Immunologic And Virologic Approaches To HIV-1 Therapeutics

我们的临床研究继续解决以下问题的几个重要方面：如何最佳地使用和管理多类组合抗逆转录病毒疗法;如何在持续抗逆转录病毒疗法的框架内整合基于免疫的疗法;如何确定开始抗逆转录病毒策略的最佳时间，以保持和重建免疫功能，同时最大限度地减少长期抗逆转录病毒毒性，以及如何优化免疫疗法的潜在用途，将其作为减少抗逆转录病毒药物暴露和提高其疗效的潜在手段。该项目的一个主要亮点是描述与HIV感染相关的免疫异常，开发安全，实用的免疫方法来治疗HIV感染患者，并利用这些基于免疫的疗法作为工具，以获得对HIV感染不同阶段患者中存在的病理生理机制的有价值的见解。在这一奋进中采用的具体工具之一是使用皮下施用白细胞介素-2（scIL-2）以逆转与进行性HIV-1感染相关的CD 4 T细胞下降。进行了一系列随机I-II期研究，确定这是一种增加HIV感染患者CD 4计数的可行方法;然后扩展这些研究以优化给药方案，以获得最大的免疫学和病毒学益处，同时最大限度地减少副作用。目前仍在努力更好地表征IL-2治疗急性和慢性刺激后淋巴细胞的功能、复制和存活。已经对接受IL-2治疗的患者队列进行了随访，现在已经延长到近19年。这些研究的一个主要发现是，使用体内和离体淋巴细胞标记的两种独立方法阐明，发现间歇性IL-2治疗诱导CD 4 T细胞亚群，特别是幼稚和中枢记忆细胞亚群的存活显著延长。对这些CD 4CD 25病毒扩增细胞（CEN）的广泛表型研究表明，它们表达与其他CD 25群体（如T调节淋巴细胞）不同的独特表面标志物模式。在两项主要的SC IL-2随机III期国际临床终点试验的背景下，该实验室与美国和国外的大量校外同事进行了广泛的系列合作。这些研究的目的是确定IL-2治疗对CD 4 T细胞数量的有利影响是否转化为与单独抗逆转录病毒治疗的接受者相比，这些患者中AIDS定义条件和/或死亡的发作显著延迟。这两项大型国际试验的数据收集于2008年11月15日完成，随后对两项研究进行了多参数分析，试图确定尼古丁诱导的CD 4+细胞数量增加与临床事件的频率和/或严重程度之间的相关性。初步数据分析于1月中旬完成，并由现场调查人员和INSIGHT领导的国际小组进行了审查。 简言之，ESPRIT的IL-2组中的患者成功地维持了比单独ART组中的患者高153个细胞/uL的平均CD 4差异。SILCAAT的IL-2组中的患者能够维持比单独ART组中的患者高57个细胞/uL的平均CD 4差异。尽管每个试验的两个组之间存在这些CD 4差异，ESPRIT和SILCAAT在证明可归因于使用IL-2加ART与单独使用ART的AIDS-定义事件或死亡的数量上没有差异方面非常一致。基于在约6000名研究受试者中的这两个一致的发现，得出结论，在HIV感染的早期或晚期阶段的患者中，皮下IL-2疗法不提供优于单独HAART的任何临床益处。基于从其他大型试验（如SMART研究）中获得的信息性见解，我们积极参与SILCAAT和ESPRIT的各种亚组分析，以尝试更好地了解观察到的结果。例如，我们正在分析来自这些试验之一的储存样本，以确定是否存在炎症标志物升高和凝血功能改变，作为临床事件差异的潜在预测因素。作为这些计划的IL-2治疗研究结论的一部分，我们仍然是一项随机、对照多中心国际试验的主要研究中心，该试验旨在比较间歇性scIL-2治疗与未接受IL-2治疗的对照患者相比，在使用或不使用围周期抗逆转录病毒治疗的情况下的效果。本多中心试验期间生成的数据已完成分析，并将在不久的将来提交发表。我们还协助对一种新的“免疫毒素”进行初步临床前试验，这是一种与假单胞菌外毒素相连的单克隆抗体，由于其对艾滋病毒感染细胞的亲和力，可能具有直接的抗病毒活性。我们也是“START”研究（抗逆转录病毒治疗的战略时机）的试验中心之一，该研究旨在确定在先前未经治疗的患者中早期引入ART是否会转化为更好的临床结果。最后，我们还继续努力，通过外联活动，包括与当地诊所建立密切关系，为医疗服务不足的人口提供更多的临床试验机会。

Our clinical research continues to address several important aspects of the following questions: how to optimally use and administer multi-class combination anti-retroviral therapy; how to integrate immune based therapies within a framework of ongoing antiretroviral therapy; how to determine the optimal time for initiation of antiretroviral strategy in order to preserve and reconstitute immune function while at the same time minimizing long-term antiretroviral toxicities, and how to optimize the potential use of immune-based therapies as a potential means both of decreasing exposure to antiretroviral drugs and of enhancing their efficacy. A major highlight of this project has been to characterize the immunologic abnormalities associated with HIV infection, develop safe, practical immunologic approaches to the adjunctive therapy of patients with HIV infection, and utilize these immune based therapies as tools for obtaining valuable insights into the pathophysiologic mechanisms present in patients at various stages of HIV infection. One of the specific tools employed in this endeavor has been the use of subcutaneous administration of interleukin-2 (scIL-2) in order to to reverse the CD4 T cell decline associated with progressive HIV-1 infection. A series of randomized phase I-II studies were carried out that established this as a feasible method for increasing the CD4 count in patients with HIV infection; these studies were then extended to optimize the dosing regimens for maximal immunologic and virologic benefit while minimizing side effects. Intensive efforts remain underway to better characterize the function, replication, and survival of lymphocytes following both acute and chronic stimulation by IL-2 therapy. Cohorts of patients have been followed who have received IL-2 treatment for periods that now extend to almost 19 years. A major finding of these studies, elucidated using two independent means of both in vivo and ex vivo lymphocyte labeling, has been the discovery that intermittent IL-2 therapy induces a marked prolongation of the survival of CD4 T cell subsets, particularly both naive and central memory cell subsets. Extensive phenotypic study of these CD4CD25 cytokine-expanded cells (CEN) shows them to express a unique pattern of surface markers distinguishable from other CD25 populations such as T regulatory lymphocytes. The laboratory has been engaged in an extensive series of collaborations with a large number of extramural colleagues, both in the US and abroad, in the context of two major randomized phase III international clinical endpoint trials of sc IL-2. The goal of these studies was to determine whether the favorable effects of IL-2 therapy on CD4 T cell number translate into a significant delay in the onset of AIDS-defining conditions and or death in such patients versus the recipients of antiretroviral therapy alone. Data collection for these two large international trials was completed on November 15, 2008, following which both studies were subjected to multi-parameter analyses attempting to establish the correlation between cytokine-induced increases in CD4+ cell numbers and the frequency and/or severity of clinical events. Preliminary data analyses were completed in mid-January and reviewed by an international panel of site investigators and INSIGHT leadership. In brief, patients in the IL-2 arm of ESPRIT were successful in maintaining an average CD4 difference of 153 cells /uL greater than those in the ART alone arm. Patients in the IL-2 arm of SILCAAT were able to maintain an average CD4 difference of 57 cells/uL greater than those in the ART alone arm. Despite these CD4 differences between the two arms of each trial, both ESPRIT and SILCAAT were remarkably consistent in demonstrating no difference in the number of AIDS-defining events or deaths that could be ascribed to using IL-2 plus ART versus using ART alone. Based upon these two consistent findings in approximately 6000 study subjects, it was concluded that sc IL-2 therapy does not provide any clinical benefit over HAART alone in patients at either the early or advanced stages of HIV infection. Based upon informative insights gained from other large trials such as the SMART study, we are actively engaged in various subanalyses of both SILCAAT and ESPRIT in order to attempt to better understand the outcomes that were observed. For example, we are in the process of analyzing stored samples from one of these trials for the presence of elevated markers of inflammation and altered coagulation as potential predictors of differences in clinical events. As part of the conclusion of these planned investigations of IL-2 therapy, we remain the lead center in a randomized, controlled multi-center international trial designed to compare the effects of intermittent scIL-2 therapy with or without the use of peri-cycle antiretroviral treatment compared to control patients not receiving IL-2. The data generated during this multi-center trial have completed analysis and are being submitted for publication in the near future. We are also assisting in the initial preclinical testing of a novel "immuno-toxin", a monoclonal antibody linked with pseudomonas exotoxin, that may have direct antiviral activity by virtue of its affinity for HIV-infected cells. We are also fully credentialed as one of the trial sites for the "START" study (Strategic Timing of AntiRetroviral Treatment) aimed at determining whether early introduction of ART in previously-untreated patients translates into better clinical outcomes. Finally, we also continue our efforts to improve access to clinical trials by local minority populations through an outreach that includes a close relationship with local clinics for medically under-served populations.