Protectivity of Freeze Dried Inactivated Rift Valley Fever Vaccine

Background: Vaccinations for animals are crucial for food production, animal welfare, public health, and animal health. They are an affordable way to stop animal sickness, increase food production efficiency, and lessen or stop the spread of zoonotic diseases to humans. Animal vaccines that are both safe and efficacious are vital to modern culture. The vaccine should induce a strong, protective and prolonged immune response against the antigenic factor. In order to achieve these goals, novel vaccination techniques and an efficient adjuvant are required to render the vaccine immunogenically protective and trigger a strong immune response. Aim: Our study aims to promote and enhance the immunogenicity against RVF virus disease through lyophilized inactivated RVF vaccine through induction of early cellular, high and prolonged humeral immunity in vaccinated animals using cabopol as stabilizer and Saponin or normal saline as a diluent at time of vaccination. Moreover, manufacturing of these vaccines is easy to be done. Results: The gained results revealed that RVF freeze-dried vaccine with Carbopol that reconstituted using Saponin elicited better immune response than that reconstituted using normal saline (NaCl). The cell mediated immune response as represented by lymphocyte blastogenesis and phagocytic activity were markedly increased with high levels when we used Saponin as a diluent than that in group vaccinated with vaccine diluted with NaCl, on the other side the humeral immune response in group vaccinated using the Saponin as diluent is more detected and stayed within the protective level till the end of 11th month post vaccination (1.5 TCID50) while the immune response induced after using normal saline as a diluent stayed within the protective level till the end of 10th month post vaccination (1.8 TCID50). Conclusion: The use of Saponin as a diluent for reconstitution of the freeze dried RVF vaccine is preferable than the use of normal saline enhancing both sheep cellular and humeral immune response.

A novel method for identifying SARS-CoV-2 infection mutants via an epitope-specific CD8^(+)T cell test

Since the outbreak of the coronavirus disease 2019(COVID-19)epidemic in 2019,the public health system has faced enormous challenges.Tracking the individuals who test positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a key step for interrupting chains of transmission of SARS-CoV-2 and reducing COVID-19-associated mortality.With the increasing of asymptomatic infections,it is difficult to track asymptomatic infections through epidemiological surveys and virus whole-genome sequencing.However,due to the cross-reactivity of neutralizing antibodies produced by multiple virus subtypes,neutralizing antibody detection cannot be used to determine whether an individual has a history of infection with a specific subtype of SARS-CoV-2.We recruited 4 human leukocyte antigen A2(HLA-A2)infections,15 individuals who received three doses of inactivated vaccines,and 30 breakthrough infections after vaccination and discussed a case-tracking approach to detect epitope-specific CD8^(+)T cells in the peripheral blood of close contacts,including accurate HLA typing based on ribonucleic acid(RNA)-sequencing and flow cytometry data and the comparison and characterization of SARS-CoV-2 HLA-A2 and HLA-A24 epitope-specific CD8^(+)T cells.From individuals who received three doses of inactivated vaccine,we observed that the CD8^(+)T cell specificity for ancestral epitopes was significantly higher than for mutated epitopes,and the fold change of CD8^(+)T cells corresponding to mutated epitopes relative to ancestral epitopes was less than 1.The enzyme-linked immunospot(ELISpot)results further validate this result.This study forms a“method for understanding the infection history of SARS-CoV-2 subtypes based on the proportion of epitope-specific CD8^(+)T cells in the peripheral blood of subjects”,covering up to 46%of the population,including HLA-A2+and HLA-A24+donors,providing a novel method for SARS-CoV-2 infected case tracing.

Expression and self-assembly of HCV structural proteins into virus-like particles and their immunogenicity

Background The synthesis of virus-like particles (VLPs) provides an important tool to determine the structural requirements for viral particle assembly and virus-host interactions. Our purpose was to express simultaneously all three structural proteins of hepatitis C virus (HCV) in insect cells to investigate the proteins assembly into VLPs and the immunogenicity of these particles KH*2/5DMethods HCV gene sequences encoding the structural proteins C, E1, and E2 were amplified with PCR, and recombinant baculoviruses were constructed using recombinant DNA techniques The expression of HCV structural proteins in insect cells was analyzed by immunofluoresceoce and SDS-PAGE The interaction of expressed structural proteins was investigated by immunoprecipitation and immunoblotting The VLPs in the insect cells were visualized by electron microscopy (EM) VLPs were then purified by sucrose gradient centrifugation and used to immunize BALB/c mice Antibodies against HCV were tested for in mouse serum samples by an ELISA assay Results The recombinant baculoviruses reBV/C and reBV/E1-E2 were constructed successfully Insect cells co-infected with reBV/C and reBV/E1-E2 expressed HCV C, E1, and E2 proteins with the expected molecular weights of 20kD, 35kD, and 66kD, respectively The results of immunoprecipitation and immunoblotting assays revealed the coimmunoprecipitation of C, E1, and E2 proteins, indicating association of the three structural proteins Electron microscopy of insect cells co-infected with reBV/C and reBV/E1-E2 demonstrated spherical particles (40 to 60 nm in diameter) similar to the HCV virions from serum samples or hepatic tissue samples of HCV infected humans The VLPs were partially purified Antibodies to HCV were detectable in the serum of mice immunized with VLPs Conclusion HCV structural proteins simultaneously expressed in insect cells can interact with each other and assemble into HCV-like particles, which are shown to be immunogenic in mice

A TDG/CBP/RARα Ternary Complex Mediates the Retinoic Acid-dependent Expression of DNA Methylation-sensitive Genes

The thymine DNA glycosylase （TDG） is a multifunctional enzyme,which is essential for embryonic development.It mediates the base excision repair （BER） of G：T and G：U DNA mismatches arising from the deamination of 5-methyl cytosine （5-MeC） and cytosine,respectively.Recent studies have pointed at a role of TDG during the active demethylation of 5-MeC within CpG islands.TDG interacts with the histone acetylase CREB-binding protein （CBP） to activate CBP-dependent transcription.In addition,TDG also interacts with the retinoic acid receptor α （RARα）,resulting in the activation of RARα target genes.Here we provide evidence for the existence of a functional ternary complex containing TDG,CBP and activated RARα.Using global transcriptome profiling,we uncover a coupling of de novo methylation-sensitive and RA-dependent transcription,which coincides with a significant subset of CBP target genes.The introduction of a point mutation in TDG,which neither affects overall protein structure nor BER activity,leads to a significant loss in ternary complex stability,resulting in the deregulation of RA targets involved in cellular networks associated with DNA replication,recombination and repair.We thus demonstrate for the first time a direct coupling of TDG＇s epigenomic and transcription regulatory function through ternary complexes with CBP and RARα.

The functional analysis of transiently upregulated miR-101 suggests a “braking” regulatory mechanism during myogenesis

Skeletal muscle differentiation is a highly coordinated process that involves many cellular signaling pathways and microRNAs(miRNAs).A group of muscle-specific miRNAs has been reported to promote myogenesis by suppressing key signaling pathways for cell growth.However,the functional role and regulatory mechanism of most non-muscle-specific miRNAs with stage-specific changes during differentiation are largely unclear.Here,we describe the functional characterization of miR-101a/b,a pair of non-muscle-specific miRNAs that show the largest change among a group of transiently upregulated miRNAs during myogenesis in C2C12 cells.The overexpression of miR-101a/b inhibits myoblast differentiation by suppressing the p38/MAPK,Interferon Gamma,and Wnt pathways and enhancing the C/EBP pathway.Mef2a,a key protein in the p38/MAPK pathway,was identified as a direct target of miR-101a/b.Interestingly,we found that the long non-coding RNA(lncRNA)Malat1,which promotes muscle differentiation,interacts with miR-101a/b,and this interaction competes with Mef2a mRNA to relieve the inhibition of the p38/MAPK pathway during myogenesis.These results uncovered a“braking”role in differentiation of transiently upregulated miRNAs and provided new insights into the competing endogenous RNA(ceRNA)regulatory mechanism in myoblast differentiation and myogenesis.

Nature:CD32a蛋白暴露艾滋病病毒"藏身地"

《自然》杂志近日发表了法国研究人员的一项最新成果：他们通过实验室研究发现，潜藏艾滋病病毒（HIV）的T细胞表面特定表达着一种名叫CD32a的蛋白，这种蛋白在未感染HIV的T细胞中却没有被检测出来。这意味着，CD32a蛋白可以作为一种生物靶标，用来开发出针对”隐身”状态HIV的全新药物。

Glycogen accumulation drives hepatocarcinogenesis by targeting the Hippo signaling pathway

Recent advances highlight accelerated glucose metabolism as one of the hallmarks of cancer cells.Normal differentiated cells usually utilize the process of mitochondrial oxidative phosphorylation to metabolize glucose into carbon dioxide(CO_(2))and adenosine triphosphate(ATP).However,the cancer cell preferentially takes advantage of aerobic glycolysis to generate lactate and ATP to support the high energy demand for rapid cancer cell proliferation even in the presence of sufficient oxygen.1 This intriguing observation was first reported by the German physiologist Otto Warburg,and thus,this process is termed“the Warburg effect”.

Wu Mengchao:A blade warrior against liver cancer

China is a big nation primarily affected by liver cancer with the number of patients with liver cancer accounting more than 50%worldwide.1,2 Dr.Wu Mengchao(August 1922-May 2021;Fig.1)has devoted almost all his energy and wisdom to fighting against liver cancer for more than half a century.Dr.Wu graduated from the Tongji University School of Medicine in 1949.In 1960,Dr.Wu worked as the chief surgeon completing the first case of surgical resection for liver cancer in China.