Generation and Characterization of a SARS-CoV-2-Susceptible Mouse Model Using Adeno-Associated Virus (AAV6.2FF)-Mediated Respiratory Delivery of the Human ACE2 Gene

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the aetiological agent of coronavirus disease 2019 (COVID-19) that has caused a pandemic with millions of human infections. There continues to be a pressing need to develop potential therapies and vaccines to inhibit SARS-CoV-2 infection to mitigate the ongoing pandemic. Epidemiological data from the current pandemic indicates that there may be sex-dependent differences in disease outcomes. To investigate these differences, we proposed to use common small animal species that are frequently used to model disease with viruses. However, common laboratory strains of mice are not readily infected by SARS-CoV-2 because of differences in the angiotensin-converting enzyme 2 (ACE2), the cellular receptor for the virus. To overcome this limitation, we transduced common laboratory accessible strains of mice of different sexes and age groups with a novel a triple AAV6 mutant, termed AAV6.2FF, encoding either human ACE2 or luciferase via intranasal administration to promote expression in the lung and nasal turbinates. Infection of AAV-hACE2-transduced mice with SARS-CoV-2 resulted in high viral titers in the lungs and nasal turbinates, establishment of an IgM and IgG antibody response, and modulation of lung and nasal turbinate cytokine profiles. There were insignificant differences in infection characteristics between age groups and sex-related differences; however, there were significant strain-related differences between BALB/c vs. C57BL/6 mice. We show that AAV-hACE2-transduced mice are a useful for determining immune responses and for potential evaluation of SARS-CoV-2 vaccines and antiviral therapies, and this study serves as a model for the utility of this approach to rapidly develop small-animal models for emerging viruses.

The menace of severe adverse events and deaths associated with viral gene therapy and its potential solution

“…AAV2 (Upstaza, to treat AADC deficiency; AADC gene) 12 Heart AAV9, [178][179][180][181][182][183][184][185] AAVMYO 186 -Kidney AAV2, 187 AAV6, 188 AAV8, 189,190 AAV6.2 190 -Cochlear cells AAV9, 191 AAV-PHP.B, [192][193][194][195][196] AAV-Anc80L65, 191,[197][198][199]200,201 -Lungs AAV1, [202][203][204] AAV6, [205][206][207] AAV6.2FF, 208,209 Abbreviation: AAV, adeno-associated viral vector.…”

Importance, Applications and Features of Assays Measuring SARS-CoV-2 Neutralizing Antibodies

“…Regarding mice, it is important to create mouse strains expressing human ACE2 to render mice susceptible for infection. The animal models show variability regarding susceptibility to different virus strains, severity of infection, symptoms and pulmonary pathology [ 127 , 128 , 129 , 130 , 131 , 132 ]. Currently the Syrian hamster model is one of the most frequently used animal models for SARS-CoV-2 infections [ 128 , 129 ].…”