Biology subjects

Stefan, C. P.

Publications and source records attributed to Stefan, C. P..

2 recordsLinked to original sources

bioRxiv2026

Phosphatidylserine receptors are critical for lethal infection by Crimean-Congo hemorrhagic fever virus

The tick-borne Crimean-Congo hemorrhagic fever virus (CCHFV) causes severe and often fatal hemorrhagic disease for which no approved countermeasures are available. Herein, we identify the phosphatidylserine receptors (PSRs) AXL, TIM-1, and TIM-4 as critical entry host factors for CCHFV in cell lines and liver-derived primary cell cultures. Small-molecule and antibody-based PSR inhibitors greatly reduced viral infection in cell culture. Germline knockout of individual PSR genes afforded partial protection against CCHFV infection, disease, and death in a murine model of lethal viral challenge. Mice engineered to lack two PSRs were completely protected from challenge, with viremia and viral replication, pathology, and inflammation in the liver and spleen reduced to baseline. Therefore, PSRs are collectively indispensable for CCHFV infection and pathogenesis. We conclude that PSRs are not just cell entry factors but bona fide determinants of infection, dissemination, and disease by CCHFV and legitimate targets for the development of new antiviral countermeasures.

microbiology↗

bioRxiv2021

Aerosol Exposure of Cynomolgus Macaques to SARS-CoV-2 Results in More Severe Pathology than Existing Models

The emergence of SARS-CoV-2 pandemic has highlighted the need for animal models that faithfully recapitulate the salient features of COVID-19 disease in humans; these models are necessary for the rapid down-selection, testing, and evaluation of medical countermeasures. Here we performed a direct comparison of two distinct routes of SARS-CoV-2 exposure, combined intratracheal/intranasal and small particle aerosol, in two nonhuman primate species: rhesus and cynomolgus macaques. While all four experimental groups displayed very few outward clinical signs, evidence of mild to moderate respiratory disease was present on radiographs and at the time of necropsy. Cynomolgus macaques exposed via the aerosol route also developed the most consistent fever responses and had the most severe respiratory disease and pathology. This study demonstrates that while all four models were suitable representations of mild COVID-like illness, aerosol exposure of cynomolgus macaques to SARS-CoV-2 produced the most severe disease, which may provide additional clinical endpoints for evaluating therapeutics and vaccines.

microbiology↗