实验性自身免疫性甲状腺炎小鼠细胞免疫状态研究

作者检测了实验性自身免疫性甲状腺炎(EAT)小鼠的细胞免疫状态,结果表明:EAT小鼠脾细胞Thy-1.2和Lyt-2阳性T细胞数显著下降并伴随L3T4/Lyt-2阳性T细胞数比值升高;甲状腺球蛋白刺激的淋巴细胞增殖明显增强,但NK细胞活性无显著变化;脾细胞产生TNF和IL-1的水平明显高于正常小鼠。提示T细胞免疫功能紊乱和细胞因子的大量释放可能是引起此病的重要因素。     

天花粉蛋白诱导小鼠Th2/Tc2亚群分化与MHC背景相关

为阐明天花粉蛋白 (Tk )诱导免疫抑制和基因调控的机制 ,应用ELISA方法动态测定小鼠OVA特异性T淋巴细胞培养上清液中T细胞亚群相关细胞因子的含量 ,观察Tk对高、低易感品系小鼠T细胞分泌细胞因子格局的影响。发现Tk作用下 ,高易感品系C5 7BL/ 6 (H 2 b)IL 4、IL 10分泌量大幅度增高 ,IFN γ显著下降 ;而低易感品系C3H/He (H 2 k)相应的细胞因子变化极小。上述结果表明 :(1)Tk可诱导功能性T细胞亚群向Th2 /Tc2方向分化 ,并导致OVA特异性T细胞增殖受抑 ;(2 )T细胞亚群分化与MHC背景密切相关。提示Tk作用下T细胞亚群的分化受MHC基因调控     

T_H细胞亚类研究新进展

1968年人们认识了淋巴细胞的两个主要亚类—T淋巴细胞和B淋巴细胞。以后的研究进一步证明,可以根据表面标志的不同,将T细胞分成两个功能不同的亚群,即带Lyt-1和L3T4表面抗原的TH细胞和带Lyt-2表面抗原的Ts/TC细胞。然而T_H和Ts细胞仍然是不均一的细胞群,Ts细胞可以再分为Ts1、Ts2和Ts3亚群,而T_H细胞由于辅助B细胞的方式不同,以及对尼龙毛柱的粘附性不同等,也可以再分为T_(H1)和T_(H2)两个亚类。这方面的进展情况我们以前曾作过介绍。近些年来,由于T细胞克隆技术的发展,各种新淋巴因子(如IL-2,     

桥本甲状腺炎免疫相关机制的研究进展

桥本甲状腺炎(HT)是一种器官特异性自身免疫性疾病,发病的具体免疫机制尚未阐明,但相关研究表明HT患者的T细胞和NK细胞数量和功能存在异常。辅助性T细胞和调节性T细胞(Treg)是T细胞的两个重要亚群,前者又包括Th1、Th2、Th17和滤泡辅助性T细胞(Tfh)等细胞。Th1/Th2比例失衡可诱导异常免疫应答;Th17细胞分泌IL-17直接促进甲状腺组织炎性反应损伤甲状腺细胞;Tfh细胞通过分泌IL-21调节B细胞功能,诱导机体特异性抗体的产生;功能异常Treg不能有效抑制自身免疫反应的发生;CD4/CD8比例异常可致免疫功能紊乱;NK细胞的免疫调节异常可影响后续免疫反应的发生。以上免疫机制均发现与HT发生有关,本文将分别对这两类T细胞亚群及NK细胞在HT发病中的作用进行综述。     

日本血吸虫感染小鼠的髓源抑制细胞对T 细胞的免疫抑制

目的:研究日本血吸虫感染小鼠模型中的髓源抑制细胞(MDSCs)的免疫抑制功能及对T细胞的作用机制。方法:构建日本血吸虫感染BALB/c小鼠模型,流式细胞术检测MDSCs动态比例变化,免疫磁珠分选小鼠骨髓中单核系MDSCs(CD11b+Gr1+Ly6G-)和粒系MDSCs (CD11b~+Gr1~+Ly6G~+)亚群细胞,Write-Giemsa染色进行形态学鉴定; CFSE法检测单核系和粒系MDSCs亚群对CD4~+T、CD8+T细胞增殖的抑制作用,Real-time PCR方法检测细胞因子IFN-γ、IL-4、IL-10、IL-13、TGF-β和精氨酸酶(ArgⅠ)、一氧化氮合酶2(NOS2)的表达。结果:血吸虫感染模型小鼠的MDSCs较对照组小鼠明显增多,以粒系MDSCs(CD11b+Gr1+Ly6G+)亚群增多为主。两个亚群细胞均能降低CD4+T、CD8+T细胞的增殖活性,粒系亚群MDSCs的抑制作用更显著; Real-time PCR结果显示两个亚群细胞的细胞因子IL-4、IL-10、IL-13、TNF-α、IFN-γ以及ArgⅠ、NOS2的表达水平均不同程度升高。结论:血吸虫感染模型小鼠体内的MDSCs显著增高,单核系MDSCs(CD11b+Gr1+Ly6G-)和粒系MDSCs(CD11b+Gr1+Ly6G+)亚群均能抑制CD4~+T、CD8~+T细胞增殖,其作用机制可能与两亚群细胞均能上调相关细胞因子IL-4、IL-10、IL-13和ArgⅠ、NOS2的表达有关。     

多种甲状腺调节因子对Graves病甲状腺细胞产生sICAM-1的影响

为了观察甲状腺调节因子如细胞因子、激素及神经递质对甲状腺细胞(TEC)细胞间粘附分子-1(ICAM-1)表达的影响,本研究在细胞培养基础上,采用ELISA法检测不同因子刺激后细胞上清液中可溶性ICAM-1(sICAM-1)的含量。结果表明:(1)细胞因子IL-1、IL-6可显著抑制TEC sICAM-1的合成,而TNF-α和IFN-γ则明显刺激sICAM-1产生;(2)肾上腺素、去甲肾上腺素、乙酰胆碱均可显著抑制TEC分泌sICAM-1;(3)促甲状腺素和地塞米松可显著抑制sICAM-1的生成;而泌乳素和雌激素则明显促进sICAM-1的产生。提示甲状腺调节因子可通过影响ICAM-1表达,参与甲状腺局部免疫调节过程。     

T细胞疫苗抑制自身免疫性甲状腺炎的发生

目的　研究T细胞疫苗 (TCV)在小鼠实验性自身免疫性甲状腺炎 (EAT)发生中的阻断作用及可能机制。方法　磁珠分离CD4 T细胞 ,体外活化 ,戊二醛处理获得T细胞疫苗 ,体内接种EAT小鼠。通过EAT评价、细胞因子测定及细胞增殖试验了解TCV对EAT的阻断作用 ;流式细胞术测定小鼠CD4 CD2 5 T细胞百分率。结果　TCV接种后小鼠体内自身抗体水平明显下降 ,甲状腺无明显病理变化 ,IL 2和IFN γ水平以及Tg刺激的淋巴细胞增殖能力均显著降低 ,同时CD4 CD2 5 T细胞百分率较EAT组有明显增高。结论　TCV接种能明显抑制小鼠EAT的发生 ,可能与机体内CD4 CD2 5 Treg细胞的增加有关     

天花粉蛋白对不同小鼠品系T细胞亚群分化的影响

为进一步探讨不同品系小鼠对天花粉蛋白(Tk)免疫抑制敏感性不同的机制,选择Tk高敏感品系(C57BL/6)和低敏感品系(C3H/He)小鼠,建立OVA特异性体外增殖系统,应用流式细胞术胞内细胞因子染色技术分析Th和Tc细胞亚群,real-time PCR检测细胞因子及相关转录因子的mRNA水平。发现Tk作用下,高敏感品系小鼠C57BL/6 IL-4阳性T细胞明显增多,表达IFN-γ阳性T细胞则显著减少。而低敏感品系C3H/He相关变化不明显。T细胞分化相关细胞因子IL-4、IL-10和IFN-γ及转录因子T-bet、gata-3的基因表达水平也呈现类似的格局。提示Tk发挥免疫抑制作用可能与其诱导的以Th2/Tc2为主的T细胞亚群有关,且这种诱导特定细胞亚群的作用在小鼠中和H-2b基因型相关。     

IL-12对BALB/c小鼠Th17细胞的分化的影响

目的: 观察细胞因子IL-12对Th17细胞分化的影响.方法: 小鼠脾淋巴细胞经抗CD3单克隆抗体(mAb)和不同浓度的重组小鼠IL-12刺激, 3 d后使用ELISA方法观察培养物上清液中IL-17的产生情况.并使用细胞内细胞因子染色的方法, 通过流式细胞术观察CD3 mAb和重组小鼠IL-12刺激对Th1和Th17细胞分化的影响.结果: Th17细胞不分泌IFN-γ、 IL-5、 IL-10等细胞因子, 不表达Foxp3, 是一个独立的细胞亚群.不同浓度的重组小鼠IL-12可以诱导抗CD3 mAb 的T细胞分泌IFN-γ, 并向Th1细胞方向分化.同时, IL-12可以抑制活化的T细胞分泌IL-17, 抑制T细胞向Th17细胞分化.结论: IL-12可以抑制Th17细胞的分化.     

Th1、Th2T细胞及其细胞因子在自身免疫性糖尿病中的作用

Ⅰ型糖尿病是T细胞介导的自身免疫性疾病,Th细胞亚群在疾病的发生过程中起了一定的作用。其中致病性免疫过程是由T细胞亚群Th1介导的,而TH2细胞亚群则是介导保护性免疫反应的。Th1型细胞因子(IL-2.IFN)通过直接促进细胞凋亡和/或上调选择性粘附分子的表达,以及Th1细胞因子可促进自身反应性T细胞在胰腺的浸润,二者均导致β细胞的破坏;Th1细胞介导的针对谷氨酸脱羧酶(GAD)的自身免疫反应增强,并通过分子内和分子间传导的机制转导至其他β细胞。Th1和Th2亚群实质上是机体在特异性抗原刺激下,Th细胞发生相对优势转化的结果。Th细胞的优势转化具有可塑性,对Th1或Th2型细胞因子或抗细胞因子单抗的研究,将为临床上自身免疫性糖尿病的治疗开辟新的途径。     

Resistance to experimental autoimmune thyroiditis: L3T4+ cells as mediators of both thyroglobulin-activated and TSH-induced suppression

Mechanisms suppressive to induction of murine experimental autoimmune thyroiditis (EAT) can be activated by pretreatment with tolerogenic doses of mouse thyroglobulin (MTg) or prior TSH infusion to raise circulatory MTg levels. MTg-activated suppressor T cells (Ts), shown earlier to be Thy-1+ and probably I-J+, were further characterized by in vivo administration of paired rat monoclonal antibodies to distinct epitopes on the L3T4 or Lyt-2 molecule, either on the day of, or subsequent to, initiation of the tolerogenic regimes. The cells required at the time of MTg pretreatment were L3T4+, Lyt-2- and low anti-L3T4 doses had no effect on their activation. The cells that mediated the strong MTg-induced resistance following pretreatment were also L3T4+; their suppressor function could only be abrogated by depletion of L3T4+, but not Lyt-2+, cells. Injection of cyclophosphamide (20-100 mg/kg) either prior to EAT induction or after Ts activation did not affect the severity of disease. Similarly, the suppressor state evoked by TSH infusion could only be abrogated by anti-L3T4 treatment. These findings indicate that both MTg-activated and TSH-induced suppression are mediated by L3T4+ cells. We hypothesize that MTg-specific Ts are present in normal, EAT-susceptible mice in low numbers to contribute to the maintenance of self-tolerance and that they are stimulated by increased levels of circulatory MTg to expand/differentiate and mediate the marked resistance to EAT induction.     

T helper cells change their Lyt-1,2 phenotype during an immune response

Evidence is presented that T helper cells change their Lyt-1,2 phenotype, from Lyt-1⁺2^? to Lyt-1^?2⁺, during a secondary response. In a secondary adoptive transfer the Lyt phenotype of carrier-primed T cells was established before and after secondary challenge using monoclonal antibodies and both positive and negative selection in the fluorescence-activated cell sorter. In a carrier-primed donor, the T helper cells were Lyt-1⁺2^? whereas 3 days after boosting the majority were Lyt-2⁺, and resistant to treatment with anti-Lyt-1 and complement. Parking experiments in lethally irradiated recipients confirmed that Lyt-2⁺ T helper cells were generated from Lyt-2^? precursors. In a primary response, both Lyt-2^? and Lyt-2⁺ T helper cells were present 4 to 20 days after immunization. Therefore T helper cells do not exhibit invariant expression of the Lyt-1,2 alloantigens.     

四种小鼠白血病细胞株免疫学分型的研究

本文通过卵白素生物素复合物(简称ABC)标记的抗Thy1.2,Lyt-1,Lyt-2和IaK~2四种单克隆抗体和马抗小鼠IgG抗体研究了L7212-85,L7811-85,L1210-86和P388-86四种小鼠白血病细胞株的免疫学分型。实验结果提示L-7212-85和L7811-85属于抑制性T淋巴细胞性白血病,P388-86属于B淋巴细胞性白血病,L1210-86属于非T非B细胞性白血病。     

Cytotoxic T lymphocyte lines reactive against murine plasmacytoma antigens: dissociation of cytotoxicity and Lyt-2 expression

The relationship between cell surface antigen expression and function in cytotoxic T cells directed against a non-H-2-restricted plasmacytoma antigen was examined using Lyt-2- variants of a continuous T cell line. This cytotoxic cell line originally had expressed Lyt-2 on all the cells as detected by flow microfluorometry, but after several months of culture, Lyt-2- variants spontaneously developed. Using cell sorting and limiting dilution cloning, Lyt-2- and Lyt-2+ cell lines were obtained, cultured and analyzed. These analyses indicated that such cytotoxic cells had similar activity regardless of Lyt-2 phenotype. This observation supports the concept that the Lyt-2 molecule is not obligatory for recognition and killing by cytotoxic T cells and emphasizes the need to clarify the precise relationship between cell surface phenotype and T cell function.     

Lyt phenotype, lymphocyte migration and the selective tissue positioning of mouse T cell sets.

Functionally defined mouse Lyt-1 and Lyt-2 cell sets were selected from peripheral lymph nodes by cytotoxic elimination with anti-Lyt monoclonal antibodies. The selected populations were labelled with 51Cr or [3H]-adenosine and traced in syngeneic recipients at 1, 24, 45 and 65 hr after intravenous injection. Recovered radioactivity in recipient organs was measured by gamma-counting. The exact tissue positioning of the labelled cells was determined by autoradiography and labelled cell counting in spleen, lymph node and Peyer's patch microenvironments. Selected cell sets differed from unselected T cells in two ways: (i) Selected Lyt-1 and Lyt-2 cells showed some decline in recovery from recipient lymph nodes at 24 hr after injection; (ii) Lyt-2 cells showed enhanced localization to Peyer's patches. Autoradiographic analysis of microenvironmental tissue positioning of [3H]-adenosine labelled cells confirmed a relatively higher localization of Lyt-2 cells in Peyer's patches than in lymph nodes. In both tissues, the majority of the labelled cells were found in T areas. In the spleen, a higher proportion of Lyt-2 cells was seen in T-independent follicular areas.     

Stable expression of Lyt-2 homodimers on L3T4+ T cell clones

The murine T lymphocyte antigen Lyt-2 is considered to act as an accessory molecule to the class I-restricted T cell receptor during antigen recognition. We have previously described two unusual Lyt-2+L3T4+ class II-restricted T cell clones whose activation by antigen is inhibited by antibodies to L3T4 but not to Lyt-2 (B. Fazekas de St. Groth et al., Proc. Natl. Acad. Sci. USA 1986. 83: 2594). The Lyt-2 immunoprecipitated from one of these clones was indistinguishable from the molecule found on splenic T cells, as analyzed under reducing conditions on polyacrylamide gels, in two-dimensional charge/size separations and in peptide mapping. The molecule from the second clone showed slightly more extensive glycosylation but was within the range described for functional Lyt-2 on cytotoxic T cell lines. Lyt-2 mRNA from both clones showed no abnormalities on Northern analysis. Lyt-2 is normally expressed on thymocytes and peripheral T cells as a heterodimer disulfide bonded to the Lyt-3 glycopeptide, yet Lyt-3 could not be detected on the cell membranes of our clones; Lyt-2 existed as stable homodimers without Lyt-3. Thus Lyt-3 is not required structurally for the spontaneous expression of Lyt-2 on lymphoid cells.     

Murine intestinal intraepithelial lymphocytes I. Relationship of a novel Thy-1-,Lyt-1-,Lyt-2+, granulated subpopulation to natural killer cells and mast cells

Highly purified populations of intraepithelial lymphocytes (IEL) were obtained from the murine small intestine. We found that 84% of IEL expressed Lyt-2 and that 45-55% possessed the unique phenotype, Thy-1-,Lyt-1-,Lyt-2+. Sixty percent of IEL had granules in their cytoplasm and thus resembled the large granulated lymphocytes associated with natural killer (NK) activity. However, less than 15% of IEL had NK activity in a 6-h assay. This activity resided in a subpopulation of Lyt-2- lymphocytes, leaving a large population of Thy-1-,Lyt-1-,Lyt-2+ granulated cells (45-55% of IEL) with unknown function. Sensitive radioenzymic assays for histamine showed that IEL from healthy CBA mice do not contain this amine. IgE-binding assays revealed that IEL, unlike mast cells, do not carry high-affinity receptors for IgE. Thus, only a small percentage of granulated IEL (less than 15%) possess NK activity, whereas 45-55% of IEL have granules, lack typical characteristics of mast cells, express the unique antigenic phenotype, Thy-1-,Lyt-1-,Lyt-2+ and have unknown function.     

Restitution of the thymus in lethally irradiated mice after transplantation of syngeneic or allogeneic bone marrow

The early restitution of the thymus of bone marrow chimeras was investigated by the immunoperoxidase technique using monoclonal antibodies against Thy-1 and Lyt-1, Lyt-2, Lyt-3. Within two weeks, normal thymus histology was restored in mice which received untreated syngeneic BM or syngeneic or allogeneic BM pretreated with SAL (specificed antilymphocytic serum). Irradiation depleted the thymic cortex of small Thy-1+, Lyt-1+2+3+ cells but did not affect a medullary population of medium sized weakly stained Thy-1+, strongly stained Lyt-1+ cells. Preceded by the appearance of an increasing number of large Thy-1+, Lyt-1- blasts (days 2 and 4), the thymic cortex was repopulated (beginning on day 6) by smaller Thy-1+ cells which acquired Lyt-1, Lyt-2 and Lyt-3 though, obviously not in a strictly sequential manner. Simultaneously, the medullary radioresistant cells disappeared, nd the medulla was subsequently repopulated (beginning on day 8) by thymocytes of a mature phenotype. Early restitution of the thymus in radiation control mice was similar to the bone marrow chimeras. The results indicate that the histological restitution of the thymus originates substantially from radioresistant precursors of host origin. Graft-versus-host reaction induced by untreated allogeneic bone marrow cells prevented normal thymic restitution. A delayed localized cortical repopulation with small Thy-1+, Lyt-1+2+3+ cells, progressive destruction of thymic architecture and almost no restoration of the medullary immunocompetent thymocytes were noted. T cell differentiation obviously was seriously affected by the injuries to the thymic microenvironment due to alloreactive T cells.