Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affin...Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affinity and specificity to the HBsAg is of great significance to the early-stage diagnosis and treatment of HBV infection. Herein, we report the selection of RNA aptamers that can specifically bind to HBsAg protein and HBsAg-positive hepatocytes. One high affinity aptamer, HBs-A22, was isolated from an initial 115 met library of -1.1 ×10^15 random-sequence RNA molecules using the SELEX procedure. The selected aptamer HBs-A22 bound specifically to hepatoma cell line HepG2.2.15 that expresses HBsAg but did not bind to HBsAg-devoid HepG2 cells. This is the first reported RNA aptamer which could bind to a HBV specific antigen. This newly isolated aptamer could be modified to deliver imaging, diagnostic, and therapeutic agents targeted at HBV-infected cells.展开更多
To investigate the effects of overall alkali of a traditional Chinese medicine “Tongbiling” (brucine and strychnine alkaloids in main) on the cytokines expression in Th1 and Th2 cells in the synovial fluid of patien...To investigate the effects of overall alkali of a traditional Chinese medicine “Tongbiling” (brucine and strychnine alkaloids in main) on the cytokines expression in Th1 and Th2 cells in the synovial fluid of patients with rheumatism arthritis and their signal pathway, the mononuclear cells in the synovial fluid (SFMC) of patients were isolated by Ficoll-Hypaque gradient centrifugation, and the CD3 + CD69 + and CD3 + HLA-DR antigen were analyzed by flow cytometry in comparison with those of the peripheral blood. The rest of cells were cultured after resuspension with RPMI 1640 culture medium. Phorbol 12,13-dibutyrate (PDB) and ionomycin were added successively into the culture with various concentration of overall alkali Tongbiling (TBL). After 4 h of cultivation, the expression of IFN-γ and IL-4 in CD3 + cells were analyzed by flow cytometry. The influence of overall alkali TBL (100?mg/L) on the intracellular calcium was investigated after Fluo-3/AM labeling and stimulation with PDB and ionomycin at 1, 2, 4 and 10?min, and the influence of TBL on the expression of CD3 + CD69 + cells were determined with stimulation of PDB for 24?h in the whole blood lymphocytes culture. It was found that the percentage of T cells bearing CD69 was significantly up-regulated (77%), while that of T cells bearing HLA-DR was 44% in the synovial mononucleated cells. After PDB and ionomycin stimulation, the expression of IFN-γ in CD3 + cells were up-regulated, but there was no change on the expression of IL-4 in CD3 + cells, indicating that ratio of Th1/Th2 was significantly increased and Th cells differentiate to Th1 cells in mainly. Four concentrations of overall alkaloid of TBL (200?mg/L, 100?mg/L, 50?mg/L, 25?mg/L) could down-regulated the expression of IFN-γ in CD3 + cells and the Th1/Th2 ratio obviously, but all the concentrations of the overall alkaloids had no effect on the expression of IL-4 in CD3 + cells. 100?mg/L concentration of the overall alkaloid did not down-regulate the intracellular calcium level. Each concentration of the overall alkaloid could down-regulated the expression CD69 obviously on the PDB-activated mouse T cells. It concluded from the above observations that the overall alkaloid of TBL could relieve the inflammatory and immune damages by suppressing the expression of Th1 type cytokines and Th1 cell differentiation, regulating the imbalance of Th1/Th2 cells and inhibiting the early activation of the T lymphocytes bearing CD69. There was no remarkable influence on the intracellular calcium signaling transduction pathway. The inhibitory effected on T cells to express IFN-γ might be due to the suppression of PKC-MAPK signaling pathway. From the standpoint of traditional Chinese medicine, this might be due to the regulation of “Yin” and “Yang” imbalance of joints to modify the pathological status in rheumatoid arthritis. This study provided an experimental basis for the application of overall alkaloids of TBL in the treatment of rheumatoid arthritis.展开更多
基金National Mega Research Program of China(2008ZX10002-011)National Natural Science Foundation of China(30700701)National High Tech-nology Research and Development program of China(2006AA02Z128)
文摘Hepatitis B virus surface antigen （HBsAg）, a specific antigen on the membrane of Hepatitis B virus （HBV）-infected cells, provides a perfect target for therapeutic drugs. The development of reagents with high affinity and specificity to the HBsAg is of great significance to the early-stage diagnosis and treatment of HBV infection. Herein, we report the selection of RNA aptamers that can specifically bind to HBsAg protein and HBsAg-positive hepatocytes. One high affinity aptamer, HBs-A22, was isolated from an initial 115 met library of -1.1 ×10^15 random-sequence RNA molecules using the SELEX procedure. The selected aptamer HBs-A22 bound specifically to hepatoma cell line HepG2.2.15 that expresses HBsAg but did not bind to HBsAg-devoid HepG2 cells. This is the first reported RNA aptamer which could bind to a HBV specific antigen. This newly isolated aptamer could be modified to deliver imaging, diagnostic, and therapeutic agents targeted at HBV-infected cells.
文摘To investigate the effects of overall alkali of a traditional Chinese medicine “Tongbiling” (brucine and strychnine alkaloids in main) on the cytokines expression in Th1 and Th2 cells in the synovial fluid of patients with rheumatism arthritis and their signal pathway, the mononuclear cells in the synovial fluid (SFMC) of patients were isolated by Ficoll-Hypaque gradient centrifugation, and the CD3 + CD69 + and CD3 + HLA-DR antigen were analyzed by flow cytometry in comparison with those of the peripheral blood. The rest of cells were cultured after resuspension with RPMI 1640 culture medium. Phorbol 12,13-dibutyrate (PDB) and ionomycin were added successively into the culture with various concentration of overall alkali Tongbiling (TBL). After 4 h of cultivation, the expression of IFN-γ and IL-4 in CD3 + cells were analyzed by flow cytometry. The influence of overall alkali TBL (100?mg/L) on the intracellular calcium was investigated after Fluo-3/AM labeling and stimulation with PDB and ionomycin at 1, 2, 4 and 10?min, and the influence of TBL on the expression of CD3 + CD69 + cells were determined with stimulation of PDB for 24?h in the whole blood lymphocytes culture. It was found that the percentage of T cells bearing CD69 was significantly up-regulated (77%), while that of T cells bearing HLA-DR was 44% in the synovial mononucleated cells. After PDB and ionomycin stimulation, the expression of IFN-γ in CD3 + cells were up-regulated, but there was no change on the expression of IL-4 in CD3 + cells, indicating that ratio of Th1/Th2 was significantly increased and Th cells differentiate to Th1 cells in mainly. Four concentrations of overall alkaloid of TBL (200?mg/L, 100?mg/L, 50?mg/L, 25?mg/L) could down-regulated the expression of IFN-γ in CD3 + cells and the Th1/Th2 ratio obviously, but all the concentrations of the overall alkaloids had no effect on the expression of IL-4 in CD3 + cells. 100?mg/L concentration of the overall alkaloid did not down-regulate the intracellular calcium level. Each concentration of the overall alkaloid could down-regulated the expression CD69 obviously on the PDB-activated mouse T cells. It concluded from the above observations that the overall alkaloid of TBL could relieve the inflammatory and immune damages by suppressing the expression of Th1 type cytokines and Th1 cell differentiation, regulating the imbalance of Th1/Th2 cells and inhibiting the early activation of the T lymphocytes bearing CD69. There was no remarkable influence on the intracellular calcium signaling transduction pathway. The inhibitory effected on T cells to express IFN-γ might be due to the suppression of PKC-MAPK signaling pathway. From the standpoint of traditional Chinese medicine, this might be due to the regulation of “Yin” and “Yang” imbalance of joints to modify the pathological status in rheumatoid arthritis. This study provided an experimental basis for the application of overall alkaloids of TBL in the treatment of rheumatoid arthritis.
