Laboratory of Dermatology and Immunodeficiencies, LIM 56, Tropical Medicine Institute, School of Medicine, University of Sao Paulo, Brazil.
Department of Dermatology, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil.
J Immunol Res. 2022 Aug 1;2022:9764002. doi: 10.1155/2022/9764002. eCollection 2022.
COVID-19 has several mechanisms that can lead to lymphocyte depletion/exhaustion. The checkpoint inhibitor molecule programmed death protein 1 (PD-1) and its programmed death-ligand 1 (PDL-1) play an important role in inhibiting cellular activity as well as the depletion of these cells. In this study, we evaluated PD-1 expression in TCD4+, TCD8+, and CD19+ lymphocytes from SARS-CoV-2-infected patients. A decreased frequency of total lymphocytes and an increased PD-1 expression in TCD4+ and CD19+ lymphocytes were verified in severe/critical COVID-19 patients. In addition, we found a decreased frequency of total monocytes with an increased PD-1 expression on CD14+ monocytes in severe/critical patients in association with the time of infection. Moreover, we observed an increase in sPD-L1 circulant levels associated with the severity of the disease. Overall, these data indicate an important role of the PD-1/PDL-1 axis in COVID-19 and may provide a severity-associated biomarker and therapeutic target during SARS-CoV-2 infection.
COVID-19 有几种机制可导致淋巴细胞耗竭/衰竭。检查点抑制剂分子程序性死亡蛋白 1（PD-1）及其程序性死亡配体 1（PDL-1）在抑制细胞活性以及这些细胞耗竭方面发挥着重要作用。在这项研究中，我们评估了 SARS-CoV-2 感染患者的 TCD4+、TCD8+和 CD19+淋巴细胞中的 PD-1 表达。在重症/危重症 COVID-19 患者中，证实总淋巴细胞频率降低，TCD4+和 CD19+淋巴细胞中 PD-1 表达增加。此外，我们还发现重症/危重症患者中总单核细胞频率降低，CD14+单核细胞上 PD-1 表达增加，且与感染时间有关。此外，我们还观察到与疾病严重程度相关的 sPD-L1 循环水平升高。总的来说，这些数据表明 PD-1/PDL-1 轴在 COVID-19 中的重要作用，并且可能为 SARS-CoV-2 感染期间提供与严重程度相关的生物标志物和治疗靶点。
