes and macrophages, thus preventing its host cell elimination. In mice, which are not naturally colonized by the bacteria, Brucella infection results in Type1 (Th1) cellular immune response which promotes a clearance of the bacterial organism. The development of this response is under the control of major cytokines like TNF-alpha, IFN-gamma and IL-12 produced at the onset of infection. We have observed that in humans, B. suis-infected macrophages which produce IL-1, IL-6, IL-10 and several chemokines including IL-8, do not secrete TNF-alpha. By constructing null mutants, we demonstrated that this inhibition involves the outer membrane protein Omp25 of Brucella, however the mechanism regulating the inhibition has not yet been clearly defined. It is likely that the Omp25-induced effect on TNF-alpha production assists bacterial evasion of antimicrobial defences at different levels. Firstly, by preventing the autocrine activation of macrophages thus inhibiting innate immunity and secondly by impairing the production of IL-12 and the development of a Th1 type specific immunity. In addition to the central role of the macrophage in Brucella infection, others cells of the innate immune response are recruited and influenced by the interactions between bacteria and host. For instance, human Vgamma9Vdelta2 T-cells play an important role in the early response to infection with intracellular pathogens. Evidence has been presented that their number dramatically increased in the peripheral blood of patients with acute brucellosis. We have shown that human Vgamma9Vdelta2 T-cells can be specifically activated by non-peptidic low molecular weight compound(s) from B. suis lysate or by soluble factors produced by B. suis-infected macrophages. Under these conditions, they produce TNF-alpha and IFN-gamma and reduce the bacterial multiplication inside infected autologous macrophages. This impairment of B. suis multiplication is due to both soluble factors released from activated gammadeltaT-cells (including TNF-alpha and IFN-gamma) and to a contact-dependent cytotoxicity directed against the infected cells. The interactions between the bacteria and these cells can counteract the intramacrophagic development of the bacteria and finally influence the further development of the host defense. We hypothesize that the chronicity or the elimination of the infection will depend on the balance between contradictory effects induced by the bacteria which favor either the host or the pathogen. Moreover, the interrelationship between the different cells must be taken into account in the analysis of the virulence of the bacteria and in the development of in vitro models of human macrophage infection.     

Effect of Immunization with Plasmid DNA Encoding for Rinderpest Virus Matrix Protein on Systemic Rinderpest Virus Infection in Rabbits

Plasmid vaccine pBK-CMVMP1LC113 expressing the matrix (M) gene of rinderpest virus was assessed for its potential to protect rabbits against a lethal viral challenge. Rabbits immunized with plasmids expressing the M gene were not protected when challenged with lapinized rinderpest virus, despite the production of anti-M antibodies, while rabbits immunized with rinderpest tissue culture vaccine were completely protected from a lethal challenge with lapinized rinderpest virus. The plasmid vaccine also had no significant effect on the lymphopenia in challenged rabbits. The results indicate that rinderpest M protein does not have a protective role in rinderpest infection.     

人工感染鸭病毒性肠炎急性病例细胞凋亡的电镜研究

应用透射电镜和超薄切片技术观察鸭病毒性肠炎病毒（Duck Enteritis Virus，DEV）CH强毒株人工感染成年鸭各组织器官的形态学特征。结果表明，脾脏、胸腺、法氏囊、十二指肠固有层中淋巴细胞除了坏死变化外还有很明显的凋亡变化，两者往往同时存在。疾病过程中，淋巴细胞凋亡数量明显增多。凋亡细胞的形态学改变是细胞体积缩小，细胞器结构正常，染色质初期浓集成团，聚集于核膜的周边，随后出现染色质凝聚，核碎裂以及凋亡小体形成等现象。淋巴细胞的坏死和凋亡共同造成了淋巴细胞的大量损耗，淋巴细胞的这种变化可能在鸭病毒性肠炎的发病机制中起着重要的作用。研究结果表明DEV急性感染可诱导成年鸭体内淋巴细胞的凋亡。     

锌对鹅免疫器官发育和T淋巴细胞的影响

试验选用120只1日龄鹅随机分成4组,A组喂以玉米大豆为基础饲粮未加锌的饲料,另三组在基础日粮中添加ZnSO4·H2O,使锌含量分别为40mg/kg(B组),110mg/kg(C组)和2000mg/kg(D组)。分别于15日龄、30日龄和55日龄测定体重以及胸腺、脾脏、腔上囊重量,分离血液淋巴细胞进行α-醋酸萘酯酶染色试验,计算淋巴细胞ANAE阳性率。结果表明,A组和D组免疫器官的生长发育受到影响,其绝对重量和生长指数低于其他组。适当增加锌含量(110mg/kg)能显著增加成熟的T淋巴细胞的数量,提高细胞免疫水平。