2例异体手移植术后受者T细胞亚群与CD3~+HLA-DR~+细胞水平的动态观察

目的　研究异体复合组织移植 手移植术后病人外周血T淋巴细胞亚群及CD3+ HLA DR +T细水平的动态变化。方法　用流式细胞术测定了 2例异体手移植术后不同时间外周血CD3+ 、CD3+ CD4+ 、CD3+ CD8+ 、CD3+ HLA DR+ (活化T细胞 )细胞百分率 ,及CD4/CD8比值 ,以病人术前一周结果作对照。结果　使用免疫抑制剂后 ,于术后第 1日CD3+ 、CD3+ CD4+ 、CD3+CD8+ 、CD3+ HLA DR+ 细胞水平 ,CD4/CD8比值都开始降低 ,以 3～ 5日为最低水平。术后 8日 ,上述指标逐渐回升 ,至 15日后基本趋于平稳 ,但CD3+ 、CD3+ CD4+ 细胞及CD4/CD8比值仍明显低于术前 ,而CD3+ CD8+ 、CD3+ HLA DR+ 细胞水平则高于术前。结论　异体复合组织 手移植术后病人外周血T淋巴细胞亚群及CD3+ HLA DR+ 细胞水平的变化与单一组织器官移植 (肾移植 )术后稳定期的变化一致 ,也与病人术后的稳定病情相吻合。     

CD4^＋CD25^＋调节性T细胞与肿瘤免疫治疗

CD4^＋CD25^＋调节性T细胞（Tregs）于1995年由Sakaguehi等首次报道，将去除了CD25^＋细胞的CD4^＋单阳细胞过继转移给裸鼠，则裸鼠发生多种自身免疫疾病；而将CD4^＋CD25^＋T细胞CD4^＋T细胞共同转移，则不发生自身免疫疾病。此研究揭示CD4^＋CD25^＋T细胞具有维持自身免疫耐受的功能。肿瘤的形成和进展与机体的免疫功能密切相关，CD4^＋CD25^＋T细胞在肿瘤免疫逃逸中起重要作用。本文就调节性T细胞在肿瘤免疫调节中的研究进展进行综述。     

CD4^＋T细胞及其亚群与多发性硬化

目的：总结近年来国内外有关多发性硬化的免疫学研究进展，分析CD4＋T淋巴细胞，Th1／Th2，CD4^＋CD25^＋T淋巴细肌与多发性硬化之间的关系。 资料来源：应用计算机检索Medline1992-12／2004-12与CD4^＋T淋巴细胞，Th1／Th2，CD4^＋CD25^＋T淋巴细胞和多发性硬化相关文章，检索词“CD4^＋T cell，Th1／Th2 cell，CD4^＋CD25^＋T Lymphocytes，Muhiple sclerosis”．并限定文章语言种类为“English”。 资料选择：就检索到的120余篇文献进行筛选，选择以CD4^＋T cell．Th1／Th2，CD4^＋CD25^＋T淋巴细胞为主要研究内容的文献27篇，无论研究对象为动物还是患者全部纳入，其中研究内容相似的，以近3年且发表在较权威杂志者优先。资料提炼：将筛选到的27篇文献按CD4^＋T淋巴细胞，Th1／Th2，CD4^＋CD25^＋T淋巴细胞与多发性硬化的关系进行分类：其中6篇与CD4^＋T淋巴细胞，3篇与Th1／Th2相关，18篇与CD4^＋CD25^＋T淋巴细胞有关。 资料综合：6篇文献，说明了CD4^＋T淋巴细胞在多发性硬化的发病过程中居于中心环节，3篇文献提示Th1/Th2细胞的失衡与多发性硬化的疾病进程有关，18篇文献提到CD4^＋CD25^＋T淋巴细胞的基础研究及其与多发性硬化的关系。 结论：病灶部位CD4^＋T淋巴细胞的增加，Th1／Th2细胞的失衡会导致多发性硬化发病。而CD4^＋CD25^＋T淋巴细胞功能的减弱与多发性硬化的发病有关，但数量是否有关还需要进一步研究。     

肺癌患者手术前后外周血CD3^＋和CD4^＋与CD16^＋及CD4^＋／CD8^＋T细胞的表达及临床意义

目的 研究肺癌患手术前后，外周血中CD3^ 、CD4^ 、CD16^ 等T淋巴细胞亚群的定量变化，并探讨其临床意义。方法 取肺癌术前及术后第10天外周血，用流式细胞仪检测CD3^ 、CD4^ 、CD16^ 等T细胞，进行定量分析，并与对照组比较。结果 肺癌患手术前CD3^ 、CD4^ 、CD16^ 等均低于对照组（P＜0．01）。肺癌未转移（淋巴结阴性）手术后CD3^ 等T细胞明显高于术前（P＜0．05）。但肺癌已转移（淋巴结阳性），手术后CD3^ 等T细胞继续下降，与术前无差异（P＞0．05）。结论 监测CD3^ 、CD4^ 、CD16^ 等淋巴细胞亚群，对肺癌患免疫功能的评价及判断预后有重要意义。     

应用SCF＋IL—2等细胞因子从脐血CD34^＋细胞扩增T细胞

肿瘤和艾滋病（ＡＩＤＳ）的基因治疗或免疫治疗的研究需要大量的Ｔ细胞克隆。尽管Ｔ细胞来源于ＣＤ３４＾＋细胞,但由于需要胸腺组织的参与,使其在体外扩增大量细胞克隆非常困难。本研究用脐血单个核细胞作为辅助细胞,在ＳＣＦ＋ＩＬ－２等细胞因了的作用下,人脐血ＣＤ３４＾＋在此培养条件下,不断产生ＣＤ４＾＋或ＣＤ８＾＋Ｔ细胞至少持续３周。在培养扩增过程中,发现ＣＤ４＾＋和ＣＤ８＾＋Ｔ细胞的比例有一个不断变化的动     

轮状病毒肠炎患儿外周血中CD3＋CD4＋CD8＋T淋巴细胞亚群的研究

轮状病毒（RV）是秋冬季婴幼儿腹泻最常见的病原菌，轮状病毒肠炎临床症状以呕吐、腹泻、发热为主。有报道认为其发病可能与细胞免疫功能有关，但国内的相关报道不多。为了了解T细胞亚群在轮状病毒肠炎发病时的作用，现对轮状病毒肠炎患儿以及健康儿童外周血中CD3、CD4、CD8和CD4／CD8值进行比较，初步探讨如下。     

卡介苗免疫大鼠的抗结核发病和CD4^＋CD8^＋双阳T细胞

目的：探讨卡介苗（BCG）对大鼠结核感染及CD4^＋CD8^＋双阳（DP）T细胞的影响。方法：60只PPD皮试阴性SD大鼠随机分成（1）卡介苗免疫（BCG）组、（2）BCG免疫后结核分枝杆菌（Mtb）攻击（BCG-TB）组、（3）Mtb攻击后不化疗（TB）组。BCG组、BCG-TB组于观察开始接种BCG。BCG-TB组、TB组于3个月末接受Mtb攻击。比较全部大鼠接种Mtb后的死亡率；实验开始和其后3、4、5、6、8个月末检测外周血中T细胞亚群。结果：BCG组、BCG-TB组无死亡；TB组感染后5个月内死亡率45％（9／20）。TB组死亡率高于BCG组和BCG-TB组，P〈O．01。实验开始时3个组组间对应参数比较差异均无显著性（P〉0．05）；3个月末BCG组、BCG-TB组之间各对应参数比较差异均无显著性（P〉O．05）；BCG组和BCG-TB组第3个月末与接种前比较，CD8^＋、DP升高，且显著高于TB组（Mtb干预之前），P〈0．01或P〈0．05。BCG组DP细胞于接种BCG后第6个月后开始回落，但仍显著高于接种前；BCG-TB组于Mtb攻击1个月后CD8^＋、DP继续升高，观察的第8个月CD8^＋、DP回落，但仍显著高于BCG接种前；TB组Mtb攻击后1个月末CD8^＋、DP有升高但低于BCG组和BCG-TB组，同时伴有CD3^＋、CD4^＋降低，差异均有显著性，P〈0．05或P〈0．01，此后维持在相近水平。Mtb攻击2个月末BCG-TB组DP高于BCG组和TB组，P〈0．05或P〈0．01。Mtb攻击5个月后3个组间DP差异无显著性（P〉0．05）。结论：BCG预防接种可保护Mtb感染宿主免于发病和死亡，增强抗结核保护性细胞免疫力表现之一为DP细胞升高，DP细胞是抗结核保护性免疫相关T细胞。DP细胞的形成与CD4^＋SP细胞上CD8^＋抗原表达有关。     

FOXP3^＋CD4^＋CD25^＋Tregs细胞介导机体的肿瘤免疫逃逸研究进展

肿瘤的发生是通过多种途径引起机体免疫系统调节紊乱导致的,因此抗自身抗原的免疫反应保护机理可以使肿瘤细胞免于被自身免疫系统识别.而FOXP3作为CD4^＋CD25^＋调节T细胞（regulatory T cells,Tregs）表面的特征性标志,可以通过下调免疫活化细胞因子的表达和上调Tregs相关的细胞表面分子的表达赋予CD4^＋CD256＋Tregs细胞免疫抑制功能,并有效抑制机体抗肿瘤免疫反应,参与肿瘤免疫逃逸.     

肺移植术后受者T细胞亚群和IL-6水平的动态变化1例并文献分析

目的：探讨肺移植术后患者T细胞亚群和白介素-6（IL-6）水平的动态变化。方法：用流式细胞仪测定1例异体肺移植患者不同时间外周血T细胞亚群细胞的百分率和CD4／CD8比值，以及用酶标ELISA法测定其不同时间外周血IL-6水平，术后监测T细胞亚群至50d，IL-6至96d，以患者术前结果作对照。结果：排异反应前CD3、CD4、CD8、NK、IL-6随着免疫抑制药应用逐渐降低，以2～4d为最低，CD4／CD8比值虽有降低，但有波动，术后第6d发生排异反应，CD3、CD4、CD8、NK迅速升高，IL-6迟于发生排异反应2d后出现高峰，予以甲强龙冲击治疗，CD3、CD4、CD8、NK并未降低到发生排异前水平，CD3、CD8、NK维持在稍低于正常的水平，CD4接近正常，CD4／CD8比值大多高于术前，IL-6也有所下降，但2个月后发生肺部霉菌等感染，IL-6也出现一个高峰。结论：外周血CD3、CD4、CD8、NK、CIN／CD8的检测，对于肺移植患者早期急性排异反应的预测有一定价值，在发生排异反应经甲强龙冲击治疗后其水平的变化与患者稳定的病情相一致，而IL-6的变化特异性不高。     

Murine CD4+ T cell subsets defined

We have used two monoclonal anti-murine T cell autoantibodies (SM3G11 and SM6C10) and multi-color immunofluorescence staining to resolve splenic CD4+ cells into four populations. Two of these populations (Fr. I and Fr. III, 35% and 10% of CD4+ cells) show mutually exclusive expression of these determinants and exhibit distinct functions. Fr. III secretes IL-4, but not IL-2 when activated by Con A, and includes memory T cells responsible for secondary antibody formation. In contrast, Fr. I secretes IL-2 but not IL-4 in response to Con A, and does not contribute to the secondary antibody response. Furthermore, these two fractions exhibit differential accessory cell dependence. Whereas Fr. III responds with B cells (and also non-B cells) as accessory cells in Con A-induced activation, Fr. I requires non-B cells. However, we found that many CD4+ cells (Fr. II, 40% of CD4+ cells) express both determinants and are not distinguishable with regard to lymphokine secretion, accessory cell effect, and memory T cell activity. Curiously, the fraction expressing neither determinant (Fr. IV, 10% of CD4+ cells) is unresponsive to experimental conditions used here. We discuss the possible relationships between these T cell subsets and the implications of differential expression of these determinants.     

Clonal analysis of functionally distinct human CD4+ T cell subsets

A large number of CD4+ T cell clones, obtained from peripheral blood T lymphocytes by direct limiting dilution, allowed us to address the question whether functional heterogeneity exists within the human CD4+ T cell subset. Cytotoxic capacity of cloned T cells was analyzed with the use of anti-CD3 antibodies and target cells bearing FcR for murine IgG. 6 of 12 CD4+ clones obtained were able to lyse Daudi or P815 cells in the presence of anti-CD3 antibodies. The remaining six CD4+ T cell clones tested did not display anti-CD3-mediated cytotoxic activity and did not acquire this cytotoxic capacity during a culture period of 20 wk. In the absence of anti-CD3 mAb, no lytic activity against Daudi, P815, and K562 target cells was observed under normal culture conditions. Phenotypic analysis of these two distinct types of CD4+ T cells did not reveal differences with regard to reactivity with CDw29 (4B4) and CD45R (2H4) mAbs that have been described to recognize antigens associated with helper suppressor/inducer (respectively) CD4+ cells. The CD4+ clones without anti-CD3-mediated cytotoxic activities (Th2) consistently showed a high expression level of CD28 antigens, whereas the cytotoxic clones (Th1) expressed low amounts of CD28. Th1 CD4+ clones did produce IL-2, IFN-gamma, and TNF-alpha/beta, whereas the Th2 T cell clones produced minimal amounts of IL-2 and only low levels of INF-gamma and TNF-alpha/beta in response to anti-CD3 mAbs and PMA. Although not all CD4+ clones did release IL-4, there was no correlation with cytotoxic activity. Moreover, as compared with the Th1 CD4+ clones, Th2 CD4+ T cell clones proliferated moderately in response to immobilized anti-CD3 mAbs. However, proliferation reached the level of the cytotoxic clones when anti-CD28 mABs were present during culture. Both CD4+ subsets provided help for B cell differentiation upon stimulation with anti-CD3 mAbs. Our data suggest that the human CD4+ subset, in analogy to the murine system, comprises two functionally distinct T cell subpopulations, both of which are able to exert helper activity for polyclonal B cell differentiation, but which differ in cytotoxic capacity, lymphokine production, and requirements for proliferation. A function for these two types of T cells in the immune response is discussed.     

Dynamic repositioning of CD4 and CD8 genes during T cell development

Although stable repression of CD4 and CD8 genes is a central feature of T cell lineage commitment, we lack detailed information about the timing and mechanism of this repression. Stable gene repression has been linked to the position of genes within the nucleus. Therefore, information about the nuclear position of CD4 and CD8 genes during T cell development could provide insights into both the mechanism of regulation of CD4 and CD8 genes, and the process of lineage commitment. Here, we report that lineage-specific repression of CD4 and CD8 genes is associated with the repositioning of alleles close to heterochromatin. We also provide evidence that the relocalization of CD4 and CD8 genes to heterochromatin can occur as an early response to positive selection signals. We discuss our results in terms of our current knowledge of CD4 and CD8 gene regulation and CD4 versus CD8 lineage commitment.     

Metabolic programming and PDHK1 control CD4+ T cell subsets and inflammation

Activation of CD4⁺ T cells results in rapid proliferation and differentiation into effector and regulatory subsets. CD4⁺ effector T cell (Teff) (Th1 and Th17) and Treg subsets are metabolically distinct, yet the specific metabolic differences that modify T cell populations are uncertain. Here, we evaluated CD4⁺ T cell populations in murine models and determined that inflammatory Teffs maintain high expression of glycolytic genes and rely on high glycolytic rates, while Tregs are oxidative and require mitochondrial electron transport to proliferate, differentiate, and survive. Metabolic profiling revealed that pyruvate dehydrogenase (PDH) is a key bifurcation point between T cell glycolytic and oxidative metabolism. PDH function is inhibited by PDH kinases (PDHKs). PDHK1 was expressed in Th17 cells, but not Th1 cells, and at low levels in Tregs, and inhibition or knockdown of PDHK1 selectively suppressed Th17 cells and increased Tregs. This alteration in the CD4⁺ T cell populations was mediated in part through ROS, as N-acetyl cysteine (NAC) treatment restored Th17 cell generation. Moreover, inhibition of PDHK1 modulated immunity and protected animals against experimental autoimmune encephalomyelitis, decreasing Th17 cells and increasing Tregs. Together, these data show that CD4⁺ subsets utilize and require distinct metabolic programs that can be targeted to control specific T cell populations in autoimmune and inflammatory diseases.     

Altered representation of naive and memory CD8 T cell subsets in HIV-infected children.

CD8 T cells are divided into naive and memory subsets according to both function and phenotype. In HIV-negative children, the naive subset is present at high frequencies, whereas memory cells are virtually absent. Previous studies have shown that the overall number of CD8 T cells does not decrease in HIV-infected children. In studies here, we use multiparameter flow cytometry to distinguish naive from memory CD8 T cells based on expression of CD11a, CD45RA, and CD62L. With this methodology, we show that within the CD8 T cell population, the naive subset decreases markedly (HIV+ vs. HIV-, 190 vs. 370 cells/microliter; P < or = 0.003), and that there is a reciprocal increase in memory cells, such that the total CD8 T cell counts remained unchanged (800 vs. 860 cells/microliter; P < or = 0.76). In addition, we show that for HIV-infected children, the naive CD8 T cell and total CD4 T cell counts correlate (chi 2 P < or = 0.001). This correlated loss suggests that the loss of naive CD8 T cells in HIV infection may contribute to the defects in cell-mediated immunity which become progressively worse as the HIV disease progresses and CD4 counts decrease.     

Functional and genomic profiling of effector CD8 T cell subsets with distinct memory fates

An important question in memory development is understanding the differences between effector CD8 T cells that die versus effector cells that survive and give rise to memory cells. In this study, we provide a comprehensive phenotypic, functional, and genomic profiling of terminal effectors and memory precursors. Using killer cell lectin-like receptor G1 as a marker to distinguish these effector subsets, we found that despite their diverse cell fates, both subsets possessed remarkably similar gene expression profiles and functioned as equally potent killer cells. However, only the memory precursors were capable of making interleukin (IL) 2, thus defining a novel effector cell that was cytotoxic, expressed granzyme B, and produced inflammatory cytokines in addition to IL-2. This effector population then differentiated into long-lived protective memory T cells capable of self-renewal and rapid recall responses. Experiments to understand the signals that regulate the generation of terminal effectors versus memory precursors showed that cells that continued to receive antigenic stimulation during the later stages of infection were more likely to become terminal effectors. Importantly, curtailing antigenic stimulation toward the tail end of the acute infection enhanced the generation of memory cells. These studies support the decreasing potential model of memory differentiation and show that the duration of antigenic stimulation is a critical regulator of memory formation.     

T suppressor cell growth factor and anti-CD3 antibodies stimulate reciprocal subsets of T lymphocytes

Because of the central role of IL-2 in clonal expansion of T cells, we have postulated that lymphocyte subpopulations with opposing regulatory functions might be independently regulated by differential requirements for expression of cell-surface IL-2-R. Purified CD4+ and CD8+ cells proliferated in an IL-2-dependent manner to crosslinked anti-T cell receptor antibodies (anti-CD3-Seph). Similarly, both CD4+ and CD8+ cells became IL-2 responsive after incubation in T suppressor cell growth factor (TsGF), a newly described approximately 8,000 Mr product of activated CD4+ cells. In support of our hypothesis, however, we observed that subpopulations of CD4+ and CD8+ cells, possessing distinct cell-surface antigens, showed differential responses to these stimuli. Those cells of suppressor-inducer or suppressor-effector phenotype failed to proliferate when cultured in anti-CD3-Seph plus IL-2, but did proliferate in an IL-2-dependent manner to TsGF. Furthermore, the suppressor-effector population was unresponsive to TsGF plus IL-2 when cocultured in anti-CD3-Seph, suggesting that functionally induced Ts may be refractory to growth stimuli. Conversely, cells with helper-inducer or cytolytic phenotype proliferated when incubated in anti-CD3-Seph and IL-2, while remaining essentially unresponsive to TsGF and IL-2. The results could not be explained by differences in the level of CD3 expression by the T cell subsets. Thus, cells within the helper and suppressor lineages appear to have distinct and reciprocal patterns for the induction of IL-2 responsiveness.     

肺结核病人CD4+ 记忆T细胞亚群的检测分析

目的 研究肺结核病人外周血总的CD4+ 记忆T细胞及抗原特异性记忆T细胞的产生及分布规律,了解记忆T细胞在结核发病中的作用。 方法 以荧光标记的抗CD4、CCR7、CD45RA三种抗体共染色,用流式细胞仪检测肺结核病人外周血总的CD4+ 记忆T细胞;以荧光标记的抗CD4、CD154、CCR7、CD45RA四种抗体共染色,检测结核抗原特异性CD4+ 记忆T细胞。通过对比分析,了解记忆T细胞分布特征。 结果 肺结核病人外周血总的CD4+ T细胞中初始T细胞、中央型记忆T细胞和效应型记忆T细胞的比例分别为59.18%±16.11%、15.4%±6.48%和16.3%±9.97%;而在抗原特异性CD4+T细胞中初始T细胞、中央型记忆T细胞和效应型记忆T细胞的比例分别为32.67%±13.94%、56.96%±12.7%和8.76%±5.62%。通过统计学比较后发现,总的CD4+ T细胞和抗原特异性CD4+ T细胞这两组之间初始细胞、中央记忆细胞和效应记忆细胞的分布均有显著性差异。 结论 肺结核病人外周血总的CD4+ T细胞中以初始细胞为主,而抗原特异性CD4+ T细胞中则以中央记忆细胞为主,说明结核病患者可以产生抗原特异性记忆T细胞,参与长效免疫,可能在防止再感染或者降低再感染的严重程度方面起了重要的作用。