The double-shelled grass carp reovirus （GCRV） is capable of endogenous RNA transcription and processing.Genome sequence analysis has revealed that the protein VP2,encoded by gene segment 2 （S2）,is the putative RNA...The double-shelled grass carp reovirus （GCRV） is capable of endogenous RNA transcription and processing.Genome sequence analysis has revealed that the protein VP2,encoded by gene segment 2 （S2）,is the putative RNA-dependent RNA polymerase （RdRp）.In previous work,we have ex-pressed the functional region of VP2 that is associated with RNA polymerase activity （denoted as rVP2390-900） in E.coil and have prepared a polyclonal antibody against VP2.To characterize the GCRV RNA polymerase,a recombinant full-length VP2 （rVP2） was first constructed and expressed in a baculovirus system,as a fusion protein with an attached His-tag.Immunofluorescence （IF） assays,together with immunoblot （IB） analyses from both expressed cell extracts and purified Histagged rVP2,showed that rVP2 was successfully expressed in Sf9 cells.Further characterization of the replicase activity showed that purified rVP2 and GCRV particles exhibited poly（C）-dependent poly（G） polymerase activity.The RNA enzymatic activity required the divalent cation Mg2＋,and was optimal at 28 ℃.The results provide a foundation for further studies on the RNA polymerases of aquareoviruses during viral transcription and replication.展开更多
In this study, the full-length VP2 gene of canine parvovirus type 2 (CPV-2) was cloned into the pBacSC vector which possesses baculovirus transmembrane domain (gp64 TM) gene, baculovirus cytoplasmic domain (gp64 CTD) ...In this study, the full-length VP2 gene of canine parvovirus type 2 (CPV-2) was cloned into the pBacSC vector which possesses baculovirus transmembrane domain (gp64 TM) gene, baculovirus cytoplasmic domain (gp64 CTD) gene, and green florescence protein (GFP) gene. Baculovirus gp64 TM and gp64 CTD in the pBacSC vector were designed to display heterologous proteins on the baculovirus envelope. After cloning the VP2 gene of CPV-2 into pBacSC vector, the recombinant plasmid pBacSC-VP2 was transformed into E. coli DH10Bac competent cells to form recombinant bacmid DNA. One recombinant baculovirus BacSC-VP2 that expresses the VP2 protein of CPV-2 was obtained. Confocal microscopy and immunogold electron microscopy were used to verify whether VP2 expressing on baculovirus envelope or cell membrane. Immunization of BALB/c mice with recombinant baculovirus BacSC-VP2, demonstrated that serum from the BacSC-VP2 treated models had higher levels of virus neutralization titers than the control groups. The results show that the recombinant baculovirus BacSC-VP2 can induce a strong immune response in a mouse model, suggesting that the pseudotyped baculovirus BacSC-VP2 can serve as a potential vaccine against CPV infections.展开更多
Objective To screen the proteins associated with four-and-a-half LIM domains 3(FHL3) 3' untranslated region(3'UTR) in glioma cells. Methods Western blot was adopted to detect the regulatory effect of poly(C)-b...Objective To screen the proteins associated with four-and-a-half LIM domains 3(FHL3) 3' untranslated region(3'UTR) in glioma cells. Methods Western blot was adopted to detect the regulatory effect of poly(C)-binding protein 2(PCBP2) on FHL3. Biotin pull-down and sliver staining were employed to screen and verify the candidate binding proteins of FHL3 3'UTR. Then liquid chromatography-tandem mass spectrometry(LC-MS/MS) and molecule annotation system were used to identify and analyze the candidate binding proteins. Immunoprecipitation was conducted to study the interaction between PCBP2 and polypyrimidine tract-binding protein 1(PTBP1), a binding protein identified by LC-MS/MS. Results PCBP2 could bind to FHL3 mRNA 3'UTR-A and inhibited the expression of FHL3 in T98 G glioms cells. 22 candidate binding proteins were identified. Among them, there were 11 RNA binding proteins, including PCBP2. PTBP1 associated with FHL3 mRNA 3'UTR and interacted with PCBP2 protein. Conclusion PCBP2 and PTBP1 can both associate with FHL3 mRNA 3'UTR through forming a protein complex.展开更多
The elementary Ca^2＋ release events, Ca2＋ sparks, has been found for a quarter of century. However, the molecular regulation of the spark generator, the ryanodine receptor （RyR） on the sarcoplasmic reticulum, rema...The elementary Ca^2＋ release events, Ca2＋ sparks, has been found for a quarter of century. However, the molecular regulation of the spark generator, the ryanodine receptor （RyR） on the sarcoplasmic reticulum, remains obscure. Although each subunit of the RyR homotetramer has a site for FKS06-binding protein （FKBP）, the role of FKBPs in modifying RyR Ca^2＋ sparks has been debated for long. One of the reasons behind the controversy is that most previous studies detect spontaneous sparks, where the mixture with out-of-focus events and local wavelets prevents an accurate characterization of Ca^2＋ sparks. In the pre- sent study, we detected Ca^2＋ sparks triggered by single L-type Ca^2＋ channels （LCCs） under loose-seal patch clamp conditions in FKS06-treated or FKBPI2.6 knockout cardiomyocytes. We found that FKBP dissociation both by FKS06 and by rapamycin decreased the Ca^2＋ spark amplitude in ventricular cardiomyocytes. This change was neither due to decreased releasable Ca^2＋ in the sarcoplasmic reticulum, nor explained by changed RyR sensitivity. Actually FKS06 increased the LCC-RyR coupling probability and curtailed the latency for an LCC to trigger a RyR Ca^2＋ spark. FKBP12.6 knockout had similar effects as FKS06/rapamycin treatment, indicating that the decreased spark amplitude was attributable to the dissociation of FKBP12.6 rather than FKBP12. We also explained how decreased amplitude of spontaneous sparks after FKBP dissociation sometimes appears to be increased or unchanged due to inappropriate data processing. Our results provided firm evidence that without the inter-RyR coordination by functional FKBP12.6, the RyR recruitment during a Ca^2＋ spark would be compromised despite the sensitization of individual RyRs.展开更多
Canine parvovirus(CPV)is a high morbidity and lethality virus which causes severe enteric disease in dogs.In an attempt to gain canine-origin neutralizing antibodies against CPV,single chain variable fragment(scFv)bac...Canine parvovirus(CPV)is a high morbidity and lethality virus which causes severe enteric disease in dogs.In an attempt to gain canine-origin neutralizing antibodies against CPV,single chain variable fragment(scFv)bacteria display libraries against the protective antigen VP2 were constructed and screened.VP2 specific scFvs were selected following three rounds of screening procedures.Selected scFvs were characterized by FCM and ELISA.Seven scFvs showed high affinity and specific binding to CPV.Moreover,the neutralizing activity of the antibody was preliminarily identified by CPV(100 TCID_(50))in vitro and scFv-2 showed the neutralizing ability with a titer of 32768.This study generated the first canine-origin neutralizing scFv against CPV.The neutralizing scFv would be constructed into full-length antibody in the future.This study laid the foundation for the generation of an effective therapeutic reagent with long half-life and no immunological rejection for the prevention and treatment of CPV infection.展开更多
[ Objective] To compare the characteristics of monoclonal antibodies against infectious bursal disease virus （IBDV） prepared with two different immunogens, VP2 protein expressed by prokaryotic system and purified IB...[ Objective] To compare the characteristics of monoclonal antibodies against infectious bursal disease virus （IBDV） prepared with two different immunogens, VP2 protein expressed by prokaryotic system and purified IBDV. [Methed] IBDV VP2 gene was amplified by RT-PCR and expressed in a prokaryotic system. The recombinant protein was purified by affinity chromatography. IBDV was pudfied by ultracentrifugation. Balb/c mice were immunized with the purified recombinant protein and IBDV, respectively. The monoclonal antibodies were screened by ELISA. [ Result] Two cell lines secreting antibodies against IBDV VP2 protein were obtained, and their ELISA titers were 1：2 × 10^4. Four cell lines secreting antibodies against I BDV were produced, and their ELISA titers were 1：2× 10^6, 1：6 × 10^4, 1：1× 10^5 and 1：4 × 10^3, respectively. All monoclonal antibodies specifically bound to their own immunogen but did not react with other viruses or proteins. After 10 -20 passages, these cell lines still secreted antibodies stably. [Condusion] The monoclonal antibodies prepared with the recombinant IBDV VP2 protein or purified IBDV can induce immune resoonse in mice. and VP2 soecific monoclonal antibodies can be obtained with VP2 orotein expressed in the Drokarvotic system as immunoQen.展开更多
Background Previous serological studies of human bocavirus(HBoV)1 could not exclude cross-reactivity with the other three HBoVs,particularly HBoV2.Methods To search for genotype-specific antibodies against HBoV1 and H...Background Previous serological studies of human bocavirus(HBoV)1 could not exclude cross-reactivity with the other three HBoVs,particularly HBoV2.Methods To search for genotype-specific antibodies against HBoV1 and HBoV2,the divergent regions(DRs)located on the major capsid protein VP3 were defined through viral amino acid alignment and structure prediction.DR-deduced peptides were used as antigens to harvest corresponding anti-DR rabbit sera.To determine their genotype specificities for HBoV1 and HBoV2,these sera samples were used as antibodies against the antigens VP3 of HBoV1 and HBoV2(expressed in Escherichia coli)in western blotting(WB),enzyme-linked immunosorbent assay(ELISA),and bio-layer interferometry(BLI)assays.Subsequently,the antibodies were evaluated with clinical specimens from pediatric patients with acute respiratory tract infection by indirect immunofluorescence assay(IFA).Results There were four DRs(DR1–4)located on VP3 with different secondary and tertiary structures between HBoV1 and HBoV2.Regarding the reactivity with VP3 of HBoV1 or HBoV2 in WB and ELISA,high intra-genotype cross-reactivity of anti-HBoV1 or HBoV2 DR1,DR3,and DR4,but not anti-DR2,was observed.Genotype-specific binding capacity of anti-DR2 sera was confirmed by BLI and IFA,in which only anti-HBoV1 DR2 antibody reacted with HBoV1-positive respiratory specimens.Conclusion Antibodies against DR2,located on VP3 of HBoV1 or HBoV2,were genotype specific for HBoV1 and HBoV2,respectively.展开更多
Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the drama...Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the dramatic expression changes of more than half of potential miR-155-targeted genes upon lipopolysaccharide(LPS)stimulation;223 genes were down-regulated and 85 genes were up-regulated,including suppressor of cytokine signaling 1(SOCS1)and transforming growth factor-β-activated kinase 1-binding protein 2(TAB2),two well-known genes involved in miR-155-mediated regulation of the Toll-like receptor 4(TLR4)signaling pathway.We also found that miR-155 acted as an anti-inflammatory mediator in the initial stage of LPS-induced inflammatory response mainly through repressing TAB2 protein translation,and as a proinflammatory mediator by down-regulating SOCS1 in the later stage.Meanwhile,overexpression of TAB23'untranslated region(UTR)in macrophages promoted the development of endotoxin tolerance by competing for binding with miR-155,which resulted in an elevated expression level of SOCS1 protein.These findings provide new insights for understanding the regulatory mechanisms in fine-tuning of LPS-induced innate immune response.展开更多
基金supported by funding from the National Natural Science Foundation of China (grants: 31172434, 31372565)
文摘The double-shelled grass carp reovirus （GCRV） is capable of endogenous RNA transcription and processing.Genome sequence analysis has revealed that the protein VP2,encoded by gene segment 2 （S2）,is the putative RNA-dependent RNA polymerase （RdRp）.In previous work,we have ex-pressed the functional region of VP2 that is associated with RNA polymerase activity （denoted as rVP2390-900） in E.coil and have prepared a polyclonal antibody against VP2.To characterize the GCRV RNA polymerase,a recombinant full-length VP2 （rVP2） was first constructed and expressed in a baculovirus system,as a fusion protein with an attached His-tag.Immunofluorescence （IF） assays,together with immunoblot （IB） analyses from both expressed cell extracts and purified Histagged rVP2,showed that rVP2 was successfully expressed in Sf9 cells.Further characterization of the replicase activity showed that purified rVP2 and GCRV particles exhibited poly（C）-dependent poly（G） polymerase activity.The RNA enzymatic activity required the divalent cation Mg2＋,and was optimal at 28 ℃.The results provide a foundation for further studies on the RNA polymerases of aquareoviruses during viral transcription and replication.
文摘In this study, the full-length VP2 gene of canine parvovirus type 2 (CPV-2) was cloned into the pBacSC vector which possesses baculovirus transmembrane domain (gp64 TM) gene, baculovirus cytoplasmic domain (gp64 CTD) gene, and green florescence protein (GFP) gene. Baculovirus gp64 TM and gp64 CTD in the pBacSC vector were designed to display heterologous proteins on the baculovirus envelope. After cloning the VP2 gene of CPV-2 into pBacSC vector, the recombinant plasmid pBacSC-VP2 was transformed into E. coli DH10Bac competent cells to form recombinant bacmid DNA. One recombinant baculovirus BacSC-VP2 that expresses the VP2 protein of CPV-2 was obtained. Confocal microscopy and immunogold electron microscopy were used to verify whether VP2 expressing on baculovirus envelope or cell membrane. Immunization of BALB/c mice with recombinant baculovirus BacSC-VP2, demonstrated that serum from the BacSC-VP2 treated models had higher levels of virus neutralization titers than the control groups. The results show that the recombinant baculovirus BacSC-VP2 can induce a strong immune response in a mouse model, suggesting that the pseudotyped baculovirus BacSC-VP2 can serve as a potential vaccine against CPV infections.
基金Supported by Peking Union Medical College Youth Fundthe Fundamental Research Funds for the Central Universities(3332013052)
文摘Objective To screen the proteins associated with four-and-a-half LIM domains 3(FHL3) 3' untranslated region(3'UTR) in glioma cells. Methods Western blot was adopted to detect the regulatory effect of poly(C)-binding protein 2(PCBP2) on FHL3. Biotin pull-down and sliver staining were employed to screen and verify the candidate binding proteins of FHL3 3'UTR. Then liquid chromatography-tandem mass spectrometry(LC-MS/MS) and molecule annotation system were used to identify and analyze the candidate binding proteins. Immunoprecipitation was conducted to study the interaction between PCBP2 and polypyrimidine tract-binding protein 1(PTBP1), a binding protein identified by LC-MS/MS. Results PCBP2 could bind to FHL3 mRNA 3'UTR-A and inhibited the expression of FHL3 in T98 G glioms cells. 22 candidate binding proteins were identified. Among them, there were 11 RNA binding proteins, including PCBP2. PTBP1 associated with FHL3 mRNA 3'UTR and interacted with PCBP2 protein. Conclusion PCBP2 and PTBP1 can both associate with FHL3 mRNA 3'UTR through forming a protein complex.
基金supported by the National Research and Development Program of China (2016YFA0500401)National Natural Science Foundation of China (31630035, 31571486, 81370203, 81461148026, 31271228 and 31327901)the Project of Beijing Municipal Science and Technology Commission (Z141100000214006)
文摘The elementary Ca^2＋ release events, Ca2＋ sparks, has been found for a quarter of century. However, the molecular regulation of the spark generator, the ryanodine receptor （RyR） on the sarcoplasmic reticulum, remains obscure. Although each subunit of the RyR homotetramer has a site for FKS06-binding protein （FKBP）, the role of FKBPs in modifying RyR Ca^2＋ sparks has been debated for long. One of the reasons behind the controversy is that most previous studies detect spontaneous sparks, where the mixture with out-of-focus events and local wavelets prevents an accurate characterization of Ca^2＋ sparks. In the pre- sent study, we detected Ca^2＋ sparks triggered by single L-type Ca^2＋ channels （LCCs） under loose-seal patch clamp conditions in FKS06-treated or FKBPI2.6 knockout cardiomyocytes. We found that FKBP dissociation both by FKS06 and by rapamycin decreased the Ca^2＋ spark amplitude in ventricular cardiomyocytes. This change was neither due to decreased releasable Ca^2＋ in the sarcoplasmic reticulum, nor explained by changed RyR sensitivity. Actually FKS06 increased the LCC-RyR coupling probability and curtailed the latency for an LCC to trigger a RyR Ca^2＋ spark. FKBP12.6 knockout had similar effects as FKS06/rapamycin treatment, indicating that the decreased spark amplitude was attributable to the dissociation of FKBP12.6 rather than FKBP12. We also explained how decreased amplitude of spontaneous sparks after FKBP dissociation sometimes appears to be increased or unchanged due to inappropriate data processing. Our results provided firm evidence that without the inter-RyR coordination by functional FKBP12.6, the RyR recruitment during a Ca^2＋ spark would be compromised despite the sensitization of individual RyRs.
基金Supported by the National Key R&D Program of China(2017YFD0501102,2016YFD0501003)Science and Technology Department of Heilongjiang Province(GX18B018)Education Department of Heilongjiang Province(TSTAU-R2018017)。
文摘Canine parvovirus(CPV)is a high morbidity and lethality virus which causes severe enteric disease in dogs.In an attempt to gain canine-origin neutralizing antibodies against CPV,single chain variable fragment(scFv)bacteria display libraries against the protective antigen VP2 were constructed and screened.VP2 specific scFvs were selected following three rounds of screening procedures.Selected scFvs were characterized by FCM and ELISA.Seven scFvs showed high affinity and specific binding to CPV.Moreover,the neutralizing activity of the antibody was preliminarily identified by CPV(100 TCID_(50))in vitro and scFv-2 showed the neutralizing ability with a titer of 32768.This study generated the first canine-origin neutralizing scFv against CPV.The neutralizing scFv would be constructed into full-length antibody in the future.This study laid the foundation for the generation of an effective therapeutic reagent with long half-life and no immunological rejection for the prevention and treatment of CPV infection.
文摘[ Objective] To compare the characteristics of monoclonal antibodies against infectious bursal disease virus （IBDV） prepared with two different immunogens, VP2 protein expressed by prokaryotic system and purified IBDV. [Methed] IBDV VP2 gene was amplified by RT-PCR and expressed in a prokaryotic system. The recombinant protein was purified by affinity chromatography. IBDV was pudfied by ultracentrifugation. Balb/c mice were immunized with the purified recombinant protein and IBDV, respectively. The monoclonal antibodies were screened by ELISA. [ Result] Two cell lines secreting antibodies against IBDV VP2 protein were obtained, and their ELISA titers were 1：2 × 10^4. Four cell lines secreting antibodies against I BDV were produced, and their ELISA titers were 1：2× 10^6, 1：6 × 10^4, 1：1× 10^5 and 1：4 × 10^3, respectively. All monoclonal antibodies specifically bound to their own immunogen but did not react with other viruses or proteins. After 10 -20 passages, these cell lines still secreted antibodies stably. [Condusion] The monoclonal antibodies prepared with the recombinant IBDV VP2 protein or purified IBDV can induce immune resoonse in mice. and VP2 soecific monoclonal antibodies can be obtained with VP2 orotein expressed in the Drokarvotic system as immunoQen.
基金supported by the Beijing Natural Science Foundation(7192029)the National Natural Science Foundation of China(82172277)the Beijing Municipal Commission of Health(2060399 PXM2017_026268_00005_00254486).
文摘Background Previous serological studies of human bocavirus(HBoV)1 could not exclude cross-reactivity with the other three HBoVs,particularly HBoV2.Methods To search for genotype-specific antibodies against HBoV1 and HBoV2,the divergent regions(DRs)located on the major capsid protein VP3 were defined through viral amino acid alignment and structure prediction.DR-deduced peptides were used as antigens to harvest corresponding anti-DR rabbit sera.To determine their genotype specificities for HBoV1 and HBoV2,these sera samples were used as antibodies against the antigens VP3 of HBoV1 and HBoV2(expressed in Escherichia coli)in western blotting(WB),enzyme-linked immunosorbent assay(ELISA),and bio-layer interferometry(BLI)assays.Subsequently,the antibodies were evaluated with clinical specimens from pediatric patients with acute respiratory tract infection by indirect immunofluorescence assay(IFA).Results There were four DRs(DR1–4)located on VP3 with different secondary and tertiary structures between HBoV1 and HBoV2.Regarding the reactivity with VP3 of HBoV1 or HBoV2 in WB and ELISA,high intra-genotype cross-reactivity of anti-HBoV1 or HBoV2 DR1,DR3,and DR4,but not anti-DR2,was observed.Genotype-specific binding capacity of anti-DR2 sera was confirmed by BLI and IFA,in which only anti-HBoV1 DR2 antibody reacted with HBoV1-positive respiratory specimens.Conclusion Antibodies against DR2,located on VP3 of HBoV1 or HBoV2,were genotype specific for HBoV1 and HBoV2,respectively.
基金the National Natural Science Foundation of China(Nos.81701568,81930041,81571524,81872248,and 91842103)the Zhejiang Provincial Natural Science Foundation of China(Nos.Y15C080001 and Z19H100001)the Zhejiang Provincial Key Laboratory for Immunity and Inflammatory Diseases for its support。
文摘Although microRNA-155(miR-155)is considered a pro-inflammatory mediator,cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells.In this study,we identified the dramatic expression changes of more than half of potential miR-155-targeted genes upon lipopolysaccharide(LPS)stimulation;223 genes were down-regulated and 85 genes were up-regulated,including suppressor of cytokine signaling 1(SOCS1)and transforming growth factor-β-activated kinase 1-binding protein 2(TAB2),two well-known genes involved in miR-155-mediated regulation of the Toll-like receptor 4(TLR4)signaling pathway.We also found that miR-155 acted as an anti-inflammatory mediator in the initial stage of LPS-induced inflammatory response mainly through repressing TAB2 protein translation,and as a proinflammatory mediator by down-regulating SOCS1 in the later stage.Meanwhile,overexpression of TAB23'untranslated region(UTR)in macrophages promoted the development of endotoxin tolerance by competing for binding with miR-155,which resulted in an elevated expression level of SOCS1 protein.These findings provide new insights for understanding the regulatory mechanisms in fine-tuning of LPS-induced innate immune response.
