Prokaryotic expression and identification of scavenger receptor B2

Prokaryotic expression of chimeric GFP-hFc protein as a potential immune-based tool

GFP is an old-yet-powerful protein marker, which has been widely used in molecular biotechnology due to its capacity of exhibiting bright green fluorescence when exposed to ultraviolet light. The hFc region of IgG antibodies is a specific binding ligand of expressed receptors on immune cells with well-known cellular-associated functions like opsonization and phagocytosis. In this present study, we proceeded to fuse gfp-hfc gene into pET-28a to create a recombinant pET-28a-gfp-hfc vector. The expression of GPF-hFc was induced by IPTG and confirmed using SDS-PAGE and followed by Western blot probed with 6xHis antibodies. This chimeric protein was utilized in specific binding experiments with protein A/G-coated magnetic beads using a fluorescence microscope. Due to its fluorescence and binding ability, GFP-hFc could be used as a model molecule for monitoring molecule detection studies, tracking nanoparticle migration and distribution, or stimulating immune responses.

The inhibition of enterovirus 71 induced apoptosis by Durvillaea antarctica through P53 and STAT1 signaling pathway

The infection of enterovirus 71 (EV71) resulted in hand, foot, and mouth disease and may lead to severe nervous system damage and even fatalities. There are no effective drugs to treat the EV71 virus and it is crucial to find novel drugs against it. Polysaccharide isolated from Durvillaea antarctica green algae has an antiviral effect. In this study, D. antarctica polysaccharide (DAPP) inhibited the infection of EV71 was demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reverse transcription polymerase chain reaction, flow cytometry, and western blot. MTT assay showed that DAPP had no toxicity on Vero cells at the concentration 250 μg/ml. Furthermore, DAPP significantly reduced the RNA level of EV71 in a dose-dependent manner. Moreover, DAPP inhibited the Vero cells apoptosis induced by EV71 via the P53 signaling pathway. Meanwhile, the expression of signal transducer and activator of transcription 1 and mammalian target of rapamycin were increased and the proinflammatory cytokines were significantly inhibited by DAPP. Taken together, these results suggested that DAPP could be a potential pharmaceutical against the infection of EV71 virus.

Recombinant Human SCARB2 Expressed in Escherichia coli and its Potential in Enterovirus 71 Blockage

Hand, foot and mouth disease is a common viral infectious disease caused by enteroviruses, including coxsackie A16 (CVA16) and enterovirus 71 (EV71). HFMD can cause severe symptoms in children which can be fatal. Human scavenger receptor class B member 2 (SCARB2) is a cellular receptor for EV71 and CVA16, providing a potential approach for preventing EV71 infection and transmission. In this present study, we constructed and assessed the potential of recombinant SCARB2, using E. coli expression system. To generate this construct, scarb2 gene was cloned into pET22b vector and expressed in E. coli BL21 (DE3). The expression of SCARB2 was induced by 0.1 mM IPTG and analyzed using SDS-PAGE, followed by Western blot. Expressed SCARB2 was in inclusion bodies and refolded to obtain the soluble form with recovery efficacy of 100%. This recombinant protein was then validated for binding with EV71 via indirect ELISA in two different pHs (7.4 and 5.5), which partially revealed the mechanism of virus–receptor interaction. These results envisaged potential applications for utilizing recombinant SCARB2 in preventing the virus transmission.

Inhibition of Enterovirus 71 by Selenium Nanoparticles Loaded with siRNA through Bax Signaling Pathways

Enterovirus 71 (EV71) is the principal pathogen leading to severe cases of hand, foot, and mouth disease (HFMD). Specific drugs for EV71 are not discovered currently. Small interfering RNA (siRNA) provides a promising antiviral treatment pathway, but it is difficult to cross cell membranes and is easy to degrade. Nanoparticles are promising for their carrying capacity currently. In this study, the siRNA targeting EV71 VP1 gene was loaded with selenium nanoparticles (SeNPs) and surface decorated with polyethylenimine (PEI) (Se@PEI@siRNA). Se@PEI@siRNA showed a remarkable interference efficiency in the nerve cell line SK-N-SH and prevented the cells to be infected. The mechanism study revealed that Se@PEI@siRNA could lighten the extent of SK-N-SH cells for staying in the sub-G1 phase. Activation of Bax apoptosis signaling was restrained either. Taken together, this study demonstrated that Se@PEI@siRNA is a promising drug against EV71 virus.