NL63: A Better Surrogate Virus for studying SARS-CoV-2

Abstract

Airborne and potentially deadly SARS-CoV-2, that causes the disease COVID-19, was discovered in late December of 2019. Till now no medications including vaccine, antibody, or any antiviral are found with success. SARS-CoV-2 is very similar to SARS-CoV-1 which was discovered in 2003, and recognizes the same host cell receptor for entry into the cell. MERS-CoV, another lethal HCoV discovered in 2012, belongs to the same group of SARS (β-type), but recognizes a different cell receptor for host cell entry. All these viruses can only be studied safely under high-level biosafety conditions to protect the laboratory workers and the environment. However, these safety precautions slow down efforts to find drugs and vaccines for COVID-19 since many scientists lack access to the required biosafety facilities. There are four more common human CoVs, such as, HCoV-229E, HCoV-OC43, HCoV-HKU1, and HCoV-NL63, which were known from many years back. They cause self-limiting respiratory infections, such as common cold, in humans, and can be studied safely in BSL2 lab. In this review, a comparison of SARS and Common cold virus were done in order to search for a better surrogate virus those can be used in BSL2 lab for identifying the disease mechanism and therapeutic intervention of SAR-CoV-2. We focused on the following key questions, like, virus-host cell interaction mechanism; the differential cell line susceptibility; species tropism; viral replication efficiency; antigen expression patterns; mechanistic pathway of apoptosis; and structure-function relationship of the virus.