To determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards in Wuhan, China, we tested air and surface samples. Contamination was greater in intensive care units than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients.
29 November 2021 in Cellular & Molecular Immunology
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is closely related to various cellular aspects associated with autophagy. However, how SARS-CoV-2 mediates the subversion of the macroautophagy/autophagy pathway remains largely unclear. In this study, we demonstrate that overexpression of the SARS-CoV-2 ORF7a protein activates LC3-II and leads to the accumulation of autophagosomes in multiple cell lines, while knockdown of the viral ORF7a gene via shRNAs targeting ORF7a sgRNA during SARS-CoV-2 infection decreased autophagy levels. Mechanistically, the ORF7a protein initiates autophagy via the AKT-MTOR-ULK1‐mediated pathway, but ORF7a limits the progression of autophagic flux by activating CASP3 (caspase 3) to cleave the SNAP29 protein at aspartic acid residue 30 (D30), ultimately impairing complete autophagy. Importantly, SARS-CoV-2 infection-induced accumulated autophagosomes promote progeny virus production, whereby ORF7a downregulates SNAP29, ultimately resulting in failure of autophagosome fusion with lysosomes to promote viral replication. Taken together, our study reveals a mechanism by which SARS-CoV-2 utilizes the autophagic machinery to facilitate its own propagation via ORF7a.
We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species.
H5N6 avian influenza viruses (AIVs) may pose a potential human risk as suggested by the first documented naturally-acquired human H5N6 virus infection in 2014. Here, we report the first cases of fatal H5N6 avian influenza virus (AIV) infection in a domestic cat and wild birds. These cases followed human H5N6 infections in China and preceded an H5N6 outbreak in chickens. The extensive migration routes of wild birds may contribute to the geographic spread of H5N6 AIVs and pose a risk to humans and susceptible domesticated animals and the H5N6 AIVs may spread from southern China to northern China by wild birds. Additional surveillance is required to better understand the threat of zoonotic transmission of AIVs.
About Me
Prof. Gao's interest is the pathogenesis of influenza virus.
Prof. Gao's interest is the pathogenesis of influenza virus.