Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia.
Infection and Immunity Program; Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria, Australia.
J Heart Lung Transplant. 2020 Nov;39(11):1300-1312. doi: 10.1016/j.healun.2020.08.014. Epub 2020 Aug 26.
Anti-viral treatments to control cytomegalovirus (CMV) after lung transplantation (LTx) are associated with toxicity and anti-viral resistance. Cellular immunotherapy with virus-specific cytotoxic T cells has yielded promising results but requires donor/recipient matching. γδ T cells are involved in anti-viral immunity and can recognize antigens independently of major histocompatibility complex molecules and may not require the same level of matching. We assessed the phenotype of circulating γδ T cells after LTx to identify the candidate populations for CMV immunotherapy.
Peripheral blood mononuclear cells were isolated from lung transplant recipients before transplantation and at routine bronchoscopies after LTx. Patients were stratified by risk of CMV disease into moderate risk (recipient CMV seropositive, n = 15) or high risk (HR) (recipient CMV seronegative/donor CMV seropositive, n = 10). CMV replication was classified as polymerase chain reaction positive (>150 copies/ml) in blood and/or bronchoalveolar lavage within the first 18 months. The phenotype of γδ T cells was assessed by multicolor flow cytometry, and T-cell receptor (TCR) sequences were determined by deep sequencing.
In HR lung transplant recipients with CMV replication, we observed striking phenotypic changes in γδ T cells, marked by an increase in the proportion of effector Vδ1+ γδ T cells expressing the activating natural killer cell receptor NKG2C. Moreover, we observed a remarkable increase in TCR diversity.
NKG2C+ Vδ1+ γδ T cells were associated with CMV replication and may indicate their potential to control infection. As such, we propose that they could be a potential target for cellular therapy against CMV.
肺移植（LTx）后，抗巨细胞病毒（CMV）的抗病毒治疗与毒性和抗病毒耐药性有关。使用病毒特异性细胞毒性 T 细胞的细胞免疫疗法已取得了可喜的成果，但需要供体/受者匹配。γδ T 细胞参与抗病毒免疫，可独立于主要组织相容性复合物分子识别抗原，并且可能不需要相同水平的匹配。我们评估了 LTx 后循环γδ T 细胞的表型，以确定 CMV 免疫治疗的候选人群。
在移植前和 LTx 后常规支气管镜检查时，从肺移植受者中分离外周血单核细胞。根据 CMV 疾病的风险将患者分层为中度风险（受者 CMV 血清阳性，n=15）或高风险（HR）（受者 CMV 血清阴性/供体 CMV 血清阳性，n=10）。在最初的 18 个月内，血液和/或支气管肺泡灌洗液中 CMV 复制的聚合酶链反应（PCR）阳性（>150 拷贝/ml）被分类。通过多色流式细胞术评估 γδ T 细胞的表型，并通过深度测序确定 T 细胞受体（TCR）序列。
在 HR 肺移植受者中，我们观察到 CMV 复制时 γδ T 细胞的表型发生了明显变化，表现为表达激活自然杀伤细胞受体 NKG2C 的效应 Vδ1+ γδ T 细胞比例增加。此外，我们观察到 TCR 多样性显著增加。
NKG2C+Vδ1+γδ T 细胞与 CMV 复制有关，可能表明其控制感染的潜力。因此，我们建议它们可能是针对 CMV 的细胞治疗的潜在目标。
