关键词: 淋巴细胞抗原6复合体, 基因座E, 新型冠状病毒, Wuhan-Hu-1 株, D614G 株, Delta 株, Omicron株, 抗病毒效应

Abstract: Objective  To investigate the inhibitory effect of lymphocyte antigen 6 complex, locus E (LY6E), on the entry of （severe acute respiratpry syndrome coronavirus 2, SARS-CoV-2） mediated by the spike protein(S)of different variant strains. Methods  Plasmid encoding human angiotensin-converting enzyme 2 (ACE2) molecules was constructed. We established Flp-In T-Rex 293/LY6E inducible expression cell lines and Flp-In T-Rex 293/chloramphenicol acetyltransferase (CAT) inducible expression cell lines, transfected human ACE2 expression plasmid, and detected the expression of ACE2 and LY6E in T-Rex 293 cells by Western blotting. The pseudoviral infection systems of SARS-CoV-2 (Wuhan-Hu-1 strain,D614G variant, Delta variant, and Omicron BA.1, BA.2, BA.2.12.1, BA.3, BA.4/5, BF.7 variant)and Lassa fever virus (LASV) were established to detect the activity of LY6E for inhibiting viral entry by using the luciferase reporter gene. The inhibitory effect of LY6E on SARS-CoV-2 mutant strain spike-mediated syncytium formation was detected by the Nano-Glo^® Live Cell Assay System. We constructed the pseudoviral infection systems of influenza A virus (IAV) to detect the inhibitory effect of LY6E on SARS-CoV-2 and its mutants spike protein-mediated entry by using pseudovirus luciferase reporter gene after amphotericin B treatment.Results  Flp-In T-Rex 293/LY6E inducible expression cell line could significantly inhibit the infection of SARS-CoV-2 (Wuhan-Hu-1 strain, D614G strain, Delta strain, and Omicron BA.1 mutantstrain),with statistical differences in relative infection rate between the pseudovirus infection of tetracycline (Tet) treated and non-treated groups(WTpp:t=33.920,P<0.001;D614Gpp:t=31.478,P<0.001;Deltapp:t=30.257,P<0.001; Omicronpp:t=21.041,P<0.001).LY6E significantly inhibited S protein-mediated syncytium formation in different mutant strains of SARS-CoV-2, and the differences in relative fluorescence units between the LY6E-expressing and non-expressing groups were statistically significant (D614G: t=18.90, P<0.001; Delta: t=22.28, P<0.001; BA.1: t=8.995, P<0.001; BA.2: t=13.57, P<0.001; BA.2.12.1: t=15.48, P<0.001; BA.3: t=13.65, P<0.001; BA.4/5: t=16.74, P<0.001; BF.7: t=22.29, P<0.001). Amphotericin B treatment did not alter the inhibitory effect of Flp-In T-Rex 293/LY6E inducible cell line on SARS-CoV-2 (Wuhan-Hu-1strain, D614G strain, Delta strain, and Omicron BA.1 mutantstrain) pseudovirus invasion, nor did it alter the enhancement of IAV infection by LY6E. The difference in the relative infection rate between the IAV pseudovirus infection of tetracycline (Tet) treated and non-treated groups was statistically significant (t=3.343, P<0.05).Conclusions  LY6E could significantly inhibit the infection of SARS-CoV-2 wild-type (Wuhan-Hu-1 strain) and multiple variants (D614G strain, Delta strain, and Omicron strain) and amphotericin B did not alter the inhibitory effect of LY6E on SARS-CoV-2(Wuhan-Hu-1strain, D614G strain, Delta strain, and Omicron strain).

Key words: lymphocyte antigen 6 complex, locus E, severe acute respiratory syndrome coronavirus 2, Wuhan-Hu-1 strain, D614G strain, Delta strain, Omicron strain, antiviral effect