Tumor-derived multiple chaperone enrichment by free-solution isoelectric focusing yields potent antitumor vaccines.
We have utilized a free-solution/isoelectric focusing technique (FS-IEF) to obtain fractions rich in multiple chaperone proteins from clarified A20 tumor lysates. Vaccines prepared from chaperone-rich fractions are capable of providing protective immunity in mice subsequently challenged intravenously with the same A20 B cell leukemia cells. This protection is at least equal to that provided by purified, tumor-derived heat-shock protein 70, which was the best chaperone immunogen in our hands against this aggressive murine leukemia model. Dosage escalation studies, however, revealed that increasing vaccine dosages actually abrogated the protective effects. The physical nature of the enriched chaperones indicates that they are associated in complexes, which may have implications for their function. FS-IEF is relatively simple, rapid, and efficient, thus making combined multi-chaperone therapy feasible.
Graner
M
M
Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, Tucson 85724-5073, USA.
Raymond
A
A
Akporiaye
E
E
Katsanis
E
E
D000818:Animals; D015153:Blotting, Western; D019496:Cancer Vaccines / Q000302:isolation & purification* / Q000627:therapeutic use; D002845:Chromatography; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000627:therapeutic use; D007525:Isoelectric Focusing / Q000379:methods*; D015448:Leukemia, B-Cell / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D051379:Mice; D008807:Mice, Inbred BALB C; D018832:Molecular Chaperones / Q000378:metabolism*; D009368:Neoplasm Transplantation; D011485:Protein Binding; D013997:Time Factors; D014407:Tumor Cells, Cultured
D019496:Cancer Vaccines; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones