The majority of COVID-19 patients experience mild to moderate disease course and recover within a few weeks. An increasing number of studies characterized the long-term changes in the specific anti-SARS-CoV-2 immune responses, but how COVID-19 shapes the innate and heterologous adaptive immune system after recovery is less well known. To comprehensively investigate the post-SARS-CoV-2 infection sequelae on the immune system, we performed a multi-omics study by integrating single-cell RNA-sequencing, single-cell ATAC-sequencing, genome-wide DNA methylation profiling, and functional validation experiments in 14 convalescent COVID-19 and 15 healthy individuals. We showed that immune responses generally recover without major sequelae after COVID-19. However, subtle differences persist at the transcriptomic level in monocytes, with downregulation of the interferon pathway, while DNA methylation also displays minor changes in convalescent COVID-19 individuals. However, these differences did not affect the cytokine production capacity of PBMCs upon different bacterial, viral, and fungal stimuli, although baseline release of IL-1Ra and IFN-γ was higher in convalescent individuals. In conclusion, we propose that despite minor differences in epigenetic and transcriptional programs, the immune system of convalescent COVID-19 patients largely recovers to the homeostatic level of healthy individuals.
Keywords: COVID-19; DNA methylation; SARS-CoV-2; convalescence; multi-omics; single-cell sequencing.
Copyright © 2022 Liu, Kilic, Li, Bulut, Gupta, Zhang, Qi, Peng, Tsay, Soon, Mekonnen, Ferreira, van der Made, van Cranenbroek, Koenen, Simonetti, Diavatopoulos, de Jonge, Müller, Schaal, Ostermann, Cornberg, Eiz-Vesper, van de Veerdonk, van Crevel, Joosten, Domínguez-Andrés, Xu, Netea and Li.