Caballero Van Dyke, M. C. | Search bioRxiv

bioRxiv2023

Development of a mutant aerosolized ACE2 that neutralizes SARS-CoV-2 in vivo

The rapid evolution of SARS-CoV-2 variants highlights the need for new therapies to prevent disease spread. SARS-CoV-2, like SARS-CoV-1, uses the human cell surface protein angiotensin-converting enzyme 2 (ACE2) as its native receptor. Here, we design and characterize a mutant ACE2 that enables rapid affinity purification of a dimeric protein by altering the active site to prevent autoproteolytic digestion of a C-terminal His10 epitope tag. In cultured cells, mutant ACE2 competitively inhibits lentiviral vectors pseudotyped with spike from multiple SARS-CoV-2 variants, and infectious SARS-CoV-2. Moreover, the protein can be nebulized and retains virus-binding properties. We developed a system for delivery of aerosolized ACE2 to K18-hACE2 mice and demonstrate protection by our modified ACE2 when delivered as a prophylactic agent. These results show proof-of-concept for an aerosolized delivery method to evaluate anti-SARS-CoV-2 agents in vivo and suggest a new tool in the ongoing fight against SARS-CoV-2 and other ACE2-dependent viruses.

microbiology↗

bioRxiv2021

The Effect of Minnelide against SARS-CoV-2 in a Murine Model

Severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, is the causative agent of coronavirus disease 2019, COVID-19, and the current COVID-19 pandemic. Even as more vaccine candidates are released, more treatment options are critically needed. Here, we investigated the use of Minnelide, a water soluble pro-drug with anti-inflammatory properties, for the treatment of COVID-19. To do this, k18-hACE2 mice were infected with SARS-CoV-2 or given PBS control intranasally. The next day mice were either treated daily with low dose (0.0025mg/day) or high dose Minnelide (0.005mg/day), or given vehicle control intraperitoneal. Mice were weighed daily, and sacrificed at day 6 and 10 post-infection to analyze viral burden, cytokine response, and pathology. We observed a reduction in viral load in the lungs of Minnelide-treated mice infected with SARS-CoV-2 at day 10 post-infection compared to day 6 post-infection. All SARS-CoV-2 infected non-treated mice were moribund six days post-infection while treatment with Minnelide extended survival for both low (60% survival) and high (100% survival) dose treated mice ten days post-infection. Interestingly, cytokine analysis demonstrated a significant reduction in IL-6 (lung and heart) and D-dimer (serum) in high dose treated SARS-CoV-2 infected mice compared to mice infected with SARS-CoV-2 alone at day 6 post-infection. Additionally, histology analysis revealed that Minnelide treatment significantly improved lung pathology ten days post-infection with SARS-CoV-2 with all the mice exhibiting normal lung tissue with thin alveolar septa and no inflammatory cells. Overall, our study exhibits potential for the use of Minnelide to improve survival in COVID-19 patients.

microbiology↗