Este articulo es un Preprint
Los preprints son informes de investigación preliminares que no han sido certificados por revisión por pares. No deben considerarse para guiar la práctica clínica o los comportamientos relacionados con la salud y no deben publicarse en los medios como información establecida.
Los preprints publicados en línea permiten a los autores recibir comentarios rápidamente, y toda la comunidad científica puede evaluar de forma independiente el trabajo y responder adecuadamente. Estos comentarios se publican junto con los preprints para que cualquiera pueda leer y servir como una revisión pospublicación.
Defective ORF8 dimerization in delta variant of SARS CoV2 leads to abrogation of ORF8 MHC-I interaction and overcome suppression of adaptive immune response
Preprint
en Inglés
| bioRxiv
| ID: ppbiorxiv-457457
ABSTRACT
In India, the breakthrough infections during second wave of COVID-19 pandemic was due to SARS-COV-2 delta variant (B.1.617.2). It was reported that majority of the infections were caused by the delta variant and only 9.8% percent cases required hospitalization whereas, only 0.4% fatality was observed. Sudden dropdown in COVID-19 infections was observed within a short timeframe, suggesting better host adaptation with evolved delta variant. Down regulation of host immune response against SARS-CoV-2 by ORF8 induced MHC-I degradation has been reported earlier. The Delta variant carried mutations (deletion) at Asp119 and Phe120 amino acids which are critical for ORF8 dimerization. The deletions of amino acids Asp119 and Phe120 in ORF8 of delta variant results in structural instability of ORF8 dimer caused by disruption of hydrogen bonding and salt bridges as revealed by structural analysis and MD simulation studies of ORF8 dimer. Further, flexible docking of wild type and mutant ORF8 dimer revealed reduced interaction of mutant ORF8 dimer with MHC-I as compared to wild type ORF8 dimer with MHC-1, thus implicating its possible role in MHC-I expression and host immune response against SARS-CoV-2. We thus propose that mutant ORF8 may not hindering the MHC-I expression thereby resulting in better immune response against SARS-CoV-2 delta variant, which partly explains the sudden drop of SARS-CoV-2 infection rate in the second wave of SARS-CoV-2 predominated by delta variant in India Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/457457v1_ufig1.gif" ALT="Figure 1"> View larger version (40K) org.highwire.dtl.DTLVardef@751eeaorg.highwire.dtl.DTLVardef@140b5b5org.highwire.dtl.DTLVardef@159a3a5org.highwire.dtl.DTLVardef@6c206_HPS_FORMAT_FIGEXP M_FIG C_FIG
cc_by_nc_nd
Texto completo:
Disponible
Colección:
Preprints
Base de datos:
bioRxiv
Idioma:
Inglés
Año:
2021
Tipo del documento:
Preprint