IL-10 & PD-1 Modulation to Reduce CMV Disease Incidence in Solid Organ Recipients

描述(申请人提供)：实体器官移植(SOT)受者中的CMV感染严重影响该疗法的康复过程和成功率。反映感染严重程度的发病率增加，可能导致移植物丢失和患者死亡，与巨细胞病毒病有关。尽管在抗病毒疗法方面取得了重大进展，但在停止抗病毒预防后，SOT接受者仍面临发展为晚期CMV病的风险。预防危及生命的CMV疾病的替代方法是管理来自CMV阳性供者(D+)的CMV阴性SOT受者(R-)的关键优先事项，因为在约30%的D+/R-患者中，CMV原发感染进展为临床疾病。我们的长期目标是确定D+/R-受体中初次抗CMV反应的质量和数量，为易患CMV病风险增加的患者制定预防和治疗策略。我们已经报道，在D+/R-肝移植(TX)患者中，在CMV病毒血症上升的情况下获得T细胞溶解功能和产生干扰素-3是不可靠的保护性免疫反应的指标。相反，CMV特异性T细胞上负免疫调节剂程序性死亡(PD)-1受体的高水平是CMV疾病的预测因素。我们的初步研究表明，在CMV症状性D+/R-患者中，抑制性白介素10的产生与PD-1的表达增加是平行的。此外，功能性的巨细胞病毒特异性T细胞，表达高水平的PD-1，表现出明显的增殖缺陷。这一建议的中心假设是，抑制性免疫信号水平的升高表明免疫受损状态，这是CMV疾病发展的先兆：免疫抑制环境的逆转应该恢复保护性CMV免疫。这项建议的目的是描述血栓后PD-1和IL-10表达的动力学特征，这将为这些负性免疫调节剂的阻断策略奠定基础。35名肝、肺和心脏D+/R-患者将在TX后6个月内每两周监测一次CMV病、CMV特异性临床参数和激活标记物PD-1和IL-10，其中约12人预计会患上CMV病。CMV特异性T细胞的免疫监测将包括用CMV病毒裂解物和6个肽库刺激后的多参数流式细胞术分析，包括免疫优势和常见的CMV抗原(pp65、IE1、IE2、US3、US32、UL99)。这些纵向数据将有助于确定原发CMV感染的SOT受者的免疫状态或免疫失调程度。接下来，将确定抗PD-1和/或IL-10抗体在恢复巨细胞病毒特异性T细胞增殖能力方面对巨细胞病毒病患者的影响。这些后一结果将被证明为设计抗体阻断平台的临床试验，用于高危SOT接受者的临床治疗，和/或提高抗CMV疫苗策略的有效性提供信息。这项R21奖将为基于抗体的临床试验提供理论基础，以减少SOT接受者CMV疾病的发病率和/或影响。公共卫生相关性：拟议的研究旨在降低接受实体器官移植(SOT)的患者的死亡率并改善临床管理。由于抗排斥和免疫抑制治疗，SOT受者对多种病原体高度易感，其中巨细胞病毒(CMV)是最严重的临床感染。在我们的项目中，我们将描述导致危及生命的CMV并发症的免疫功能障碍，目的是制定预防或治疗策略，以逆转高危SOT患者的此类缺陷。

DESCRIPTION (provided by applicant): CMV infection in solid organ transplant (SOT) recipients strongly impacts the course of recovery and success rate of this therapy. Increased morbidity that reflects the severity of infection, which can lead to graft loss and patient death, is associated with CMV disease. Despite significant advances in antiviral regimens, SOT recipients remain at risk for developing late CMV disease, after discontinuation of antiviral prophylaxis. Alternative approaches to preventing life-threatening CMV disease are a critical priority in the management of CMV-negative recipients (R-) of SOT from a CMV-positive donor (D+), since CMV primary infection progresses to clinical disease in ~30% of D+/R-. Our long term goal is to characterize quality and quantity of primary anti- CMV response in D+/R- recipients, for developing preventive and therapeutic strategies for patients susceptible to increased risk of CMV disease. We have reported that the acquisition of T-cell lytic function and IFN-3 production in response to rising CMV viraemia is an unreliable indicator of a protective immune response, in D+/R- liver transplant (Tx) patients. In contrast, high levels of the negative immune-modulator programmed death (PD)-1 receptor on CMV-specific T-cells are predictive of CMV disease. Our Preliminary Studies indicate that in CMV symptomatic D+/R- patients there is a parallel increased production of suppressive interleukin (IL)- 10 with increased expression of PD-1. Additionally, functional CMV-specific T-cells, expressing high PD-1 levels, show a marked deficit of proliferation. The central hypothesis of this proposal is that elevated levels of inhibitory immune-signaling indicate a state of immune impairment, which precedes development of CMV disease: reversal of the immunosuppressive environment should restore protective CMV immunity. The objective of this proposal is to characterize the post-Tx kinetics of PD-1 and IL-10 expression, which will lay the ground work for a blocking strategy of these negative immuno-modulators. A cohort of 35 liver, lung and heart D+/R- patients, in which ~12 are expected to develop CMV disease, will be monitored biweekly within 6 months after Tx, for CMV disease, CMV-specific clinical parameters and activation markers, PD-1 and IL-10. Immune- monitoring of CMV-specific T-cells will include multi-parameter flow cytometry analyses following stimulation with CMV viral lysate and 6 peptide libraries, encompassing immunodominant and frequently recognized CMV antigens (pp65, IE1, IE2, US3, US32, UL99). These longitudinal data will help identify the immune status or degree of immune-dysregulation of SOT recipients with primary CMV infection. Next, the impact of anti-PD-1 and/or IL-10 antibodies in restoring the proliferative capacity of CMV-specific T-cells will be determined in patients with CMV disease. These latter results will prove informative to design a clinical trial of an antibody blockade platform, to be used in the clinical management of high risk SOT recipients, and/or to increase the efficacy of anti-CMV vaccination strategies. This R21 award will provide the rationale for antibody-based clinical trials to reduce the incidence and/or impact of CMV disease incidence in SOT recipients. PUBLIC HEALTH RELEVANCE: The proposed studies are aimed to reduce the mortality and improve the clinical management of patients that have received solid organ transplantation (SOT). Due to anti-rejection and immunosuppressive treatments, SOT recipients become highly susceptible to several pathogens, among which cytomegalovirus (CMV) is the most significant clinical infection impairing recovery. In our project, we will characterize the immune dysfunctions that lead to life-threatening CMV complications, with the purpose of formulating preventive or therapeutic strategies to revert such defects in high risk SOT patients.