Mechanisms of Kidney Injury in COVID-19 - PROJECT SUMMARY/ABSTRACT
The SARS-CoV-2 pandemic has infected millions of individuals in the US and caused hundreds of thousands of
deaths. We and others have shown that COVID-19 is also strongly associated with devastating and usually rare
kidney pathophysiologies, such as collapsing glomerulopathy (CG). As in HIV infection, CG in COVID-19 patients
mostly affects individuals with high-risk APOL1 genotypes, which are more prevalent in Black and some Hispanic
patients. To guide treatment, there is a pressing need to understand whether COVID-19 nephropathy is due to
direct viral infection or indirect mechanisms, such as cytokines or physiologic disturbances that emanate from
the lung infection. Addressing this need has been hampered by poorly validated reagents, and misinterpretation
of immunohistochemistry and electron microscopy findings. We have assembled a multi-investigator team to
uncover the mechanisms of kidney injury due to SARS-CoV-2 infection. We will bring expert and complementary
expertise in anatomic, autopsy and renal pathology, integrative genomic analysis, human kidney organoid
systems and mouse immunology. We will use primary human tissue specimens, in vitro human kidney
model systems and a new mouse model of COVID-19 to define direct and indirect mechanisms of SARS-
CoV-2 associated kidney injury in three specific aims. Aim 1: Using kidney tissue specimens from COVID-
19 patients and controls, we will define the spectrum of kidney manifestations in individuals that have been
infected with SARS-CoV-2. We will use immunohistochemistry, in situ hybridization, and proteomics to define
SARS-CoV-2 kidney infection in a diverse population. In patients with COVID-19 associated CG, we will define
molecular changes of this disease using spatial transcriptomic profiling, and the association with APOL1 status.
These studies will define the relationship of SARS-CoV-2 infection to COVID-19 associated kidney diseases and
uncover molecular mechanisms that underlie direct and indirect modes of kidney injury. Aim 2: Human kidney
organoids provide a physiologically relevant model of SARS-CoV-2 infection. We will define cellular, morphologic
and molecular hallmarks of SARS-CoV-2 infection in human kidney organoids and organotypic tissue slices.
Using established iPSC cells with APOL1 high-risk alleles, we will determine the impact of APOL1 genotype on
infection and inflammatory cytokine induced kidney injury. These studies will establish which kidney cells are
capable of being infected by SARS-CoV-2, and kidney cell type specific molecular changes induced by viral
infection and inflammatory cytokines. Aim 3: We will use a recently developed mouse adapted SARS-CoV-2
virus to determine the effect of SARS CoV-2 infection on kidney function in vivo. Using newly described BAC-
transgenic mice that express human APOL1 G0, G1 or G2 alleles, we will define the influence of human APOL1
high-risk alleles on kidney function and kidney injury during SARS-CoV-2 infection. The successful development
of these models will establish a paradigm for investigating viral infection associated kidney injury and leverage
mouse genetics to define mechanisms of kidney injury and CG, and well as future therapeutic interventions.