Research Finds Super-Antigen-Like Motif Not Present in Other SARS Coronaviruses

A study published by PNAS on October 13, 2020, found hyperinflammatory syndrome reminiscent of toxic shock syndrome (TSS) is observed in severe COVID-19 patients, including children with Multisystem Inflammatory Syndrome in Children (MIS-C). These researchers showed that the SARS-CoV-2 spike contains sequence and structure motifs highly similar to those of a bacterial superantigen and may directly bind T cell receptors.

They further reported a skewed T cell receptor repertoire in COVID-19 patients with severe hyper-inflammation, in support of such a superantigenic effect.

Notably, the superantigen-like motif is not present in other SARS family coronaviruses, which may explain the unique potential for SARS-CoV-2 to cause both MIS-C and the cytokine storm observed in adults with COVID-19.

Previously, a September 8, 2020 study published in Nature stated: 'Different SARS-CoV-2 strains haven’t yet had a major impact on the course of the COVID-19 pandemic, but they might in future.'