Coimmunization with IL-15 plasmid enhances the longevity of CD8 T cells induced by DNA encoding hepatitis B virus core antigen

AIM： To test the feasibility of delivering a plasmid encoding IL-15 as a DNA vaccine adjuvant for improving the immune responses induced by hepatitis B virus core gene DNA vaccine. METHODS： We used RT-PCR based strategies to develop IL-15 expression constructs. We first confirmed that the gene could be expressed in Escherichia coli due to the poor expression of IL-15. Then the bioactivity of IL-15 plasmid expression product was identified by CTLL-2 proliferation assay. One hundred micrograms of DNA from each of the IL-15 eukaryotic expressed plasmid and the recombinant plasmid harboring DNA encoding the 144 amino acids of the N-terminus of HBV core gene （abbreviated pHBc144） was used to co-immunize C57 BL/6 mice. The titer of anti-HBcIgG was detected by ELISA and the antigen-specific CD8^＋T cells （CD8^＋IFN-γ^＋ T cells） were detected by intracellular cytokine staining at different time points. RESULTS： After co-immunization by pIL-15 and pHBc144 DNA vaccine the antigen-specific CD8^＋ cells of mice increased gradually, the first peak of immune response appeared 14 d later, then the number of antigen-specific CD8^＋Ts cells decreased gradually and maintained at a steady level in 3 mo. After boosting, the number of antigen-specific CD8^＋T cells reached the second peak 10 d later with a double of the 1st peak, then the number of antigen-specific CD8^＋T cells decreased slowly. IL-15 as a gene adjuvant had no significant effect on humoral immune responses induced by hepatitis B virus core gene DNA vaccine, but increased the memory antigen-specific CD8^＋T cells induced by hepatitis B virus core gene DNA vaccine. CONCLUSION： DNA vaccine constructed by HBc Ag 1-144 amino acid induces effective cell immunity, and cytokine plasmid-delivered IL-15 enhances the longevity of CD8^＋ T cells.

Continuous-wave operation of InAs/InP quantum dot tunable external-cavity laser grown by metal-organic chemical vapor deposition

We demonstrate high-performance broadband tunable external-cavity lasers(ECLs) with the metal-organic chemical vapor deposition(MOCVD) grown In As/In P quantum dots(QDs) structures. Without cavity facet coatings, the 3-d B spectral bandwidth of the Fabry–Perot(FP) laser is approximately 10.8 nm, while the tuning bandwidth of ECLs is 45 nm.Combined with the anti-reflection(AR)/high-reflection(HR) facet coating, a 92 nm bandwidth tuning range has been obtained with the wavelength covering from 1414 nm to 1506 nm. In most of the tuning range, the threshold current density is lower than 1.5 k A/cm2. The maximum output power of 6.5 m W was achieved under a 500 m A injection current.All achievements mentioned above were obtained under continuous-wave(CW) mode at room temperature(RT).

Filamentation initiated by Cas2 and its association with the acquisition process in cells

Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity.The process is critical for the ecology of the oral microflora and oral health.Although molecular mechanisms for spacer acquisition are known,it has never been established if this process is associated with the morphological changes of bacteria.In this study,we demonstrated a novel Cas2-induced filamentation phenotype in E.coli that was regulated by co-expression of the Cas1 protein.A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function.By imaging analysis,we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division.This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.

How EFL Learners from China and ASEAN Countries Politely Express Disagreement in an English Context:A Comparative Study

This paper aims to make a comparative study of cross-cultural communication upon a special speech act-"disagreement".38 undergraduates from China and 30 undergraduates from ASEAN countries were involved.They responded to the DCT(discourse completion test).Five contexts were selected and detailed descriptions of the scenarios were given.Social distance and gender were selected as the main variants in this study.From the results,we found that both groups of undergraduates generally ten d to use the same politeness strategies according to the same social distance,but gender was a more significant factor in politeness strategies adoption among EFL learners from ASEAN countries.Females tend to use negative strategies more than males do.We can conclude from the results that EFL learners from China and ASEAN countries incline to adopt the same politeness strategies in English context,but females from ASEAN countries are less likely to say“no”directly to express their disagreement compared to their counterpart.Those findings may offer reference to both sides during the pragmatic occasions of communicating.

IFN-γ increases efficiency of DNA vaccine in protecting ducks against infection

AIM： To detect the effects of DNA vaccines in combination with duck IFN-γ gene on the protection of ducks against duck hepatitis B virus （DHBV） infection. METHODS： DuIFN-γ cDNA was cloned and expressed in COS-γ cells, and the antiviral activity of DuIFN-γ was detected and neutralized by specific antibodies, Ducks were vaccinated with DHBpreS/S DNA alone or coimmunized with plasmid expressing DuIFN-γ. DuIFN-γ mRNA in peripheral blood mononuclear cells （PBMCs） from immunized ducks was detected by semi-quantitative competitive RT-PCR. Anti-DHBpreS was titrated by enzyme-linked immunosorbent assay （EUSA）. DHBV DNA in sera and liver was detected by Southern blot hybridization, after ducks were challenged with high doses of DHBV. RESULTS： DuIFN-γ expressed by COS-γ was able to protect duck fibroblasts against vesicular stomatitis virus （VSV） infection in a dose-dependent fashion, and anti DuIFN-γ antibodies neutralized the antiviral effects. DuIFN-γ in the supernatant also inhibited the release of DHBV DNA from LMH-D2 cells. When ducks were co-immunized with DNA vaccine expressing DHBpreS/S and DuIFN-γ gene as an adjuvant, the level of DuIFN-γ mRNA in PBMCs was higher than that in ducks vaccinated with DHBpreS/S DNA alone. However, the titer of anti-DHBpreS elicited by DHBpreS/S DNA alone was higher than that co-immunized with DuIFN-γ gene and DHBpreS/S DNA. After being challenged with DHBV at high doses, the load of DHBV in sera dropped faster, and the amount of total DNA and cccDNA in the liver decreased more significantly in the group of ducks co-immunized with DuIFN-γ gene and DHBpreS/S DNA than in other groups.

RBD-Fc-based COVID-19 vaccine candidate induces highly potent SARS-CoV-2 neutralizing antibody response

The pandemic of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has posed serious threats to global health and economy,thus calling for the development of safe and effective vaccines.The receptorbinding domain(RBD)in the spike protein of SARS-CoV-2 is responsible for its binding to angiotensin-converting enzyme 2(ACE2)receptor.It contains multiple dominant neutralizing epitopes and serves as an important antigen for the development of COVID-19 vaccines.Here,we showed that immunization of mice with a candidate subunit vaccine consisting of SARS-CoV-2 RBD and Fc fragment of human IgG,as an immunopotentiator,elicited high titer of RBD-specific antibodies with robust neutralizing activity against both pseudotyped and live SARS-CoV-2 infections.The mouse antisera could also effectively neutralize infection by pseudotyped SARS-CoV-2 with several natural mutations in RBD and the IgG extracted from the mouse antisera could also show neutralization against pseudotyped SARS-CoV and SARS-related coronavirus(SARSr-CoV).Vaccination of human ACE2 transgenic mice with RBD-Fc could effectively protect mice from the SARS-CoV-2 challenge.These results suggest that SARS-CoV-2 RBD-Fc has good potential to be further developed as an effective and broad-spectrum vaccine to prevent infection of the current SARS-CoV-2 and its mutants,as well as future emerging SARSr-CoVs and re-emerging SARS-CoV.

Griffithsin with A Broad-Spectrum Antiviral Activity by Binding Glycans in Viral Glycoprotein Exhibits Strong Synergistic Effect in Combination with A Pan-Coronavirus Fusion Inhibitor Targeting SARS-CoV-2 Spike S2 Subunit

Dear Editor,The pandemic of coronavirus disease 2019(COVID-19)caused by SARS-Co V-2 has posed a significant threat to global public health and economy,thus calling for the rapid development of effective therapeutics and prophylactics.Repurposing existing medicines with clinical safety profiles offers a more rapid hope of combating COVID-19pandemic than developing a new therapeutic.

Effect of chlorine dioxide on avian influenza A(H7N9)virus

Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.

Profibrogenic macrophage-targeted delivery of mitochondrial protector via exosome formula for alleviating pulmonary fibrosis

Pulmonary fibrosis(PF)is a devastating lung disease with limited treatment options.During this pathological process,the profibrogenic macrophage subpopulation plays a crucial role,making the characterization of this subpopulation fundamentally important.The present study revealed a positive correlation between pulmonary macrophages with higher mitochondrial mass(Mø^(mitohigh))and fibrosis.Among the Mø^(mitohigh)subpopulation of CD206^(+)M2,characterized by higher expression of dynamin 1-like(Drp1),as determined by flow cytometry and RNA-seq analysis,a therapeutic intervention was developed using an exosome-based formula composed of pathfinder and therapeutics.A pathfinder exosome called“exosome^(MMP19)(Exo^(MMP19))”,was constructed to display matrix metalloproteinase-19(^(MMP19))on the surface to locally break down the excessive extracellular matrix(ECM)in the fibrotic lung.A therapeutic exosome called“exosome therapeutics(Exo^(Tx))”,was engineered to display D-mannose on the surface while encapsulating siDrp1 inside.Prior delivery of Exo^(MMP19)degraded excessive ECM and thus paved the way for Exo^(Tx)to be delivered into Mø^(mitohigh),where Exo^(Tx)inhibited mitochondrial fission and alleviated PF.This study has not only identified Mø^(mitohigh)as profibrotic macrophages but it has also provided a potent strategy to reverse PF via a combination of formulated exosomes.

Polyoxometalate-Based Ionic Frameworks for Highly Selective CO_(2) Capture and Separation

During the utilization of structural and functional advantages of polyoxometalates(POMs)for enhanced applications,a suitable assembly of these clusters in framework materials to act as binding nodes represents a promising approach.In contrast to well-developed coordination/covalent combinations,we have developed a convenient strategy to build porous structures of POMs with smaller-sized counterions as bridging ligands via ionic interactions to reinforce their capability in gas adsorption in parallel to metal-organic frameworks(MOFs)/covalent organic frameworks(COFs).With this goal,a series of POMs-based ionic frameworks(IFs)were constructed with triol-ligand modified Anderson-Evans-type clusters as building blocks,and their sodium counter-cations were used as linkers.The three-dimensional(3D)open-frameworks obtained displayed unusually selective CO_(2) capturing capability and efficient separation from their N_(2),H_(2),and CH_(4) mixtures under low pressure at room temperature.Among the synthesized IFs,the cobalt-centered cluster exhibited the best performance for the uptake and selective separation of CO_(2) over N_(2) and CH_(4) in a range of 0-1 bar,while the nickel-centered cluster displayed the highest selectivity over H_(2) at 1 bar.Breakthrough experiments based on real binary gas mixtures demonstrated that the cobalt-containing framework illustrated high performance in the actual gas separation and sustained stability against a simulated operating environment.

ProtoporphyrinⅨand verteporfin potently inhibit SARS-CoV-2 infection in vitro and in a mouse model expressing human ACE2

The SARS-CoV-2 infection is spreading rapidly worldwide.Efficacious antiviral therapeutics against SARSCo V-2 is urgently needed.Here,we discovered that protoporphyrin IX(Pp IX)and verteporfin,two Food and Drug Administration(FDA)-approved drugs,completely inhibited the cytopathic effect produced by SARS-CoV-2 infection at 1.25 lmol/L and 0.31 lmol/L,respectively,and their EC50 values of reduction of viral RNA were at nanomolar concentrations.The selectivity indices of Pp IX and verteporfin were 952.74 and 368.93,respectively,suggesting a broad margin of safety.Importantly,Pp IX and verteporfin prevented SARS-CoV-2 infection in mice adenovirally transduced with human angiotensin-converting enzyme 2(ACE2).The compounds,sharing a porphyrin ring structure,were shown to bind viral receptor ACE2 and interfere with the interaction between ACE2 and the receptor-binding domain of viral S protein.Our study suggests that Pp IX and verteporfin are potent antiviral agents against SARS-CoV-2 infection and sheds new light on developing novel chemoprophylaxis and chemotherapy against SARS-CoV-2.