Identifying SARS-CoV-2-related coronaviruses in Malayan pangolins.

The ongoing outbreak of viral pneumonia in China and across the world is associated with a new coronavirus, SARS-CoV-21. This outbreak has been tentatively associated with a seafood market in Wuhan, China, where the sale of wild animals may be the source of zoonotic infection2. Although bats are probable reservoir hosts for SARS-CoV-2, the identity of any intermediate host that may have facilitated transfer to humans is unknown. Here we report the identification of SARS-CoV-2-related coronaviruses in Malayan pangolins (Manis javanica) seized in anti-smuggling operations in southern China. Metagenomic sequencing identified pangolin-associated coronaviruses that belong to two sub-lineages of SARS-CoV-2-related coronaviruses, including one that exhibits strong similarity in the receptor-binding domain to SARS-CoV-2. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 suggests that pangolins should be considered as possible hosts in the emergence of new coronaviruses and should be removed from wet markets to prevent zoonotic transmission.

Inhibition of autophagy enhances adenosine­induced apoptosis in human hepatoblastoma HepG2 cells.

In cancer research, autophagy acts as a double­edged sword: it increases cell viability or induces cell apoptosis depending upon the cell context and functional status. Recent studies have shown that adenosine (Ado) has cytotoxic effects in many tumors. However, the role of autophagy in Ado­induced apoptosis is still poorly understood. In the present study, Ado­induced apoptotic death and autophagy in hepatoblastoma HepG2 cells was investigated and the relationship between autophagy and apoptosis was identified. In the present study, it was demonstrated that Ado inhibited HepG2 cell growth in a time­ and concentration­dependent manner and activated endoplasmic reticulum (ER) stress, as indicated by G0/G1 cell cycle arrest, the increased mRNA and protein levels of GRP78/BiP, PERK, ATF4, CHOP, cleaved caspase­3, cytochrome c and the loss of mitochon-drial membrane potential (ΔΨm). Ado also induced autophagic flux, revealed by the increased expression of the autophagy marker microtubule­associated protein 1 light chain 3­II (LC3­II), Beclin­1, autophagosomes, and the degradation of p62, as revealed by western blot analysis and macrophage­derived chemokine (MDC) staining. Blocking autophagy using LY294002 notably entrenched Ado­induced growth inhibition and cell apoptosis, as demonstrated with the increased expression of cytochrome c and p62, and the decreased expression of LC3­II. Conversely, the autophagy inducer rapamycin alleviated Ado­induced apoptosis and markedly increased the ΔΨm. Moreover, knockdown of AMPK with si­AMPK partially abolished Ado­induced ULK1 activation and mTOR inhibition, and thus reinforced CHOP expression and Ado­induced apoptosis. These results indicated that Ado­induced ER stress resulted in apoptosis and autophagy concurrently. The AMPK/mTOR/ULK1 signaling pathway played a protective role in the apoptotic procession. Inhibition of autophagy may effectively enhance the anticancer effect of Ado in human hepatoblastoma HepG2 cells.

Seroconversion to pandemic (H1N1) 2009 virus and cross-reactive immunity to other swine influenza viruses.

To assess herd immunity to swine influenza viruses, we determined antibodies in 28 paired serum samples from participants in a prospective serologic cohort study in Hong Kong who had seroconverted to pandemic (H1N1) 2009 virus. Results indicated that infection with pandemic (H1N1) 2009 broadens cross-reactive immunity to other recent subtype H1 swine viruses.

Detection of diverse astroviruses from bats in China.

Astroviruses infect humans and many different animal species and are associated with gastroenteritis. Recent studies first detected the virus from bat species in Hong Kong. To understand astrovirus distribution in the wider region further, we examined the prevalence of this virus family in bat specimens collected from a large geographical region of mainland China. We collected 500 anal swabs from 20 bat species in 51 natural habitats from 11 provinces of China and tested these for astroviruses. Our study revealed a remarkably high genetic diversity of astroviruses; five monophyletic groups were identified in bats, including two novel groups. Evidence for varying degrees of host restriction for astroviruses from bats has been found. Phylogenetic analyses also provided insight into the inter-species transmission of Mamastrovirus.

Detection and phylogenetic analysis of group 1 coronaviruses in South American bats.

Bat coronaviruses (Bt-CoVs) are thought to be the precursors of severe acute respiratory syndrome coronavirus. We detected Bt-CoVs in 2 bat species from Trinidad. Phylogenetic analysis of the RNA-dependent RNA polymerase gene and helicase confirmed them as group 1 coronaviruses.

Establishment of stably expressed human RANTES gene in prunella vulgaris cell clone / 生物工程学报

To express interesting human genes in herbal cells for boosting their specific pharmacological activities, RANTES gene cloned from human peripheral blood lymphocyte (PBL) mRNA was introduced into A. tumefaciens strain LBA4404 harboring pAL4404 plasmid via tumor-inducing (Ti) plasmid-derived intermediate expression vector pROKII. In vitro cultured P. vulgaris cells were transformed by leaf-disk cocultivation procedure. Integration of RANTES gene in the genome of transformed cells was confirmed by Southern blotting, and expression of RANTES gene in transformed cells was analyzed by RT-PCR amplification, Western blotting and enzyme-linked immunosorbent assay (ELISA). The peroxidase activity of PBL was utilized as a detection index of cellular chemotropism induction by recombinant RANTES. The results have shown the RANTES gene was integrated in transgenic P. vulgaris cells, and RANTES gene-stably expressed cell clones were available, which could pave the way to obtain transgenic P. vulgaris plants demonstrating specific pharmacological activities.