The pandemic coronavirus disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). As the first step of the viral replication, the virus attaches to the host cell surface before entering the cell. The viral Spike protein recognizes and attaches to the Angiotensin-Converting Enzyme 2 (ACE2) receptor found on the surface of type I and II pneumocytes, endothelial cells, and ciliated bronchial epithelial cells. Drugs targeting the interaction between the Spike protein and ACE2 may offer protection against the viral infection.
In Brazil, a variant called P.1 was first identified in the summer of 2020. This variant has many mutations that may lead to higher transmissibility and infectivity. The Spike (P.1) (SARS-CoV-2) Pseudotyped Lentiviruses were produced with SARS-CoV-2 Variant Spike (Genbank Accession #QHD43416.1 with P.1 mutations, see below for details) as the envelope glycoproteins instead of the commonly used VSVG. These pseudovirions contain the enhanced green fluorescent protein (eGFP) gene driven by a CMV promoter, therefore, the spike-mediated cell entry can be determined via eGFP fluorescence. The Spike (P.1) (SARS-CoV-2) pseudotyped lentivirus can be used to measure the activity of neutralizing antibody against SARS-CoV-2 (P.1) variant using a Biosafety Level 2 facility.