Preparation and Identification of Anti-lactoferrin Single Chain Fv Antibody / 医学研究杂志

Objective To prepare a specific anti-lactoferrin single chain variable fragment(ScFv).Methods Anti-lactoferrin clones were screened from a 'naive' phage antibody library against the immobilized lactoferrin antigen,then the clones were transformed to the E.coli HB2151 to give soluble expression of antibody fragments.The culture supernatant containing ScFv was purified by immobilized metal affinity chromatography,and then determined with SDS-PAGE and ELISA.Results The results demonstrated that ScFvs were specific;they did not react with transferrin,lysozyme and bovine serum albumin in ELISA.The SDS-PAGE showed that the ScFvs had high purity through affinity chromatography and the molecular weight of them was about 32 kD.Conclusions The successful generation of the ScFvs against lactoferrin provides a basis for further study and clinical applications for dry eye and other ocular diseases.

Construction of an eukaryotic expression vector encoding human granzyme B and it's expression in Hep2 cells / 中国病理生理杂志

AIM: To construct pVAX1-GrB. METHODS: Lymphocytes from human laryngeal carcinoma tissue were separated from tumor tissue. The fragment of granzyme B (GrB) was amplified by RT-PCR and was recombined to the downstream of T7 promoter in the vector pVAX1. The construction was transfected into Hep2 cells with lipofectamine 2000. The expression of protein was identified by indirect immunofluorescent antibody assay. RESULTS: It has been proved that the sequence of the RT-PCR product was totally consistent with the data of GenBank by DNA sequencing analysis. The GrB cDNA fragment was cloned into the vector of pVAX1 in the right direction and the open reading fragment of GrB was maintained. The target protein was detected in the transfected Hep2 cells. CONCLUSION: The pVAX1-GrB plasmid was successfully constructed and expressed. [

Cloning and eukaryotic expressing of GPI-B7-1 in CHO / 中国病理生理杂志

AIM: To construct human GPI-B7-1 fusion protein and investigate the therapeutic potentials in the treatment of tumors. METHODS: The chimeric GPI anchored-B7-1 gene was obtained by overlap PCR and inserted into expressing vector pcDNA3.1, named pc3.1/GPI-B7-1. pc3.1/GPI-B7-1was transfected into CHO cells by lipofectamine ~2 000 reagent. The CHO cells, expressing GPI-B7-1 on membranes, were obtained after selecting by G418. That was confirmed by flow cytometry, SDS-PAGE and Western blot. RESULTS: Recombinant vector pc3.1/GPI-B7-1 was successfully constructed and sequence result indicated that it was identical with reference sequence. The protein on transfected CHO cell membrane selected by G418 was confirmed to be GPI-anchored protein by flow cytometry, and GPI-B7-1 approximately 60 kD was conformed by SDS-PAGE and Western blot. CONCLUSION: A large amount of GPI-B7-1 fusion protein was obtained and will be further studied in the treatment of tumors.2? [

Cloning and sequence analysis of death associated protein kinase gene ORF and DAPK1 inducing Raji cell apoptosis / 中国病理生理杂志

AIM: Open reading frame(ORF) of death associa ted protein kinase1(DAPK1) gene was cloned for studying on tumor forming and met astasis.METHODS: Based on nucleotide sequence of DAPK1 gene f rom GenBank, a pair of primers was designed. DAPK1 gene ORF was transfected into Raji cells in expression vector pcDNA3.1(+) with lipofectamine reagent. Morphol ogic assessment of apoptosis was performed with fluorescence microscope cytotoxi city and cell viability was assayed by MTT. RESULTS: DAPK1 gene ORF was amprified from K562 cells by RT-PCR. It was cloned into plasmid pMD18-T and sequenced. There were seven mutation in 4 300 bp nucleotide sequence rel ativel y to DAPK1 nucleotide sequence from GenBank, but six was synonymous mutation and one was single nucleotide polymorphism. 4 300 bp nucleotide of DAPK1 gene O RF was transfected into Raji cells. DAPK1 gene expression was detected in 48 h a fter it was transfected into Raji cells. Then Raji cells showed apoptosis.CONCLUS ION: Large fragment gene was cloned by RT-PCR and transfected into Raji cells successfully. Over-expression of DAPK1 gene induced Raji cells apoptosis.