Wang, J.-Y. | Search bioRxiv

bioRxiv2021

The plastid genome characteristics of a moth orchid (Phalaenopsis wilsoniii, Orchidaceae)

Phalaenopsis wilsonii is a typical deciduous species in the horticulturally well-known genus, Phalaenopsis. Tshi species is belonging to the section Aphyllae in moth orchid, and is endemic to South China. Although the Aphyllae section display the deciduous feature that is unique in this genus, their genetic information is still insufficient and limited them as breeding parent in moth orchid. Here, we reported and characterized the complete chloroplast genome for Phalaenopsis wilsonii. We found the total size of the chloroplast genome was 145,373 bp, constituting of a large single copy (LSC) region (84,996 bp), a small single-copy region (10,668 bp) and two inverted repeats (IRs) regions (24,855 bp). Based on homologous searching on database, we annotated 76 protein-coding genes, 38 tRNA, and 8 rRNA. The phylogenetic reconstruction revealed that P. wilsonii show the closest relationship with P. lowii within subgenus Parishianae.

genomics↗

bioRxiv2020

Human Surfactant Protein D Binds S1 and Receptor Binding Domain of Spike protein and acts as an entry inhibitor of SARS-CoV-2 Pseudotyped viral particles in vitro

Human SP-D is a potent innate immune molecule whose presence at pulmonary mucosal surfaces allows immune surveillance role against pulmonary pathogens. Higher levels of serum SP-D have been reported in patients with severe acute respiratory syndrome coronavirus-1 (SARS-CoV). Studies have suggested the ability of human SP-D to recognise spike glycoprotein of SARS-CoV; its interaction with HCoV-229E strain leads to viral inhibition in human bronchial epithelial (16HBE) cells. Previous studies have reported that a recombinant fragment of human SP-D (rfhSP-D) composed of 8 Gly-X-Y repeats, neck and CRD region, can act against a range of viral pathogens including influenza A Virus and Respiratory Syncytial Virus in vitro, in vivo and ex vivo models. In this context, this study was aimed at examining the likely protective role of rfhSP-D against SARS-CoV-2 infection. rfhSP-D showed a dose-responsive binding to S1 spike protein of SARS-CoV-2 and its receptor binding domain. Importantly, rfhSP-D inhibited interaction of S1 protein with the HEK293T cells overexpressing Angiotensin Converting Enzyme 2. The protective role of rfhSP-D against SARS-CoV-2 infection as an entry inhibitor was further validated by the use of pseudotyped lentiviral particles expressing SARS-CoV-2 S1 protein; ~0.5 RLU fold reduction in viral entry was seen following rfhSP-D treatment (10 g/ml). The results highlight the therapeutic potential of rfhSP-D in SARS-CoV-2 infection and merits pre-clinical studies in murine models.

microbiology↗