title: Expression and purification of the cancer antigen SSX2: a potential cancer vaccine.
abstract: SSX2 is a cancer testis antigen expressed in a wide variety of cancers, including synovial sarcoma and melanoma. It holds promise as a potential antigen for cancer immunotherapy. A process for the production of recombinant SSX2 was developed by overexpressing a His-tagged fusion protein of SSX2 in Escherichia coli C41 (DE3). A T-7 promoter system was employed and a plasmid was introduced into the strain to compensate for rare codons in the SSX2 sequence. The production of SSX2 was scaled up to a 2-L fermentation that was operated under fed-batch conditions to improve productivity. After 32h cultivation, the wet cell mass reached 260mg/ml, with SSX2 produced mainly as inclusion bodies at a concentration of 1.1g/L. Urea-solubilized SSX2 was purified by nickel affinity, ion exchange and hydrophobic interaction chromatography. The recovery of SSX2 was 20%, and over 87% purity was obtained with an endotoxin level of 0.11EU/microg. The purified recombinant SSX2 was characterized by ELISA and was shown to be recognized by human sera that have been reported to carry anti-SSX2 antibodies.
authors.affiliation: Graduate Field of Microbiology, Cornell University, Ithaca, NY 14853, USA. ch322@cornell.edu
authors.forename: Chung-Jr
authors.initials: CJ
authors.lastname: Huang
authors.forename: Rishard H
authors.initials: RH
authors.lastname: Chen
authors.forename: Todd
authors.initials: T
authors.lastname: Vannelli
authors.forename: Frank
authors.initials: F
authors.lastname: Lee
authors.forename: Erika
authors.initials: E
authors.lastname: Ritter
authors.forename: Gerd
authors.initials: G
authors.lastname: Ritter
authors.forename: Lloyd J
authors.initials: LJ
authors.lastname: Old
authors.forename: Carl A
authors.initials: CA
authors.lastname: Batt
mesh_terms: D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification*; D019496:Cancer Vaccines / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D009369:Neoplasms / Q000276:immunology; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D013584:Sarcoma, Synovial / Q000276:immunology; D013997:Time Factors
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; C093962:synovial sarcoma X breakpoint proteins