In Vivo protection from SARS-CoV-2 infection by ATN-161 in k18-hACE2 transgenic mice

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an infectious disease that has spread worldwide. Current treatments are limited in both availability and efficacy, such that improving our understanding of the factors that facilitate infection is urgently needed to more effectively treat infected individuals and to curb the pandemic. We and others have previously demonstrated the significance of interactions between the SARS-CoV-2 spike protein, integrin α5β1, and human ACE2 to facilitate viral entry into host cells in vitro. We previously found that inhibition of integrin α5β1 by the clinically validated small peptide ATN-161 inhibits these spike protein interactions and cell infection in vitro. In continuation with our previous findings, here we have further evaluated the therapeutic potential of ATN-161 on SARS-CoV-2 infection in k18-hACE2 transgenic (SARS-CoV-2 susceptible) mice in vivo. We discovered that treatment with single- or repeated intravenous doses of ATN-161 (1 mg/kg) within 48 h after intranasal inoculation with SARS-CoV-2 lead to a reduction of lung viral load, viral immunofluorescence, and improved lung histology in a majority of mice 72 h post-infection. Furthermore, ATN-161 reduced SARS-CoV-2-induced increased expression of lung integrin α5 and αv (an α5-related integrin that has also been implicated in SARS-CoV-2 interactions) as well as the C–X–C motif chemokine ligand 10 ( Cxcl10 ), further supporting the potential involvement of these integrins, and the anti-inflammatory potential of ATN-161, respectively, in SARS-CoV-2 infection. To the best of our knowledge, this is the first study demonstrating the potential therapeutic efficacy of targeting integrin α5β1 in SARS-CoV-2 infection in vivo and supports the development of ATN-161 as a novel SARS-CoV-2 therapy.

Can the SARS-CoV-2 Spike Protein Bind Integrins Independent of the RGD Sequence?

“…Of interest, one motif was found to be similar to the ATN-161 pentapeptide, which has been shown to block against SARS-CoV-2 infection in vivo ( Amruta et al, 2021 )⁠. The RGD-based drug, Cilengitide, and the RGD peptide were also found to inhibit spike-integrins interactions on endothelial cells ( Nader et al, 2021 ; Robles et al, 2021 )⁠.…”

“…This was also the case for the similarity between the ATN-161 pentapeptide sequence (PHSCN) and the spike STPCN motif, in which both the P and S residues are present but in a different order. Furthermore, the similarity to the ATN-161 pentapeptide is interesting considering studies that suggest its protective ability against SARS-CoV-2 infection, although the peptide has been suggested to also bind the RGD-binding site on integrins ( Amruta et al, 2021 ; Beddingfield et al, 2021 )⁠. Structural analysis to investigate the accessibility of the motifs on the spike protein may lend more insights into their potential ability to bind integrins.…”

Natural and Experimental SARS-CoV-2 Infection in Domestic and Wild Animals

“…Together, the combination of multiple transgenic hACE2-expressing mouse models under various promoters, adenovirus-based methods for transduction of multiple mouse strains with hACE2, mouse-adapted SARS-CoV-2 strains, and the susceptibility of mice to emerging VOC has resulted in laboratory mice becoming highly useful models for SARS-CoV-2 infection studies and efficacy testing of vaccines and therapeutics [ 220 , 221 , 222 , 223 , 224 ].…”

ATN-161 Ameliorates Ischemia/Reperfusion-induced Oxidative Stress, Fibro-inflammation, Mitochondrial damage, and Apoptosis-mediated Tight Junction Disruption in bEnd.3 Cells

“…Our laboratory has shown that endothelial cell-specific integrin α5β1 gene deficiency results in significant resistance to ischemic stroke injury in mice [ 11 ]. Furthermore, treatment with a novel α5β1 integrin inhibitor, the pentapeptide ATN-161, reduces neuroinflammation, stabilizes ECM remodeling and is neuroprotective in murine ischemic stroke and protection from SARS-CoV-2 infection in k18-hACE2 transgenic mice [ 12 , 8 ]. To further elucidate ATN-161’s precise therapeutic mechanisms of action, we studied ATN-161 in an in vitro model of stroke, oxygen–glucose deprivation/reoxygenation (OGD/R) in brain endothelial cells.…”