Identification of ferroptosis-associated genes and potential pharmacological targets in sepsis-induced myopathy.

Background: The role of Ferroptosis in the course of sepsis-induced myopathy is yet unclear. The objective of our work is to identify key genes connected with Ferroptosis in sepsis-induced myopathy and investigate possible pharmaceutical targets related to this process. This research aims to provide new insights into the management of sepsis-induced myopathy. Methods: We got the GSE13205 dataset from the Gene Expression Omnibus (GEO) and extracted Ferroptosis-associated genes from the FerrDb database. After conducting a functional annotation analysis of these genes, we created a protein-protein interaction network using Cytoscape software to identify important genes. Subsequently, we employed CMap to investigate prospective pharmaceuticals that could target these crucial genes. Results: A total of 61 genes that are expressed differently (DEGs) have been found concerning Ferroptosis. These genes are involved in a wide range of biological functions, including reacting to signals from outside the cell and the availability of nutrients, programmed cell death, controlling apoptosis, and responding to peptides, chemical stressors, and hormones. The KEGG pathway study revealed that these pathways are involved in Ferroptosis, autophagy, P53 signaling, PI3K-Akt signaling, mTOR signaling, HIF-1 signaling, endocrine resistance, and different tumorigenic processes. In addition, we created a network that shows the simultaneous expression of important genes and determined the top 10 medications that have the potential to treat sepsis-induced myopathy. Conclusion: The bioinformatics research undertaken sheds insight into the probable role of Ferroptosis-associated genes in sepsis-induced myopathy. The identified critical genes show potential as therapeutic targets for treating sepsis-induced myopathy, offering opportunities for the development of tailored medicines.

Disparate macrophage responses are linked to infection outcome of Hantan virus in humans or rodents.

Hantaan virus (HTNV) is asymptomatically carried by rodents, yet causes lethal hemorrhagic fever with renal syndrome in humans, the underlying mechanisms of which remain to be elucidated. Here, we show that differential macrophage responses may determine disparate infection outcomes. In mice, late-phase inactivation of inflammatory macrophage prevents cytokine storm syndrome that usually occurs in HTNV-infected patients. This is attained by elaborate crosstalk between Notch and NF-κB pathways. Mechanistically, Notch receptors activated by HTNV enhance NF-κB signaling by recruiting IKKß and p65, promoting inflammatory macrophage polarization in both species. However, in mice rather than humans, Notch-mediated inflammation is timely restrained by a series of murine-specific long noncoding RNAs transcribed by the Notch pathway in a negative feedback manner. Among them, the lnc-ip65 detaches p65 from the Notch receptor and inhibits p65 phosphorylation, rewiring macrophages from the pro-inflammation to the pro-resolution phenotype. Genetic ablation of lnc-ip65 leads to destructive HTNV infection in mice. Thus, our findings reveal an immune-braking function of murine noncoding RNAs, offering a special therapeutic strategy for HTNV infection.

Remdesivir (GS-5734) Impedes Enterovirus Replication Through Viral RNA Synthesis Inhibition.

Human enteroviruses are responsible for diverse diseases, from mild respiratory symptoms to fatal neurological complications. Currently, no registered antivirals have been approved for clinical therapy. Thus, a therapeutic agent for the enterovirus-related disease is urgently needed. Remdesivir (GS-5734) is a novel monophosphoramidate adenosine analog prodrug that exhibits potent antiviral activity against diverse RNA virus families, including positive-sense Coronaviridae and Flaviviridae and negative-sense Filoviridae, Paramyxoviridae, and Pneumoviridae. Currently, remdesivir is under phase 3 clinical development for disease COVID-19 treatment. Here, we found that remdesivir impeded both EV71 viral RNA (vRNA) and complementary (cRNA) synthesis, indicating that EV71 replication is inhibited by the triphosphate (TP) form of remdesivir. Moreover, remdesivir showed potent antiviral activity against diverse enteroviruses. These data extend the remdesivir antiviral activity to enteroviruses and indicate that remdesivir is a promising antiviral treatment for EV71 and other enterovirus infections.

N6-methyladenosine modifications enhance enterovirus 71 ORF translation through METTL3 cytoplasmic distribution.

During replication, numerous viral RNAs are modified by N6-methyladenosine (m6A), the most abundant internal RNA modification. m6A is believed to regulate elements of RNA metabolism, such as splicing, stability, translation, secondary structure formation, and viral replication. In this study, we assessed the occurrence of m6A modification of the EV71 genome in human cells and revealed a preferred, conserved modification site across diverse viral strains. A single m6A modification at the 5' UTR-VP4 junction was shown to perform a protranslational function. Depletion of the METTL3 methyltransferase or treatment with 3-deazaadenosine significantly reduced EV71 replication. Specifically, METTL3 colocalized with the viral dsRNA replication intermediate in the cytoplasm during EV71 infection. As a nuclear resident protein, METTL3 relies on the binding of the nuclear import protein karyopherin to its nuclear localization signal (NLS) for nuclear translocation. We observed that EV71 2A and METTL3 share nuclear import proteins. The results of this study revealed an inner mechanism by which EV71 2A regulates the subcellular location of METTL3 to amplify its own gene expression, providing an increased understanding of RNA epitranscriptomics during the EV71 replication cycle.

Recombinant BCG With Bacterial Signaling Molecule Cyclic di-AMP as Endogenous Adjuvant Induces Elevated Immune Responses After Mycobacterium tuberculosis Infection.

Bacillus Calmette-Guerin (BCG) is a live attenuated vaccine against tuberculosis (TB) and remains the most commonly used vaccine worldwide. However, BCG has varied protective efficiency in adults and has safety concerns in immunocompromised population. Thus, effective vaccines are necessary for preventing the prevalence of TB. Cyclic di-AMP (c-di-AMP) is a bacterial second messenger which regulates various cellular processes and host immune response. Previous work found that c-di-AMP regulates bacterial physiological function, pathogenicity and host type I IFN response. In this study, we constructed a recombinant BCG (rBCG) by overexpressing DisA, the diadenylate cyclase of Mycobacterium tuberculosis (Mtb), and observed the physiological changes of rBCG-DisA. The immunological characteristics of rBCG-DisA were investigated on humoral and cellar immune responses in a mice infection model. Our study demonstrated that overexpression of DisA in BCG does not affect the growth but reduces the length of BCG. rBCG-DisA-immunized mice show similar humoral and cellar immune responses in BCG-immunized mice. After Mtb infection, the splenic lymphocytes from both BCG and rBCG-DisA-immunized mice produced more IFN-γ, IL-2, and IL-10 than the un-immunized (UN) mice, while the cytokine levels of the rBCG-DisA group increased significantly than those of the BCG group. The transcription of IFN-ß, IL-1ß and autophagy related genes (Atgs) were up-regulated in macrophages after treated with c-di-AMP or bacterial infection. The productions of IL-6 were increased after Mtb challenge, especially in the rBCG-DisA-immunized mice. Strikingly, H3K4me3, the epigenetic marker of innate immune memory, was found in both two immunized groups, and the rBCG-DisA group showed stronger expression of H3K4me3 than that of BCG. In addition, the pathological changes of rBCG-DisA immunized mice were similar to that of BCG-immunized mice. The bacterial burdens in the lungs and spleens of BCG- and rBCG-DisA-immunized mice were significantly decreased, but there was no significant difference between the two immunized groups. Together, these results suggested that compared to BCG, rBCG-DisA vaccination, induces stronger immune responses but did not provided additional protection against Mtb infection in this study, which may be related to the innate immunity memory. Hence, c-di-AMP is a promising immunomodulator for a further developed BCG as a better vaccine.

Expression of Rv2031c-Rv2626c fusion protein in Mycobacterium smegmatis enhances bacillary survival and modulates innate immunity in macrophages.

Dormancy-associated antigens encoded by the dormancy survival regulon (DosR) genes are required for survival of Mycobacterium tuberculosis (Mtb) in macrophages. However, mechanisms underlying survival of Mtb in macrophages remains to be elucidated. A recombinant Mycobacterium smegmatis strain (rMs) expressing a fusion protein of two dormancy­associated antigens Rv2031c and Rv2626c from Mtb was constructed in the present study. In an in vitro culture, growth rate of rMs was lower compared with Ms. A total of 24 h following infection of murine macrophages with rMs or Ms, percentage of viable cells decreased and the number of bacteria in viable cells increased compared with Ms, demonstrating that virulence and intracellular survival of rMs were enhanced. Compared with macrophages infected with Ms, necrosis of macrophages infected with rMs was increased, while apoptosis was inhibited. Macrophages infected with rMs secreted more interferon­Î³ and interleukin­6, but fewer nitric oxide and tumor necrosis factor­α, compared with macrophages infected with Ms. The present study demonstrated that the fusion protein composed of dormancy­associated antigens Rv2031c and Rv2626c in Ms serves a physiological function of a dormancy­associated antigen and modulates innate immunity of host macrophages, therefore favoring intracellular bacillary survival.

Structural basis for neutralization of Japanese encephalitis virus by two potent therapeutic antibodies.

Japanese encephalitis virus (JEV), closely related to dengue, Zika, yellow fever and West Nile viruses, remains neglected and not well characterized 1 . JEV is the leading causative agent of encephalitis, and is responsible for thousands of deaths each year in Asia. Humoral immunity is essential for protecting against flavivirus infections and passive immunization has been demonstrated to be effective in curing disease2,3. Here, we demonstrate that JEV-specific monoclonal antibodies, 2F2 and 2H4, block attachment of the virus to its receptor and also prevent fusion of the virus. Neutralization of JEV by these antibodies is exceptionally potent and confers clear therapeutic benefit in mouse models. A single 20 µg dose of these antibodies resulted in 100% survival and complete clearance of JEV from the brains of mice. The 4.7 Å and 4.6 Å resolution cryo-electron microscopy structures of JEV-2F2-Fab and JEV-2H4-Fab complexes, together with the crystal structure of 2H4 Fab and our recent near-atomic structure of JEV 4 , unveil the nature and location of epitopes targeted by the antibodies. Both 2F2 and 2H4 Fabs bind quaternary epitopes that span across three adjacent envelope proteins. Our results provide a structural and molecular basis for the application of 2F2 and 2H4 to treat JEV infection.

The Long Noncoding RNA NEAT1 Exerts Antihantaviral Effects by Acting as Positive Feedback for RIG-I Signaling.

Hantavirus infection, which causes zoonotic diseases with a high mortality rate in humans, has long been a global public health concern. Over the past decades, accumulating evidence suggests that long noncoding RNAs (lncRNAs) play key regulatory roles in innate immunity. However, the involvement of host lncRNAs in hantaviral control remains uncharacterized. In this study, we identified the lncRNA NEAT1 as a vital antiviral modulator. NEAT1 was dramatically upregulated after Hantaan virus (HTNV) infection, whereas its downregulation in vitro or in vivo delayed host innate immune responses and aggravated HTNV replication. Ectopic expression of NEAT1 enhanced beta interferon (IFN-ß) production and suppressed HTNV infection. Further investigation suggested that NEAT1 served as positive feedback for RIG-I signaling. HTNV infection activated NEAT1 transcription through the RIG-I-IRF7 pathway, whereas NEAT1 removed the transcriptional inhibitory effects of the splicing factor proline- and glutamine-rich protein (SFPQ) by relocating SFPQ to paraspeckles, thus promoting the expression of RIG-I and DDX60. RIG-I and DDX60 had synergic effects on IFN production. Taken together, our findings demonstrate that NEAT1 modulates the innate immune response against HTNV infection, providing another layer of information about the role of lncRNAs in controlling viral infections.IMPORTANCE Hantaviruses have attracted worldwide attention as archetypal emerging pathogens. Recently, increasing evidence has highlighted long noncoding RNAs (lncRNAs) as key regulators of innate immunity; however, their roles in hantavirus infection remain unknown. In the present work, a new unexplored function of lncRNA NEAT1 in controlling HTNV replication was found. NEAT1 promoted interferon (IFN) responses by acting as positive feedback for RIG-I signaling. This lncRNA was induced by HTNV through the RIG-I-IRF7 pathway in a time- and dose-dependent manner and promoted HTNV-induced IFN production by facilitating RIG-I and DDX60 expression. Intriguingly, NEAT1 relocated SFPQ and formed paraspeckles after HTNV infection, which might reverse inhibitive effects of SFPQ on the transcription of RIG-I and DDX60. To the best of our knowledge, this is the first study to address the regulatory role of the lncRNA NEAT1 in host innate immunity after HTNV infection. In summary, our findings provide additional insights regarding the role of lncRNAs in controlling viral infections.

DDX50 inhibits the replication of dengue virus 2 by upregulating IFN-ß production.

Dengue virus (DENV) infects approximately 390 million people per year, and each of the four DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) is capable of causing infection. At present, there is no antiviral drug available for the treatment of DENV. Several DExD/H-box helicases have been shown to be involved in the antiviral immune response or viral replication. In the present study, we investigated the role of DDX50 in DENV-2 RNA replication. Our data showed that the level of DENV-2 RNA increased in DDX50 knockdown cells during an early stage of viral infection and decreased in DDX50-overexpressing cells. DDX50, in conjunction with RIG-I and MDA5, upregulated the production of IFN-ß in infected cells through an additive effect on the IFN-ß promoter. Furthermore, transcription of several IFN-stimulated genes was increased in DDX50-overexpressing cells infected with DENV-2. These results provide evidence that DDX50 negatively regulates DENV-2 replication during the early stages of infection by inducing IFN-ß production.

Construction and immunological characterization of CD40L or GM-CSF incorporated Hantaan virus like particle.

Infection of Hantaan virus (HTNV) usually causes hemorrhagic fever with renal syndrome (HFRS). China has the worst epidemic incidence of HFRS as well as high fatality. Inactivated whole virus has been used for HFRS vaccination, however there are still problems such as safety concerns. CD40 ligand (CD40L) and granulocyte macrophage colony-stimulating factor (GM-CSF) are well-known immune stimulating molecules that can enhance antigen presenting, lymphocytes activation and maturation, incorporation of CD40L and GM-CSF to the surface of virus like particles (VLPs) can greatly improve the vaccination effect. We constructed eukaryotic vectors expressing HTNV M segment and S segment, as well as vectors expressing HTNV M segment with CD40L or GM-CSF, our results showed successful production of CD40L or GM-CSF incorporated HTNV VLPs. In vitro stimulation with CD40L or GM-CSF anchored HTNV VLP showed enhanced activation of macrophages and DCs. CD40L/GM-CSF incorporated VLP can induce higher level of HTNV specific antibody and neutralizing antibody in mice. Immunized mice splenocytes showed higher ability of secreting IFN-γ and IL-2, as well as enhancing CTL activity. These results suggest CD40L/GM-CSF incorporated VLP can serve as prospective vaccine candidate.

Incorporation of GM-CSF or CD40L Enhances the Immunogenicity of Hantaan Virus-Like Particles.

A safe and effective Hantaan virus (HTNV) vaccine is highly desirable because HTNV causes an acute and often fatal disease (hemorrhagic fever with renal syndrome, HFRS). Since the immunity of the inactivated vaccine is weak and the safety is poor, HTNV virus-like particles (VLPs) offer an attractive and safe alternative. These particles lack the viral genome but are perceived by the immune system as virus particles. We hypothesized that adding immunostimulatory signals to VLPs would enhance their efficacy. To accomplish this enhancement, we generated chimeric HTNV VLPs containing glycosylphosphatidylinositol (GPI)-anchored granulocyte macrophage colony-stimulating factor (GM-CSF) or CD40 ligand (CD40L) and investigated their biological activity in vitro. The immunization of mice with chimeric HTNV VLPs containing GM-CSF or CD40L induced stronger humoral immune responses and cellular immune responses compared to the HTNV VLPs and Chinese commercial inactivated hantavirus vaccine. Chimeric HTNV VLPs containing GM-CSF or CD40L also protected mice from an HTNV challenge. Altogether, our results suggest that anchoring immunostimulatory molecules into HTNV VLPs can be a potential approach for the control and prevention of HFRS.

Isolation of Endogenously Assembled RNA-Protein Complexes Using Affinity Purification Based on Streptavidin Aptamer S1.

Efficient isolation of endogenously assembled viral RNA-protein complexes is essential for understanding virus replication mechanisms. We have developed an affinity purification strategy based on an RNA affinity tag that allows large-scale preparation of native viral RNA-binding proteins (RBPs). The streptavidin-binding aptamer S1 sequence was inserted into the 3' end of dengue virus (DENV) 5'-3' UTR RNA, and the DENV RNA UTR fused to the S1 RNA aptamer was expressed in living mammalian cells. This allowed endogenous viral ribonucleoprotein (RNP) assembly and isolation of RNPs from whole cell extract, through binding the S1 aptamer to streptavidin magnetic beads. Several novel host DENV RBPs were subsequently identified by liquid chromatography with tandem mass spectrometry (LC-MS/MS), including RPS8, which we further implicate in DENV replication. We proposed efficient S1 aptamer-based isolation of viral assembled RNPs from living mammalian cells will be generally applicable to the purification of high- and low-affinity RBPs and RNPs under endogenous conditions.

LSm1 binds to the Dengue virus RNA 3' UTR and is a positive regulator of Dengue virus replication.

Dengue virus (DENV) is a mosquito-transmitted flavivirus that can cause severe disease in humans. The DENV positive strand RNA genome contains 5' and 3' untranslated regions (UTRs) that have been shown to be required for virus replication and interaction with host cell proteins. In the present study LSm1 was identified as a host cellular protein involved in DENV RNA replication. By using two independent methodologies, we demonstrated a critical interaction between LSm1 and the 3' UTR of DENV. Furthermore, the confocal immunofluorescence analysis showed that the interaction between LSm1 and viral RNA is located in P-body around nucleoli in the cytoplasm. LSm1 knockdown by siRNA specifically reduced the levels of viral RNA in DENV-infected cells and infectious DENV particles in the supernatant. These results provide evidence that LSm1 binding to the DENV RNA 3' UTR positively regulates DENV RNA replication.

NLRP3 inflammasome is responsible for Hantavirus inducing interleukin-1ß in THP-1 cells.

Persistent high fever is one typical clinical symptom of hemorrhagic fever with renal syndrome (HFRS) and circulating interleukin-1ß (IL-1ß) is elevated throughout HFRS. The mechanisms responsible for viral induction of IL-1ß secretion are unknown. In the present study, Hantaan virus (HTNV) induced the secretion of IL-1ß in the human monocytic cell line THP-1. Induction of IL-1ß by HTNV relies on the activation of caspase-1. Small hairpin RNA knockdown in HTNV-infected THP-1 cells indicated that nucleotide-binding domain, leucine-rich repeat containing protein 3 (NLRP3) recruits the adaptor apoptosis-associated speck-like protein and caspase-1 to form an NLRP3 inflammasome complex, crucial for the induction of IL-1ß. In HTNV-infected THP-1 cells, reactive oxygen species release, but not extracellular adenosine triphosphate, was crucial for IL-1ß production. In conclusion, Hantavirus induces the formation of the NLRP3 inflammasome in THP-1 cells and this may be responsible for the elevated IL-1ß levels in HFRS patients.

Hantaan virus can infect human keratinocytes and activate an interferon response through the nuclear translocation of IRF-3.

Hantaan virus (HTNV) is a rodent-borne virus that causes hemorrhagic fever with renal syndrome (HFRS) in Asia and can be transmitted to humans through bites or the inhalation of aerosolized urine, droppings, or saliva of infected rodents. Keratinocytes predominate in the epidermis and reportedly serve as a replication site for multiple vector-borne viruses, little is known about the susceptibility of human skin cells to HTNV infection. Therefore, we aimed to evaluate whether human keratinocytes support HTNV replication and elicit an immune response against HTNV infection. We found that a human keratinocyte cell line, HaCaT, supports HTNV replication. In addition, retinoic acid inducible gene-I (RIG-I) and melanoma differentiation associated gene-5 (MDA5) play key roles in the detection of HTNV infection in HaCaT cells and in the up-regulation of interferon (IFN)-ß expression, which subsequently leads to the production of a large amount of antiviral interferon-stimulated genes (ISGs) and other chemokines used for immune cell recruitment. Furthermore, we suggest that interferon regulatory factor (IRF)-3, as opposed to NF-κB/p65 or IRF-7, is translocated to the nucleus to induce IFN-ß. However, the early induction of chemokine CXCL10 was a direct result of HaCaT cells counteracting HTNV infection and was not due to the induction of IFN. Overall, our data demonstrate, for the first time, the permissiveness of human keratinocytes to HTNV infection.

AUF1 is recruited to the stress granules induced by coxsackievirus B3.

Stress granules (SGs) are cytoplasmic granules that are formed in cells when stress occurs. In this study, we found that SGs formed in cells infected with coxsackievirus B3 (CVB3), evidenced with the co-localization of some accepted SG markers in the viral infection-induced granules. We further discovered that adenosine-uridine (AU)-rich element RNA binding factor 1 (AUF1), which can bind to mRNAs and regulate their translation, was recruited to the SGs in response to high dose of CVB3 by detecting the co-localization of AUF1 with SG markers. Similar results were also observed in the enterovirus 71 (EV71)-infected cells. Finally, we demonstrated that AUF1 was also recruited to arsenite-induced SGs, suggesting that the recruitment of AUF1 to SG is not a specific response to viral infection. In summary, our data indicate that both CVB3 and EV71 infections can induce SG formation, and AUF1 is a novel SG component upon the viral infections. Our findings may shed light on understanding the picornavirus-host interaction.

Recombinant fusion proteins FPTD-Grb2-SH2 and FPTD-Grb2-SH2M inhibit the proliferation of breast cancer cells in vitro.

Growth factor receptor bound protein 2 (Grb2) is a key adaptor performing a principal role in the oncogenic Ras signaling pathway. In the present study, we generated two fusion proteins. One contained an Src homology 2 (SH2) domain of Grb2, a signal peptide sequence, FLAG-tag sequence, PTD region and we named it FPTD-Grb2-SH2, while the other contained one mutant SH2 domain, added to a signal peptide sequence, FLAG-tag sequence, PTD region and we named it FPTD-Grb2-SH2M. Western blot analysis and immunofluorescence assay were used to investigate the expression and location of the fusion proteins in breast cancer cells. The proliferation and migration of the cells were estimated by MTT and Transwell cell migration assays, respectively. Flow cytometric analysis was performed to evaluate the apoptosis of the breast cancer cells. The recombinant proteins FPTD-Grb2-SH2 and FPTD-Grb2-SH2M were successfully expressed in the breast cancer cell lines regardless of HER2-phenotype, and they suppressed breast cancer cell growth and migration as expected from the lack of SH3 domain. Both FPTD-Grb2-SH2 and FPTD-Grb2-SH2M exhibited significant toxicity to breast cancer cells. The present study demonstrated that the recombinant proteins FPTD-Grb2-SH2 and FPTD-Grb2-SH2M may be used for anticancer drug development.

Induction of specific humoral and cellular immune responses in a mouse model following gene fusion of HSP70C and Hantaan virus Gn and S0.7 in an adenoviral vector.

Heat shock proteins (HSPs) display adjuvant functions when given as fusion proteins to enhance vaccination efficiency. To evaluate enhanced potency of Hantaan virus (HTNV) glycoprotein (GP) and nucleocapsid protein (NP) immunogenicity by heat shock protein 70 (HSP70), a recombinant adenovirus rAd-GnS0.7-pCAG-HSP70C expression vector was developed by genetically linking the HSP70 C-terminal gene (HSP70 359-610 aa, HSP70C) to the Gn and 0.7 kb fragment of the NP (aa1-274-S0.7). C57BL/6 mice were immunized with these recombinant adenoviral vectors. A series of immunological assays determined the immunogenicity of the recombinant adenoviral vectors. The results showed that rAd-GnS0.7-pCAG-HSP70C induced a stronger humoral and cellular immune response than other recombinant adenoviruses (rAd-GnS0.7-pCAG and rAd-GnS0.7) and the HFRS vaccine control. Animal protection experiments showed that rAd-GnS0.7-pCAG-HSP70C was effective at protecting C57BL/6 mice from HTNV infection. The results of the immunological experiments showed that HSP70C lead to enhanced vaccine potency, and suggested significant potential in the development of genetically engineered vaccines against HTNV.

Identification of peptides that bind hepatitis C virus envelope protein E2 and inhibit viral cellular entry from a phage-display peptide library.

Hepatitis C virus (HCV) envelope protein E2 is required for the entry of HCV into cells. Viral envelope proteins interact with cell receptors in a multistep process, which may be a promising target for the development of novel antiviral agents. In this study, a heptapeptide M13 phage-display library was screened for peptides that bind specifically to prokaryotically expressed, purified truncated HCV envelope protein E2. ELISA assay was used to quantify the binding of the peptides to HCV E2 protein. Flow cytometry, quantitative reverse-transcription PCR and western blotting were used to investigate the inhibition effect of one peptide on HCV infection in hepatoma cells (Huh7.5) in vitro. Four peptides capable of binding specifically to HCV E2 protein were obtained after three rounds of biopanning. Peptide C18 (WPWHNHR), with the highest affinity for binding HCV E2 protein, was synthesized. The results showed that peptide C18 inhibited the viral infectivity of both HCV pseudotype particles (HCVpp) harboring HCV envelope glycoproteins and cell-culture produced HCV (HCVcc). Thus, this study demonstrated that peptide C18 is a potential candidate for anti-HCV therapy as a novel viral entry inhibitor.

A recombinant pseudotyped lentivirus expressing the envelope glycoprotein of hantaan virus induced protective immunity in mice.

BACKGROUND: Hantaviruses cause acute hemorrhagic fever with renal syndrome (HFRS). Currently, several types of inactivated HFRS vaccines are widely used, however the limited ability of these immunogen to elicit neutralizing antibodies restricts vaccine efficacy. Development of an effective vaccine to overcome this weakness is must. METHODS: In the present study, a recombinant pseudotyped lentivirus bearing the hantaan virus (HTNV) envelope glycoproteins (GP), rLV-M, was constructed. C57BL/6 mice were immunized with the rLV-M and a series of immunological assays were conducted to determine the immunogenicity of the recombinant pseudotyped lentivirus. The humoral and cell-mediated immune responses induced by rLV-M were compared with those of the inactivated HFRS vaccine. RESULTS: Indirect immunofluorescence assay (IFA) showed the rLV-M expressed target proteins in HEK-293 cells. In mice, the rLV-M efficiently induced GP-specific humoral responses and protection against HTNV infection. Furthermore, the rLV-M induced higher neutralizing antibody titers than the inactivated HFRS vaccine control. CONCLUSIONS: The results indicated the potential of using a pseudotyped lentivirus as a delivery vector for a hantavirus vaccine immunogen.