Objective: To study the antifibrotic effects of genistein(GE) and quercetin(QU) on rat hepatic stellate HSC-T6 cell proliferation stimulated with platelet-derived growth factor (PDGF), collagen synthesis and type I pr...Objective: To study the antifibrotic effects of genistein(GE) and quercetin(QU) on rat hepatic stellate HSC-T6 cell proliferation stimulated with platelet-derived growth factor (PDGF), collagen synthesis and type I procollagen messenger RNA (mRNA) expression stimulated with transforming growth factor b1 (TGFb1). Methods: Cell proliferation was measured by crystal violet staining assay. Collagen synthesis was determined by 3H-proline incorporation assay. Type I procollagen mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR). Results: GE (25~70 mmolL-1) and QU (6.25~50 mmolL-1) concentration-dependently attenuated PDGF-driven HSC-T6 cell proliferative activity. TGFb1-stimulated collagen synthesis was also reduced. This was associated with a decrease in type I procollagen mRNA expression, indicating an effect at a pretranslational level. Conclusion: GE and QU may have therapeutic potential against liver fibrosis by regulating PDGF and TGFb1 actions.展开更多
Tumor cell-derived exosomes have been proposed as non-cellular nanomeric vaccine which could induce potent anti- tumor immune response in mice. In order to develop the protocols to prepare tumor cell-derived exosomes ...Tumor cell-derived exosomes have been proposed as non-cellular nanomeric vaccine which could induce potent anti- tumor immune response in mice. In order to develop the protocols to prepare tumor cell-derived exosomes for basic research and clinical trail, we isolated exosomes from ovalbumin (OVA)-expressing thymoma cells EG.7-OVA by various preparation methods. We demonstrate the non-sedimentation method is simple, rapid, efficient with higher yield and purity of exosomes. EG.7-OVA-derived exosomes are 40-100 nm in diameter sequestered by lipid bi-layer, and contain rich heat shock protein (HSP) and OVA. The result of the size distribution determination is consistent with the calculation by the visual microscopic inspection, with 90.4% particles at the range of 50-90 nm. Moreover, as a model antigen of the EG.7 cells, OVA concentra- tion in EG.7-derived exosomes can be regarded as a good quality control parameter. Therefore, we have established a platform to efficiently prepare exosomes for tumor immunotherapy.展开更多
Specific antibody responses could be induced in serumfree condition.Specific anti-SRBC or anti-SRBC ghost antibody were induced from anti-Thy treated (T-depleted) murine spleen cells in serum-free culture in the prese...Specific antibody responses could be induced in serumfree condition.Specific anti-SRBC or anti-SRBC ghost antibody were induced from anti-Thy treated (T-depleted) murine spleen cells in serum-free culture in the presence of Con A conditioned medium.This induction system may facilitate the study of lymphokine functions on antigen triggered B cells. In T cell-replaced cultures,the antibody responses of B cells could be successfully induced when soluble SRBC membrane proteins were used as antigens.It thus indicates that antigen together with lymphokines are sufficient to drive B cells to become antibody secreting cells in the absence of T cells.The T cell-replaced system provides a more stable way for in vitro immunization and may be applied to monoclonal antibody production when in vivo immunization is difficult to be carried out.展开更多
The purpose of present work is a measurement of telomere length dynamic in proliferating cells in vitro by modified flow-FISH method. This method is a combination of two modifications： telomere length measurement in ...The purpose of present work is a measurement of telomere length dynamic in proliferating cells in vitro by modified flow-FISH method. This method is a combination of two modifications： telomere length measurement in differentiated cells by surface antigen and analysis of cells divisions＇ number by vital dye dilution. Lymphocytes were activated by anti-CD3 Abs with IL-2 presents and grown in vitro for 7 days. Cells division＇s number was measured by dilution of CFSE vital dye which cells were stained previously activation. For telomere length measurement we used flow-FISH method with Cy3 labeled telomere PNH probe. Using this method we evaluated the dynamic of telomere length in CD4＋ and CD8＋ T-cells after 7 days culturing in vitro and revealed the difference in telomere lengthening and shortening versus division rounds in cell subsets. In CD8＋ cells telomeres start lengthen on a second division with the maximum on 4th division round becoming more that 20% longer compared with undividing cells. In CD4＋ cells telomeres did not have any length peculiarities through all division rounds demonstrating different telomere regulation in subsets. This probably occurs due to the higher level ofhTERT protein expression in CD8＋ than CD4＋ cells do.展开更多
SAMHD1(Sterile Alpha Motif and Histidine-aspartate Domain containing protein 1) has been documented as a host factor that restricts HIV-1 and some DNA viruses. In this work, we attempted to explore possible effects of...SAMHD1(Sterile Alpha Motif and Histidine-aspartate Domain containing protein 1) has been documented as a host factor that restricts HIV-1 and some DNA viruses. In this work, we attempted to explore possible effects of SAMHD1 on exogenous DNA and show that SAMHD1 exerts a general inhibition on the expression of exogenous DNA in vitro and in mice. This inhibition is achieved through repressing transcription of exogenous DNA. Intriguingly, unlike SAMHD1’s restriction of HIV-1, such restriction does not require the dNTPase or RNase activities, or T592 phosphorylation of SAMHD1. Mechanistically,SAMHD1 enhances the expression of interferon regulatory factor-1(IRF1), while IRF1 upregulation was demonstrated to inhibit exogenous DNA expression in a similar fashion as SAMHD1. IFNk1, whose induction has been associated with IRF1 activation, is dispensable for SAMHD1/IRF1-mediated restriction of exogenous DNA, and neither type Ⅰ nor Ⅱ interferons appear to be involved. We also demonstrate that SAMHD1/IRF1-mediated restriction can effectively inhibit hepatitis B virus(HBV) antigen expression and progeny virus production in mouse models. In conclusion, these data support restriction of exogenous DNA as a novel function of SAMHD1.展开更多
基金Project supported by the National Natural Science Foundation of China No: 39670837
文摘Objective: To study the antifibrotic effects of genistein(GE) and quercetin(QU) on rat hepatic stellate HSC-T6 cell proliferation stimulated with platelet-derived growth factor (PDGF), collagen synthesis and type I procollagen messenger RNA (mRNA) expression stimulated with transforming growth factor b1 (TGFb1). Methods: Cell proliferation was measured by crystal violet staining assay. Collagen synthesis was determined by 3H-proline incorporation assay. Type I procollagen mRNA level was determined by reverse transcription polymerase chain reaction (RT-PCR). Results: GE (25~70 mmolL-1) and QU (6.25~50 mmolL-1) concentration-dependently attenuated PDGF-driven HSC-T6 cell proliferative activity. TGFb1-stimulated collagen synthesis was also reduced. This was associated with a decrease in type I procollagen mRNA expression, indicating an effect at a pretranslational level. Conclusion: GE and QU may have therapeutic potential against liver fibrosis by regulating PDGF and TGFb1 actions.
文摘Tumor cell-derived exosomes have been proposed as non-cellular nanomeric vaccine which could induce potent anti- tumor immune response in mice. In order to develop the protocols to prepare tumor cell-derived exosomes for basic research and clinical trail, we isolated exosomes from ovalbumin (OVA)-expressing thymoma cells EG.7-OVA by various preparation methods. We demonstrate the non-sedimentation method is simple, rapid, efficient with higher yield and purity of exosomes. EG.7-OVA-derived exosomes are 40-100 nm in diameter sequestered by lipid bi-layer, and contain rich heat shock protein (HSP) and OVA. The result of the size distribution determination is consistent with the calculation by the visual microscopic inspection, with 90.4% particles at the range of 50-90 nm. Moreover, as a model antigen of the EG.7 cells, OVA concentra- tion in EG.7-derived exosomes can be regarded as a good quality control parameter. Therefore, we have established a platform to efficiently prepare exosomes for tumor immunotherapy.
文摘Specific antibody responses could be induced in serumfree condition.Specific anti-SRBC or anti-SRBC ghost antibody were induced from anti-Thy treated (T-depleted) murine spleen cells in serum-free culture in the presence of Con A conditioned medium.This induction system may facilitate the study of lymphokine functions on antigen triggered B cells. In T cell-replaced cultures,the antibody responses of B cells could be successfully induced when soluble SRBC membrane proteins were used as antigens.It thus indicates that antigen together with lymphokines are sufficient to drive B cells to become antibody secreting cells in the absence of T cells.The T cell-replaced system provides a more stable way for in vitro immunization and may be applied to monoclonal antibody production when in vivo immunization is difficult to be carried out.
文摘The purpose of present work is a measurement of telomere length dynamic in proliferating cells in vitro by modified flow-FISH method. This method is a combination of two modifications： telomere length measurement in differentiated cells by surface antigen and analysis of cells divisions＇ number by vital dye dilution. Lymphocytes were activated by anti-CD3 Abs with IL-2 presents and grown in vitro for 7 days. Cells division＇s number was measured by dilution of CFSE vital dye which cells were stained previously activation. For telomere length measurement we used flow-FISH method with Cy3 labeled telomere PNH probe. Using this method we evaluated the dynamic of telomere length in CD4＋ and CD8＋ T-cells after 7 days culturing in vitro and revealed the difference in telomere lengthening and shortening versus division rounds in cell subsets. In CD8＋ cells telomeres start lengthen on a second division with the maximum on 4th division round becoming more that 20% longer compared with undividing cells. In CD4＋ cells telomeres did not have any length peculiarities through all division rounds demonstrating different telomere regulation in subsets. This probably occurs due to the higher level ofhTERT protein expression in CD8＋ than CD4＋ cells do.
基金This work was supported by National Natural Science Foundation of China(81472226,81971921 and 31670166)National Key Project for Infectious Diseases of China(2017ZX10202202 and 2018ZX10301208)+1 种基金Chinese Academy of Medical Sciences(2018PT31044)Shanghai Municipal Education Commission(2017-01-07-00-07-E00057).
文摘SAMHD1(Sterile Alpha Motif and Histidine-aspartate Domain containing protein 1) has been documented as a host factor that restricts HIV-1 and some DNA viruses. In this work, we attempted to explore possible effects of SAMHD1 on exogenous DNA and show that SAMHD1 exerts a general inhibition on the expression of exogenous DNA in vitro and in mice. This inhibition is achieved through repressing transcription of exogenous DNA. Intriguingly, unlike SAMHD1’s restriction of HIV-1, such restriction does not require the dNTPase or RNase activities, or T592 phosphorylation of SAMHD1. Mechanistically,SAMHD1 enhances the expression of interferon regulatory factor-1(IRF1), while IRF1 upregulation was demonstrated to inhibit exogenous DNA expression in a similar fashion as SAMHD1. IFNk1, whose induction has been associated with IRF1 activation, is dispensable for SAMHD1/IRF1-mediated restriction of exogenous DNA, and neither type Ⅰ nor Ⅱ interferons appear to be involved. We also demonstrate that SAMHD1/IRF1-mediated restriction can effectively inhibit hepatitis B virus(HBV) antigen expression and progeny virus production in mouse models. In conclusion, these data support restriction of exogenous DNA as a novel function of SAMHD1.
