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Objective·To investigate the effects of several key proteins of severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2) on macropinocytosis in various cell models. Methods· The interactions between spike protein receptor-binding domain (S-RBD), nucleocapsid protein (N) and non-structural protein-7 (NSP7) of SARS-COV-2 and HEK-293T intracellular proteins were explored by co-immunoprecipitation assay. In vitro, S-RBD, N and NSP7 proteins of SARS-CoV-2 were incubated with HEK-293T/bEnd. 3/Beas-2b cells (normal cell models), respectively, and the changes of macropinocytosis level of cells labeled with fluorescein isothiocyanate (FITC) -70 kDa-dextran were observed. In vitro, S-RBD, N and NSP7 proteins of SARS-CoV-2 were incubated with inflammatory cells induced by lipopolysaccharide (LPS), respectively, and the changes of macropinocytosis level of inflammatory cells were analyzed. In the normal cell models and inflammatory cell model, EIPA or lipoprotein nano-drug carriers loaded with Rab5 small interfering RNA (siRNA) were used to inhibit the macropinocytosis induced by SARS-CoV-2 proteins, respectively, and the uptake of S-RBD, N and NSP7 proteins by cells were further observed. Results· The three proteins of SARSCOV- 2 could bind to Rab small GTPase proteins after being absorbed into cells. It was found that S-RBD, N and NSP7 proteins of SARS-COV-2 could induce the macropinocytosis after entering the HEK-293T/bEnd. 3/Beas-2b cells. Furthermore, the three proteins of SARS-COV-2 could enhance the megapinocytosis of the inflammatory cell. After treatment with EIPA (75 μmol/L) or lipoprotein nano-drug carriers loaded with Rab5 siRNA, the uptake of S-RBD, N and NSP7 proteins were decreased in both types of cells. Conclusion·S-RBD, N and NSP7 proteins of SARS-CoV-2 can up-regulate megapinocytosis levels in various cell models, especially in the case of combined inflammation infection. At the same time, macropinocytosis inhibitor / lipoprotein nano-drug carrier can inhibit the macropinocytosis up-regulated by the above proteins, and then reduce the entry levels of viral proteins. [Key words] macropinocytosis; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); EIPA; Rab5 [ABSTRACT FROM AUTHOR]