Semliki forest virus vectors engineered to express higher IL-12 levels induce efficient elimination of murine colon adenocarcinomas
Rodriguez-Madoz JR, Prieto J, Smerdou C.
Division of Gene Therapy, School of Medicine, Center for Applied Medical Research, University of Navarra, Avenida Pio XII 55, 31008 Pamplona, Spain.
Magazine: Molecular Therapy
Date: Jul 1, 2005Hepatology
To evaluate the use of alphavirus vectors for tumor treatment we have constructed and compared two Semliki Forest virus (SFV) vectors expressing different levels of IL-12. SFV-IL-12 expresses both IL-12 subunits from a single subgenomic promoter, while in SFV-enhIL-12 each IL-12 subunit is expressed from an independent subgenomic promoter fused to the SFV capsid translation enhancer. This latter strategy provided an eightfold increase of IL-12 expression.
We chose the poorly immunogenic MC38 colon adenocarcinoma model to evaluate the therapeutic potential of SFV vectors. A single intratumoral injection of 10(8) viral particles of SFV-IL-12 or SFV-enh-IL-12 induced>or=80% complete tumor regressions with long-term tumor-free survival. However, lower doses of SFV-enhIL-12 were more efficient than SFV-IL-12 in inducing antitumoral responses, indicating a positive correlation between the IL-12 expression level and the therapeutic effect. Moreover, repeated intratumoral injections of suboptimal doses of SFV-enhIL-12 increased the antitumoral response. In all cases SFV vectors were more efficient at eliminating tumors than a first-generation adenovirus vector expressing IL-12. In addition, the antitumoral effect of SFV vectors was only moderately affected by preimmunization of animals with high doses of SFV vectors.
This antitumoral effect was produced, at least partially, by a potent CTL-mediated immune response.
CITATION Mol Ther. 2005 Jul;12(1):153-63
you maybe interested
The Clínica is the greater private hospital with technological equipment of Spain, all in a single center.
The professionals of the Clínica perform continuous research and training, always to the benefit of the patient.
Learn why we are different from other healthcare centers. Quality, speed, comfort and results.