To obtain short peptides simulating antigenic epitopes related to natural resistance against Schistosoma japonicum (S.j) in rats, and to explore their immune protection against S.j in mice, phage random peptide librar...To obtain short peptides simulating antigenic epitopes related to natural resistance against Schistosoma japonicum (S.j) in rats, and to explore their immune protection against S.j in mice, phage random peptide library of 12 amino acids were screened with purified IgG from normal rat sera. Positive clones that were obtained after three rounds of biopanning were detected by ELISA, and two of them were sequenced. Kunming mice were immunized with mixed phage clones. Each mouse was challenged with 40±1 S.j cercariae, and all mice were perfused 45 days post-challenge. The worms and the liver eggs were counted. The results were that the specific phages binding to IgG were enriched 300 folds after three rounds of biopanning. Twenty clones were detected by ELISA and 19 of them bound to the specific IgG of rat sera. The sequence of two clones revealed no homology with other sequences in the GenBank. Compared with the control groups, the reduction rates of the worm burden and liver egg were 33.6% and 59.8%, respectively. It was concluded that the specific peptides, which simulate antigenic molecules correlated with natural resistance to S.j in rats could be obtained by immunosceening phage random peptide library and a protective immunity against S.j can be detected by these epitopes in mice.展开更多
A primary cDNA expression library with a titer of 5.0 × 105 PFU mL-1 was constructed from mRNA extracted from larval Haemaphysalis qinghaiensis ticks in order to identify certain genes,which would then be used as...A primary cDNA expression library with a titer of 5.0 × 105 PFU mL-1 was constructed from mRNA extracted from larval Haemaphysalis qinghaiensis ticks in order to identify certain genes,which would then be used as candidate molecules for development of effective vaccines to control this parasite.Totally 11 positive clones,which designated as HqL01-11,were obtained by immunoscreening of the library using a polyclonal antibody generated in rabbit with larval tick protein extract.Results of sequence analysis from BLASTN searching revealed that 6 of them had no significant homology with the adult H.qinghaiensis ticks’ known genes,4 of them had no significant homology with all genes deposited in GenBank database.HqL07,HqL08,HqL09,and HqL11 were deposited to GenBank database,and accession numbers were EF605263,EF605264,EF605265,and EF605266,respectively.Subsequently,HqL07 and HqL09 were expressed in vitro and the molecular weights of the corresponding expressed products were 60 and 70 kDa,respectively.Western blot analyses showed that HqL07 and HqL09 had immunogenicity.This study laid the foundation for future production of genetically engineered vaccines for the immunological control of H.qinghaiensis.展开更多
基金This study was supported by grants from WHO/TDR (980255) and the Science Commission of Hunan Province (00jzy2115)
文摘To obtain short peptides simulating antigenic epitopes related to natural resistance against Schistosoma japonicum (S.j) in rats, and to explore their immune protection against S.j in mice, phage random peptide library of 12 amino acids were screened with purified IgG from normal rat sera. Positive clones that were obtained after three rounds of biopanning were detected by ELISA, and two of them were sequenced. Kunming mice were immunized with mixed phage clones. Each mouse was challenged with 40±1 S.j cercariae, and all mice were perfused 45 days post-challenge. The worms and the liver eggs were counted. The results were that the specific phages binding to IgG were enriched 300 folds after three rounds of biopanning. Twenty clones were detected by ELISA and 19 of them bound to the specific IgG of rat sera. The sequence of two clones revealed no homology with other sequences in the GenBank. Compared with the control groups, the reduction rates of the worm burden and liver egg were 33.6% and 59.8%, respectively. It was concluded that the specific peptides, which simulate antigenic molecules correlated with natural resistance to S.j in rats could be obtained by immunosceening phage random peptide library and a protective immunity against S.j can be detected by these epitopes in mice.
基金supported by the Na- tional High-Tech R&D Program (2006AA10A207)the National Key Technology R&D Program (2007- BAD40B06)+1 种基金the Natural Resource Platform Project (2005DKA21104)the National Natural Science Foundation of China (30270992) as well
文摘A primary cDNA expression library with a titer of 5.0 × 105 PFU mL-1 was constructed from mRNA extracted from larval Haemaphysalis qinghaiensis ticks in order to identify certain genes,which would then be used as candidate molecules for development of effective vaccines to control this parasite.Totally 11 positive clones,which designated as HqL01-11,were obtained by immunoscreening of the library using a polyclonal antibody generated in rabbit with larval tick protein extract.Results of sequence analysis from BLASTN searching revealed that 6 of them had no significant homology with the adult H.qinghaiensis ticks’ known genes,4 of them had no significant homology with all genes deposited in GenBank database.HqL07,HqL08,HqL09,and HqL11 were deposited to GenBank database,and accession numbers were EF605263,EF605264,EF605265,and EF605266,respectively.Subsequently,HqL07 and HqL09 were expressed in vitro and the molecular weights of the corresponding expressed products were 60 and 70 kDa,respectively.Western blot analyses showed that HqL07 and HqL09 had immunogenicity.This study laid the foundation for future production of genetically engineered vaccines for the immunological control of H.qinghaiensis.
