P21-activated kinase 1 (PAK1)-mediated cytoskeleton rearrangement promotes SARS-CoV-2 entry and ACE2 autophagic degradation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has had a significant impact on healthcare systems and economies worldwide. The continuous emergence of new viral strains presents a major challenge in the development of effective antiviral agents. Strategies that possess broad-spectrum antiviral activities are desirable to control SARS-CoV-2 infection.

Antibodies targeting a quaternary site on SARS-CoV-2 spike glycoprotein prevent viral receptor engagement by conformational locking.

SARS-CoV-2 continues to evolve, with many variants evading clinically authorized antibodies. To isolate monoclonal antibodies (mAbs) with broadly neutralizing capacities against the virus, we screened serum samples from convalescing COVID-19 patients. We isolated two mAbs, 12-16 and 12-19, which neutralized all SARS-CoV-2 variants tested, including the XBB subvariants, and prevented infection in hamsters challenged with Omicron BA.

SARS-CoV-2 hijacks neutralizing dimeric IgA for nasal infection and injury in Syrian hamsters.

Prevention of robust severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in nasal turbinate (NT) requires evaluation of IgA neutralizing antibodies. Here, we report the efficacy of receptor binding domain (RBD)-specific monomeric B8-mIgA1 and B8-mIgA2, and dimeric B8-dIgA1, B8-dIgA2 and TH335-dIgA1 against intranasal SARS-CoV-2 challenge in Syrian hamsters. These antibodies exhibited comparable neutralization potency against authentic virus by competing with human angiotensin converting enzyme-2 (ACE2) receptor for RBD binding.

Antibodies that neutralize all current SARS-CoV-2 variants of concern by conformational locking.

SARS-CoV-2 continues to evolve and evade most existing neutralizing antibodies, including all clinically authorized antibodies. We have isolated and characterized two human monoclonal antibodies, 12-16 and 12-19, which exhibited neutralizing activities against all SARS-CoV-2 variants tested, including BQ.1.

A molecularly engineered, broad-spectrum anti-coronavirus lectin inhibits SARS-CoV-2 and MERS-CoV infection in vivo.

"Pan-coronavirus" antivirals targeting conserved viral components can be designed. Here, we show that the rationally engineered H84T-banana lectin (H84T-BanLec), which specifically recognizes high mannose found on viral proteins but seldom on healthy human cells, potently inhibits Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (including Omicron), and other human-pathogenic coronaviruses at nanomolar concentrations. H84T-BanLec protects against MERS-CoV and SARS-CoV-2 infection in vivo.

A small animal model of chronic hepatitis E infection using immunocompromised rats.

Background & Aims: HEV variants such as swine genotypes within species (HEV-A) and rat HEV (; HEV-C1) cause chronic hepatitis E in immunocompromised individuals. There are few reliable and accessible small animal models that accurately reflect chronic HEV infection. We aimed to develop an immunocompromised rat model of chronic hepatitis E infection.

The spike receptor-binding motif G496S substitution determines the replication fitness of SARS-CoV-2 Omicron sublineage.

The replication and pathogenicity of SARS-CoV-2 Omicron BA.2 are comparable to that of BA.1 in experimental animal models.

Coronaviruses exploit a host cysteine-aspartic protease for replication.

Highly pathogenic coronaviruses, including severe acute respiratory syndrome coronavirus 2 (refs. ) (SARS-CoV-2), Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-1 (ref. ), vary in their transmissibility and pathogenicity.

A broadly neutralizing antibody protects Syrian hamsters against SARS-CoV-2 Omicron challenge.

The strikingly high transmissibility and antibody evasion of SARS-CoV-2 Omicron variants have posed great challenges to the efficacy of current vaccines and antibody immunotherapy. Here, we screen 34 BNT162b2-vaccinees and isolate a public broadly neutralizing antibody ZCB11 derived from the IGHV1-58 family. ZCB11 targets viral receptor-binding domain specifically and neutralizes all SARS-CoV-2 variants of concern, especially with great potency against authentic Omicron and Delta variants.

Pathogenicity, transmissibility, and fitness of SARS-CoV-2 Omicron in Syrian hamsters.

The in vivo pathogenicity, transmissibility, and fitness of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.

SARS-CoV-2 infection induces inflammatory bone loss in golden Syrian hamsters.

Extrapulmonary complications of different organ systems have been increasingly recognized in patients with severe or chronic Coronavirus Disease 2019 (COVID-19). However, limited information on the skeletal complications of COVID-19 is known, even though inflammatory diseases of the respiratory tract have been known to perturb bone metabolism and cause pathological bone loss. In this study, we characterize the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on bone metabolism in an established golden Syrian hamster model for COVID-19.

An antibody class with a common CDRH3 motif broadly neutralizes sarbecoviruses.

The devastation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made clear the importance of pandemic preparedness. To address future zoonotic outbreaks due to related viruses in the sarbecovirus subgenus, we identified a human monoclonal antibody, 10-40, that neutralized or bound all sarbecoviruses tested in vitro and protected against SARS-CoV-2 and SARS-CoV in vivo. Comparative studies with other receptor-binding domain (RBD)-directed antibodies showed 10-40 to have the greatest breadth against sarbecoviruses, suggesting that 10-40 is a promising agent for pandemic preparedness.

Probable Animal-to-Human Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Delta Variant AY.127 Causing a Pet Shop-Related Coronavirus Disease 2019 (COVID-19) Outbreak in Hong Kong.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect human and other mammals, including hamsters. Syrian (Mesocricetus auratus) and dwarf (Phodopus sp.) hamsters are susceptible to SARS-CoV-2 infection in the laboratory setting.

ACE2-like carboxypeptidase B38-CAP protects from SARS-CoV-2-induced lung injury.

Angiotensin-converting enzyme 2 (ACE2) is a receptor for cell entry of SARS-CoV-2, and recombinant soluble ACE2 protein inhibits SARS-CoV-2 infection as a decoy. ACE2 is a carboxypeptidase that degrades angiotensin II, thereby improving the pathologies of cardiovascular disease or acute lung injury. Here we show that B38-CAP, an ACE2-like enzyme, is protective against SARS-CoV-2-induced lung injury.

Low Environmental Temperature Exacerbates Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Golden Syrian Hamsters.

Background: The effect of low environmental temperature on viral shedding and disease severity of Coronavirus Disease 2019 (COVID-19) is uncertain.

Methods: We investigated the virological, clinical, pathological, and immunological changes in hamsters housed at room (21°C), low (12-15°C), and high (30-33°C) temperature after challenge by 105 plaque-forming units of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Results: The nasal turbinate, trachea, and lung viral load and live virus titer were significantly higher (~0.

Targeting highly pathogenic coronavirus-induced apoptosis reduces viral pathogenesis and disease severity.

Infection by highly pathogenic coronaviruses results in substantial apoptosis. However, the physiological relevance of apoptosis in the pathogenesis of coronavirus infections is unknown. Here, with a combination of in vitro, ex vivo, and in vivo models, we demonstrated that protein kinase R-like endoplasmic reticulum kinase (PERK) signaling mediated the proapoptotic signals in Middle East respiratory syndrome coronavirus (MERS-CoV) infection, which converged in the intrinsic apoptosis pathway.

Robust SARS-CoV-2 infection in nasal turbinates after treatment with systemic neutralizing antibodies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by a burst in the upper respiratory portal for high transmissibility. To determine human neutralizing antibodies (HuNAbs) for entry protection, we tested three potent HuNAbs (IC range, 0.0007-0.

Beneficial effect of combinational methylprednisolone and remdesivir in hamster model of SARS-CoV-2 infection.

Effective treatments for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Dexamethasone has been shown to confer survival benefits to certain groups of hospitalized patients, but whether glucocorticoids such as dexamethasone and methylprednisolone should be used together with antivirals to prevent a boost of SARS-CoV-2 replication remains to be determined. Here, we show the beneficial effect of methylprednisolone alone and in combination with remdesivir in the hamster model of SARS-CoV-2 infection.

Coinfection by Severe Acute Respiratory Syndrome Coronavirus 2 and Influenza A(H1N1)pdm09 Virus Enhances the Severity of Pneumonia in Golden Syrian Hamsters.

Background: Clinical outcomes of the interaction between the co-circulating pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and seasonal influenza viruses are unknown.

Methods: We established a golden Syrian hamster model coinfected by SARS-CoV-2 and mouse-adapted A(H1N1)pdm09 simultaneously or sequentially. The weight loss, clinical scores, histopathological changes, viral load and titer, and serum neutralizing antibody titer were compared with hamsters challenged by either virus.

Oral SARS-CoV-2 Inoculation Establishes Subclinical Respiratory Infection with Virus Shedding in Golden Syrian Hamsters.

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is transmitted largely by respiratory droplets or airborne aerosols. Despite being frequently found in the immediate environment and feces of patients, evidence supporting the oral acquisition of SARS-CoV-2 is unavailable. Using the Syrian hamster model, we demonstrate that the severity of pneumonia induced by the intranasal inhalation of SARS-CoV-2 increases with virus inoculum.