Immunological Changes of Chicks Immunized with Marek‘s Disease Vaccines and Challenged with Virulent MD Virus

The experiment was conducted to inoculate one-day old chicks with Marek‘s disecae(MD) trivalent and herpesvirus of turkey(HVT) vaccines separately,and then to challenge them with virulent MD virus(vMDV) at the age of 15 days,and 5,25,45,and 75 days after the challenge with vMDV,comparing with the cotrol-challenged chicks without immunization,to detect the immunoprotetive efficacy and dynamic changes of the inductive activity of interleukin-2(IL-2),expression of IL-2 receptor and proliferative function of T cells in thymus and spleen;the number of ANAET,APT,cells and IgG,IgM,IgA antibody-producing cells in Bursa Fabricius,spleen,thymus,cecal tonsil and Harder gland;as the amount of T cells and IgG,IgA in peripheral blood as well as the content of IgG,IgM and IgA in the tear,trachea washings,bile and intestinal fluids of the experimental chicks.The experimental results firstly demonstrate that the immunoregulation of IL-2,and IL-2 receptor,the cellualr and humoral immune resposes were significantly enhanced in the central and peripheral immune organs;the local mucosal immune funcsignificantly enhanced in the central and peripheral immune organs;the local mucosal immune function were markedly amplified in the respiratory and digestive tracts of the immunized-challenged,chicks,which were closely correlated with the immunoprotection against MD;the immune response and immunoprotective effect of the trivalent vaccine-immunized chicks wrer much better than those of HVT vaccine-immunized chicks.     

Immunological changes of chicken infected with marek‘s disease virus

The experiment was conducted to infect one-day old healthy AA chicks with virulent Marek‘s disease virus(MDV).Compared with the uninfected control chicks,it was undertaken to detect the inductive activity of interlukin-2,expression of IL-2 recepter(IL-2R)and proliferative reaction of T cell in the thymus and spleen;to determine the number of α-naphthyl esterase positive T cells,acid phosphatase positive T cells and antibody forming cells in the thymus,Bursa Fabricius,spleen,cecal tonsil,Harder gand and mucosal lympoid tissue of bronchus;to check the number of T cell in peripheral blood as well as the dynamic changes of the amount of IgG,IgM and IgA in the serum,tear,trachea washings and intestinal secretions of infected chickens at 5,25,45 days old,respectively.The experimental results reveal that immunoregulation of IL-2 in immune organs of infected chicknens was disordered;the cellular and humoral immune functions were significantly depressed in the central and peripheral immune organs;the local or mucosal immune defense function were also markedly decreased in respiratory and digestive tracts.     

Studies on lmmunoregulation of Cytokine of Chickens after Inoculation with Marek‘s Disease Vaccines

The spleenic and thymus T lymphocyte proliferaitive reactions(TLPR) were enhanced,the interleukin 2(IL-2)inductive activity was raised,and the IL-2 receptor (IL-2R)iductive expression was increased significantly in chickens after inoculation with trivalent Marek‘s discase vaccine in comparison with control chickens and those after vaccination with herpesvirus of turkey (HVT) vaccine.In chickens after inoculation with HVT vaccine,in contrast with control chickens,the spleenic TLPR was strengthened and IL-2R inductive expression was hoisted significantly,the thymus TLPR,spleeinc and thymus T lymphocyte IL-2 inductive activity,the thymus T lymphocyte IL-2R inductive expression were not significantly increased.     

Effect of Zinc Toxicity on Lymphoid Organs in Chickens

The experiment was conducted with the objective of studies on effects of zinc toxicity on lymphoid organs by the methods of experimental pathology and flow cytometry (FCM). 200 one-day-old Avian broilers were divided into four groups randomly, and fed on diets as follows: controls (Zn 100mg kg^-1)and zinc toxic (Zn 1 500 mg kg^-1, zinc toxic group Ⅰ; Zn 2000 mg kg^-1, zinc toxic group Ⅱ; Zn 2 500 mg kg^-1, zinc toxic group Ⅲ) for seven weeks. The weight and growth index of the thymus, spleen and bursa of Fabricius were reduced in both zinc toxic group Ⅱ and zinc toxic group Ⅲ when compared with those of control group. The G0/G1 phase of the cell cycles of the lymphoid organs was higher, and S, G2 M phases lower in zinc toxic groups Ⅱ and Ⅲ than in control group. Lymphocytes were depleted and degenerate in the lymphoid organs. The reticular cells of the bursa of Fabricius proliferated and the reticular cells of the thymus were also degenerate and necrotic,particularly in zinc toxic groups Ⅱ and Ⅲ. The results demonstrated that more than 1500 mg kg^-1 impaired the progression of lymphocytes from the G0/G1 phase to S phase obviously, inhibited the development of lymphoid organs and caused marked pathological changes in the lymphoid organs. Potential mechanisms underlying these observations are also discussed.     

Studies on Immunoregulation of Cytokine of Chickens after Inoculation with Marek''''s Disease Vaccines

The spleenic and thymus T lymphocyte proliferaitivc reactions (TLPR) were enhanced, the intcrlcukin 2(IL-2) inductive activity was raised, and the IL-2 receptor (IL-2R) inductive expression was increased significantly in chickens after inoculation with trivalcnt Marck's disease vaccine in comparison with control chickens and those after vaccination with herpcsvirus of turkey (HVT) vaccine. In chickens after inoculation with HVT vaccine, in contrast with control chickens, the splcenic TLPR was strengthened and IL-2R inductive expression was hoisted significantly, the thymus TLPR, splccnic and thymus T lymphocyte IL-2 inductive activity, the thymus T lymphocyte IL-2R inductive expression were not significantly increased.     

Immunosuppressant Effect of Long Term and Subtherapeutic Chlortetracycline in Broiler

Experiments were conducted with 270 Abore Acre male broilers to study the influence of dietary chlortetracycline (CTC) on the bursal, thymus and spleen weight index and T, B cell proliferation and antibody responses of broilers. Results show that 50mg/kg CTC had no significant inhibitory effect on thymus and spleen weight index, and T, B cell proliferation of broilers at 21 days old. 150mg/kg CTC had significant inhibitory effect on bursal, thymus and spleen, and T, B cell proliferation (P＜0.05). Dietary CTC had a direct inhibitory effect on lymphocyte proliferation in vitro. 50mg/kg and 150mg/kg CTC had a significant inhibitory effect on the antibody responses to BSA (P＜0.01). Results demonstrated that subtherapeutic and long term CTC had significant inhibitory effects on immune organs and antibody response. The immunosuppressant effect became higher when the level of CTC increased. 150mg/kg CTC increased the growth rate of broilers significantly.     

Neospora caninum immune mapped protein 1(NcIMP1) is a novel vaccine candidate against neosporosis

The Neospora caninum immune mapped protein 1(Nc IMP1) was identified as a membrane protein,and a previous study indicated that Nc IMP1 could be a promising vaccine candidate against neosporosis. In this study, the immune response and protection efficacy of Nc IMP1 were evaluated. The coding sequence of Nc IMP1 was inserted into the eukaryotic expression vector pc DNA3.1(+), resulting in the recombination plasmid pc DNAIMP1, which was used for the intramuscular immunization of BALB/c mice. After immunization, the immune response was evaluated using a lymphoproliferative assay and cytokine and antibody measurements. Quantification of the cerebral parasite burden of mice challenged with 2106 N. caninum was performed 14 days after the last immunization. The results showed that the mice immunized with pc DNA-IMP1 developed a high level of specific antibody responses against recombinant Nc IMP1,with a mixed Ig G1/Ig G2 a response and a predominance of Ig G2 a production. The cellular immune response was associated with the production of IFN-γ, IL-2, IL-4 and IL-10 cytokines. The experiment was terminated 30 days p.i.,and the cerebral parasite burden in each mouse was assessed by quantitative PCR. The parasite burden was significantly reduced in the pc DNA-IMP1-vaccinated mice. These data suggest that IMP1 is a promising vaccine candidate against neosporosis.     

Type I strain of Toxoplasma gondii from chicken induced different immune responses with that from human,cat and swine in chicken

In this study,four strains of Toxoplasma gondii with the same genetic type(Type I) originated from chicken,human,cat and swine were used to compare the immune responses in resistant chicken host to investigate the relationships between the parasite origins and the pathogenicity in certain host.A total of 300,10-day-old chickens were allocated randomly into five groups which named JS(from chicken),CAT(from cat),CN(from swine),RH(from human) and a negative control group(—Ve) with 60 birds in each group.Tachyzoites of four different T.gondii strains(JS,CAT,CN and RH) were inoculated intraperitoneally with the dose of 1×10~7 in the four designed groups,respectively.The negative control(-Ve) group was mockly inoculated with phosphate-buffered saline(PBS) alone.Blood and spleen samples were obtained on the day of inoculation(day 0) and at days 4,11,25,39 and 53 post-infection to screen the immunopathological changes.The results demonstrated some different immune characters of T.gondii infected chickens with that of mice or swine previous reported.These differences included up-regulation of major histocompatibility complex class Ⅱ(MHC Ⅱ) molecules in the early stage of infection,early peak expressions of interleukin(IL)-12(IL-12) and-10(IL-10) and long keep of IL-17.These might partially contribute to the resistance of chicken to T.gondii infection.Comparisons to chickens infected with strains from human,cat and swine,chickens infected with strain from chicken showed significant high levels of CD4~+ and CD8~+ T cells,interferon gamma(IFN-γ),IL-12 and IL-10.It suggested that the strain from chicken had different ability to stimulate cellular immunity in chicken.     

Dynamic Pathology and Antigen Location Study on Broiler Breeders with Coinfection of Marek＇s Disease Virus and Reticuloendotheliosis Virus

To further understand the generation and development of coinfection of Marek＇s disease virus （MDV） and reticuloendotheliosis virus （REV） in broiler breeders, and then find the method and optimal time of differential diagnosis for complex clinic multiple infection, the authors studied the pathohistological changes, apoptosis, immunohistochemistry （immunofluorescence）, and ultrastructure of tumor tissues of broiler breeders inoculated with MDV and REV. The study showed that proliferation of small lymphocytes was seen in the main organs at the age of 1 week, then immature lymphocytes, all kinds of lymphocytes, primitive reticulum cells, and Marek＇s disease cells （MDCs） were observed at 2-9 weeks. Apoptosis of lymphocytes could not be seen until the age of 10 weeks in the immune system. Immunohistochemistry detection showed that the positive signs of MDV and REV antigen were observed in the main organs at 2 weeks of age. Multi-morphology lymphocytes, MDV, and REV, mitotic figures and apoptosis of lymphocytes were observed with the help of transmission electron microscopy. MDV cooperating with REV promotes the course of disease of coinfection. Differential diagnosis can be done by immunohistochemistry in the early stage （before 2 weeks）, and histopathology in the late stage （post 4 weeks）. MDCs, primitive reticulum cells, immature lymphocytes, and two kinds of virions can serve as a basis for bistopathology differential diagnosis.     

Immunotoxicity assessment of cadinene sesquiterpenes from Eupatorium adenophorum in mice

Sesquiterpenes in Eupatorium adenophorum are abundant in leaves and have great development potential as biopesticides. The toxicity of sesquiterpenes in immune cells and their corresponding immune functions are not fully understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-(acetyloxy)-9-oxoageraphorone(DAOA) and 9-oxo-10,11-dehydro-agerophorone(ODA) by using histopathology and toxicology methods in vitro and in vivo in lymphocytes and natural killer cells in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg-1 body weight(BW) of DAOA/ODA every day for a week. S erious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg-1DAOA/ODA. Mice cytology was also affected with significant cellular alterations, increased splenocytes apoptosis rates(P0.01), proliferation reduction(P0.05) and natural killer cells activities reduction(P0.05) when given 150–300 mg kg-1DAOA/ODA, the severities of which were dose-dependent. Howev er, a 75 mg kg-1 dose of DAOA/ODA showed no change in tissue or cytology after the 7 day treatment, and therefore was considered to be within acceptable safety parameters. Taken together, cadinene sesquiterpenes, as a type of toxic botanical component, have low environmental risks in small doses and should be further studied for their use as biopesticides.     

Immunological Changes of Chicks Immunized with March＇s Disease Vaccines and Challenged with Virulent MD Virus

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鸡马立克氏病疫苗免疫后的免疫学变化

实验对１日龄雏鸡接种ＭＤ三价疫苗或ＨＶＴ疫苗后的免疫应答变化进行了检测．发现ＭＤ疫苗免疫后：（１）脾脏、胸腺Ｔ细胞ＩＬ—２诱生活性和ＩＬ—２Ｒ表达明显增强或增多，表明ＩＬ—２的免疫调节作用增强；（２）胸腺、法氏囊和脾脏中Ｔ细胞和抗体生成细胞数量及Ｔ细胞增殖功能明显增高，表明中枢与外周免疫器官的细胞免疫和体液免疫应答显著增强；（３）盲肠扁桃体、哈德尔腺、支气管粘膜淋巴组织中Ｔ细胞和抗体生成细胞数量以及泪液、气管液、肠液、胆汁中ＩｇＡ，ＩｇＧ，ＩｇＭ含量明显增多，表明呼吸道与消化道的局部免疫应答也显著增强；（４）ＭＤ三价疫苗免疫鸡的上述免疫应答变化比ＨＶＴ疫苗免疫鸡明显．     

传染性法氏囊病疫苗免疫种鸡后子代雏鸡的免疫学变化

应用现代免疫学新技术对传染性法氏囊病 (IBD)疫苗免疫种鸡后 ,其子代雏鸡外周血液和免疫器官组织的免疫学变化进行了动态研究。结果发现 :传染性法氏囊病疫苗免疫种鸡后 ,其子代雏鸡外周血液 T、B细胞数量和 Ig G,Ig M,Ig A含量及免疫器官组织的 T细胞、Ig G,Ig M,Ig A抗体生成细胞数量均不同程度地高于未免疫的相应对照雏鸡 ,表明 IBD疫苗免疫母鸡后 ,子代雏鸡外周血液和免疫器官组织的体液免疫和细胞免疫功能明显增强。而传染性法氏囊病超强毒攻击子代雏鸡后 ,未免疫的子代雏鸡 ,外周血液和免疫器官组织的上述各项指标均明显低于疫苗免疫的子代雏鸡 ,这与 IBDV感染雏鸡后 ,其免疫器官组织严重损害 ,淋巴细胞变性坏死等有关 ,也是导致感染雏鸡免疫抑制的基础     

鸡贫血因子病的免疫病理学变化

 用鸡贫血病毒（CAV）感染1日龄健康AA雏鸡，以未感染同龄雏鸡为对照，在感染后7、14、21、28、35、42和49d检测其免疫器官与体重比值，胸腺、脾脏T细胞白细胞介素2（IL-2）和干扰素（IFN）诱生活性，胸腺、法氏囊、脾脏T、B细胞增殖反应，胸腺、法氏囊、脾脏、盲肠扁桃体及哈德尔腺中α-萘酚酯酶阳性[ANAE#+（+）]T细胞、IgG、IgM、IgA抗体生成细胞数量，外周血液中T、B细胞数量，血清、泪液、气管液、肠液、胆汁中IgG、IgM、IgA含量的动态变化。揭示了感染鸡细胞因子IL-2、IFN的免疫调节发生障碍、中枢与外周免疫器官的细胞免疫和体液免疫功能呈现抑制，呼吸道与消化道的局部免疫防御功能降低。     

雏鸡经马立克氏病疫苗免疫后IL－2及IL－2R的变化

雏鸡经马立克氏病（ＭＤ）三价疫苗免疫后，脾脏和胸腺Ｔ淋巴细胞白细胞介素２（ＩＬ－２）诱导活性比未免疫健康对照雏鸡和火鸡疱疹病毒（ＨＶＴ）疫苗免疫雏鸡显著升高（Ｐ＜０．０１，Ｐ＜０．０１和Ｐ＜０．０１，Ｐ＜０．０５），白细胞介素２受体（ＩＬ－２Ｒ）诱导表达显著增加（Ｐ＜０．０１，Ｐ＜０．０１和Ｐ＜０．０１Ｐ＜０．０１）；雏鸡经ＨＶＴ疫苗免疫后，脾脏Ｔ淋巴细胞ＩＬ－２Ｒ诱导表达比未免疫健康对照雏鸡显著增加（Ｐ＜０．０５），脾脏和胸腺Ｔ淋巴细胞ＩＬ－２诱导活性和胸腺丁淋巴细胞ＩＬ－２Ｒ诱导表达虽见升高和增加，但无统计学显著性差异（Ｐ＞０．０５）。     

感染鸡贫血因子病毒雏鸡免疫器官T细胞变化

对１日龄感染和未感染鸡传染性贫血病毒（ＣＩＡＶ）雏鸡的免疫器官组织Ｔ细胞数量的动态变化进行了检测．结果发现，１日龄雏鸡感染ＣＩＡＶ后，其中枢免疫器官胸腺、法氏囊和外周免疫器官脾脏以及局部免疫组织盲肠扁桃体和哈德尔腺的Ｔ细胞数量，于感染ＣＩＡＶ后７～２８ｄ较对照组明显减少，表明１日龄感染ＣＩＡＶ雏鸡免疫器官组织的细胞免疫功能明显降低．     

芦荟多糖提高鸡免疫功能的研究

[目的]研究芦荟多糖对鸡免疫功能的作用。[方法]采用环磷酰胺复制雏鸡免疫抑制模型,通过多项免疫学指标检测,探讨芦荟多糖对正常、免疫抑制及新城疫疫苗免疫雏鸡免疫功能的影响。[结果]芦荟多糖可以增加健康雏鸡的增重,促进免疫器官胸腺、脾脏和法氏囊的发育,特别是胸腺的发育,对正常雏鸡血清IFN-γ和血清IL-2具有一定的诱生能力;芦荟多糖对于环磷酰胺引起的雏鸡免疫抑制试验显示,可以明显增加免疫抑制雏鸡的增重,能促进血清IL-2和IFN-γ的诱生,提高机体的抵抗力,特别是在高剂量对IL-2的诱生作用上差异显著（P〈0.05）;芦荟多糖能够提高ND抗体水平。[结论]芦荟多糖可以改善正常雏鸡的免疫状态、增重和细胞因子诱生水平。     

感染传染性法氏囊病毒雏鸡对新城疫疫苗的免疫应答抑制和机理

本研究在雏鸡1日龄时感染法氏囊病毒,14日龄时点眼、滴鼻接种新城疫疫苗,检测了感染鸡ND免疫后其外周血液、泪液、气管液、肠液、胆汁中IgG,IgM,IgA含量,血液T细胞免疫功能和脾脏B细胞抗体生成功能、血清、泪液和气管液HI滴度的变化,测定了血液T,B细胞与淋巴细胞数量以及法氏囊、胸腺、脾脏、盲肠扁桃体、哈德尔腺、十二指肠粘膜、丕氏斑,支气管粘膜的浆细胞和酸性α-萘酚酯酶阳性T细胞(ANAE~+T)数量的动态变化。结果如下: 1)1日龄感染IBDV雏鸡ND免疫后,其法氏囊、脾脏、盲肠扁桃体、十二指肠粘膜固有层、丕氏斑、哈德尔腺、支气管粘膜固有层的浆细胞数量和脾脏B细胞抗体生成功能均显著降低;外周血液B细胞数量、HI滴度、血清、泪液、气管液、肠液和胆汁IgG,IgA,IgM含量较对照免疫鸡显著减少,这表明感染鸡对ND疫苗的全身和消化道、呼吸道相关局部的体液免疫应答功能显著抑制。 2)感染鸡ND免疫后,其胸腺、脾脏、法氏囊、消化道和呼吸道相关局部免疫组织的ANAE~+T细胞数量、外周血液T细胞免疫功能和T细胞数量均显著低于正常免疫鸡,这说明感染鸡对ND疫苗的全身和局部细胞免疫应答机能显著减弱。 3)ND强毒攻击后,感染鸡的ND免疫保护率明显低于健康免疫鸡,其免疫保护效应降低,与其对ND强毒的全身和消化道、呼吸道局部体液免疫和细胞免疫反应水平显著下降密切相关。     

感染传染性法氏囊病毒雏鸡的免疫抑制及其机理

本实验共用412只滨白雏鸡,分别在1日龄或4周龄时感染 IBDV,检测了雏鸡感染后其外周血液、泪液、气管液、肠液、胆汁中 IgG,IgM 和 IgA 含量、血液 T 细胞免疫功能和脾脏 B 细胞抗体生成功能、血液 T,B 细胞、淋肥细胞数量以及法氏囊、胸腺、脾脏、盲肠扁桃体、丕氏斑、十二指肠、哈德尔腺、支气管粘膜中浆细胞和酸性α-萘酚酯酶阳性 T 细胞(ANAE+T)数量的动态变化,结果如下:(1)雏鸡感染 IBDV 后,法氏囊、脾脏的浆细胞明显减少,脾脏 B 细胞抗体生成功能降低;胸腺、法氏囊、脾脏的 ANAE+T 细胞数量显著下降,说明感染鸡免疫器官的体液免疫功能和细胞免疫功能显著减弱.(2)IBDV 感染雏鸡引起呼吸道和消化道局部免疫组织一哈德尔腺、支气管粘膜、盲肠扁桃体、十二指肠粘膜固有层,丕氏斑的浆细胞和 ANAE+T 细胞较对照鸡显著减少;泪液、气管液、胆汁、肠液中 IgG,IgA,IgM 含量明显下降,表明感染鸡呼吸道和消化道局部的细胞免疫和体液免疫水平均显著降低.(3)感染鸡外周血液 T,B 细胞数量减少,T 细胞功能降低,IgG,IgA,IgM 含量明显下降,表明和标志全身体液免疫和细胞免疫水平降低,是免疫器官细胞免疫和体液免疫功能显著降低的反映和表现.(4)1日龄雏鸡感染 IBDV 后,B 细胞功能抑制时间明显长于 T 细胞,证明感染鸡 B 细胞功能的损害重于 T 细胞.(5)4周龄雏鸡感染 IBDV 引起的免疫抑制程度低于1日龄感染鸡,呈现一定的感染日龄差异.     

雏鸡应用益生素后胸腺和脾脏T细胞数量变化

为了揭示益生素对雏鸡免疫器官的细胞免疫增强效果,采用酸性非特异性酯酶染色法,研究雏鸡饲喂益生素后免疫器官细胞免疫动态变化。结果表明,雏鸡应用益生素后,胸腺和脾脏T细胞数量均较未饲喂益生素的对照雏鸡不同程度增加,且胸腺和脾脏细胞免疫增强。上述免疫指标显示益生素Ⅰ组又略高于益生素Ⅱ组,说明益生素Ⅰ的免疫增强效果优于益生素Ⅱ。