ABSTRACT
Cytokine release syndrome (CRS), or 'cytokine storm', is the leading side effect during chimeric antigen receptor (CAR)-T therapy that is potentially life-threatening. It also plays a critical role in viral infections such as Coronavirus Disease 2019 (COVID-19). Therefore, efficient removal of excessive cytokines is essential for treatment. We previously reported a novel protein modification tool called the QTY code, through which hydrophobic amino acids Leu, Ile, Val and Phe are replaced by Gln (Q), Thr (T) and Tyr (Y). Thus, the functional detergent-free equivalents of membrane proteins can be designed. Here, we report the application of the QTY code on six variants of cytokine receptors, including interleukin receptors IL4Rα and IL10Rα, chemokine receptors CCR9 and CXCR2, as well as interferon receptors IFNγR1 and IFNλR1. QTY-variant cytokine receptors exhibit physiological properties similar to those of native receptors without the presence of hydrophobic segments. The receptors were fused to the Fc region of immunoglobulin G (IgG) protein to form an antibody-like structure. These QTY code-designed Fc-fusion receptors were expressed in Escherichia coli and purified. The resulting water-soluble fusion receptors bind to their respective ligands with K d values affinity similar to isolated native receptors. Our cytokine receptor-Fc-fusion proteins potentially serve as an antibody-like decoy to dampen the excessive cytokine levels associated with CRS and COVID-19 infection.
ABSTRACT
OBJECTIVE: To investigate the clinical treatment and assess the knowledge and use of the coronavirus disease 2019 (COVID-19) treatment plan issued by the nation. METHODS: A nationwide questionnaire survey on line was administered to medical staffs involved in COVID-19 treatment on February 28th, 2020. The questionnaire included drug treatment, respiratory support therapy, sedation and analgesia, continuous renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO), etc. RESULTS: There were 1 103 respondents, of whom 699 (504 doctors and 195 nurses) participated in the treatment of COVID-19. Finally, 432 doctors and 170 nurses from 9 provinces submitted valid questionnaires. The results of the questionnaire surveys of doctors and nurses were basically the same. Considering that doctors dominated in the diagnosis and treatment of COVID-19, the results of the questionnaires of doctors were mainly analyzed. The doctors participating in the survey were mainly from Hubei (29.2%), followed by Henan (24.5%), Guizhou (22.7%), and Guangxi (14.6%), etc. 55.4% of the doctors came from tertiary three hospitals, and most of them have senior titles (56.4%). 232 doctors (53.7%) participated in the treatment of mild COVID-19, and 200 doctors (46.3%) participated in the treatment of severe and critically ill patients. More than 95% of the doctors expressed that they would carry out antiviral treatment for patients with COVID-19 regardless of disease severity. The main antiviral drugs included α-interferon (69.5%), lopinavir/ritonavir (65.0%), abidol (60.0%), and ribavirin (55.7%). The choice of antiviral drugs was highly consistent with the national treatment programs of COVID-19. At the same time, 95.5% of doctors would routinely prescribe antibiotics to severe and critically ill patients. 94.0% of doctors agreed to prescribe low-dose glucocorticoid therapy to severe and critically ill patients. About 2/3 of doctors would perform lung recruitment or prone position treatment for critical patients with invasive ventilation. 79.0% of doctors preferred to use deep sedation for patients with invasive ventilation. About 1/3 of doctors believed that CRRT should be initiated early, and nearly 1/3 of doctors suggested that ECMO should be used more aggressively in critically ill patients. CONCLUSIONS: Medical staffs are familiar with the national treatment plan of COVID-19 and willing to follow it. However, as a new disease, we have limited knowledge about COVID-19 and there are still many controversies. Further practical training is needed to make clinicians more aware of the disease, and more evidence-based evidence is needed to guide clinical treatment.