The Potential of Developing Pan-Coronaviral Antibodies to Spike Peptides in Convalescent COVID-19 Patients

Abstract

Coronaviruses share conservative spike protein (S) on their enveloped membrane surface, where S1 subunit recognizes and binds the cellular receptor, and the S2 subunit mediates membrane fusion. This similarity raises the question: does coronaviral infection by one create protection to others? Convalescent SARS-CoV-2 (COVID-19) sera were tested for cross reactivity with peptides from Middle East respiratory syndrome coronavirus (MERS-CoV) which shares 74% homology. Our results showed significant cross-reactivity with a peptide of the heptad repeat 2 (HR2) domain of the MERS-CoV spike protein. Sera samples of 47 validated seropositive convalescent COVID-19 patients and 40 sera samples of control patients, collected in pre-COVID time were used to establish cross-bind reactivity with the MERS-CoV peptide. Significantly stronger binding ( p < 0.0001) was observed for IgG antibodies in convalescent COVID-19 patients compared to the control group. In ELISA, MERS-CoV peptide helps to discriminate post-COVID-19 populations and non-infected ones by the presence of antibodies in blood samples. This suggests that polyclonal antibodies established during SARS-CoV-2 infection can recognize and probably decrease severity of MERS-CoV and other coronaviral infections. The high homology of the spike protein domain also suggests that the opposite effect can be true: coronaviral infections produce cross-reactive antibodies effective against SARS-CoV-2. The collected data prove that despite the core HR2 region is hidden in the native viral conformation, its exposure during cell entry makes it highly immunogenic. Since inhibitory peptides to this region were previously described, this opens new possibilities in fighting coronaviral infections and developing vaccines effective even after possible viral mutations. Supplementary Information The online version contains supplementary material available at 10.1007/s00005-021-00607-8.

Rapid Generation of Coronaviral Immunity Using Recombinant Peptide Modified Nanodiamonds

“…The minor differences in the amino-acid sequence are identified in red, and the sequence shares 81% identify and 86% of similarity with the HR2 helix of MERS-CoV (PDB ID: 4NJL) and 46% identify and 74% of similarity with the HR2 helix of SARS-CoV-2 (as illustrated in Figure 1 b); corresponding sequence alignment is represented in Figure S1 . This peptide was also lately demonstrated to induce cross-coronaviral humoral immune response [ 25 , 26 ]. Spike protein (S protein) is mediating membrane fusion between coronaviruses such as MERS-CoV and SARS-CoV-2 and host cells [ 27 ].…”

Amplification‐Free Detection of SARS‐CoV‐2 Down to Single Virus Level by Portable Carbon Nanotube Biosensors

“…It is also an important identification site for in vitro diagnosis. [35,36] Here, the spike protein aptamer (Sp-aptamer) was used as a probe to detect the spike protein through binding to the S1 subregion of the spike protein. [37] Compared to antibodies, aptamers are synthetic oligonucleotides with high specificity and long-term stability.…”

Outer Membrane Vesicles: An Emerging Vaccine Platform

“…When treated with E. coli , OMVs can also cause apoptosis of host cells by developing the G2 phase arrest, or they can carry virulence factors that cause cell death of epithelial cells of the gut [ 34 ]. Neisseria meningitidis OMVs can stimulate the human neutrophils to produce cytokines and chemokines such as interleukin 1-beta, IL-8, tumor necrosis factor-alpha, macrophage inflammatory proteins 1 alpha, and 1 beta [ 41 ]. Gamma interferon-stimulated can maintain or increase the inflammation reaction.…”