IFN-γ Increases the Expression of SARS-CoV-2 Receptors on Vero E6 Cells

Publication Date


Document Type


Committee Members

Nancy J. Bigley, Ph.D. (Committee Chair); Dawn P. Wooley, Ph.D. (Committee Member); Lucile E. Wrenshall, M.D., Ph.D. (Committee Member); Marjorie M. Markopoulos, Ph.D. (Committee Member)

Degree Name

Master of Science (MS)


Respiratory epithelial cells are the initial target for SARS-CoV-2 infection. IFN-γ is known to increase the expression of ACE-2, an initial receptor for SARS-CoV-2, on epithelial cells. This study focuses on examining the effect of IFN-γ for ACE-2, TMPRSS2, and neuropilin-1 on Vero E6 cells using two immunofluorescence methods, namely, direct (membrane) fluorescence method and Cytation5 method. Direct fluorescence was determined using an Accu-Scope and ImageJ analysis. Using this method, significance (p<0.023) was observed only for ACE-2 when Vero E6 cells were treated with IFN-γ. Cytation5 fluorescence was determined using a Bio-tek Cytation5 plate reader. The results showed that IFN-γ significantly increased (p<0.001) the expression of ACE-2, neuropilin-1, and TMPRSS2. These results indicate Cytation5 is a more sensitive method for determining the expression of receptors on Vero E6 cells. The elevated levels of SARS-CoV-2 receptors expression resulting from IFN-γ treatment makes the epithelial cells more susceptible targets of SARS-CoV-2 infection. IFN-γ is most likely provided by innate immune cells in the initial COVID-19 infection, consequently contributing to the severity of disease.

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Department or Program

Microbiology and Immunology

Year Degree Awarded