Resende, F.; Queiroz-Junior, C. M.; Ascencao, F. R.; Chaves, I. d. M.; Lacerda, L. d. S. B.; Rocha, F.; Teixeira, D.; Galvao, I.; Costa, V.; Fonseca, T.; Gualberto, A.; Santos, A. L. d. C.; Martins, J.; Lima, E. B. d. S.; Monteiro, A. H. A.; Zaidan, I.; Grossi, L.; Costa, P. A. C.; Beltrami, V. A.; de Sousa, L. P.; Guimaraes, P. P. G.; Campolina-Silva, G.; Teixeira, M. M.; Pinho, V.; Costa, V. V.

Exacerbated inflammation is a major contributor to tissue damage and mortality in infectious diseases, including SARS-CoV-2. The resolution phase of inflammation is critical for restoring tissue homeostasis following an injury. Annexin A1 (AnxA1) is a ubiquitous protein that plays a fundamental role in the resolution of inflammation, including in preclinical models of infectious disease. Here, we investigated the role of AnxA1 in coronavirus infection and its potential as a host-targeted therapeutic strategy against SARS-CoV-2. Wild-type (WT) and AnxA1 knockout (AnxA1KO) mice were intranasally infected with the murine betacoronavirus MHV-3 to study the endogenous role of AnxA1. Immunohistochemistry and Western blot analyses in the lungs of MHV-3-infected mice revealed increased AnxA1 expression and its cleavage, which was associated with neutrophilic infiltration (Ly6G+ cells) mainly in peribronchiolar and perivascular regions. AnxA1-deficient mice exhibited higher neutrophilic infiltration and lung damage, alongside increased CXCL1 production in the lungs, when compared to WT-infected mice. In a murine model of SARS-CoV-2 infection in K18-hACE2 mice, we found increased AnxA1 cleavage associated with lung inflammation. Treatment of SARS-CoV-2-infected K18-hACE2 mice with the AnxA1-mimetic peptide, Ac2-26, reduced lung damage and lethality, without altering the host ability to deal with viral replication. Notably, Ac2-26-treated mice exhibited similar levels of protection to that afforded by the nucleotide analogue Remdesivir, following SARS-CoV-2 infection. Our findings highlight the protective role of the endogenous AnxA1 in mitigating coronavirus-induced lung inflammation and underscore the therapeutic potential of AnxA1 mimetic Ac2-26 as a host-targeted therapy against SARS-CoV-2.