BALB/c mice were immunized using synthetic tandem polypeptide of Cap protein epitope of porcine circovirus type 2 （PCV2） as the antigen. By using lym-phocyte hybridoma technique, a hybridoma cellline stably secretin...BALB/c mice were immunized using synthetic tandem polypeptide of Cap protein epitope of porcine circovirus type 2 （PCV2） as the antigen. By using lym-phocyte hybridoma technique, a hybridoma cellline stably secreting monoclonal an-tibody against PCV2-rCap protein was successful y obtained and named as 670#. The ascites titer of the obtained monoclonal antibody was 1∶100 000. Western blot results showed that the monoclonal antibody could react with prokaryotical y ex-pressed PET32a-ORF2 recombinant protein, eukaryotical y expressed ORF1-ORF2 tandem protein and PCV2 whole virus celllysate. Indirect EILSA demonstrated that the monoclonal antibody could bind with ORF1-ORF2 tandem protein. Indirect im-munofluorescence assay （IFA） indicated that the monoclonal antibody could identify native PCV2 virus. The preparation of this monoclonal antibody provided technical tools for epitope analysis and molecular diagnosis of PCV2 virus.展开更多
AIM: To investigate the reactivity of a panel of 8 mouse anti-hepatitis B surface antigen (HBsAg) monoclonal antibodies (mAbs) using a collection of 9 recombinant HBsAg mutants with a variety of amino acid substitutio...AIM: To investigate the reactivity of a panel of 8 mouse anti-hepatitis B surface antigen (HBsAg) monoclonal antibodies (mAbs) using a collection of 9 recombinant HBsAg mutants with a variety of amino acid substitutions mostly located within the “a” region.METHODS: The entire HBs genes previously cloned into a mammalian expression vector were transiently transfected into COS7 cells. Two standard unmutated sequences of the ayw and adw subtypes served as controls. Secreted mutant proteins were collected and measured by three commercial diagnostic immunoassays to assess transfection efficiency. Reactivity of anti-HBs mAbs with mutated HBsAgs was determined by sandwich enzyme-linked immunosorbent assay (ELISA).RESULTS: Reactivity of anti-HBs mAbs with mutated HBsAgs revealed different patterns. While three mutants reacted strongly with all mAbs, two mutants reacted weakly with only two mAbs and the remaining proteins displayed variable degrees of reactivity towards different mAbs. Accordingly, four groups of mAbs with different but overlapping reactivity patterns could be envisaged. One group consisting of two mAbs (37C5-S7 and 35C6-S11) was found to recognize stable linear epitopes conserved in all mutants. Mutations outside the “a” determinant at positions 120 (P→S), 123(T→N) and 161(M→T) were found to affect reactivity of these mAbs.CONCLUSION: Our findings could have important implications for biophysical studies, vaccination strategies and immunotherapy of hepatitis B virus (HBV) mutants.展开更多
AIM: To explore the inhibitory effects of pokeweed antiviral protein seed (PAP-S) and PAP encoded by a eukaryotic expression plasmid on hepatitis B virus (HBV) replication in vitro. METHODS: HepG2 2.2.15 cells in cult...AIM: To explore the inhibitory effects of pokeweed antiviral protein seed (PAP-S) and PAP encoded by a eukaryotic expression plasmid on hepatitis B virus (HBV) replication in vitro. METHODS: HepG2 2.2.15 cells in cultured medium were treated with different concentrations of PAP-S. HBsAg, HBeAg and HBV DNA in supernatants were determined by ELISA and fluorescent quantitative PCR respectively. MTT method was used to assay for cytotoxicity. HepG2 were cotransfected with various amounts of PAP encoded by a eukaryotic expression plasmid and replication competent wild-type HBV 1.3 fold over- length plasmid. On d 3 after transfection, HBsAg and HBeAg were determined by using ELISA. Levels of HBV core-associated DNA and RNA were detected by using Southern and Northern blot, respectively. RESULTS: The inhibitory effects of PAP-S on HBsAg, HBeAg and HBV DNA were gradually enhanced with the increase of PAP concentration. When the concentration of PAP-S was 10 μg/mL, the inhibition rates of HBsAg, HBeAg and HBV DNA were 20.9%, 30.2% and 50%, respectively. After transfection of 1.0 μg and 2.0 μg plasmid pXF3H-PAP, the levels of HBV nucleocapside- associated DNA were reduced by 38.0% and 74.0% respectively, the levels of HBsAg in the media by 76.8% and 99.7% respectively, and the levels of HBeAg by 72.7% and 99.3% respectively as compared with controls. Transfection with 2 μg plasmid pXF3H-PAP reduced the levels of HBV nucleocapside-associated RNA by 69.0%.CONCLUSION: Both PAP-S and PAP encoded by a eukaryotic expression plasmid could effectively inhibit HBV replication and antigen expression in vitro, and the inhibitory effects were dose-dependent.展开更多
Expression vector inserted with E2/NS1 gene derived from genotype Ⅲ Chinese isolates of HCV was transfected into mammalian cells to express E2 glycoprotein. Expressed protein was used as antigen for an- ti-E2 antibod...Expression vector inserted with E2/NS1 gene derived from genotype Ⅲ Chinese isolates of HCV was transfected into mammalian cells to express E2 glycoprotein. Expressed protein was used as antigen for an- ti-E2 antibody detection in 19 cases of hepatitis C patients by Western blot. It was first to express E2 gly- coprotein of genotype Ⅲ Chinese hepatitis C virus isolates. For anti-E2 detection, 14 cases of patients were positive of antibodies against E2(73. 7 % ). These results indicated that E2 glycoprotein expressed in mam-malian cells had good immunogenicity and cross reactivity to serum infected with genotype Ⅱ Chinese hep-atitis C virus isolates.展开更多
Obstructive jaundice occurs in patients suffering from cholelithiasis and from neoplasms affecting the pancreas and the common bile duct.The absorption,distribution and elimination of drugs are impaired during this pa...Obstructive jaundice occurs in patients suffering from cholelithiasis and from neoplasms affecting the pancreas and the common bile duct.The absorption,distribution and elimination of drugs are impaired during this pathology.Prolonged cholestasis may alter both liver and kidney function.Lactam antibiotics,diuretics,non-steroidal anti-inflammatory drugs,several antiviral drugs as well as endogenous compounds are classified as organic anions.The hepatic and renal organic anion transport pathways play a key role in the pharmacokinetics of these compounds.It has been demonstrated that acute extrahepatic cholestasis is associated with increased renal elimination of organic anions.The present work describes the molecular mechanisms involved in the regulation of the expression and function of the renal and hepatic organic anion transporters in extrahepatic cholestasis,such as multidrug resistanceassociated protein 2,organic anion transporting polypeptide 1,organic anion transporter 3,bilitranslocase,bromosulfophthalein/bilirubin binding protein,organic anion transporter 1 and sodium dependent bile salt transporter.The modulation in the expression of renal organic anion transporters constitutes a compensatory mechanism to overcome the hepatic dysfunction in the elimination of organic anions.展开更多
Dose-dependent IgY antibody response to different amounts oforthopox virus （OPV） antigen has been studied in immunized chickens for two different OPV strains （vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9....Dose-dependent IgY antibody response to different amounts oforthopox virus （OPV） antigen has been studied in immunized chickens for two different OPV strains （vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9.2× 10^7PFU）. The antibody responses to different immunizations were tested and compared by indirect immunofluorescence antibody test. Our results, together with the literature, show that the antigen dose used for immunization plays an important role for the production of specific Abs. An increase in antigen concentration may achieve higher Ab titers but, dependent on the immunogenicity of OPV antigen, it can also lead to an immune depression. However, in this study we found that OPV played a positive correlation between antigen concentration and Ab-titer.展开更多
Objective： To prepare and identity monoclonal antibodies （McAbs） against the capsid proteins of adenovirus vector. Methods： BALB/c mice were immunized with a mixture of the purified adenovirus vector （Adv） and A...Objective： To prepare and identity monoclonal antibodies （McAbs） against the capsid proteins of adenovirus vector. Methods： BALB/c mice were immunized with a mixture of the purified adenovirus vector （Adv） and AI（OH）3. McAbs were produced using cell fusion technique in a conventional way. The sensitivity and specificity of monoclonal antibodies was identified by indirect enzyme linked immunosorbent assay （ELISA）, immunocytochemical staining and Western blotting. Results： Six strains of hybridoma cells （A4H11, A8C7, F1H5, G1D2, G4E3 and H2G8） that can stably secrete the IgG1 McAb against Adv were obtained. After 3 months subculture and low concentration of serum adapting culture, six strains retained their stability to secrete McAb. The ascites titers were between 1：10^6 and 1：10^8. Western blot analysis demonstrated that all the McAbs reacted with one protein （about 114 kDa） which is present in wild type 3 adenovirus （wtAd3）, wild type 5 adenovirus （wtAd5）, wild type 7 adenovirus （wtAd7） and adenovirus vector. Conclusion： Successfully prepared six strains of hybridoma cell secreted monoclonal antibodies against the hexon proteins of adenovirus vector, and provided the substantial foundation of preclinical research of adenovirus vectors.展开更多
P74 is a per os infectivity factor of baculovirus.Here,we report the production of three monoclonal antibodies (mAbs),denoted as 20D9,20F9 and 21E1,raised against P74 of Helicoverpa armigera nucleopolyhedrovirus (Hear...P74 is a per os infectivity factor of baculovirus.Here,we report the production of three monoclonal antibodies (mAbs),denoted as 20D9,20F9 and 21E1,raised against P74 of Helicoverpa armigera nucleopolyhedrovirus (HearNPV),and the identification of their recognition epitopes.The full-length P74,without the transmembrane domains at the C-terminus,was first divided into three segments (N,M and C,respectively),based on the proposed cleavage model for the protein,which were then expressed individually.Western blot analyses revealed specific cross-reactions with the N fragment,for both 20D9 and 21E1.Extensive truncation,followed by prokaryotic expression,of the P74 N fragment was then performed in order to screen for linear epitopes of P74.The recognition regions of 20D9 and 21E1 were revealed to be localized at R144-T153 and T199-C219,respectively.In addition,immunofluorescence microscopy indicated that 20D9 and 20F9 could recognize native P74 in HearNPV-infected cells.These findings will facilitate further investigations of the proteolytic processing of HearNPV P74,and of its involvement in virus-host interactions.展开更多
The present study deals with the co-ordination of cytokine （IL-4 and IFN-7） expression and kinetics of peste des petits ruminants （PPR） virus antigen and antibody in PPRV infected and vaccinated goats. The infecte...The present study deals with the co-ordination of cytokine （IL-4 and IFN-7） expression and kinetics of peste des petits ruminants （PPR） virus antigen and antibody in PPRV infected and vaccinated goats. The infected animals exhibited mixed cytokine （both TH1 and TH2） responses in the initial phase of the disease. The infected and dead goats had increased IFN-T response before their death; while IL-4 remained at the base level. The cytokine expression in recovered animals was almost similar to that of vaccinated ones, where a unique biphasic response of IL-4 expression was observed with an up-regulation of IFN-T on 7th days post vaccination （dpv）. Analysis of PPR virus antigen and antibody kinetics in different components of blood from infected and vaccinated animais revealed that the PPR virus antigen load was highest in plasma followed by serum and blood of the infected animals, whereas vaccinated animals showed only marginal positivity on 9th dpv. The antibody titer was high in serum followed by plasma and blood in both vaccinated and infected animals. Therefore, it is inferred that the presence of antigen and antibody were significant with the expression of cytokine, and that a decreased response of IL-4 was noticed during intermediate phase of the disease i.e., 7 to 12m days post infection （dpi）. This indicates the ability to mount a functional TH2 response after 14th dpi could be a critical determinant in deciding the survival of the PPR infected animal.展开更多
Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a s...Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic ca- pacity of the virus＇s structural proteins for preparing an effective vaccine has not been available. In this study, some sin- gle-chain variable fragment antibodies （scFv）, which could specifically recognize grass carp IgM, were selected from a con- structed mouse naive antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from vi- rus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.展开更多
基金Supported by National Natural Science Foundation of China(31302071)AgriculturalScience and Technology Independent Innovation Fund of Jiangsu Province(TechnicalInnovation)[CX(13)3065]~~
文摘BALB/c mice were immunized using synthetic tandem polypeptide of Cap protein epitope of porcine circovirus type 2 （PCV2） as the antigen. By using lym-phocyte hybridoma technique, a hybridoma cellline stably secreting monoclonal an-tibody against PCV2-rCap protein was successful y obtained and named as 670#. The ascites titer of the obtained monoclonal antibody was 1∶100 000. Western blot results showed that the monoclonal antibody could react with prokaryotical y ex-pressed PET32a-ORF2 recombinant protein, eukaryotical y expressed ORF1-ORF2 tandem protein and PCV2 whole virus celllysate. Indirect EILSA demonstrated that the monoclonal antibody could bind with ORF1-ORF2 tandem protein. Indirect im-munofluorescence assay （IFA） indicated that the monoclonal antibody could identify native PCV2 virus. The preparation of this monoclonal antibody provided technical tools for epitope analysis and molecular diagnosis of PCV2 virus.
基金Supported by Tehran University of Medical Sciences
文摘AIM: To investigate the reactivity of a panel of 8 mouse anti-hepatitis B surface antigen (HBsAg) monoclonal antibodies (mAbs) using a collection of 9 recombinant HBsAg mutants with a variety of amino acid substitutions mostly located within the “a” region.METHODS: The entire HBs genes previously cloned into a mammalian expression vector were transiently transfected into COS7 cells. Two standard unmutated sequences of the ayw and adw subtypes served as controls. Secreted mutant proteins were collected and measured by three commercial diagnostic immunoassays to assess transfection efficiency. Reactivity of anti-HBs mAbs with mutated HBsAgs was determined by sandwich enzyme-linked immunosorbent assay (ELISA).RESULTS: Reactivity of anti-HBs mAbs with mutated HBsAgs revealed different patterns. While three mutants reacted strongly with all mAbs, two mutants reacted weakly with only two mAbs and the remaining proteins displayed variable degrees of reactivity towards different mAbs. Accordingly, four groups of mAbs with different but overlapping reactivity patterns could be envisaged. One group consisting of two mAbs (37C5-S7 and 35C6-S11) was found to recognize stable linear epitopes conserved in all mutants. Mutations outside the “a” determinant at positions 120 (P→S), 123(T→N) and 161(M→T) were found to affect reactivity of these mAbs.CONCLUSION: Our findings could have important implications for biophysical studies, vaccination strategies and immunotherapy of hepatitis B virus (HBV) mutants.
基金the National Natural Sciences Foundation ofChina, No. 30671860
文摘AIM: To explore the inhibitory effects of pokeweed antiviral protein seed (PAP-S) and PAP encoded by a eukaryotic expression plasmid on hepatitis B virus (HBV) replication in vitro. METHODS: HepG2 2.2.15 cells in cultured medium were treated with different concentrations of PAP-S. HBsAg, HBeAg and HBV DNA in supernatants were determined by ELISA and fluorescent quantitative PCR respectively. MTT method was used to assay for cytotoxicity. HepG2 were cotransfected with various amounts of PAP encoded by a eukaryotic expression plasmid and replication competent wild-type HBV 1.3 fold over- length plasmid. On d 3 after transfection, HBsAg and HBeAg were determined by using ELISA. Levels of HBV core-associated DNA and RNA were detected by using Southern and Northern blot, respectively. RESULTS: The inhibitory effects of PAP-S on HBsAg, HBeAg and HBV DNA were gradually enhanced with the increase of PAP concentration. When the concentration of PAP-S was 10 μg/mL, the inhibition rates of HBsAg, HBeAg and HBV DNA were 20.9%, 30.2% and 50%, respectively. After transfection of 1.0 μg and 2.0 μg plasmid pXF3H-PAP, the levels of HBV nucleocapside- associated DNA were reduced by 38.0% and 74.0% respectively, the levels of HBsAg in the media by 76.8% and 99.7% respectively, and the levels of HBeAg by 72.7% and 99.3% respectively as compared with controls. Transfection with 2 μg plasmid pXF3H-PAP reduced the levels of HBV nucleocapside-associated RNA by 69.0%.CONCLUSION: Both PAP-S and PAP encoded by a eukaryotic expression plasmid could effectively inhibit HBV replication and antigen expression in vitro, and the inhibitory effects were dose-dependent.
基金National Ninth-Five-Year Study Plan CMB foundation
文摘Expression vector inserted with E2/NS1 gene derived from genotype Ⅲ Chinese isolates of HCV was transfected into mammalian cells to express E2 glycoprotein. Expressed protein was used as antigen for an- ti-E2 antibody detection in 19 cases of hepatitis C patients by Western blot. It was first to express E2 gly- coprotein of genotype Ⅲ Chinese hepatitis C virus isolates. For anti-E2 detection, 14 cases of patients were positive of antibodies against E2(73. 7 % ). These results indicated that E2 glycoprotein expressed in mam-malian cells had good immunogenicity and cross reactivity to serum infected with genotype Ⅱ Chinese hep-atitis C virus isolates.
基金Supported by Grants from FONCYT(PICT 2007,No.00966, PICT 2010,No.2127)CONICET(PIP 2009-2011,No.1665, PIP2012-2015,No.00014)UNR PID(2008-2011/2012-2015)
文摘Obstructive jaundice occurs in patients suffering from cholelithiasis and from neoplasms affecting the pancreas and the common bile duct.The absorption,distribution and elimination of drugs are impaired during this pathology.Prolonged cholestasis may alter both liver and kidney function.Lactam antibiotics,diuretics,non-steroidal anti-inflammatory drugs,several antiviral drugs as well as endogenous compounds are classified as organic anions.The hepatic and renal organic anion transport pathways play a key role in the pharmacokinetics of these compounds.It has been demonstrated that acute extrahepatic cholestasis is associated with increased renal elimination of organic anions.The present work describes the molecular mechanisms involved in the regulation of the expression and function of the renal and hepatic organic anion transporters in extrahepatic cholestasis,such as multidrug resistanceassociated protein 2,organic anion transporting polypeptide 1,organic anion transporter 3,bilitranslocase,bromosulfophthalein/bilirubin binding protein,organic anion transporter 1 and sodium dependent bile salt transporter.The modulation in the expression of renal organic anion transporters constitutes a compensatory mechanism to overcome the hepatic dysfunction in the elimination of organic anions.
文摘Dose-dependent IgY antibody response to different amounts oforthopox virus （OPV） antigen has been studied in immunized chickens for two different OPV strains （vaccinia virus, 7.0× 10^6 PFU and cowpox virus, 9.2× 10^7PFU）. The antibody responses to different immunizations were tested and compared by indirect immunofluorescence antibody test. Our results, together with the literature, show that the antigen dose used for immunization plays an important role for the production of specific Abs. An increase in antigen concentration may achieve higher Ab titers but, dependent on the immunogenicity of OPV antigen, it can also lead to an immune depression. However, in this study we found that OPV played a positive correlation between antigen concentration and Ab-titer.
文摘Objective： To prepare and identity monoclonal antibodies （McAbs） against the capsid proteins of adenovirus vector. Methods： BALB/c mice were immunized with a mixture of the purified adenovirus vector （Adv） and AI（OH）3. McAbs were produced using cell fusion technique in a conventional way. The sensitivity and specificity of monoclonal antibodies was identified by indirect enzyme linked immunosorbent assay （ELISA）, immunocytochemical staining and Western blotting. Results： Six strains of hybridoma cells （A4H11, A8C7, F1H5, G1D2, G4E3 and H2G8） that can stably secrete the IgG1 McAb against Adv were obtained. After 3 months subculture and low concentration of serum adapting culture, six strains retained their stability to secrete McAb. The ascites titers were between 1：10^6 and 1：10^8. Western blot analysis demonstrated that all the McAbs reacted with one protein （about 114 kDa） which is present in wild type 3 adenovirus （wtAd3）, wild type 5 adenovirus （wtAd5）, wild type 7 adenovirus （wtAd7） and adenovirus vector. Conclusion： Successfully prepared six strains of hybridoma cell secreted monoclonal antibodies against the hexon proteins of adenovirus vector, and provided the substantial foundation of preclinical research of adenovirus vectors.
基金supported by the National Science Foundation of China(31130058 to Z.H.).Monoclonal Antibodies against HearNPV P74
文摘P74 is a per os infectivity factor of baculovirus.Here,we report the production of three monoclonal antibodies (mAbs),denoted as 20D9,20F9 and 21E1,raised against P74 of Helicoverpa armigera nucleopolyhedrovirus (HearNPV),and the identification of their recognition epitopes.The full-length P74,without the transmembrane domains at the C-terminus,was first divided into three segments (N,M and C,respectively),based on the proposed cleavage model for the protein,which were then expressed individually.Western blot analyses revealed specific cross-reactions with the N fragment,for both 20D9 and 21E1.Extensive truncation,followed by prokaryotic expression,of the P74 N fragment was then performed in order to screen for linear epitopes of P74.The recognition regions of 20D9 and 21E1 were revealed to be localized at R144-T153 and T199-C219,respectively.In addition,immunofluorescence microscopy indicated that 20D9 and 20F9 could recognize native P74 in HearNPV-infected cells.These findings will facilitate further investigations of the proteolytic processing of HearNPV P74,and of its involvement in virus-host interactions.
文摘The present study deals with the co-ordination of cytokine （IL-4 and IFN-7） expression and kinetics of peste des petits ruminants （PPR） virus antigen and antibody in PPRV infected and vaccinated goats. The infected animals exhibited mixed cytokine （both TH1 and TH2） responses in the initial phase of the disease. The infected and dead goats had increased IFN-T response before their death; while IL-4 remained at the base level. The cytokine expression in recovered animals was almost similar to that of vaccinated ones, where a unique biphasic response of IL-4 expression was observed with an up-regulation of IFN-T on 7th days post vaccination （dpv）. Analysis of PPR virus antigen and antibody kinetics in different components of blood from infected and vaccinated animais revealed that the PPR virus antigen load was highest in plasma followed by serum and blood of the infected animals, whereas vaccinated animals showed only marginal positivity on 9th dpv. The antibody titer was high in serum followed by plasma and blood in both vaccinated and infected animals. Therefore, it is inferred that the presence of antigen and antibody were significant with the expression of cytokine, and that a decreased response of IL-4 was noticed during intermediate phase of the disease i.e., 7 to 12m days post infection （dpi）. This indicates the ability to mount a functional TH2 response after 14th dpi could be a critical determinant in deciding the survival of the PPR infected animal.
基金supported by the National Basic Research Program of China (2009CB118701,2009CB118704)the National Natural Science Foundation of China (31072233,31172434)
文摘Grass carp （Ctenopharyngodon idella） is an important species of freshwater aquaculture fish in China. However, grass carp reovirus （GCRV） can cause fatal hemorrhagic disease in yearling populations. Until now, a strategy to define the antigenic ca- pacity of the virus＇s structural proteins for preparing an effective vaccine has not been available. In this study, some sin- gle-chain variable fragment antibodies （scFv）, which could specifically recognize grass carp IgM, were selected from a con- structed mouse naive antibody phage display cDNA library. The identified scFv C1B3 clone was shown to possess relatively higher specific binding activity to grass carp IgM. Furthermore, ELISA analysis indicated that the IgM level in serum from vi- rus-infected grass carp was more than two times higher than that of the control group at 5-7 days post infection. Moreover, Western blot analysis demonstrated that the outer capsid protein VP7 has a specific immuno-binding-reaction with the serum IgM from virus-infected grass carp. Our results suggest that VP7 can induce a stronger immune response in grass carp than the other GCRV structural proteins, which implies that VP7 protein could be used as a preferred immunogen for vaccine design.
