Objective To clone the gene of autolysin(LytA) which are from different clinical strains of Streptococcus pneumoniae and express them in Escherichia coli. Methods The LytA gene was amplified by PCR from the total DNA of S.pneumoniae. Primers were designed according to the LytA gene sequence of R6. Recombinant plasmids were constructed and the sequences of different clinical strains were analyzed through method of bioinformatics. The cloned genes were expressed in E.coli and detected by SDS-PAGE. Results Complete LytA gene were amplified from all of the different clinical strains of S.pneumoniae and recombinant plasmids pGEX-4T-1-LytA were constructed successfully. After comparing the sequence of DNA and supposed protein, we find some differences. Induced by IPTG, LytA gene was expressed effectively in E.coli Jm109. Result of SDS-PAGE showed that the molecular weight of expressed protein was 62 kD, the same as calculated. Conclusions The sequences encoding LytA from different clinical strains of S.pneumoniae were cloned, the recombinant plasmids pGEX-4T-1-LytA was constructed successfully. Sequence analysis showed that there have difference among the gene and amino acid sequences of LytA from different clinical strains. Further studies should be focused on whether the difference contributes to activity of autolysin and the drug-resistance of S.pneumoniae.

Aim To search the effective malaria mixed gene vaccine and to explore the immune response of vaccinated host. The recombinant pcDNA3-EBA175/HRP Ⅱ was injected alone or mixed with pcDNA3-Pfs25 of Plasmodium falciparum into mice by intramuscular route. The muscle of injected parts were treated previously, e.g. injecting 50μl of 0. 5％bupivacaine into the muscle of left latter leg, with 2mm depth. To observed the changes of IgG antibody value, the splenic lymphocyte proliferation, the ratio of CD4+/CD8+ subgroups and NK cell killing activity. After injecting recombinant pcDNA3-EBA175/HRP Ⅱ alone or mixed with pcDNA3-Pfs25 into mice by intramuscular route, it showed that sera IgG value increased, the splenic T lymphocyte proliferation stimulated by specific antigen of Plasmodium falciparum increased, the ratio of CD4+/CD8+ decreased and NK cell activity increased. Enhanced immune injection could improve host's immune reaction.It is suggested intramuscular injection is an effective immune route, and mice inoculated with coding two gene recombinant alone or that mixed with sexual stage gene recombinant could all induce increased humoral and cellular immune response, and NK cell activity.

Objective To establish a rapid, specific and sensitive diagnostic technique for the human T. gondii infection with hematopoietic stem cell transplantation and discuss its clinical significance. Me- thods Fifty-six patients subject to hematopoietic stem cell transplantation were detected with ELISA and PCR. Results Among 56 recipients of hematopoietic stem cell transplantation, 7 were positive for T. gondii antigen and 10 were positive for SAG3 gene fragment respectively with the positive rate being 14.3 % and 17.8 % in the ELISA and PCR screening respectively. Twenty healthy people were negative for anti-Toxo antibody.Conclusion PCR is an accurate, relatively rapid, sensitive and specific method for detecting SAG3 gene of T. gondii, and can be considered a valuable additional tool for identification of T. gondii infections.

Objective To Construct the prokaryotic expression vector of the fusion gene IFN-?1b/CSPⅡ. MethodsIFN-?1b was amplified from the human genomic DNA by PCR and cloned into prokaryotic expression vector pGEX-4T-1. The recombinant plasmid pGEX-4T-1/IFN-?1b was constructed. Circumsporozoite proteinⅡ(CSPⅡ) was amplified from the Plasmodium falciparum genomic DNA by PCR and was cloned into the prokaryotic expression vector pGEX-4T-1. The recombinant plasmid pGEX-4T-1/CSPⅡ was constructed. IFN-?1b was cut from the recombinant plasmid pGEX-4T-1/IFN-?1b digested with BamHⅠ and EcoRⅠ and ligated with the recombinant plasmid pGEX-4T-1/CSPⅡ also digested with BamHⅠ and EcoRⅠ . The recombinant prokaryotic plasmid pGEX-4T-1/IFN-?1b/CSPⅡ was constructed. The fusion gene IFN-?1b/CSPⅡ was expressed in E.coli by IPTG. Results The prokaryotic expression vector pGEX-4T-1/IFN-?1b, pGEX-4T-1/CSPⅡ and pGEX-4T-1/IFN-?1b/CSPⅡ were identified by PCR, enzyme digestion and gene sequencing. The expressed fusion protein/IFN-?1b/CSPⅡ in E.coli was identified by SDS-PAGE and Western blot. Conclusion The prokaryotic expression vector of the fusion gene IFN-?1b/CSPⅡ was successfully constructed, which was then expressed in E.coli .

Objective To produce prokaryotic recombinant protein glyceraldehyde-3-phosphate dehydrogenase of Clonorchis sinensis (CsGAPDH), analyze its enzyme activity and immunological function. Methods The recombinant CsGAPDH was purified according to the protocol of GST?Bind~TM kit and was digested with thrombin proteinase and eluted with wash buffer. The BALB/c mice were inoculated with the purified protein. The antisera collected from the mice were used to detect the titres of IgG antibodies by ELISA, and Western blotting was used to identify the specificity of the antisera with the purified CsGAPDH. S-P immunohistochemistry method was used to confirm the expression and distribution of CsGAPDH in adult Clonorchis sinensis with the polyclonal antibodies from immunized BALB/c mice. The CsGAPDH catalytic activity was evaluated employing the conventional substrate glyceraldehydes-3-phosphate (3-GAP). Results SDS-PAGE showed a single purified protein band. Gel scanning analysis revealed that the protein purity of CsGAPDH was 90%. ELISA analysis showed an increased IgG value. S-P immunohistochemistry analysis demonstrated that the recombinant plasmid pGEX-4T-1-GAPDH expressed and distributed in muscle cell membrane of immune mice. Western blotting result suggested that CsGAPDH protein contained essential epitopes with high antigenic activities. This protein CsGAPDH could catalyzed 3-GAP with enzymatic active unit of 2 872 U min~-1ml~-1. Conclusion The recombinant protein CsGAPDH shows a proper enzymatic activity and immunogenicity.

Objective To obtain and characterize a novel gene of Schistosoma japonicum. Methods Looking for a novel gene through expressed sequence tags(EST),then predicting its function with the help of software on line. Finally the novel gene was cloned into an eukaryotic plasmid pEGFP N3. Results A novel gene with complete ORF was obtained. It has homogeneity with Defender Against Apoptotic Death 1 of human and pig. Conclusions EST is a good method to find new genes and analyse them with the help of software on line and characterize their function.

Objective] To amplify,clone and express of a gene encoding hexose transporter of Plasmodium falcipuram(PfHT1) from Southern China isolate FCC1/HN for studing the immune of recombinant which protective from malaria parasite infection. [Methods] Cultivation of P.falciparum isolate FCC1/HN in vitro; extraction of genomic DNA from FCC1/HN using the alkali specific cleavage method; PCR amplification of PfHT1 and cloning into eukaryotic expression vector, pEGFPN3. The recombinant was introduced into mammalian cells, HEPG2 by using liposome\|mediated transfection. [Results] The gene encoding PfHT1 was specifically amplified from the genomic DNA of P.falciparum isolate FCC1/HN. The size of amplified fragment was 1 516 base pair. The eukaryotic expression recombinant, pN3\|HT1 , was constructed and expressed steadily in the hepatocarcinoma cell lines, HEPG2. [Conclusion] The gene encoding PfHT1 was successfully amplified and cloned. The pN3\|HT1/HEPG2 cell line was built for expressing fusion protein of GFP\|HT1.

Objective] To determine the nucleotide sequence of the 3′\|termal of the RESA gene Plasmodium falciparum isolate FCC1/HN, and find out the differences of the sequences of RESA gene among isolate FCC1/HN,FC27,NF7 and Palo Alto. [Methods] 3′\|terminal fragment of RESA gene of P.falciparum isolate FCC1/HN was amplified by PCR method, then was cloned into pMD18\|T vector. The recombinant was screened and identified by BamHI+XhoI and PCR technique. The nucleotide sequence of the 3′\|terminal of the RESA gene was determined by the dideoxy chain termination method. DNASTAR and BLAST software were used to compare and analyze the RESA gene sequences among the different isolates. [Results] The 3′\|termal fragment of the RESA gene with about 846 bp was specifically amplified by PCR, the recombinant pMD18\|T\|RESA was successfully constructed. Different degrees of diversity of the RESA gene sequences were found among P.falciparum isolates FCC1/HN、FC27,NF7 and Palo Alto. [Conclusion] There were differences in the sequences of RESA gene among the P.falciparum isolate FCC1/HN and three other isolates (FC27,NF7 and Palto alto).

Objective To screen a new schistosome vaccine candidate. \ Methods\ Schistosoma japonicum adult cDNA library was screened using sera from immune rabbits vaccinated with irradiated cercariae and monoclonal antibodies against membrane antigen of S.japonicum schistosomula. Three different fragments of S.japonicum cDNA genes were cloned into pGEM-T vector. The sequences of the inserts were determined using an automatic DNA sequencer and were analysed using Blast program. One of the unknown genes (B8) was selected and its ORF sequence (291 bp) was subcloned into eukaryotic expression vector. The recombinant plasmids were identified by restrictive enzymes and PCR amplification. The positive recombinant plasmids (pBK/SjB8) were transformed into host bacteria XL1-blue, and were then induced by IPTG for expression. SDS-PAGE and Western blotting analysis of total cellular protein from the bacteria were performed to detect the gene products. Results The results demonstrated that ORF of SjB8 gene was subcloned into the plasmid pBK-CMV and could express as fusion protein in XL1-blue. The results of SDS-PAGE and Western-blot also showed that the molecular weight of the fusion protein with 3 kDa ?-galactosidase was approximately 13\^6 kDa and the actual molecular weights of the SjB8 was 10\^6 kDa. The expressed fusion product of pBK/Sj-B8 could be recognized by immune serum and McAb. Conclusion A new gene of S.japonicum vaccine candidate (SjB8) was cloned into eukaryotic expression vector pBK-CMV and could express 10\^6 kDa schistosome protein. The results provide foundation for further study of the protein for its posibility as candidate vaccine.

Objectve To detect whether the CTP(phosphocholine cytidylyltransferase) gene was expressed in the asexual erythrocytic stages of Plasmodium falciparum (FCC 1/HN )by using the RT - PCR and to construct eukaryotic expression vector of CTP. Method The erythrocytic stage parasites of Plasmodium falciparum were cultured as described by Trager and Jensen. RNA from erythrocytic stage parasite was extracted by using Trizol reagent. The complete genes coding for CTP gene isolates FCCI/HN were amplified by reverse transcriptase -polymerase chain reaction(RT- PCR). CTP gene was cloned into eukaryotic expression vector pcDNA3. Results CTP encoding gene was amplified from the erythrocytic stages of Plasmodiumfalciparum (FCC 1/HN) and eukaryotic expression vector of CTP was constructed. Conclusion CTP gene was expressed in the erythrocytic stages of Plasmodium falciparum (FCC 1/HN) and eukaryotic expression vector of CTP was successfully constructed.