Related Experiment Video
Updated: Sep 1, 2025

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes
Published on: September 28, 2018
Upregulation of PD-1 Expression and High sPD-L1 Levels Associated with COVID-19 Severity
Danielle Rosa Beserra1, Ricardo Wesley Alberca1, Anna Claudia Calvielli Castelo Branco1
1Laboratory of Dermatology and Immunodeficiencies, LIM 56, Tropical Medicine Institute, School of Medicine, University of Sao Paulo, Brazil.
Abstract:
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.
Related Concept Videos
Single Nucleotide Polymorphisms-SNPs
COPD: Pathogenesis and Clinical Features
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...
Neural Regulation
EPS and iPS Cells in Disease Research
Abnormal Proliferation

