ETIB Clinical Trials

我们对成人免疫重建的研究表明，幼稚T细胞和TCR库的严重缺陷在胸腺生成更新有限的老年患者中发展并持续存在。为了开发IL-7作为一种潜在的治疗剂，以提高这些患者的初发人群，我们开始了第一个I期研究重组人IL-7（rhIL-7）的管理在人类。我们证明，rhIL-7隔日治疗两周可使循环中的CD 4+和CD 8 + T细胞数量呈剂量依赖性显著增加，并在治疗后6至12周的随访试验中持续存在。14，15此外，rhIL-7治疗不成比例地增加了CCR 7 + CD 27 + CD 45 RA+幼稚和CCR 7 + CD 27 + CD 45 RA-中枢记忆细胞，其代表成熟TCR库的最多样化的组分，以CCR 7-CD 27-CD 45 RA +/-效应物群体为代价。幼稚细胞在总CD 8+群体中的比例增加了多达39%。我们进一步证明，IL-7产生了一个长期的细胞扩增（Ki 67+）和抗凋亡因子（Bcl-2）在幼稚和记忆T细胞的升高，但不是在效应T细胞。这种差异的部分基础是效应T细胞，特别是CD 8效应细胞中IL-7 R（CD 127）的表达相对较低。类似地，具有低IL-7 R表达的Treg细胞在IL-7治疗开始后没有显示出相同的周期中细胞百分比的急剧增加，并且作为总CD 4群体的百分比下降。由于这种群体转移的程度，我们假设IL-7将导致CD 4+和CD 8 + T细胞中TCR多样性的总体增加。我们在6名受试者中，在rhIL-7治疗后0天和1周（第21天）对分选的CD 4和CD 8群体使用谱型分析评估TCR多样性。这些受试者中有三名年龄超过60岁，第四名患者在最近的化疗后严重缺乏T细胞。对于每一个病人，我们比较了治疗前和治疗后的光谱型偏离高斯样正常供体标准。通过Wilcoxon配对非参数分析比较了光谱分析前后的总体多样性（22个BV家族中每个家族与正常供体标准的差异）。我们确定，与基线相比，IL-7治疗后，6例受试者中有4例的CD 4+、CD 8+或两种T细胞群的库多样性出现统计学显著性增加（P 0.05）。这种原始和中央记忆T细胞的扩增以及效应细胞的不成比例损失在CD 8群体中特别明显，其中5/6的患者具有显著的转变或向增加的库多样性的强烈趋势。考虑到治疗持续时间短，一些患者年龄大，以及我们观察到的即使是最原始的T细胞（分选的CD 31 + CD 45 RA + CD 4细胞）中PCR评估的TREC频率下降，这种多样性的增强主要是由于差异性群体扩增，而不是IL-7诱导的胸腺输出。因此，我们已经表明，rhIL-7有可能诱导胸腺非依赖性T细胞生长的幼稚和CM人口和提高外周T细胞群的库多样性。一项新的临床试验正在研究这种修复是否具有功能重要性，该试验目前正在招募患者。我们还启动了一项新的临床试验，以治疗慢性移植物抗宿主病的肺部并发症，即闭塞性细支气管炎。初步结果令人鼓舞，研究仍在进行中。一项新的试验也开始用清髓性疗法治疗白血病，并评估通过调节胸腺功能来改善免疫重建。在一项涉及无关供体异基因外周血干细胞移植的试验中，我们开发了一个广泛的、临床注释的免疫重建相关实验室值数据库。该数据集表明，类固醇治疗对T细胞数量几乎没有直接影响，并证实了我们关于与CMV感染相关的CD 8 + T细胞扩增的数据。类固醇对T细胞亚群分布的定性影响正在研究中。

Our studies of adult immune reconstitution have demonstrated that severe deficits in naive T cells and TCR repertoire develop and persist in older patients with limited renewal of thymopoiesis. In order to develop IL-7 as a potential therapeutic agent to enhance nave populations in these patients, we initiated the first phase I study of recombinant human IL-7 (rhIL-7) administration in humans. We demonstrated that two weeks of alternate day treatment with rhIL-7 produced a marked dose-dependent increase in the numbers of circulating CD4+ and CD8+ T cells that persisted in follow-up assays at 6 to 12 weeks post treatment.14,15 Furthermore, rhIL-7 therapy disproportionately increased CCR7+CD27+CD45RA+ naive and CCR7+CD27+CD45RA- central memory cells, which represent the most diverse components of the mature TCR pool, at the expense of the CCR7-CD27-CD45RA+/- effector populations. The proportion of naive cells in the total CD8+ population increased by as much as 39%. We further documented that IL-7 produced a prolonged period of cellular expansion (Ki67+ ) and elevation of anti-apoptotic factors (Bcl-2) in naive and memory T cells, but not in effector T cells. Part of the basis for this disparity is the relatively low expression of the IL-7R(CD127) in effector T cells, particularly CD8 effectors. Similarly Treg cells, which have low expression of IL-7R, did not show the same sharp increase in the percentage of cells in cycle following initiation of IL-7 therapy and declined as a percentage of the total CD4 population. Because of the extent of this population shift, we hypothesized that IL-7 would lead to an overall increase in TCR diversity in CD4+ and CD8+ T-cells. We assessed TCR diversity using spectratype analysis on sorted CD4 and CD8 populations at day 0 and one week after rhIL-7 therapy (day 21) in six subjects. Three of these subjects were over 60 years of age, and a fourth patient was severely T cell deficient following recent chemotherapy. For each patient, we compared pre- and post-therapy spectratype divergence from a Gaussian-like normal donor standard. The global diversity (divergence from a normal donor standard in each of 22 BV families) of pre and post spectratypes was compared by Wilcoxon paired non-parametric analysis. We determined that 4 of the 6 subjects had a statistically significant increase (P < .05) in repertoire diversity following IL-7 treatment, as compared to baseline, in either the CD4+, CD8+, or both T-cell populations. This expansion of nave and central memory T cells and the disproportional loss in effector cells was particularly evident in CD8 populations in which 5/6 patients had either a significant shift or a strong trend toward increased repertoire diversity. Given the short duration of therapy, the advanced ages of some patients, and the PCR-assessed decline in the frequency of TREC in even the most nave T cells (sorted CD31+CD45RA+ CD4 cells) that we observed, this enhancement in diversity was due primarily to differential population expansion, not IL-7 induced thymic output. We have thus shown that rhIL-7 has the potential to induce thymic-independent T-cell growth in naive and CM populations and enhance repertoire diversity in peripheral T-cell populations. Whether this repair of repertoire is of functional importance is being addressed in a new clinical trial which is now accruing patients. We have also initiated a new clinical trial to treat the pulmonary complication of chronic graft versus host disease known as bronchiolitis obliterans. Preliminary results are encouraging and the study remains open and active. A new trial has also begun to treat leukemia with myeloablative therapy and assess improvement in immune reconstitution by modulation of thymus function. In a trial involving unrelated donor allogeneic peripheral blood stem cell transplantation, we have developed an extensive, clinically annotated data base of laboratory values relevant to immune reconstitution. This data set has shown that steroid therapy has little immediate effect on T cell numbers, and confirms our data on expansion of CD8+ T cells associated with CMV infection. The qualitative effect of steroids on T cell subset distribution is under investigation.