Abstract
COVID-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China in late 2019. The novel virus rapidly spread across the world, leading to the ongoing COVID-19 pandemic that has caused significant social and economic turmoil worldwide. During the last two years, multiple studies have focused on epidemiological surveillance, vaccine development, and discovery of therapeutic agents, while others have evaluated the impact of the virus in animal species. Since the onset of the SARS-CoV-2 outbreak, there have been numerous reports of SARS-CoV-2 infections in multiple animals (e.g., ferrets, tigers), some strongly linked to human-to-animal virus transmission due to close contact with infected human COVID-19 patients. A number of studies have used in silico analyses to predict the susceptibility of certain animal species to SARS-CoV-2, while others have attempted to study this phenomenon in vitro and/or using animal models. Here, we evaluated the potential for SARS-CoV-2 to infect cells from animals relevant to New Zealand. Since the human angiotensin converting enzyme 2 (hACE2) protein is the main receptor for SARS-CoV-2, we generated stably transfected cell lines expressing the ACE2 genes from 10 mammals, i.e., cow, dolphin, hedgehog, possum, rabbit, rat, sheep, stoat and ferret, including human ACE2 as reference. ACE2 protein expression was confirmed using qRT-PCR and Western Blot assays. The susceptibility of the HEK293/ACE2 cells to SARS-CoV-2 was assessed with a panel of pseudo-typed viruses, expressing the spike from different SARS-CoV-2 variants (Wuhan to omicron). With the exception of the ACE2 from hedgehog and rat, which showed limited infectivity, all the other animal ACE2 proteins allowed infection by the different SARS-CoV-2 spike pseudo-typed viruses. Interestingly, these results were not able to be reproduced when we used a replication-competent SARS-CoV-2, i.e., none of the HEK293/ACE2 cells were susceptible, definitely not permissive, to infection by the authentic SARS-CoV-2. Our study reinforces the notion that multiple factors, other than the ACE2 receptor, are necessary for SARS-CoV-2 to successfully enter and replicate in animal cells. Ongoing and further studies are needed to discern the susceptibility of certain animal species to SARS-CoV-2 and other coronaviruses, which could not only establish SARS-CoV-2 reservoirs but could also threaten potentially vulnerable animals in New Zealand.