AIM: To obtain the short peptides mimic antigenic epitopes selected by rat natural antibodies to schistosomes, and to explore their immunoprotection against schistosomiasis in mice.METHODS: Adults worm antigens (AWA) ...AIM: To obtain the short peptides mimic antigenic epitopes selected by rat natural antibodies to schistosomes, and to explore their immunoprotection against schistosomiasis in mice.METHODS: Adults worm antigens (AWA) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked transferred immunoblotting methods with normal SD rat sera (NRS). The killing effects on schistosomula with fresh and heat-inactivated sera from SD rats were observed. Then the purified IgG from sera of SD rats was used to biopan a phage random peptide library and 20 randomly selected positive clones were detected by ELISA and 2 of them were sequenced.Sixty female mice were immunized thrice with positive phage clones (0, 2nd, 4th wk). Each mouse was challenged with 40 cercariae, and all mice were killed 42 d after challenge. The worms and the liver eggs were counted. RESULTS: NRS could specifically react to the molecules of 75 000, 47 000, 34 500 and 23 000 of AWA. Sera from SD rats showed that the mortality rate of schistosomula was 76.2%, and when the sera were heat-inactivated in vitro, the mortality rate was decreased to 41.0% after being cultured for 48 h. The specific phages bound to IgG were enriched about 300-folds after three rounds of biopanning. Twenty clones were detected by ELISA, 19 of them bound to the specific IgG of rat sera. Immunization with these epitopes was carried out in mice. Compared with the control groups, the mixture of two mimic peptides could induce 34.9% (P = 0.000) worm reduction and 67.6% (P = 0.000) total liver egg reduction in mice. Two different mimic peptides could respectively induce 31.0% (P = 0.001), 14.5% (P = 0.074) worm reduction and 61.2% (P = 0.000), 35.7% (P = 0.000) total liver egg reduction. The specific antibody could be induced by immunization of the mimic peptides, and the antibody titer in immunized mice reached more than 1:6 400 as detected by ELISA.CONCLUSION: Specific peptides mimic antigenic molecules can be obtained by biopanning the phage random peptide library and a partially protective immunity against schistosome infection can be stimulated by these phage epitopes in mice.展开更多
Amphiphilic dendritic poly（glutarnic acid）-b-polyphenylalanine copolymers were synthesized using generation 3 dendritic poly（glutamic acid） as the macroinitiator in the ring-opening polymerization of NCA-Phe. The ...Amphiphilic dendritic poly（glutarnic acid）-b-polyphenylalanine copolymers were synthesized using generation 3 dendritic poly（glutamic acid） as the macroinitiator in the ring-opening polymerization of NCA-Phe. The block copolymers self-assembled micelles with polyphenylalanine segments as core and dendritic poly（glutamic acid） segments as shell. The biocompatibility of the micelles was studied. The release of the anticancer drug doxorubicin from the micelles was investigated in vitro. The results showed that the sustaining release of the drug could last for 60 h. The micellar drug release system was efficient in inhibiting the proliferation of HepG2 liver cancer cells, 75% cancer cells were killed under appropriate in vitro incubation.展开更多
基金Supported by the WHO/TDR, No. 980255 and the Science Commission of Hunan Province, No. 00jzy2115
文摘AIM: To obtain the short peptides mimic antigenic epitopes selected by rat natural antibodies to schistosomes, and to explore their immunoprotection against schistosomiasis in mice.METHODS: Adults worm antigens (AWA) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked transferred immunoblotting methods with normal SD rat sera (NRS). The killing effects on schistosomula with fresh and heat-inactivated sera from SD rats were observed. Then the purified IgG from sera of SD rats was used to biopan a phage random peptide library and 20 randomly selected positive clones were detected by ELISA and 2 of them were sequenced.Sixty female mice were immunized thrice with positive phage clones (0, 2nd, 4th wk). Each mouse was challenged with 40 cercariae, and all mice were killed 42 d after challenge. The worms and the liver eggs were counted. RESULTS: NRS could specifically react to the molecules of 75 000, 47 000, 34 500 and 23 000 of AWA. Sera from SD rats showed that the mortality rate of schistosomula was 76.2%, and when the sera were heat-inactivated in vitro, the mortality rate was decreased to 41.0% after being cultured for 48 h. The specific phages bound to IgG were enriched about 300-folds after three rounds of biopanning. Twenty clones were detected by ELISA, 19 of them bound to the specific IgG of rat sera. Immunization with these epitopes was carried out in mice. Compared with the control groups, the mixture of two mimic peptides could induce 34.9% (P = 0.000) worm reduction and 67.6% (P = 0.000) total liver egg reduction in mice. Two different mimic peptides could respectively induce 31.0% (P = 0.001), 14.5% (P = 0.074) worm reduction and 61.2% (P = 0.000), 35.7% (P = 0.000) total liver egg reduction. The specific antibody could be induced by immunization of the mimic peptides, and the antibody titer in immunized mice reached more than 1:6 400 as detected by ELISA.CONCLUSION: Specific peptides mimic antigenic molecules can be obtained by biopanning the phage random peptide library and a partially protective immunity against schistosome infection can be stimulated by these phage epitopes in mice.
基金supported by the National Basic Research Program of China (973 Program,2011CB606206)National High-Tech Research & Development Program of China (863 Program,2007AA021801)+2 种基金National Natural Science Foundation of China (50633020 & 50830105)Sichuan Youth Science & Technology Foundation (07ZQ026-013)Open Fund of Engineering Research Center of Biomass Materials,Ministry of Education (2010LF4002)
文摘Amphiphilic dendritic poly（glutarnic acid）-b-polyphenylalanine copolymers were synthesized using generation 3 dendritic poly（glutamic acid） as the macroinitiator in the ring-opening polymerization of NCA-Phe. The block copolymers self-assembled micelles with polyphenylalanine segments as core and dendritic poly（glutamic acid） segments as shell. The biocompatibility of the micelles was studied. The release of the anticancer drug doxorubicin from the micelles was investigated in vitro. The results showed that the sustaining release of the drug could last for 60 h. The micellar drug release system was efficient in inhibiting the proliferation of HepG2 liver cancer cells, 75% cancer cells were killed under appropriate in vitro incubation.
