CD45RA／CD45RO临床研究进展

目的：探讨CD45RA／CD45RO的研究现状从而有效的指导临床工作。方法：查阅近年来国内外CD45RA／CIM5RO的相关文献,对其最新研究进行总结。结果：作为跨膜酪氨酸磷酸蛋白酶,CIM5RA／CD45RO在哺乳动物淋巴细胞信号传导、增殖和活化中有重要作用,是区分初始和记忆T细胞的重要标志。结论：CD45RA／CD45RO的检测在人类自身免疫疾病和病毒感染性疾病的诊断方面有重要意义。     

慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型的研究

目的 探讨慢性乙型肝炎患者外周血CD8+/CD28+淋巴细胞及其亚型与其临床状态和HBV复制的关系.方法 采用流式细胞技术多色荧光分析法,检测研究对象的外周血CD8+淋巴细胞、CD45RO、CD45RA以及CD28的表达及HBV病毒载量.结果 ①慢性HBV携带组CD8+淋巴细胞CD28的表达率(10.64±5.09%)明显低于慢性乙肝组和正常对照组;而CD45RA和CD45RO的表达差异无统计学意义;②慢性乙肝组CD8+/CD45RO+/CD28+的表达(10.99±7.33%)明显高于正常对照组,而慢性乙肝组和慢性HBV携带组CD8+/CD45RA+/CD28+表达率均明显低于正常对照组;③HBeAg阴性慢性乙肝CD8+/CD45RO+/CD28+表达率明显高于阳性组,而CD8+/CD45RA+/CD28+表达率两组无差别.结论 慢性HBV携带者处于病毒携带状态可能与CD8细胞上协同分子CD28的表达低下有关;CD8+/CD45RO+/CD28+亚型淋巴细胞数的升高与慢性乙肝的病情进展及血清HBeAg转换有关.     

SLE患者CD45RA^＋和CD45RO^＋T细胞亚群的变化

利用流式细胞术及免疫双荧光染色法，检测３５例系统性红斑狼疮（ＳＬＥ）患者外周血ＣＤ４５ＲＡ和ＣＤ４５ＲＯＴ细胞亚群，结果表明：ＳＬＥ患者ＣＤ４细胞降低，ＣＤ８细胞增高，ＣＤ４／ＣＤ８降低，ＣＤ４ＣＤ４５ＲＡ细胞在病情活动期降低，在稳定期回升，ＣＤ４ＣＤ４５ＲＯ细胞在活动期有增高倾向，在稳定期下降，ＣＤ８ＣＤ４５ＲＡ及ＣＤ８ＣＤ４５ＲＯ细胞均在活动期增高，又均在稳定期降至正常水平，提示ＣＤ４５ＲＡ和     

再生障碍性贫血患者CD34+与T淋巴细胞亚群CD45RA+、CD45RO+表达的相关性研究

再生障碍性贫血（Aplastic anemia，从，简称再障）是一种获得性骨髓造血功能衰竭症。近年来研究发现免疫系统紊乱与再障的发生密切相关，某些药物、化学毒物、病毒感染等都是再障的病因，但不管再障的初始病因如何，免疫系统对造血系统的损伤在再障的发病过程中起核心作用。CD45抗原是白细胞分化抗原，在细胞的生长、增殖、功能活化等过程中具有重要的作用。CIM5RA、CIM5RO是CIM5分子的两类亚型，分别代表初始／活化T细胞，有关CD45表达与AA的发病机制的研究尚未见于国内外报道。     

蕈样肉芽肿患者外周血单一核细胞CD45RA及CD45RO表达的研究

目的探讨蕈样肉芽肿（Mycosis fungoides,MF）患者外周血单个核细胞CD45RA及CD45RO的表达及其与MF发病的关系。方法应用双荧光抗体标记、流式细胞仪检测15例MF患者外周血单个核细胞CD45RA及CD45RO的表达。结果（1）MF患者外周血CD3^＋、CD3^＋CD8^＋细胞与正常对照比较差异不显著（P〉0.05）。（2）MF患者外周血CD4^＋细胞低于正常对照,差异非常显著（P〈0.001）。（3）MF患者外周血T细胞CD3^＋CD4^＋/CD3^＋CD8^＋比值低于正常对照,差异显著（P〈0.001）。（4）MF患者外周血CD45RA^＋细胞低于正常对照,差异非常显著（P〈0.001）,CD45RO^＋细胞高于正常对照,差异非常显著（P〈0.001）。（5）MF患者外周血CD45RO^＋/CD45RA^＋比值高于正常对照,差异非常显著（P〈0.001）。（6）MF患者外周血CD4^＋CD45RA^＋细胞低于正常对照,差异非常显著（P〈0.001）。（7）MF患者外周血CD4^＋CD45RO^＋细胞及CD8^＋CD45RO^＋细胞均高于正常对照,差异非常显著（均P〈0.001）。（8）MF患者外周血CD4^＋CD45RO^＋/CD4^＋CD45RA^＋比值及CD8^＋CD45RO^＋/CD8^＋CD45RA^＋比值均高于正常对照,差异非常显著（P〈0.01及P〈0.001）。结论MF患者外周血中,不仅存在CD4^＋亚群失调和CD4^＋/CD8^＋比值降低,而且在CD4^＋和CD8^＋亚群中也存在CD45RA^＋、CD45RO^＋亚群失调和CD45RO^＋/CD45RA^＋比值升高,从而导致的机体免疫功能紊乱,可能与MF的发病或病情加剧有关。     

桥本氏甲状腺炎患者外周血中CD4+ CD45RO+ 记忆性T 细胞的表达及意义

目的:检测初诊桥本氏甲状腺炎(Hashimoto’s thyroiditis,HT)患者外周血CD4+ CD45RO+ 记忆性T 细胞比例,探讨其在HT 发病中的意义。方法:收集初诊的HT 患者作为病例组(HT,n =53),另外选取年龄、性别相匹配的正常人作为对照组(HC,n =43),并根据甲状腺功能状态将HT 组分为甲状腺功能正常组(HT-A,n =15)、亚临床甲减组(HT-B,n =14)和临床甲减组(HT-C,n =24)。流式细胞仪检测外周静脉血中CD4+ CD45RO+记忆性T 细胞比例,酶联免疫吸附法检测血清中IFN 、IL-17 水平,化学发光法检测甲状腺功能及甲状腺特异性抗体滴度。结果:HT 组外周血中CD4+ CD45RO+ 记忆性T 细胞比例、IFN 、IL-17、TPOAb 与TgAb 水平均显著高于HC 组,P<0.01。双变量相关分析显示HT 患者外周血CD4+ CD45RO+记忆性T 细胞的比例与IFN 、TPOAb、TgAb 均呈正相关(P<0.01,P =0.015,P<0.01)。结论:CD4+ CD45RO+ 记忆性T 细胞在HT 患者外周血中呈高表达,CD4+ CD45RO+记忆性T 细胞可能参与了HT 的发病过程。     

慢性乙型肝炎患者外周血CD45RA+、CD45RO+T淋巴细胞亚群的特点及临床意义

目的：探讨慢性乙型肝炎患者外周血CD4^＋CD45RA^＋、CD4^＋CD45RO^＋、CD8^＋CD45RA^＋和CD8^＋CD45RO^＋T淋巴细胞亚群的特点及其与肝病病情的关系。方法：采集46例轻中度慢性乙型肝炎患者、58例重度慢性乙型肝炎患者和30例健康人的外周抗凝血，应用流式细胞技术三色荧光分析法对其外周血中CD4^＋CD45RA^＋、CD4^＋CD45RO^＋、CD8^＋CD45RA^＋和CD8^＋CD45RO＋T淋巴细胞亚群进行检测。结果：轻中、重度慢性乙型肝炎患者与正常人相比，其外周血中CD4^＋、CD8^＋T细胞均无明显改变；CD8^＋CD45RA^＋T细胞均明显降低，CD8^＋CD45RO^＋T细胞均明显增高，而CD4^＋CD45RA^＋、CD4^＋CD45RO^＋T细胞均无明显改变；重度慢性乙型肝炎患者与轻中度慢性乙型肝炎患者相比，CD8^＋CD45RA^＋T细胞明显降低（P〈0.05），CD8^＋CD45RO^＋T细胞明显升高（P〈0.05）。结论：乙型肝炎慢性化过程中，CD8^＋CD45RO^＋T细胞起重要作用且与慢性乙型肝炎患者病情的进展呈正相关；检测CD4^＋CD45RA^＋、CD4^＋CD45RO^＋、CD8^＋CD45RA^＋和CD8^＋CD45RO^＋T淋巴细胞亚群比检测CD4^＋和CD8^＋T细胞亚群更能正确、充分、全面地了解慢性乙型肝炎的发病机制和预后，从而有效地指导临床治疗。     

SARS患者急性期外周血CD3+、CD4+及CD8+细胞数量的变化

目的 探讨SARS患者外周血T淋巴细胞亚群的变化及其临床意义。方法 用全自动血细胞分析仪检测44例SARS患者外周血白细胞计数及分类，用流式细胞仪检测SARS患者外周血T淋巴细胞亚群；并与正常对照组比较。结果 与对照组比较，SARS组患者白细胞总数显著下降，淋巴细胞百分数和绝对数显著下降，粒细胞绝对数显著下降，粒细胞百分数显著增加；CD3^ 、CD4^ 和CD8^ 细胞绝对数显著下降，CD3^ 、CD4^ 及CD8^ 细胞百分数和CD4^ /CD8^ 比值与对照组比较无显著性差异。结论 SARS冠状病毒感染损伤患者细胞免疫功能。     

甲真菌病患者外周血淋巴细胞免疫表型的分析

目的 探讨甲真菌病患者外周血淋巴细胞免疫表型的情况.方法 应用流式细胞仪对24例甲真菌病患者及20例健康人的外周血淋巴细胞亚群和自然杀伤细胞进行测定与分析.结果 甲真菌患者外周血CD8+淋巴细胞明显高于健康对照组(P<0.05),而CD3+细胞,CD4+细胞,CD4+/CD8+、CD19+细胞、CD16+CD 56+细胞与对照组变化不明显.结论 甲真菌患者存在着一定程度的细胞免疫异常,以CD8+细胞介导的免疫反应占主要地位.     

Phenotypic changes associated with activation of CD45RA+ and CD45RO+ T cells.

Resting CD45RO+, mature/memory, T cells are phenotypically distinct from intermediate CD45RO+/CD45RA+ and CD45RA+, immature/virgin, T cells, and are characterized by high levels of expression of a number of adhesion molecules, such as CD2, CD18, CD58 and CD29. The kinetics of up-regulation of molecules, like CD25 and CD54 associated with activation, were similar in both subsets and suggested that their high level expression was associated with later events rather than initial recognition and signal transduction. CD45RA+ T cells, unlike CD45RO+ T cells, were unable to proliferate in response to mitogenic combinations of CD2 monoclonal antibodies (mAb), although in combination with submitogenic doses of PMA both up-regulation of cell-surface molecules and proliferation occurred. In addition, recruitment of CD45RA+ T cells by CD2 mAb-activated CD45RO+ T cells can occur.     

Protein kinase C isoform expression in CD45RA+ and CD45RO+ T lymphocytes.

Differences in levels of specific enzymes utilized in intracellular signalling could be a factor in the distinct signalling properties observed in memory and naive T cells. We have studied the expression of both classical and non-classical protein kinase of C (PKC) isoenzymes in CD45RA and CD45RO cells using a combination of Western blot and flow cytometric analysis. These data indicate that CD45RA cells express higher levels of PKC alpha, PKC beta and PKC delta than CD45RO cells. In addition, CD45RA+ cells show greater proliferative activity when stimulated with phorbol myristate acetate (PMA) and calcium ionophore than their CD45RO+ counterparts. Variations in the levels of these isoenzymes could be implicated in functional differences, such as proliferation and cytokine production, in these cell subsets.     

CD4+ CD45RA+ and CD4+ CD45RO+ T cells differ in their TCR-associated signaling responses.

Peripheral CD4+ T cells can be divided into two different functional populations based on the expression of distinct isoforms of the surface molecule CD45. We have investigated the differences in the proximal signaling induced by anti-CD3 monoclonal antibody in purified populations of "naive" CD45RA+ and "memory" CD45RO+ human CD4+ T cells. Expression of cell surface CD3, CD4 and CD28 was comparable between RA+ and RO+ cells. However, TCR-directed stimulation in the form of anti-CD3 produced markedly different patterns of intracellular signaling. Greater inositol triphosphate generation occurred in naive cells and the rise in intracellular free calcium was also substantially greater in naive than in memory cells. Cells with the naive phenotype were considerably more active in TCR-dependent tyrosine phosphorylation, both at an overall level and specifically in terms of TCR-zeta and ZAP-70 phosphorylation. Despite these differences in phosphorylation, the amounts of TCR-zeta, ZAP-70 and Ick were equivalent between the two subsets. These findings suggest that the TCR-dependent signaling is differentially regulated in naive and memory CD4+ T cells. This may be due to differences in the way that the two isoforms of the CD45 phosphatase regulate the activity of proximal kinases in the TCR signaling pathway, and could be an important means by which the unique functions of differentiated T cell populations are maintained.     

Oligoclonal Expansion of CD45RO+ T Lymphocytes in Omenn Syndrome

Omenn syndrome comprises a rare form of combined immunodeficiency with T_H2-type features of eosinophilia and elevated IgE. Previous studies have led to reports of restricted heterogeneity in the T lymphocyte repertoire, and in vitro cloned T lymphocytes have been shown to produce IL-4 and IL-5. We hypothesized that (1) T cell receptor V(D)J DNA sequence analysis would confirm and further define the putative restricted heterogeneity, and (2) increased production of IL-4 and IL-5 should be found in nonstimulated T lymphocytes, if the molecular pathogenesis of Omenn syndrome is an uncontrolled T_H2 state. We report the results of molecular analyses of T lymphocytes from an untreated 3-month-old patient. Oligoclonal T cell receptor variable gene usage was found. Sequence analysis revealed sets of identical V(D)J sequences, each in-frame, with apparently normal N-diversification and no obvious antigen combining site motif. From fresh, nonstimulated lymphocytes, proinflammatory T_H1 cytokines could be detected, but T_H2 cytokines could not, so that a simple T_H1/T_H2 paradigm cannot explain the eosinophilia and elevated IgE in Omenn syndrome. Our studies fully document for the first time at the molecular level that clonally expanded populations of T lymphocytes are present in Omenn syndrome.     

CD45 isoform phenotypes of human T cells: CD4(+)CD45RA(-)RO(+) memory T cells re-acquire CD45RA without losing CD45RO

We have studied the alterations in CD45R phenotypes of CD4(+)CD45RA(-)RO(+) T cells in recipients of T cell-depleted bone marrow grafts. These patients are convenient models because early after transplantation, their T cell compartment is repopulated through expansion of mature T cells and contains only cells with a memory phenotype. In addition, re-expression of CD45RA by former CD4(+)CD45RA(-) T cells can be accurately monitored in the pool of recipient T cells that, in the absence of recipient stem cells, can not be replenished with CD45RA(+) T cells through the thymic pathway. We found that CD4(+)CD45RA(-)RO(+) recipient T cells could re-express CD45RA but never reverted to a genuine CD4(+)CD45RA(+)RO(-) naive phenotype. Even 5 years after transplantation, they still co-expressed CD45RO. In addition, the level of CD45RA and CD45RC expression was lower ( approximately 35 %) than that of naive cells. In contrast, the level of CD45RB expression was comparable to that of naive cells. We conclude that CD4(+)CD45RA(-)RO(+) T cells may re-express CD45(high) isoforms but remain distinguishable from naive cells by their lower expression of CD45RA / RC and co-expression of CD45RO. Therefore, it is likely that the long-lived memory T cell will be found in the population expressing both low and high molecular CD45 isoforms.     

Selective deficiency of CD4+/CD45RA+ lymphocytes in patients with ataxia-telangiectasia

Several immunological abnormalities have been observed in ataxia-telangiectasia (AT), the most consistent being defects of immunoglobulin isotypes, decreased T-cell numbers, and reduced proliferative responses to mitogens. We examined the distribution of T lymphocytes expressing distinctive surface Ag characteristic of naive (CD45RA+) and memory (CD29+, CD45RO+) T cells, in both CD4+ and CD8+ (bright and dim) lymphocytes from 13 AT patients, compared with healthy agematched controls. We found that, irrespective of age, patients with AT had a severe deficiency of CD4+/CD45RA+ lymphocytes. This decrease accounted for the reduction of total CD4+ cells, since the absolute numbers ofmemory CD4+ cells were not significantly different in AT and in controls. Functional tests revealed poor proliferative responses to phytohemagglutinin and normal responses to soluble Ag (tetanus toxoid) in AT patients. These data fit with the distribution ofnaive andmemory cells, which are known to respond predominantly to mitogens or to recall Ag, respectively. CD45RA molecules were normally expressed on CD8+ lymphocytes. This rules out a generalized defect of regulation or differential splicing as the cause of defective expression of CD45RA on CD4+ cells. The selective deficiency of CD4+CD45RA+ may provide a cellular basis for some functional T-cell abnormalities of AT patients. Furthermore, it might practically serve for an early, or even prenatal, diagnosis of this disease.     

Comparison of lymphokine secretion and mRNA expression in the CD45RA+ and CD45RO+ subsets of human peripheral blood CD4+ and CD8+ lymphocytes

Flow cytometric analysis of human peripheral blood T lymphocytes demonstrated that the majority of the CD4⁺ cells were CD29⁺ or CD45RO⁺ “mature” cells while the CD8⁺ cells were primarily CD45RA⁺ “naive” cells. After an initial separation into CD4⁺ and CD8⁺ cells and a secondary separation into CD45 subsets, lymphokine secretion was assessed after phorbol 12-myristate 13-acetate and ionomycin or fixed anti-CD3 stimulation. Within the respective CD45 subsets, CD4⁺ cells produced more interleukin (IL)-2, IL-4, and IL-6; but the CD8⁺ cells secreted more interferon-γ and granulocyte/macrophage-colony-stimulating factor. Tumor necrosis factor-α secretion was similar in the matched CD45 subsets. Northern analysis revealed a parallel pattern of lymphokine mRNA expression in the four lymphocyte subsets. These results suggest that human CD8⁺ peripheral blood lymphocytes have a significant capacity to secrete lymphokines, and that the low lymphokine production observed in unseparated CD8⁺ cells reflects the higher percentage of less functional CD45RA⁺ cells.     

Distribution of CD45RA and CD45RO T-lymphocyte subsets in rheumatoid arthritis synovial tissue

We have characterized the lymphocytes in the synovium of patients with rheumatoid arthritis (RA) by immunohistochemistry using monoclonal antibodies directed against B lymphocytes, T lymphocytes, and antibodies directed against CD45RA and CD45RO, which define T-cell subsets. Both CD45RA+ and CD45RO+ T lymphocytes were detected in the perivascular regions. CD45RA+ lymphocytes were present primarily in perivascular areas of moderate to large lymphocytic infiltration. Some synovial perivascular lymphocytic aggregates were organized into focal areas of CD45RA+ B lymphocytes surrounded by CD45RO+ T lymphocytes. In areas of diffuse lymphocytic infiltration, the T lymphocytes were CD45RO+. These data suggest that both CD45RO+ and CD45RA+ T lymphocytes enter the RA synovial tissue via the synovial vasculature and that, once in the tissue, the CD45RA+ T lymphocytes may undergo activation/maturation and acquire the CD45RO phenotype.