HCMV-induced innate-like CD8 T cells and allogeneic HCT outcome

项目摘要 人巨细胞病毒（HCMV）以50-100%的感染率感染所有人群，并通过以下方式保持潜伏状态： 先天和适应性监视。然而，它是疾病和死亡的一个重要原因， 免疫重建和抑制，例如在新生儿和实体器官或造血细胞接受者中 移植经典HCMV肽特异性αβ细胞毒性T淋巴细胞对HCMV的免疫应答 已经进行了充分的研究，NKG 2C+自然杀伤细胞响应HCMV感染的发展， 目前正在积极调查重新启用的问题。然而，除了这些淋巴细胞，大量的αβ- 还在HCMV-1中观察到表达NKG 2C和其他NK相关受体的TCR CD 8 T细胞。 血清阳性的健康供体和患者。这些天然样NKG 2C + CD 8 T细胞似乎具有广泛的活性 对AML和HCMV感染的细胞没有活性，对未感染的同种异体成纤维细胞没有活性， PD-I的表达响应于CD 3刺激。RNAseq分析显示，NKG 2C + CD 8 T细胞 转录因子Bcl 11b的表达减少，Bcl 11b对于切断先天命运至关重要， T细胞的早期胸腺发育。该建议的中心假设是HCMV暴露诱导 NKG 2C + CD 8 T细胞群，通过将克隆型T细胞转向先天命运， 下调Bcl 11b，改变TCR信号传导并促进替代识别途径 白血病患者。该提案的第一个目的是评估NKG 2C+成员的T细胞身份。 CD 8 T细胞群体（克隆性、TCR特异性和信号传导）以及它们的转录和表观遗传 程序通过Bcl 11b丢失而从其他CD 8 T细胞改变。第二个目标是评估NK的功能， NKG 2C + CD 8 T细胞上相关的激活和抑制受体，目的是鉴定 其抗肿瘤和抗HCMV活性背后的机制。最后，在与该中心的合作中， 国际血液和骨髓移植，广泛的造血细胞移植患者样本 将利用数据库和临床数据库来确定移植后是否出现 NKG 2C + CD 8 T细胞群影响白血病复发风险和总生存期。在一起，结果 这些研究不仅将阐明这种先天性T细胞群的治疗潜力， 适应性和先天性的命运是可以连接起来的。

PROJECT SUMMARY Human cytomegalovirus (HCMV) infects all populations with a penetrance of 50-100% and is kept latent by innate and adaptive surveillance. However, it is a significant cause of morbidity and mortality in conditions of immune reconstitution and suppression, such as in neonates and recipients of solid organ or hematopoietic cell transplants. The T cell response to HCMV through classical HCMV peptide-specific αβ cytotoxic T lymphocytes has been well-studied, and the development of NKG2C+ natural killer cells in response to HCMV infection and reactivation is under active investigation. In addition to these lymphocytes, however, large populations of αβ- TCR CD8 T cells that express NKG2C and other NK-associated receptors have also been observed in HCMV- seropositive healthy donors and patients. These innate-like NKG2C+ CD8 T cells appear to have broad activity against AML and HCMV-infected cells, no activity against uninfected allogeneic fibroblasts, and reduced expression of PD-1 in response to CD3 stimulation. RNAseq analysis has revealed that NKG2C+ CD8 T cells have reduced expression of the transcription factor Bcl11b, critical for cutting off alternative innate fates during the early thymic development of T cells. The central hypothesis of this proposal is that HCMV exposure induces an NKG2C+ CD8 T cell population by diverting clonotypic T cells toward an innate fate through the downregulation of Bcl11b, which alters TCR signaling and promotes alternative recognition pathways beneficial to leukemia patients. The first aim of the proposal is to evaluate the T cell identity of members of the NKG2C+ CD8 T cell population (clonality, TCR specificity and signaling) and how their transcriptional and epigenetic programs are altered from other CD8 T cells by Bcl11b loss. The second aim will assess the function of the NK- associated activating and inhibitory receptors on the NKG2C+ CD8 T cells, with the goal of identifying the mechanism behind their anti-tumor and anti-HCMV activity. Finally, in a collaboration with the Center for International Blood and Marrow Transplantation, an extensive hematopoietic cell transplantation patient sample bank and clinical database will be utilized to determine whether the post-transplantation emergence of an NKG2C+ CD8 T cell population impacts the risk of leukemia relapse and overall survival. Together, the results of these studies will elucidate not only the therapeutic potentials of this innate-like T cell population but also how adaptive and innate fates can be bridged.