Research Of MUC1 Therapeutic Vaccine Based On Heat Shock Protein

MUC1 is one kind of mucins which is widely expressed both by normal glandular epithelial cells and the carcinoma developed from them. MUC1 is a high molecular weigh glycoprotein with a large amount of carbohydrates O-linked to the protein core. It is a transmembrane protein with a unique extracellular domain consisting mainly of variable number of tandem repeats(VNTRs) which is made up of 20 amino acids.The unique characteristics of MUC1 in many types of epithelial cancers, such as excessive expression,aberrant cellular distribution and underglycosylation-induced exposure of the normally cryptic core protein,have made MUC1 a promising candidate antigen in cancer immunotherapy. The PDTRP epitope of MUC1 core protein can not only be recognized by MUC1 antibody,but also be recognized and killed by cytotoxic T lymphocytes(CTLs) . Our work aimed to develop a new therapeutic vaccine based on heat shock protein against cancers, such as non small cell lung cancer(NSCLC) etc.In recent years, investigators found out that HSP-peptides complex can deliver the antigen to MHC-I restricted antigen presenting pathway through receptor (CD91) mediated phagocytosis, and then, cellular immunity is activated. We select the hsp65 of M.tuberculosis to fuse with murine BP24 gene or human BP25 gene as the therapeutic vaccine, which can present the antigen to MHC-I restricted pathway and activate cellular immunity against tumor.In present study, We cloned murine BP24 and human BP25 gene and constructed a pET28a-HSP65BP24Ztag and pET28a-HSP65BP25Ztag expression vector. HSP65BP24 and HSP65BP25 fusion protein was expressed at high level in E.coli. After Ammonium sulfate precipitation, cation exchanger chromatography and hydrophobic interaction chromatography, protein sample that has the purity above 90% was achieved. Utilizing the Lewis lung cancer cell line of murine to construct the model of carcinoma, an immunotherapy based on the administration of an adjuvant-free fusion protein has been developed. The result indicates that prophylactic immunization with HSP65BP24...