SARS-CoV-2 infection paralyzes cytotoxic and metabolic functions of the immune cells

Yogesh Singh,Christoph Trautwein,Rolf Fendel,Naomi Krickeberg,Georgy Berezhnoy,Rosi Bissinger,Stephan Ossowski,Madhuri S Salker,Nicolas Casadei,Olaf Riess

doi:10.1016/j.heliyon.2021.e07147

Abstract

The SARS-CoV-2 virus is the causative agent of the global COVID-19 infectious disease outbreak, which can lead to acute respiratory distress syndrome (ARDS). However, it is still unclear how the virus interferes with immune cell and metabolic functions in the human body. In this study, we investigated the immune response in acute or convalescent COVID-19 patients. We characterized the peripheral blood mononuclear cells (PBMCs) using flow cytometry and found that CD8+ T cells were significantly subsided in moderate COVID-19 and convalescent patients. Furthermore, characterization of CD8+ T cells suggested that convalescent patients have significantly diminished expression of both perforin and granzyme A. Using 1H-NMR spectroscopy, we characterized the metabolic status of their autologous PBMCs. We found that fructose, lactate and taurine levels were elevated in infected (mild and moderate) patients compared with control and convalescent patients. Glucose, glutamate, formate and acetate levels were attenuated in COVID-19 (mild and moderate) patients. In summary, our report suggests that SARS-CoV-2 infection leads to disrupted CD8+ T cytotoxic functions and changes the overall metabolic functions of immune cells.

Highlights

The first cases of severe acute respiratory coronavirus-2 (SARS-CoV2) infection appeared in December 2019, in Wuhan, China [1]
peripheral blood mononuclear cells (PBMCs) were isolated and cryopreserved from blood samples obtained from COVID-19 patients suffering from mild (‘Mild’) or moderate/severe (‘Moderate’) disease or were already recovered (‘Convalescent’) and from healthy controls (‘HC’)
We found that the percentage of CD8þ T cells was decreased in moderate and convalescent patients compared to HC

Summary

Introduction

The first cases of severe acute respiratory coronavirus-2 (SARS-CoV2) infection appeared in December 2019, in Wuhan, China [1]. This zoonotic virus has infected more than 127.8 million people (30.03.2021) and has resulted in more than 2.78 million death worldwide [2, 3]. COVID-19 symptoms are heterogeneous and range from asymptomatic to mild, moderate, and severe pathological symptoms, presenting with or without pneumonia [10, 11]. Most infected people develop mild to moderate illness and recover without hospitalization [12, 13]. Older COVID-19 patients can develop acute severe respiratory distress syndrome (ARDS) due to a cytokine storm which is a life-threatening situation, requiring ventilation and intensive care support [16, 17, 18, 19, 20]

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Discussion

Conclusion