Tumour therapy using cytokine-expressing semliki forest virus vectors

Abstract

Semliki Forest Virus (SFV) vector is a transient RNA based suicidal expression vector system and has been previously used as a potential anti-cancer agent. Recently, a new enhanced SFV vector has been developed, pSFV10-E. Cells transfected with this vector yield up to ten times more foreign protein than cells transfected with original (non-enhanced) expression vector pSFV10. The two IL-12 gene subunits were cloned from mouse splenocytes and inserted into the pSFV10-E and pSFV10 vectors. Both the pSFV-mIL-12 constructs were characterised for their expression levels qualitatively and quantitatively in BHK-21 and K-BALB cells. The secretion of biologically active mIL-12 was confirmed by inducing splenocytes for IFN-y production using IL-12 expressed by BHK-21 and K-BALB cells. K-BALB, CT26, and 4T1 tumours are the experimental tum our models in our study.