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1.
摘要 目的:探讨传染性单核细胞增多症(IM)患儿外周血T细胞活化分子CD38和人类白细胞抗原DR(HLA-DR)表达水平的临床意义。方法:采用流式细胞术分别检测45例IM患儿急性期和恢复期的活化分子CD38和HLA-DR在T细胞的表达水平,并与30例健康体检儿童进行对比。分析IM患儿急性期CD38和HLA-DR在T细胞的表达水平与EB病毒载量、肝功能指标、外周血异型淋巴细胞比例、淋巴细胞计数的相关性,并采用ROC曲线分析CD8+CD38+T和CD8+HLA-DR+T细胞百分比的诊断效能。结果:与对照组比较,IM急性期患儿的CD38和HLA-DR在T细胞的表达水平显著升高(P<0.05)。CD8+CD38+T、CD8+HLA-DR+T细胞百分比分别与EBV-DNA、ALT、AST、LDH、异型淋巴细胞百分比、淋巴细胞计数呈正相关(P<0.05),与白蛋白(ALB)呈负相关(P<0.05);CD4+CD38+T、CD4+HLA-DR+T细胞百分比与上述指标无显著相关性(P均>0.05)。IM恢复期CD38和HLA-DR在T细胞的表达水平较急性期明显降低(P<0.05)。ROC曲线分析CD8+CD38+T、CD8+HLA-DR+T细胞百分比显示诊断儿童IM的AUC值分别为0.931和0.993,特异度均为100%,灵敏度分别为88.89 %和93.33 %。结论:流式法检测CD38和HLA-DR在T细胞的变化有助于判断病情变化。外周血CD8+CD38+T、CD8+HLA-DR+T细胞百分比不仅能反映出IM急性期肝功能损伤严重程度,还可作为儿童IM的流式诊断指标。  相似文献   

2.
摘要 目的:研究消疬膏对脾胃虚弱证颈部淋巴结核患者CD4+CD25highFoxP3+调节性T淋巴细胞和胃肠激素的影响。方法:选择南京市中西医结合医院于2020年3月~2022年1月期间收治的颈部淋巴结核患者120例。按照随机数字表法分为对照组(60例)和研究组(60例)。对照组接受常规抗结核方案,研究组接受消疬膏联合常规抗结核方案,两组疗程均为6个月。观察两组治疗前和治疗6个月后的中医证候积分、CD4+CD25highFoxP3+调节性T淋巴细胞相关指标和胃肠激素的变化,记录两组治疗期间用药安全性。结果:两组治疗6个月后肿疡大小、肿疡皮色、面色、纳呆、倦怠乏力、便溏、舌质、脉象评分均下降,且研究组低于对照组(P<0.05)。研究组治疗6个月后CD4+CD25highFoxP3+调节性T淋巴细胞、白介素-10(IL-10)水平低于对照组,γ-干扰素(IFN-γ)水平高于对照组(P<0.05)。研究组治疗6个月后胆囊收缩素(CCK)、胃泌素(GAS)水平低于对照组,胃动素(MTL)水平高于对照组(P<0.05)。研究组的不良反应总发生率低于对照组(P<0.05)。结论:消疬膏治疗脾胃虚弱证颈部淋巴结核患者,可有效改善患者临床症状,可能与调节CD4+CD25highFoxP3+调节性T淋巴细胞和胃肠激素水平有关。  相似文献   

3.
目的 探讨组蛋白去乙酰化酶3(HDAC3)对外周CD4+ T细胞分化及功能的调控作用。方法 采用CD4cre酶介导Hdac3杂合基因缺失小鼠(Hdac3fl/flCD4cre+/-)及其野生型正常对照小鼠(Hdac3fl/fl,WT),流式细胞术检测HDAC3缺失对外周CD4+和CD8+ T细胞比例和数量的影响;在体外佛波酯(PMA)和离子霉素(Ionomycin)刺激条件下,流式细胞术检测HDAC3缺失对CD4+ T细胞中IFN-γ、IL-4和IL-17A的表达以及Tfh细胞产生的影响;采用ELISA检测HDAC3缺失对小鼠血清IFN-γ、IL-4和IL-17表达的影响;分选Hdac3fl/flCD4cre+/-和WT小鼠外周初始CD4+ T细胞,分别在Th1和Th2分化条件下培养,细胞内染色检测HDAC3缺失对Th1、Th2以及Th17相关细胞因子及其特异转录因子表达的影响;采用Microarray检测HDAC3缺失对CD4+ T细胞分化亚群相关基因表达的影响;采用链脲佐菌素(STZ)处理小鼠构建I型糖尿病(TIDM)疾病模型,检测HDAC3缺失对T1DM发病的影响。结果 与WT小鼠相比,Hdac3fl/flCD4cre+/-小鼠外周CD4+和CD8+ T细胞的比例和数量显著降低。Hdac3fl/flCD4cre+/-小鼠CD4+ T细胞及血清中IFN-γ的表达显著降低,而IL-4和IL-17A的表达显著增加,Tfh细胞比例也显著增加;HDAC3缺失抑制体外培养CD4+ T细胞向Th1分化但促进其向Th2分化;Microarray检测发现HDAC3缺失导致Th1型细胞谱系基因表达降低,而Th2、Th17以及Tfh细胞谱系基因表达增加;在STZ诱导条件下,HDAC3缺失抑制小鼠T1DM的发生和CD4+ T细胞向Th1分化。结论 HDAC3促进外周CD4+ T细胞向Th1细胞分化并加重T1DM的发生。  相似文献   

4.
摘要 目的:探讨桥本甲状腺炎(HT)患者血清微小核糖核酸(miR)-326、miR-155与甲状腺相关抗体和辅助性T细胞17(Th17)/调节性T细胞(Treg)细胞因子失衡的相关性。方法:选择2021年1月至2022年10月空军军医大学唐都医院收治的HT患者82例作为研究组,同期接受体检的健康人80例作为对照组,比较两组血清miR-326、miR-155、甲状腺功能参数[促甲状腺激素(TSH)、游离三碘甲状原氨酸(FT3)、游离甲状腺素(FT4)]、甲状腺相关抗体[甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TGAb)]、Th17、Treg水平及其细胞因子水平,并分析HT患者血清miR-326、miR-155与甲状腺相关抗体和Th17/Treg细胞因子失衡的相关性。结果:研究组TSH、TPOAb、TGAb显著高于对照组,FT3、FT4显著低于对照组(P<0.05)。研究组血清miR-326、miR-155表达水平显著高于对照组(P<0.05)。研究组Th17、Th17/Treg、白细胞介素-17(IL-17)、γ干扰素(IFN-γ)显著高于对照组,Treg、白细胞介素-10(IL-10)水平显著低于对照组(P<0.05)。Pearson相关分析显示,HT患者血清miR-326、miR-155分别与TSH、TPOAb、TGAb、Th17、Th17/Treg、IL-17、IFN-γ呈正相关,与FT3、FT4、Treg、IL-10呈负相关(P<0.05)。结论:HT患者血清miR-326、miR-155水平异常升高,其水平与TPOAb、TGAb自身抗体及Th17/Treg失衡相关,血清miR-326、miR-155可能通过影响Th17/Treg免疫平衡,促进HT的发生和发展。  相似文献   

5.
摘要 目的:探讨狼疮性肾炎(LN)患者血清中性粒细胞胞外诱捕网(NETs)、肿瘤坏死因子样凋亡微弱诱导剂(TWEAK)、外周血分化簇(CD)4+T/CD8+T比例与疾病活动度及肾脏预后的关系。方法:选取2021年8月~2022年8月川北医学院附属医院肾内科收治的LN患者137例(LN组),根据系统性红斑狼疮疾病活动指数(SLEDAI)-2000评分分为轻度活动组(52例)、中度活动组(45例)、重度活动组(40例)。随访1年,根据肾脏相关终点事件发生情况分为预后不良组(43例)和预后良好组(94例),另选取同期76名体检健康志愿者(对照组)。采用酶联免疫吸附法检测血清NETs、TWEAK水平,流式细胞术检测外周血CD4+T/CD8+T比例。Spearman相关性分析LN患者血清NETs、TWEAK和外周血CD4+T/CD8+T与SLEDAI-2000评分的相关性,多因素Logistic回归分析LN患者预后不良的因素,受试者工作特征曲线分析血清NETs、TWEAK和外周血CD4+T/CD8+T对LN患者预后不良的预测价值。结果:与对照组比较,LN组血清NETs、TWEAK水平升高,外周血CD4+T/CD8+T降低(P<0.05)。轻度活动组、中度活动组、重度活动组血清NETs、TWEAK依次升高,外周血CD4+T/CD8+T依次降低(P<0.05)。LN患者SLEDAI-2000评分与血清NETs、TWEAK呈正相关,与外周血CD4+T/CD8+T呈负相关(P<0.05)。慢性肾脏病分期4期、SLEDAI-2000评分升高、NETs升高、TWEAK升高为LN患者预后不良的独立危险因素,估算肾小球滤过率升高、CD4+T/CD8+T升高为独立保护因素(P<0.05)。血清NETs、TWEAK和外周血CD4+T/CD8+T联合预测LN患者预后不良的曲线下面积为0.943,大于血清NETs、TWEAK和外周血CD4+T/CD8+T单独预测的0.790、0.788、0.799(P<0.05)。结论:LN患者血清NETs、TWEAK水平升高,外周血CD4+T/CD8+T降低,与疾病活动度及肾脏预后不良密切相关,血清NETs、TWEAK联合外周血CD4+T/CD8+T预测LN患者肾脏预后的价值较高。  相似文献   

6.
摘要:目的 观察转录因子Oct-4在IIIB期结肠癌患者癌组织中的表达,并探讨Oct-4表达水平、部位同CD45RO+淋巴细胞浸润密度之间的相关性,为结肠癌的诊断和判断预后提供依据。方法 选取佳木斯大学附属第一医院65例经外科手术治疗切除的ⅢB期结肠癌患者的癌组织标本、36例癌旁组织标本及24例正常结肠组织标本。采用免疫组织化学染色法检测Oct-4,比较各组组织中Oct-4水平以及分布状况。同时,分析其与CD45RO+淋巴细胞浸润密度的关系。结果 (1)Oct-4在结肠癌组织中高表达,在结肠癌旁组织中表达较弱,在正常结肠组织中无表达。(2)Oct-4蛋白表达中、强阳性的结肠癌组织中CD45RO+细胞浸润密度低于Oct-4水平阴性、弱阳性表达的组织。细胞核中表达Oct-4蛋白的结肠癌组织中CD45RO+T淋巴细胞浸润密度高于核浆共表达的结肠癌组织。结论 Oct-4在IIIB期结肠癌肿瘤细胞中表达,可作为诊断的参考指标;且Oct-4表达水平的高低可作为判断预后的标准。  相似文献   

7.
目的:比较黑龙江省HIV/AIDS患者与健康对照者(healthy controls,HCs)外周血CD4+CD25+FoxP3+调节性T细胞数量、免疫抑制功能的变化,探讨CD4+CD25+FoxP3+调节性T细胞在HIV/AIDS感染过程中的作用。方法:采用流式细胞仪检测21例HIV/AIDS患者及20例健康对照组的外周血CD4+CD25+FoxP3+调节性T细胞数量的百分比及绝对数量;采用共同培养方法检测HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞免疫抑制功能的变化;实时荧光定量聚合酶链反应(RT-FQ-PCR)检测HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞中FoxP3mRNA的表达。结果:黑龙江省HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞比率明显高于HCs(P<0.01),而CD4+CD25+FoxP3+调节性T细胞的绝对计数显著下降,且与CD4+T细胞绝对计数成反比;混合淋巴细胞共同培养结果显示,HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞的抑制功能无明显变化;HIV/AIDS患者外周血CD4+CD25+FoxP3+调节性T细胞的FoxP3 mRNA相对表达量无显著变化。结论:黑龙江省HIV/AIDS患者CD4+CD25+FoxP3+调节性T细胞的数量变化与病情相关。  相似文献   

8.
摘要 目的:探讨五灵胶囊联合富马酸丙酚替诺福韦片对慢性乙型肝炎(CHB)患者氧化应激、CD4+CD25+调节性T细胞和血清基质金属蛋白酶-1(MMP-1)、基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶组织抑制因子-1(TIMP-1)的影响。方法:纳入苏州大学附属传染病医院2021年6月~2022年12月期间收治的CHB患者122例,采用随机数字表法分为对照组(n=61,富马酸丙酚替诺福韦片)和研究组(n=61,五灵胶囊联合富马酸丙酚替诺福韦片)。对比两组疗效、氧化应激指标、CD4+CD25+调节性T细胞、肝功能指标[总胆红素(TBIL)、谷丙转氨酶(ALT)、谷氨酰转肽酶(GGT)]、血清MMP-1、MMP-2、TIMP-1水平和不良反应发生情况。结果:研究组的临床总有效率高于对照组(P<0.05)。两组治疗后丙二醛(MDA)下降,且研究组低于对照组同时间点;超氧化物歧化酶(SOD)升高,且研究组高于对照组同时间点(P<0.05)。两组治疗后CD4+CD25+调节性T细胞下降,且研究组低于对照组同时间点(P<0.05)。两组治疗后MMP-1、MMP-2、TIMP-1下降,且研究组低于对照组同时间点(P<0.05)。两组治疗后TBIL、ALT、GGT下降,且研究组低于对照组同时间点(P<0.05)。两组不良反应总发生率组间对比未见差异(P>0.05)。结论:五灵胶囊联合富马酸丙酚替诺福韦片治疗CHB患者,可有效减轻机体氧化应激,调节CD4+CD25+调节性T细胞和血清MMP-1、MMP-2、TIMP-1水平。  相似文献   

9.
CD4+CD25+调节性T细胞是CD4+T细胞的一个重要亚群,具有免疫抑制和免疫无能两大功能。CD4+CD25+T细胞与自身免疫性疾病的发生、移植耐受具有密切关联。近几年的研究表明,CD4+CD25+T细胞与肿瘤的发生发展和转归亦有着密切联系。本文就调节性T细胞的作用机制及特点与肿瘤免疫的关系作一综述。  相似文献   

10.
目的:探讨CD8+CD122+T细胞在脑缺血过程中的作用及其机制。方法:线栓法建立小鼠大脑中动脉栓塞模型(MCAO);激光共聚焦显微镜检测小鼠脑缺血组织中CD8+CD122+T细胞浸润情况;流式细胞仪检测脑缺血组织中CD8+CD122+T细胞/CD3+T细胞的比例及脾和胸腺中CD8+CD122+T细胞数量变化;RT-PCR方法检测CD8+CD122+T细胞对氧糖剥夺(Oxygen-glucose deprivation,OGD)条件下星形胶质细胞表达TNF-α,IL-1β,IFN-γ的影响。结果:各时间点脑缺血组织中均有CD8+CD122+T细胞浸润,且随脑缺血时间延长,缺血侧脑组织中CD8+CD122+T细胞/CD3+T细胞比例逐渐增加,5 d和7 d组差异显著,与非缺血侧相比,P5d0.05,P7d0.05;MCAO小鼠脾及胸腺中CD8+CD122+T细胞呈现先增高后降低的趋势。星形胶质细胞经OGD处理后,与对照组相比,IFN-γ、TNF-α、IL-1β表达显著增高,PIFN-γ0.01、PTNF-α0.001、PIL-1β0.01;CD122-blocked组与CD8+组相比,IFN-γ、TNF-α、IL-1β表达明显增高,PIFN-γ0.05、PTNF-α0.05、PIL-1β0.01;CD8+组与HBSS组相比,IFN-γ表达降低,P0.05;IL-1β表达有降低的趋势。结论:CD8+CD122+T细胞在脑缺血过程中发挥保护性作用,其保护作用通过CD122抑制星形胶质细胞TNF-α,IL-1β,IFN-γ炎症因子表达实现的。  相似文献   

11.
Memory T cells display phenotypic heterogeneity. Surface antigens previously regarded as exclusive markers of naive T cells, such as L-selectin (CD62L), can also be detected on some memory T cells. Moreover, a fraction of CD45RO+ (positive for the short human isoform of CD45) memory T cells reverts to the CD45RA+ (positive for the long human isoform of CD45) phenotype. We analyzed patients with biopsy-proven localized Wegener's granulomatosis (WG) (n = 5), generalized WG (n = 16) and age- and sex-matched healthy controls (n = 13) to further characterize memory T cells in WG. The cell-surface expression of CD45RO, CD45RA, CD62L, CCR3, CCR5 and CXCR3 was determined on blood-derived T cells by four-color flow cytometric analysis. The fractions of CCR5+ and CCR3+ cells within the CD4+CD45RO+ and CD8+CD45RO+ memory T cell populations were significantly expanded in localized and generalized WG. The mean percentage of Th1-type CCR5 expression was higher in localized WG. Upregulated CCR5 and CCR3 expression could also be detected on a fraction of CD45RA+ T cells. CD62L expression was seen on approximately half of the memory T cell populations expressing chemokine receptors. This study demonstrates for the first time that expression of the inducible inflammatory chemokine receptors CCR5 and CCR3 on CD45RO+ memory T cells, as well as on CD45RA+ T cells ('revertants'), contributes to phenotypic heterogeneity in an autoimmune disease, namely WG. Upregulated CCR5 and CCR3 expression suggests that the cells belong to the effector memory T cell population. CCR5 and CCR3 expression on CD4+ and CD8+ memory T cells indicates a potential to respond to chemotactic gradients and might be important in T cell migration contributing to granuloma formation and vasculitis in WG.  相似文献   

12.
The interleukin-23 (IL-23) pathway plays a critical role in the pathogenesis of multiple chronic inflammatory disorders, however, inter-individual variability in IL-23-induced signal transduction in circulating human lymphocytes has not been well-defined. In this study, we observed marked, reproducible inter-individual differences in IL-23 responsiveness (measured by STAT3 phosphorylation) in peripheral blood CD8+CD45RO+ memory T and CD3+CD56+ NKT cells. Age, but not gender, was a significant (Pearson’s correlation coefficient, r = −0.37, p = 0.001) source of variability observed in CD8+CD45RO+ memory T cells, with IL-23 responsiveness gradually decreasing with increasing age. Relative to cells from individuals demonstrating low responsiveness to IL-23 stimulation, CD8+CD45RO+ memory T cells from individuals demonstrating high responsiveness to IL-23 stimulation showed increased gene expression for IL-23 receptor (IL-23R), RORC (RORγt) and CD161 (KLRB1), whereas RORA (RORα) and STAT3 expression were equivalent. Similar to CD4+ memory T cells, IL-23 responsiveness is confined to the CD161+ subset in CD8+CD45RO+ memory T cells, suggesting a similar CD161+ precursor as has been reported for CD4+ Th17 cells. We observed a very strong positive correlation between IL-23 responsiveness and the fraction of CD161+, CD8+CD45RO+ memory T cells (r = 0.80, p<0.001). Moreover, the fraction of CD161+, CD8+CD45RO+ memory T cells gradually decreases with aging (r = −0.34, p = 0.05). Our data define the inter-individual differences in IL-23 responsiveness in peripheral blood lymphocytes from the general population. Variable expression of CD161, IL-23R and RORC affects IL-23 responsiveness and contributes to the inter-individual susceptibility to IL-23-mediated defenses and inflammatory processes.  相似文献   

13.
Interleukin-21 (IL-21)+CD4+ T cells are involved in the immune response against hepatitis B virus (HBV) by secreting IL-21. However, the role of IL-21+CD4+ T cells in the immune response against chronic hepatitis C (CHC) virus infection is poorly understood. This study aimed to investigate the role of IL-21+CD4+ T cells in CHC patients and the potential mechanisms. The study subjects included nineteen CHC patients who were grouped by viral load (low, < 106 RNA copies/ml, n = 8; high, > 106 RNA copies/ml, n = 11). The peripheral frequency of HCV-specific IL-21+CD4+ T cells was higher in the low viral load group and was negatively correlated with the serum HCV RNA viral load in all CHC patients. Meanwhile, IL-21+ cells accumulated in the liver in the low viral load group. In vitro, IL-21 treatment increased the expression of proliferation markers and cytolytic molecules on HCV-specific CD8+ T cells. In summary, these findings suggest that HCV-specific IL-21+CD4+ T cells might contribute to HCV control by rescuing HCV-specific CD8+ T cells in CHC patients.  相似文献   

14.
The CD45RA and CD45RO isoforms have been reported to define complementary subsets among CD4+ T cells: CD45RA CD4+ T cells are considered "virgin T cells" and CD45RO "primed T cells." We investigated the secretion of lymphokines by human CD4+ CD45RO and CD4+ CD45RA T helper cells after mitogen stimulation. CD45RA and CD45RO CD4+ T cells were isolated by negative immunoselection using magnetic beads. CD45RO cells, but not CD45RA cells, proliferate well in response to pokeweed mitogen (PWM) or insoluble anti-CD3. Both subpopulations produced interleukin (IL)-2, IL-6, and interferon (IFN)-gamma when stimulated with PWM for 1-4 days. Only Day 1 supernatants from CD45RO cells contained moderate amounts of IL-4. After 14 days of continuous culture and stimulation with PWM, the CD45RA subset had lost the expression of CD45RA and gained that of CD45RO. When long-term cultured CD45RA or CD45RO cells were treated with insoluble anti-CD3, they incorporated [3H]thymidine at similar levels, but only CD45RO cells secreted IL-4 and significantly increased their secretion of IFN-gamma. These data indicate that despite phenotype conversion, the two subpopulations maintain functional differences in the secretion of lymphokines, thus suggesting that circulating CD45RA and CD45RO cells may represent different lines of differentiation.  相似文献   

15.
The functional distinction between CD45RA+ and CD45RO+ cells within the human CD4+ T cell subset is well established. This study was undertaken to investigate whether a similar division can be made within the CD8+ T cell population. A quantitative comparison was made of the requirements for activation and differentiation of CD8+CD45RA+ and CD8+CD45RO+ cells. Stimulation of T lymphocytes with anti-CD3 mAb immobilized at high-density induced strong proliferation and CTL activity in both CD45RA+ and CD45RO+ cells. Suboptimal TCR/CD3 triggering, in contrast, induced substantially higher levels of proliferation and CTL activity in CD8+CD45RO+ cells compared with their CD45RA+ counterparts. Lymphokine secretion (i.e., Il-2 and TNF-alpha) was under any condition more readily induced in CD8+CD45RO+ cells. Markedly, proliferation of both CD8+CD45RA+ and CD8+CD45RO+ T cells initiated by anti-CD3 mAb immobilized at high densities was not inhibited by addition of anti-CD25 mAb, in contrast to proliferation induced by suboptimal anti-CD3 mAb concentrations. These findings show that a functional division between CD45RA+ and CD45RO+ T cells with distinct requirements for activation and differentiation may also be made in the CD8+ subset.  相似文献   

16.
目的:探究桥本氏病(HT)合并甲状腺乳头状癌(PTC)患者血清甲状腺相关激素水平的变化及意义。方法:对我院148例HT患者的临床资料进行回顾性分析,根据其是否合并PTC分为HT合并PTC组(n=68)和单纯HT组(n=80)。比较两组患者性别、年龄及血清促甲状腺激素(TSH)、甲状腺功能指标[游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)]、抗甲状腺抗体[甲状腺球蛋白抗体(TGAb)、甲状腺过氧物酶抗体(TPOAb)]水平等临床资料差异,分析血清TSH水平变化及意义。结果:HT合并PTC组患者男性比例、年龄、病程及血清TSH水平均大于单纯HT组,血清TGAb、TPOAb水平则均小于单纯HT组(P0.05);血清FT3、FT4水平比较差异无统计学意义(P0.05)。HT合并PTC患者组血清TSH4.2 m IU/L患者占比高于血清TSH正常组(P0.05)。血清TSH4.2 m IU/L患者中HT合并PTC患者的占比大于血清TSH水平正常的患者(P0.05)。HT合并PTC患者中,血清TSH水平4.2 m IU/L患者中央区淋巴结转移发生率高于血清TSH水平正常患者(P0.05);血清TSH4.2 m IU/L与血清TSH正常患者多灶癌发生率比较差异无统计学意义(P0.05)。结论:HT患者血清TSH水平升高可能促进其甲状腺组织癌变,HT合并PTC患者血清TSH水平升高可能促进其中央区淋巴结转移。  相似文献   

17.
CD45RO+ T cells are referred to as memory or helper-inducer while CD45RA+ T cells are regarded as naive or suppressor-inducer T cells. The former population predominates in the peripheral blood and even more in the synovial fluid of patients with rheumatoid arthritis, to the expense of the latter population. Within the CD45RB+ compartment, there appears to be more of the fully-differentiated than of the early-differentiated CD4+ T cells. In spite of the fact that these lymphocytes are close to undergoing apoptosis, this programmed cell death is inhibited in the rheumatoid synovium.  相似文献   

18.
The role of the accessory molecule ICAM-1 in activation of subpopulations of human T cells was examined using the bacterial superantigen staphylococcal enterotoxin A (SEA) as a MHC class II and TCR-dependent polyclonal T cell activator. Human T cells responded with different sensitivity to SEA when presented on mouse accessory cells expressing a human transfected MHC class II gene product. Mouse L cells cotransfected with both MHC class II (DR2A or DR7) and ICAM-1-stimulated T cells at 100-fold lower concentrations of SEA as compared to the single transfected cells. mAb reacting with the CD11a, CD18, or ICAM-1 molecules efficiently inhibited T cell activation with the cotransfected HLA-DR2A/ICAM-1 cell but did not influence T cell activation with the HLA-DR2A single transfected cell. Analysis of the ICAM-1 requirement on CD4+ memory (CD4+45RO+) and naive (CD4+45RA+) T cells revealed that CD4+45RA+ naive Th cells were hyporesponsive to SEA-induced activation with the HLA-DR2A single transfectant. However, cotransfection of ICAM-1 enabled these cells to respond to low doses of SEA implicating that they are more dependent on accessory molecules than the CD4+45RO+ cells. rICAM-1 immobilized on a plastic surface, was able to strongly costimulate SEA-induced T cell activation with the HLA-DR2A single transfectant, suggesting that costimulatory signals mediated to the T cells through LFA-1 can be delivered physically separated from the TCR signal. CD4+45RO+ memory and CD4+45RA+ naive Th cells apparently differ in their capacities to be activated by SEA bound to HLA-DR. Although the TCR molecule densities are similar in these two subsets, costimulation with ICAM-1 is required for activation of the CD4+45RA+, but not the CD4+45RO+ T cell subset at 1 to 10,000 ng/ml concentrations of SEA. This observation indicates different activation thresholds of naive and memory Th cells when triggering the TCR over a wide dose interval of superantigen.  相似文献   

19.
We have used HSCA-2, an mAb that recognizes a sialic acid-dependent epitope on the low molecular mass (approximately 115-kDa) glycoform of CD43 that is expressed in resting T and NK cells, to examine the expression characteristics and stimulatory functions of CD43 in human CD4+ memory T cells. Having previously reported that the memory cells that respond to recall Ags in a CD4+ CD45RO+ T cell population almost all belong to a subset whose surface CD43 expression levels are elevated, we now find that exposing these same memory T cells to HSCA-2 mAb markedly increases their proliferative responsiveness to recall Ags. We think it unlikely that this increase in responsiveness is a result of CD43-mediated monocyte activation, especially given that the HSCA-2 mAb differs from all previously used CD43 mAbs in having no obvious binding specificity for monocyte CD43. Predictably, treatment with HSCA-2 mAb did not lead to significant recall responses in CD4+ CD45RO+ T cells, whose CD43 expression levels were similar to or lower than those of naive cells. Other experiments indicated that the HSCA-2 mAb was capable of enhancing the proliferative responsiveness of CD4+ memory T cells that had been exposed to polyclonal stimulation by monocyte-bound CD3 mAb and could also act in synergy with CD28 mAb to enhance the responsiveness of CD4+ T cells to CD3 stimulation. Taken together, these findings suggest that the CD43 molecules expressed on CD4+ memory T cells may be capable of enhancing the costimulatory signaling and hence providing accessory functions to TCR-mediated activation processes.  相似文献   

20.
EBV infection in humans induces CD8+ T cell memory to viral epitopes derived from both lytic and latent cycle Ags. We have analyzed the relationship between the phenotype and function of the memory pool of T cells specific for these Ags. Lytic epitope-specific populations were heterogeneous in terms of CD45RO/RA and CD28 expression, whereas latent epitope-specific populations were uniformly CD45RO+ and CD28+, consistent with the higher antigenic challenge from lytic epitopes driving some memory cells toward a CD45RA+, CD28- phenotype. However, both types of memory population showed immediate epitope-specific cytotoxicity and type 1 cytokine production in ex vivo assays. Cytotoxic function was not associated with preactivated T cells, as EBV-specific populations were negative for activation markers such as CD69 or CD38, nor could cytotoxic function be ascribed to CD27- or CD56+ subsets, as such cells were not detected in EBV-specific memory. Furthermore, cytotoxicity was not limited to CD45RA+ and/or CD28- fractions, but also was observed in CD45RO+, CD28+ populations in lytic and latent epitope-specific memory. Cytokine (IFN-gamma, TNF-alpha) responses, measured by intracytoplasmic staining after peptide stimulation, also were detectable in CD45RO+ and RA+ subsets as well as CD28+ and CD28- subsets. Of other markers that were heterogeneous in both lytic and latent epitope populations, CCR7 gave the best discrimination of functionality; thus, CCR7+ cells consistently failed to give an IFN-gamma or TNF-alpha response, whereas many CCR7- cells were responsive. Our data are consistent with effector functions having a broad distribution among phenotypically distinct subsets of "effector memory" cells that have lost the CCR7 marker.  相似文献   

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