BSG/CD147 and ACE2 Receptors Facilitate Direct SARS-CoV-2 Infection of Human iPS Cell-Derived Kidney Podocytes

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the Coronavirus disease 2019 (COVID-19), which was declared a pandemic by the World Health Organization (WHO) in March 2020. The disease has killed more than 3.8 million people worldwide. While cells in the respiratory system are the initial target for SARS-CoV-2, clinical studies suggest that COVID-19 can become a multi-organ disease in the most severe cases. Still, the direct affinity of SARS-CoV-2 for cells in other organs such as the kidneys, which are often affected in severe COVID-19, remains poorly understood. Here, we employed a human induced pluripotent stem (iPS) cell-derived model to investigate the affinity of SARS-CoV-2 for kidney glomerular podocytes. Global gene expression and qPCR analyses revealed that human iPS cell-derived podocytes express many host factor genes (including ACE2, BSG/CD147, PLS3, ACTR3, DOCK7, TMPRSS2, CTSL CD209, and CD33) associated with SARS-CoV-2 binding and viral processing. Infection of podocytes with live SARS-CoV-2 or spike-pseudotyped lentiviral particles revealed viral uptake by the cells at low Multiplicity of Infection (MOI of 0.01) as confirmed by RNA quantification and immunofluorescence studies. Our results also indicate that direct infection of human iPS cell-derived podocytes by SARS-CoV-2 virus can cause cell death and podocyte foot process retraction, a hallmark of podocytopathies and progressive glomerular diseases including collapsing glomerulopathy observed in patients with severe COVID-19 disease. Additionally, antibody blocking experiments identified BSG/CD147 and ACE2 receptors as key mediators of spike binding activity in human iPS cell-derived podocytes. These results show that SARS-CoV-2 can infect kidney glomerular podocytes in vitro, making this model potentially useful for kidney-specific antiviral drug screening and mechanistic studies of COVID-19 organotropism.Funding Information: S.M. is a recipient of the Whitehead Scholarship in Biomedical Research, a Chair’s Research Award from the Department of Medicine at Duke University, a MEDx Pilot Grant on Biomechanics in Injury or injury repair, a Burroughs Wellcome Fund PDEP Career Transition Ad Hoc Award, a Duke Incubation Fund from the Duke Innovation & Entrepreneurship Initiative, and a George O’Brien Kidney Center Pilot Grant (P30DK081943). R.B. is a recipient of the Lew’s Predoctoral Fellowship in the Center for Biomolecular and Tissue Engineering (CBTE) at Duke University (T32 Support NIH Grant T32GM800555); M.A.B. is a recipient of an NSF graduate research fellowship; and X.M. is a recipient of the graduate research fellowship from the International Foundation for Ethical Research, INC.Declaration of Interests: The authors have no conflict of interests.Ethics Approval Statement: All cell lines used for this study were obtained under appropriate material transfer agreements and approved by all involved institutional review boards.