The Spike Protein of the Emerging Betacoronavirus EMC Uses a Novel Coronavirus Receptor for Entry, Can Be Activated by TMPRSS2, and Is Targeted by Neutralizing Antibodies

Abstract

fThe novel human coronavirus EMC (hCoV-EMC), which recently emerged in Saudi Arabia, is highly pathogenic and could pose a significant threat to public health. The elucidation of hCoV-EMC interactions with host cells is critical to our understanding of the pathogenesis of this virus and to the identification of targets for antiviral intervention. Here we investigated the viral and cellular determinants governing hCoV-EMC entry into host cells. We found that the spike protein of hCoV-EMC (EMC-S) is incorporated into lentiviral particles and mediates transduction of human cell lines derived from different organs, including the lungs, kidneys, and colon, as well as primary human macrophages. Expression of the known coronavirus receptors ACE2, CD13, and CEACAM1 did not facilitate EMC-S-driven transduction, suggesting that hCoV-EMC uses a novel receptor for entry. Directed protease expression and inhibition analyses revealed that TMPRSS2 and endosomal cathepsins activate EMC-S for viruscell fusion and constitute potential targets for antiviral intervention. Finally, EMC-S-driven transduction was abrogated by serum from an hCoV-EMC-infected patient, indicating that EMC-S-specific neutralizing antibodies can be generated in patients. Collectively, our results indicate that hCoV-EMC uses a novel receptor for protease-activated entry into human cells and might be capable of extrapulmonary spread. In addition, they define TMPRSS2 and cathepsins B and L as potential targets for intervention and suggest that neutralizing antibodies contribute to the control of hCoV-EMC infection.

Middle East Respiratory Syndrome Coronavirus Spike Protein Delivered by Modified Vaccinia Virus Ankara Efficiently Induces Virus-Neutralizing Antibodies

“…In addition, we obtained evidence for putative S1 and S2 cleavage of full-length S as predicted recently (6,21). The HA tag fused to the C terminus of S HA enabled us to detect two glycoprotein subpopulations, full-length S (ϳ210 kDa) and subdomain S2 (ϳ85 kDa), by anti-HA Western blot analysis (Fig.…”

Ortadoğu Solunum Yetmezliği Sendromu Koronavirüsü

“…MERS-CoV S protein 377-662 rezidülerindeki reseptör bağ-lanma/kritik nötralizan bölgenin tanımlanması bu yeni enfeksiyon için aşı geliştirilmesinde etkili olabilir (27)(28)(29).…”

Phage and Yeast Display

“…The MERSCoV uses the major envelope spike (S) glycoprotein trimer for attachment and entry into target cells, with the S1 domain containing the dipeptidyl peptidase 4 (DPP4) receptor binding site and the S2 region mediating membrane fusion (69, 70). Previous reports involving infected patients describe the production of S proteindirected neutralizing antibodies (71).…”