Molecular mimicry in multisystem inflammatory syndrome in children.

2024
https://researcherprofiles.org/profile/532364381
39112696
Bodansky A, Mettelman RC, Sabatino JJ, Vazquez SE, Chou J, Novak T, Moffitt KL, Miller HS, Kung AF, Rackaityte E, Zamecnik CR, Rajan JV, Kortbawi H, Mandel-Brehm C, Mitchell A, Wang CY, Saxena A, Zorn K, Yu DJL, Pogorelyy MV, Awad W, Kirk AM, Asaki J, Pluvinage JV, Wilson MR, Zambrano LD, Campbell AP, Overcoming COVID-19 Network Investigators, Thomas PG, Randolph AG, Anderson MS, DeRisi JL
Abstract

Multisystem inflammatory syndrome in children (MIS-C) is a severe, post-infectious sequela of SARS-CoV-2 infection, yet the pathophysiological mechanism connecting the infection to the broad inflammatory syndrome remains unknown. Here we leveraged a large set of samples from patients with MIS-C to identify a distinct set of host proteins targeted by patient autoantibodies including a particular autoreactive epitope within SNX8, a protein involved in regulating an antiviral pathway associated with MIS-C pathogenesis. In parallel, we also probed antibody responses from patients with MIS-C to the complete SARS-CoV-2 proteome and found enriched reactivity against a distinct domain of the SARS-CoV-2 nucleocapsid protein. The immunogenic regions of the viral nucleocapsid and host SNX8 proteins bear remarkable sequence similarity. Consequently, we found that many children with anti-SNX8 autoantibodies also have cross-reactive T cells engaging both the SNX8 and the SARS-CoV-2 nucleocapsid protein epitopes. Together, these findings suggest that patients with MIS-C develop a characteristic immune response to the SARS-CoV-2 nucleocapsid protein that is associated with cross-reactivity to the self-protein SNX8, demonstrating a mechanistic link between the infection and the inflammatory syndrome, with implications for better understanding a range of post-infectious autoinflammatory diseases.

Journal Issue
Volume 632 of Issue 8025