Virological characteristics correlating with SARS-CoV-2 spike protein fusogenicity

Abstract

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) spike (S) protein is essential in mediating membrane fusion of the virus with the target cells. Several reports demonstrated that SARS-CoV-2 S protein fusogenicity is reportedly closely associated with the intrinsic pathogenicity of the virus determined using hamster models. However, the association between S protein fusogenicity and other virological parameters remains elusive. In this study, we investigated the virological parameters of eleven previous variants of concern (VOCs) and variants of interest (VOIs) correlating with S protein fusogenicity. S protein fusogenicity was found to be strongly correlated with S1/S2 cleavage efficiency and plaque size formed by clinical isolates. However, S protein fusogenicity was less associated with pseudoviral infectivity, pseudovirus entry efficiency, and viral replication kinetics. Taken together, our results suggest that S1/S2 cleavage efficiency and plaque size could be potential indicators to predict the intrinsic pathogenicity of newly emerged SARS-CoV-2 variants.

Virological characteristics of the SARS-CoV-2 BA.2.86 variant

“…We then investigated the fusogenicity of BA.2.86 S protein by the S-protein-mediated membrane fusion assay (Figure S2D). 16 The surface expression level of BA.2.86 S was comparable to that of the parental BA.2 S (Figure S2E). Several mutations in BA.2.86 significantly increased the expression level of BA.2 S on the cell surface (Figure S2E).…”

“…To test the effect of each mutation on pseudovirus infectivity, we generated a total of 33 BA.2 derivatives that bear respective mutations in BA.2.86 (Figure 2B). Most of the mutations did not affect BA.2 S pseudovirus Mami Nagashima, 22 Kenji Sadamasu, 22 Kazuhisa Yoshimura, 22 The Genotype to Phenotype Japan (G2P-Japan) Consortium, Akatsuki Saito, 21,23,24 Jumpei Ito, 14,25 Takashi Irie, 26 Shinya Tanaka, 13,18, * Jiri Zahradnik, 11, * Terumasa Ikeda, 8, * Kazuo Takayama, 10,27, * Keita Matsuno, 2,3,7,28, * Takasuke Fukuhara, 1,2,3,4,5,6,27,29, * and Kei Sato 14,15,16,25,30,31,32,34,35, * infectivity (Figure 2B). On the other hand, consistent with our previous reports, 11,14,15 certain mutations in the RBD, such as N460K and F486P, increased the pseudovirus infectivity (Figure 2B).…”

“…As previously described, sample preparation for western blotting was performed with minor modifications. 16,57 For western blotting, HEK293T cells (2 3 10 6 cells) were cotransfected with 2 mg of psPAX2-IN/HiBiT, 2 mg of pWPI-Luc2, and 1 mg of plasmids expressing SARS-CoV-2 S using TransIT-LT1 according to the manufacturer's protocol. At 2 d posttransfection, cell culture supernatants were collected, filtered, and subjected to ultracentrifugation using 20% sucrose (22,000 3 g, 4 C, 2 h).…”

SARS-CoV-2 inactivation: assessing the efficacy of GO-anchored filters versus various commercial masks

“…Plaque assays were conducted to measure the antiviral efficiency of the GO-anchored mask against the BA.5 variant, as reported previously. 10,11,[15][16][17][18][19] The details about the experimental procedure are shown in the ESI. †…”

“…The isolation and titration of the BA.5 variant (strain TKYS14631; GISAID ID: EPI_ISL_12812500) has been described previously. 15,16 This variant was used to investigate the antiviral activity of different commercial masks and GO samples against SARS-CoV-2. Eight different commercial face masks include hydro silver titanium mask (Hyd [AgTiO 2 ]), copper oxide mask, silver ion ceramic mask, special dolomite "CDM (BR-p3, contain Ca and Mg) mask, pioneer mask, CLEANXIA mask, sharp mask and surgical mask (using Viablock non-woven fabric) were purchased from the local market.…”