ABSTRACT
Hyper-transmissibility with decreased disease severity are typical characteristics of Omicron variant. To understand this phenomenon, we used various bioinformatics approaches to analyze randomly selected genome sequences (one each) of the Gamma, Delta, and Omicron variants submitted to NCBI from 15 to 31 December 2021. We show that: (i) Pathogenicity of SARS-CoV-2 variants decreases in the order: Wuhan > Gamma > Delta > Omicron; however, the antigenic property follows the order: Omicron > Gamma > Wuhan > Delta. (ii) Omicron Spike RBD has lower pathogenicity but higher antigenicity than that of other variants. (iii) Decreased disease severity by Omicron variant may be due to its decreased pro-inflammatory and IL-6 stimulation and increased IFN-{gamma} and IL-4 induction efficacy. (iv) Mutations in N protein are associated with decreased IL-6 induction and human DDX21-mediated increased IL-4 production in Omicron. (v) Due to mutations, the stability of S, M, N, and E proteins decrease in the order: Omicron > Gamma > Delta > Wuhan. (vi) Stronger Spike-hACE2 binding in Omicron is associated with its increased transmissibility. However, the lowest stability of the Omicron Spike protein makes Spike-hACE2 interaction unstable for systemic infection and for causing severe disease. Finally (vii), the highest instability of Omicron E protein may also be associated with decreased viral maturation and low viral load leading to less severe disease and faster recovery. Our method may be used for other similar viruses, and these findings will contribute to the understanding of the dynamics of SARS-CoV-2 variants and the management of emerging variants.
Subject(s)
Infections , Poult Enteritis Mortality Syndrome , Reflex, AbnormalABSTRACT
Recently, two cases of complete remission of classical Hodgkin lymphoma (cHL) and follicular lymphoma (FL) after SARS-CoV-2 infection were reported. However, the precise molecular mechanism of this rare event is yet to be understood. Here, we hypothesize a potential anti-tumor immune response of SARS-CoV-2 and based on computational approach show that (i) SARS-CoV-2 Spike-RBD may bind to extracellular domains of CD15, CD27, CD45, and CD152 receptors of cHL or FL, (ii) upon internalization, SARS-CoV-2 membrane (M) protein and Orf3a may bind to gamma-tubulin complex component 3 (GCP3) at its tubulin gamma-1 chain (TUBG1) binding site, (iii) M protein may also interact with TUBG1 blocking its binding to GCP3, (iv) both M and Orf3a may render the GCP2-GCP3 lateral binding where M possibly interacts with GCP2 at its GCP3 binding site and Orf3a to GCP3 at its GCP2 interacting residues, (v) interactions of M and Orf3a with these gamma-tubulin ring complex components potentially block the initial process of microtubule nucleation, leading to cell cycle arrest and apoptosis, (vi) Spike-RBD may also interact with and block PD-1 signaling similar to pembrolizumab and nivolumab like monoclonal antibodies and may induce B-cell apoptosis and remission, (vii) finally, the TRADD interacting PVQLSY motif of Epstein-Barr virus LMP-1, that is responsible for NF-kB mediated oncogenesis, potentially interacts with SARS-CoV-2 Mpro, nsp7, nsp10, and Spike proteins and may regulate the LMP-1 mediated cell proliferation. Taken together, our results suggest a possible therapeutic potential of SARS-CoV-2 in proliferative disorders.