Submitted July 17, 2006
Accepted November 30, 2006
Cell-free production of scFv fusion proteins: an
efficient approach for personalized lymphoma vaccines
Gregory Kanter, Junhao Yang, Alexei Voloshin, Shoshana Levy, James R Swartz, and Ronald Levy*
Dept of Medicine, Division of Oncology, Stanford University Medical Center, Stanford, CA
Dept of Chemical Engineering, Stanford University, Stanford, CA
Dept of Bioengineering, Stanford University, Stanford, CA
* Corresponding author; email: levy{at}stanford.edu.
The unique immunoglobulin (Ig) idiotype on the surface of each B cell lymphoma represents an ideal tumor-specific antigen for use as a therapeutic vaccine. We have used an E. coli-based, cell-free protein-expression system to produce a vaccine within hours of cloning the Ig genes from a B cell tumor. We demonstrated that a fusion protein consisting of an idiotypic single chain Fv antibody fragment (scFv) linked to a cytokine (GM-CSF) or to an immunostimulatory peptide was an effective lymphoma vaccine. These vaccines elicited humoral immune responses against the native Ig protein displayed on the surface of a tumor and protected mice against tumor challenge with efficacy equal to that of the conventional Ig produced in a mammalian cell and chemically coupled to keyhole limpet hemocyanin. The cell-free E. coli system offers a platform for rapidly generating individualized vaccines, thereby allowing much more efficient application in the clinic.
