COVID 19 research
in the BIO divison
One of our teams (Dr. R. Benoit) is specialized in the design of protein nanoparticles, using building blocks found in nature (molecular biomimetics). Virus capsids, for example, are naturally occurring protein nanoparticles that exist in a wide variety of shapes and sizes. Many copies of only few types of protein subunits spontaneously assemble to form these viral envelopes. Through recombinant DNA technology, other proteins or peptides can be fused to the subunits, resulting in the display of the attachments on the nanoparticle surface. This technology can be extremely useful for many applications. For example, engineered virus-like particles with optimized stability and epitope exposure can function as improved vaccines. Unlike viruses, the particles do not contain viral genetic material and they are therefore non-infectious. This also makes them ideal tools for the development of novel methods, for example for the specific detection of viruses.
SARS-CoV-2/ACE-2 pseudovirus entry blocking assay
The spike glypcoprotein S of SARS-CoV-2 uses the human Angiotensin Converting Enzyme 2 (ACE2) as an entry receptor and recognizes it with a similar affinity to the 2002–2003 SARS-CoV isolates, which suggests it can spread efficiently in humans, in agreement with the numerous SARS-CoV-2 human-to-human transmission events reported to date (Walls et al., 2020).
In collaboration with its academic partners at the PSI, InterAx Biotech is establishing a pseudovirus entry assay using murine leukemia virus based pseudotyped particles expressing the SARS-CoV-2 spike protein (and other relevant SARS-CoV-2 envelope proteins). The assay is described in detail in Walls et al. (2020) and Millet et al. (2016, 2019) and will enable a medium-throughput (96 well format) screen for blocking the interaction of the SARS-CoV-2 spike glycoprotein (and other envelope proteins) and the human ACE2 expressed in a host target cell line. This assay is suitable to be performed in the BSL-2 facilities at PSI and non-infective compounds ranging from small molecules to antibody sera can be tested. For detailed information please send an Email to firstname.lastname@example.org with COVID-19 in the header.
Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell. 2020 Mar 6. pii: S0092-8674(20)30262-2.
Millet JK, Tang T, Nathan L, Jaimes JA, Hsu HL, Daniel S, Whittaker GR. Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting. J Vis Exp., 2019 Mar 1;(145).
Millet JK, Whittaker GR. Murine Leukemia Virus (MLV)-based Coronavirus Spike-pseudotyped Particle Production and Infection. Bio Protoc. 2016 Dec 5;6(23). pii: e2035