4天香烟烟雾暴露联合poly(I:C)刺激对小鼠肺部免疫应答及干扰素表达的影响

目的：探讨短期香烟烟雾暴露联合poly(I:C)刺激对小鼠肺部免疫应答及干扰素表达的影响。方法：BALB/c小鼠随机分为4组：对照组、熏烟组、poly(I:C)组和熏烟联合poly(I:C)组。检测支气管肺泡灌洗液（BALF）中总细胞数及细胞分类计数;普通光镜下观察各组细胞形态;荧光定量PCR检测肺组织细胞因子、趋化因子和干扰素及干扰素刺激基因表达。结果：与对照组相比,熏烟联合poly(I:C)组总细胞数计数、巨噬细胞与中性粒细胞计数明显升高（P<0.05）,且熏烟联合poly(I:C)组巨噬细胞计数高于poly(I:C)组;与poly(I:C)组比较,熏烟联合poly(I:C)组小鼠气道灌洗液巨噬细胞体积较大,呈圆形或不规则形,细胞质较多空泡;与对照组相比,熏烟联合poly(I:C)组小鼠肺组织中性粒细胞趋化因子CXCL1(P<0.05)、CXCL2(P<0.01)和淋巴细胞趋化因子CCL2(P<0.01) mRNA表达升高,肺组织IL-1β、IL-6、TNF-α mRNA表达明显升高（P<0.01）,肺组织IFN-β(P<0.01)、IFN-γ(...     

人滋养细胞TLR3信号通路活化抑制血管生成因子表达

目的 研究人类妊娠早期滋养细胞Toll样受体3(TLR3)活化对胎盘血管生成相关因子表达的影响,探讨该通路在妊娠期高血压疾病中的作用.方法 以TLR3配体刺激原代滋养细胞和永生化滋养细胞系swan71,不同时间点收集上清液及细胞.ELISA测定培养上清液中sFlt-1和PIGF浓度,real-time PCR法测定上述分子mRNA表达水平.结果 Poly(I∶C)刺激swan71后24、48和120 h,sFlt-1浓度显著高于未处理组(P＜0.05).Poly(I∶C)刺激原代滋养细胞后sFlt-1 mRNA水平升高,PlGF mRNA水平下降(P＜0.05).Poly(I∶C)诱导sFlt-1 mRNA的表达呈时间和剂量依赖性,24 h时效分析见其在处理2h达到峰值,PlGF mRNA则跌至最低水平(P＜0.05).Poly(I∶C)处理8～12 h,TLR3 mRNA水平亦显著升高(P＜0.05).结论 滋养细胞TLR3信号通路激活诱导sFlt-1表达,抑制PlGF表达,导致血管生成障碍,可能参与妊娠期高血压疾病的发生.     

CD4+T细胞活化诱导细胞凋亡在原发性胆汁性肝硬化小鼠模型中的作用研究

目的 研究CD4+T细胞活化诱导细胞凋亡(activation induced cell death, AICD)在poly I∶C诱导的原发性胆汁性肝硬化(primary biliary cirrhosis, PBC)小鼠模型中的作用.方法 30只C57BL/6雌性小鼠随机分为模型组和对照组,模型组小鼠腹腔注射poly I∶C 5 mg/kg,对照组小鼠注射等体积无菌PBS,16周后通过测定血清抗线粒体抗体(antimitochondrial antibody, AMA)、碱性磷酸酶(alkali phosphatase, ALP)及肝脏HE染色验证模型.磁珠分离小鼠脾脏CD4+ T细胞,分别以Con A和anti-CD3体外诱导细胞凋亡;实时荧光定量PCR测定T细胞中凋亡相关基因Fas、FasL和TRAIL(tumor necrosis factor-related apoptosis-inducing ligand)的表达;Western blot检测CD4+ T细胞中抗凋亡基因Bcl-2的表达.结果 poly I∶C注射16周后模型组小鼠血清AMA均为阳性,同时肝组织汇管区出现不同程度的炎性细胞浸润,而对照组AMA均为阴性,肝组织未出现明显病变.模型组小鼠血清ALP[(110.4±18.3) U/L]显著高于对照组[(52.2±15.4) U/L], P<0.001;模型组小鼠脾CD4+ T细胞AICD显著低于对照组(P<0.001),同时定量PCR结果表明:FasL mRNA水平较对照组有所降低(P<0.05),而两组Fas水平差异无统计学意义(P>0.05),TRAIL水平则显著低于对照组(P<0.001);Western blot结果表明模型鼠的抗凋亡蛋白Bcl-2的表达较对照组显著增高.结论 TH1细胞的凋亡缺陷可能在PBC小鼠模型的发病机制中有重要作用,该缺陷可能是由于自身免疫机制引起凋亡相关分子Fas体系及TRAIL的表达变化引起,同时通过上调Bcl-2的表达抑制自身反应性T细胞的凋亡.     

TRAIL及TRAIL受体在慢性乙型肝炎患者外周血淋巴细胞的表达

目的　探讨TRAIL(TNF relatedapoptosis inducingligand)及TRAIL受体 (TRAIL R)mRNA在慢性乙型肝炎患者外周血淋巴细胞 (peripheralbloodlymphocytes,PBL)中的表达。方法　分离 2 0例正常人、2 4例慢性乙型肝炎患者及 2 4例慢性重型乙型肝炎患者之PBL ,体外单独或与植物血凝素(PHA)共同培养 4 8h ,荧光素吖啶橙和溴乙啶染色PBL ,观察其凋亡细胞比例 ,采用逆转录 聚合酶链反应 (RT PCR)方法检测TRAIL、TRAIL RmRNA在PBL中的表达。结果　与正常对照组相比 ,活化诱导的淋巴细胞凋亡在慢性乙型肝炎患者明显增高 ,而在慢性重型肝炎患者则降低 ,差异有显著性 (P<0 .0 1)。PHA活化前 ,TRAILmRNA在上述 3组研究对象外周血淋巴细胞均不表达 ;PHA活化后 ,其表达明显上调 ,且慢性乙型肝炎组高于正常对照组 ,慢性重症肝炎组低于正常对照组 ,差异有显著性(P <0 .0 1)。 4个TRAIL R的mRNA在 3组研究对象外周血淋巴细胞均有表达 ,两两比较差异无显著性 (P >0 .0 5 )。经PHA活化后 ,TRAIL R2mRNA表达明显上调 (P <0 .0 1) ,TRAIL R3mRNA表达完全消失 ,TRAIL R1与 R4的mRNA表达无明显改变 (P >0 .0 5 )。结论　慢性乙型肝炎患者外周血淋巴细胞存在凋亡紊乱现象 ,TRAIL参与了乙型肝炎患者外周血淋巴细胞活化诱导细胞死亡 (     

NOD/SCID孕鼠淋巴细胞表型检测和NK细胞活性分析

目的观察NOD/SCID小鼠免疫状况和生育力特征,并分析NK细胞亚群对同基因交配组合NOD/SCID×NOD/SCID妊娠结局的影响。方法采用流式细胞术对未孕和孕13.5 d的NOD/SCID小鼠进行淋巴细胞表型分析,并系统地观察和比较NOD/SCID×NOD/SCID和BALB/c×BALB/c小鼠的生育力特征。分别采用多聚次黄苷酸-胞苷酸(polyinosinic-polycytidylic acid,poly I∶C)或抗asialoGM1单抗(anti-asialo GM1)刺激或抑制NK细胞活性,并分别观察这些因素对妊娠结局的影响。结果与对照组NOD/SCID小鼠相比,poly I∶C处理组NOD/SCID×NOD/SCID小鼠平均每窝产仔数增多,而注射抗asialo GM1单抗则使胚胎吸收率增高,进而平均每窝产仔数显著减少。结论在NOD/SCID小鼠孕期母-胎界面保持适当水平的NK细胞活性对妊娠结局有利。     

卡介苗联合Poly I:C接种对新生期小鼠脾脏T细胞的影响

目的 研究卡介苗(BCG)联合Poly I:C新生期接种对小鼠脾脏T细胞功能亚群发育的影响.方法 新生清洁级BALB/c小鼠32只,分4组:对照组、BCG组、Poly I:C组、BCG和Poly I:C联合接种组,新生期接种4周后取脾细胞用流式细胞仪检测CD3+ CD8+ IFN-γ+、CD3+ CD8- IFN-γ+、CD3+ CD8+ IL-4+ 、CD3+ CD8- IL-4+、CIM+ Foxp3+ T细胞的比例,其分别代表Tc1、TH1、Tc2、TH2和调节性T细胞(Treg)亚群.结果 BCG组、Poly I:C组、BCG和Poly I:C联合接种组TH1、Tc1细胞比例明显高于对照组(P＜0.05或P＜0.01),3个接种组间比较差异无统计学意义;Tc2、TH2和Treg比例各组间比较差异没有统计学意义;3个接种组TH1/TH2和总IFN-γ/IL-4比值明显高于对照组(P＜0.05或P＜0.01),联合接种组TH1/TH2比值高于BCG组(P＜0.05),Tc1/Tc2比值各组间差异没有统计学意义;CD4+ Foxp3+ T细胞比例各组间比较差异没有统计学意义.结论 新生期BCG和Poly I:C接种均能促进TH1、Tc1细胞亚群的发育,提高TH1/TH2比值,其联合接种在TH1/TH2水平可能具有一定的协同作用,但不能影响CD4+ Foxp3+ Treg细胞的比例.     

病毒拟似物Poly(I:C)诱导人卵巢颗粒细胞病毒反应蛋白viperin表达

目的探讨病毒拟似物对人卵巢颗粒细胞病毒反应蛋白表达的影响,明确颗粒细胞在卵巢病毒感染时的反应。方法将原代培养的人卵巢颗粒细胞分为对照组、病毒拟似物Poly(I:C)处理组、卵泡刺激素(FSH)处理组。CCK8法测定细胞增殖活力、real-time PCR法测定干扰素-β(IFN-β)、viperin mRNA表达,Western blot法测定viperin蛋白表达。结果原代接种培养5 d后,FSH可诱导颗粒细胞增殖(P0.05),Poly(I:C)10μg/m L对细胞增殖活力无显著影响。Poly(I:C)刺激后24 h内诱导IFN-β、viperin mRNA表达明显上调,其中IFN-β于刺激后2 h表达水平达到峰值(P0.05),viperin于刺激后8 h达到峰值(P0.05),刺激后24 h,两者mRNA表达水平均回归刺激前水平。Poly(I:C)诱导颗粒细胞viperin蛋白表达,水平随Poly(I:C)浓度上升。结论病毒拟似物能够诱导颗粒细胞表达病毒反应蛋白viperin。     

自身免疫性甲状腺炎 小鼠的巨噬细胞极化失衡及代谢方式改变

目的探讨巨噬细胞极化失衡及其代谢途径改变在自身免疫性甲状腺炎(AIT)发生发展中的意义。方法将4周龄NOD.H-2~(h4)雌鼠随机均分为对照组、AIT组(给予0.05%碘化钠水)。HE染色观察甲状腺组织淋巴细胞浸润情况并进行甲状腺炎性程度评分;ELISA测定血清甲状腺球蛋白抗体(TgAb);免疫荧光分析甲状腺组织中M1型和M2型巨噬细胞比例;细胞能量代谢分析仪(Seahorse)分析细胞能量代谢,测定细胞外酸化率(ECAR)、耗氧率(OCR)。结果 AIT组甲状腺组织有明显的淋巴细胞浸润,AIT的发病率明显高于对照组(P0.05)。与对照组相比,AIT组小鼠甲状腺组织中M1型巨噬细胞占比增多,M2型占比减少(P0.05);AIT组小鼠的最大ECAR和OCR值均明显高与对照组(P0.05)。结论巨噬细胞的极化失衡及其代谢改变对AIT的发生发展有着重要影响。     

Poly(I∶C)和LPS共刺激对人气道上皮细胞趋化因子表达的影响及机制

目的:研究模拟病毒感染及内毒素共刺激对气道上皮细胞趋化因子表达的影响。方法:人气道上皮细胞(16HBE)给予聚肌胞苷酸[poly(I∶C)]、内毒素(LPS)、地塞米松及p38MAPK抑制剂(SB203580)处理,用RT-PCR检测刺激6 h后IL-8、干扰素诱导蛋白10(IP-10)mRNA的转录水平,用ELISA检测刺激24 h后培养上清液中IL-8和IP-10蛋白含量。结果:10μg/mL LPS刺激后IL-8 mRNA及蛋白表达较对照组升高,IP-10 mRNA及蛋白表达未见明显升高;加入0.1μg/mL poly(I∶C)共刺激后IL-8和IP-10的mRNA及蛋白表达对照组及LPS组升高,差异有统计学意义。不同浓度poly(I∶C)(0.001、0.01、0.1μg/mL)刺激后IL-8、IP-10 mR-NA和蛋白表达呈浓度依赖性升高;各组分别加入10μg/mLLPS共刺激后IL-8、IP-10 mRNA及蛋白表达未见进一步升高。③地塞米松(1μmol/L)及SB203580(20μmol/L)分别预处理30 min后给予0.1μg/mL poly(I∶C)及10μg/mL LPS共刺激,两组IL-8、IP-10 mRNA及IL-8、IP-10蛋白表达较共刺激组和共刺激+DMSO组降低,差异有统计学意义(P<0.01和P<0.05),其中地塞米松的抑制效应强于p38MAPK抑制剂。结论:poly(I∶C)和LPS共刺激能够诱导气道上皮细胞趋化因子的表达,poly(I∶C)能加重LPS所致气道上皮细胞趋化因子IL-8的表达。糖皮质激素及p38MAPK抑制剂具有抑制模拟病毒感染及内毒素诱导气道上皮细胞趋化因子表达,提示两者在病毒诱导的AECOPD中具有潜在治疗价值。     

亚硒酸钠对实验性自身免疫性甲状腺炎大鼠甲状腺细胞凋亡的影响

目的 探讨亚硒酸钠对实验性自身免疫性甲状腺炎(EAT)大鼠甲状腺细胞凋亡的影响.方法 Wistar大鼠分为正常对照组、自身免疫性甲状腺炎(EAT)组和硒干预EAT组.制备EAT大鼠模型,硒干预EAT组给予亚硒酸钠灌胃.用放射免疫法(RIA)测定各组大鼠自身抗体水平,HE染色观察甲状腺组织病理改变及TUNEL法标记甲状腺组织中凋亡细胞,观察甲状腺细胞凋亡情况.结果 正常对照组、EAT组、硒干预EAT组的TgAb分别(6.94±1.13)%、(36.24±3.64)%、(17.23±2.90)%,TmAb分别为(5.96±1.40)%、(27.12±5.06)%、(15.98±2.45)%.硒干预EAT组TgAb、TmAb水平较EAT组明显下降(P<0.05).各组大鼠甲状腺组织炎症程度及凋亡程度评分结果比较显示,不同组别的甲状腺组织病变程度间差别有显著性(P<0.001),硒干预EAT组的甲状腺滤泡破坏程度较EAT组减轻,淋巴细胞浸润减少(P<0.05),甲状腺细胞的凋亡数量较EAT组明显减少(P<0.05).结论 亚硒酸钠可能通过抑制甲状腺细胞的凋亡来减轻或抑制自身免疫性甲状腺炎的免疫损伤.     

Experimental study on the effects of chronic iodine excess on thyroid function, structure, and autoimmunity in autoimmune-prone NOD.H-2h4 mice

Iodine is an essential component of thyroid hormones; high intake may lead to thyroid disease. Epidemiologic researches have shown that exposure to iodine may be involved in the onset and development of autoimmune thyroiditis. Iodine may induce hypothyroidism in patients with autoimmune thyroiditis in a dose-dependent manner. The aim of the present study was to investigate the effects of dosages of iodine on thyroid autoimmunity, morphology, structure, and function in autoimmune-prone animals. NOD.H-2h4 mice were randomly divided into normal iodine, 5-fold, 10-fold, 100-fold, 1,000-fold iodine excess group, anesthetized by diethyl ether and bleed from eye socket vein at 4, 8, 16, and 24 weeks after the commencement of experiment. Iodine and thyroid hormone levels in the thyroid tissue and sera, serum thyroglobulin antibody levels, as well as thyroid gland histological appearance were measured. Excessive iodine caused thyroid goiter, and there was a positive correlation between the thyroid weight and the dosage of iodine (r = 0.64–0.92, P < 0.01). Iodine overdose ultrastructurally damaged thyroid epithelial cells in a dose-dependent manner. The incidence of thyroiditis, as well as the degree of lymphocytic infiltration in the thyroid gradually increased as the dosage increased (r = 0.87–0.98, P ≤ 0.05). Excessive iodine intake might induce goiter, lead to thyroiditis, worsen lymphocytic infiltration, as well as damage to the thyroid follicular structure in a dose-dependent manner in autoimmune-prone NOD.H-2h4 mice.     

Thyroid epithelial cell hyperplasia in IFN-gamma deficient NOD.H-2h4 mice

The role of inflammatory cells in thyroid epithelial cell (thyrocyte) hyperplasia is unknown. Here, we demonstrate that thyrocyte hyperplasia in IFN-gamma-/- NOD.H-2h4 mice has an autoimmune basis. After chronic exposure to increased dietary iodine, 60% of IFN-gamma-/- mice had severe thyrocyte hyperplasia with minimal or moderate lymphocyte infiltration, and thyroid dysfunction with reduced serum T4. All mice produced anti-thyroglobulin autoantibody. Some wild-type NOD.H-2h4 mice had isolated areas of thyrocyte hyperplasia with predominantly lymphocytic infiltration, whereas IL-4-/- and 50% of wild-type NOD.H-2h4 mice developed lymphocytic thyroiditis but no thyrocyte hyperplasia. Both thyroid infiltrating inflammatory cells and environmental factors (iodine) were required to induce thyrocyte hyperplasia. Splenocytes from IFN-gamma-/- mice with thyrocyte hyperplasia, but not splenocytes from na?ve IFN-gamma-/- mice, induced hyperplasia in IFN-gamma-/- NOD.H-2h4.SCID mice. These results may provide clues for understanding the mechanisms underlying development of epithelial cell hyperplasia not only in thyroids but also in other tissues and organs.     

Intracellular adhesion molecule-1 up-regulation on thyrocytes by iodine of non-obese diabetic.H2(h4) mice is reactive oxygen species-dependent

Intracellular adhesion molecule-1 (ICAM-1) expression on the thyroid follicular cells of non-obese diabetic (NOD).H2(h4) mice is enhanced by iodide treatment, which correlates with autoimmune thyroid disease in genetically susceptible NOD.H2(h4) mice. The current study examines the mechanism of iodine-enhanced up-regulation of ICAM-1 on the surface of thyroid cells. We hypothesized that the up-regulation of ICAM-1 is due to a transient increase in production of reactive oxygen species (ROS). ROS may initiate signalling of the ICAM-1 gene promoter, enhancing up-regulated ICAM-1 protein on the cell surface. Single-cell suspensions of thyroid follicular cells from thyroiditis-susceptible NOD.H2(h4) or non-susceptible BALB/c mice were treated in vitro with sodium iodide. Extracellular and intracellular ROS were assessed by luminol-derived chemiluminescence and flow cytometry assays respectively. Our results demonstrate that thyroid follicular cells of NOD.H2(h4) generate higher levels of ROS compared with cells from non-susceptible strains of mice. Expression of a subunit protein of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, p67(phox), was analysed by Western blot immunoassay. A constitutive expression of the p67(phox) subunit protein was observed in NOD.H2(h4) mice prior to iodine treatment. No such expression was found in BALB/c mice. Treatment of NOD.H2(h4) thyroid cells with diphenyleneiodium, an inhibitor of NADPH oxidase, reduced generation of ROS and of ICAM-1 protein expression. Thus, thyrocytes from NOD.H2(h4) mice produce enhanced levels of ROS that may be mediated by NADPH oxidase. Consequently, in NOD.H2(h4) mice the ROS-induced signal for ICAM-1 up-regulation may contribute to mononuclear cellular infiltration of the thyroid gland and the progression of autoimmune thyroid disease.     

Role of MHC class I expression and CD8(+) T cells in the evolution of iodine-induced thyroiditis in NOD-H2(h4) and NOD mice

Dietary iodine has long been known to influence the development of human autoimmune thyroid disease. In nonobese diabetic (NOD) and NOD-H2(h4) mice elevated dietary iodine has been shown to induce autoimmune thyroid disease. Immune responses to thyroid antigens can be detected in these mouse strains, including T cell responses in the NOD-H2(h4) mouse to thyroid peroxidase. Cell transfer studies and antibody depletion experiments reveal a requirement for both CD4(+) T cells and CD8(+) T cells in the development of thyroid autoimmunity. Histological analyses of the thyroids show that following 1 week of iodine administration MHC class I expression is elevated on thyroid follicular cells and CD4(+) and CD8(+) T cells have begun to infiltrate the gland. Although MHC class II expression on thyroid epithelial cells was also elevated, the tempo of expression was slower and the extent of expression was far less than that for MHC class I. Depletion of CD8(+) T cells at early stages of disease induction inhibited not only thyroid infiltration and autoantibody production but also reduced the levels of MHC expression in the thyroid, suggesting that cytokine production by infiltrating lymphocytes was responsible for the increased MHC expression.     

Dysregulated Toll-like receptor expression and signaling in bone marrow-derived macrophages at the onset of diabetes in the non-obese diabetic mouse

The expression, responsiveness and regulation of mouse Toll-like receptors (TLRs) in bone marrow-derived macrophages (BM-?) were investigated prior to and following the development of diabetes. Expression of TLR3 and TLR5 was significantly higher in newly diabetic non-obese diabetic (NOD) mice when compared with pre-diabetic and control strains of mice. The TLR3 ligand poly(I)poly(C) triggered up-regulation of its own receptor in NOR and pre-diabetic NOD, but TLR3 was already highly expressed in diabetic NOD mice. Expression levels of TLR3 correlated with poly(I)poly(C)-triggered IFN activity. LPS triggered down-regulation of TLR4 in pre-diabetic NOD, NOR and BALB/c, while levels of TLR4 remained consistently elevated in type 1 diabetic NOD and type 2 diabetic NZL mice. Dysregulation of TLR4 expression in the diabetic state correlated with increased nuclear factor kappa B (NF-kappaB) activation in response to the TLR4 ligand LPS and higher expression of IL-12p40, tumor necrosis factor alpha (TNFalpha), IL-6 and inducible nitric oxide synthase but lowered expression of IL-10. Exposure of bone marrow precursor cells from NOD mice to a hyperglycemic environment during differentiation into macrophages resulted in elevated levels of TLR2 and TLR4 and the cytokine TNFalpha. The results indicate that macrophage precursors are influenced by systemic changes in diabetes favoring altered TLR expression and sensitivity that may influence susceptibility to macrophage-mediated diabetes complications and explain inappropriate responses to infection in diabetes.     

Identification of nuclear spliceosomal antigens targeted by NOD mouse antibodies following sodium iodide intake

The non-obese diabetic (NOD) mouse spontaneously develops a range of autoreactive responses including an autoantibody response to nuclear antigens. As elevated dietary iodine has been shown to increase thyroid autoimmune pathology in NOD mice, the effect of sodium iodide (NaI) on the development of anti-nuclear antibodies (ANA) was assessed. Interestingly, the NaI symporter is expressed in both thyroid and salivary glands. Elevated dietary iodine was found to increase the percentage of male NOD mice developing autoantibodies. Specifically, the nuclear autoantibodies that develop in NOD mice were shown to target specific spliceosomal components. The target specificity of the autoantibodies was determined using recombinant spliceosomal proteins and shown to include U1A, U170K, U2B', U2A', as well as the Sm proteins D1, D2, and B. The autoantibody isotypes most consistently represented were IgG2a and IgG2b.     

Iodination of murine thyroglobulin enhances autoimmune reactivity in the NOD.H2 mouse

Autoimmune thyroiditis in humans has been linked to excess iodine intake. A causative relationship between dietary iodine and thyroiditis has been clearly established in animal models of thyroiditis, including the NOD.H2(h4) mouse strain, which develops enhanced thyroiditis spontaneously after supplementation of drinking water with sodium iodide. To assess the mechanisms by which iodine may contribute to disease pathogenesis, we have purified hypoiodinated thyroglobulin (Lo-I Tg) from the thyroids of mice fed methimazole and potassium perchlorate. This preparation contained only a trace of iodine and was poorly reactive to monoclonal antibody 42C3, which has been shown previously to distinguish hypoiodinated from normal Tg. A cloned T cell line 2D11 from a diseased NOD.H2(h4) mouse proliferated in response to normal Tg, but not to Lo-I Tg. Serum antibodies from NOD.H2(h4) mice with thyroiditis were poorly reactive to Lo-I Tg. To determine that these changes were due specifically to iodine content, Lo-I Tg was reiodinated in vitro. Reiodination of Lo-I Tg partially re-established the reactivity of NOD.H2(h4) serum antibodies. The data demonstrate that the reactivity of thyroglobulin-specific antibodies and certain T cells are dependent on the iodine content of thyroglobulin. These findings suggest that iodine contributes to autoimmune thyroiditis in the NOD.H2(h4) mouse by directly enhancing the antigenicity of thyroglobulin.     

A novel and effective approach of developing aggressive experimental autoimmune gastritis in neonatal thymectomized BALB/c mouse by polyinosinic:polycytidylic acid

Neonatal thymectomy induces autoimmune gastritis (AIG) in 40-70% of BALB/c mice. We presumed that induction of autoimmunity by polyinosinic:polycytidylic acid (poly I:C) might allow development of a more aggressive model of AIG. A group of BALB/c mice were thymectomized on day 3 after birth. Neonatal thymectomized mice were either injected with poly I:C or phosphate-buffered saline (PBS). Non thymectomized neonatal BALB/c mice were injected with only poly I:C. All neonatal thymectomized mice injected with poly I:C developed 3 cardinal features of AIG: (1) moderate to severe degree gastritis (2) presence of autoantibody to H(+)/K(+) ATPase and (3) loss of parietal cells. However, only 70% of the PBS-treated neonatal thymectomized BALB/c mice developed some, but not, all features of AIG. A mild degree of AIG was seen in 12 of 31 nonthymectomized BALB/c mice administered with only poly I:C. Administration of poly I:C in neonatal thymectomized BALB/c mice in the first and second week appeared to be the most effective for induction of aggressive AIG. The levels of interleukin (IL)-6, IL-12p70, interferon-gamma and tumour necrosis factor-alpha were significantly higher in poly I:C-injected thymectomized mice compared to PBS-injected neonatal thymectomized mice (P < 0.05). The frequencies of CD4(+)CD25(+) regulatory T cells in the spleen were significantly decreased in neonatal thymectomized mice administered with poly I:C compared to PBS-treated neonatal thymectomized mice (P < 0.01). Taken together, these results suggest that induction of inflammatory cytokines and reduction of regulatory T cells by poly I:C might contribute to the development of an aggressive model of AIG in neonatal thymectomized BALB/c mice.     

The effects of alpha interferon on the development of autoimmune thyroiditis in the NOD H2h4 mouse

Alpha interferon (alphaIFN) therapy is known to induce thyroid autoimmunity in up to 40% of patients. The mechanism is unknown, but Th1 switching has been hypothesized. The aim of our study was to examine whether alphaIFN accelerated the development of thyroiditis in genetically susceptible mice. We took advantage of NOD-H2h4, a genetically susceptible animal model, which develops thyroiditis when fed a high iodine diet. Six to eight week old male NOD H2h4 mice were injected with mouse alphaIFN (200 units) or with saline three times a week for 8 weeks. All mice drank iodinated water (0.15%). Mice were sacrificed after 8 weeks of injection. Their thyroids were examined for histology and blood was tested for antithyroglobulin antibody levels. T4 and glucose levels were also assessed. In the IFN-injected group, 6/13 (46.2%) developed thyroiditis and/or thyroid antibodies while in the saline-injected group, only 4/13 (30.8%) developed thyroiditis and/or thyroid antibodies (p = 0.4). The grade of thyroiditis was not different amongst the two groups. None of the mice developed clinical thyroiditis or diabetes mellitus. Our results showed that alphaIFN treatment did not accelerate thyroiditis in this mouse model. This may imply that alphaIFN induces thyroiditis in a non-genetically dependent manner, and this would not be detected in a genetically susceptible mouse model if the effect were small. Alternatively, it is possible that alphaIFN did not induce thyroiditis in mice because, unlike in humans, in mice alphaIFN does not induce Th1 switching.     

Spontaneous autoimmune thyroiditis in NOD.H-2h4 mice

NOD.H-2h4 mice, which express I-Ak on the NOD genetic background, spontaneously develop autoimmune thyroiditis (SAT) and anti-mouse thyroglobulin (MTg) autoantibodies. The incidence of SAT is nearly 100% in mice of both sexes 6-8 weeks after administration of 0.05% NaI in the drinking water. After reaching maximum severity, inflammation is chronic over the next 3-4 months. All mice that develop thyroid lesions also produce MTg-specific IgG1 and IgG2b autoantibodies. Thyroid lesions and anti-MTg autoantibodies did not develop in CBA/J (H-2(k)) or NOD.SWR(H-2(q)) mice after administration of NaI water. Both CD4(+)and CD8(+)T cells are involved in the initial development of SAT. Depletion of CD4(+), but not CD8(+), T cells after thyroid lesions have developed also markedly reduced SAT severity, indicating that CD4(+)T cells are required for both developing and maintaining SAT. Analysis of cytokine gene expression indicated that both Th1 and Th2 cytokines were expressed in thyroids of NOD.H-2h4 mice with SAT. Th1 and proinflammatory cytokines were maximally expressed 4-6 weeks after mice began receiving NaI water, while Th2 cytokine gene expression was greatest at 8-15 weeks, when lesions had reached maximal severity and were in the chronic phase. TGF-beta was highly expressed in NOD.H-2h4 thyroids, irrespective of whether the mice had received NaI water or had thyroid lesions.