Expression of soluble TGF-β receptor II by recombinant Vaccinia virus enhances E7 specific immunotherapy of HPV16 tumors
Abstract:
Therapeutic immunization with double recombinants of vaccinia virus (VACV) co-expressing sTβRII increased rejection of established TC-1 tumors in C57BL/6 mice in comparison with single recombinant expressing SigE7LAMP. Recombinant VACV derived from vaccination strain Praha expressed either the sTβRII (ectodomain) or chimeric protein fused to immunoglobulin Fc fragment (sTβRII-Fc-Jun) under control of two different promotors together with the immunogenic tumor associated antigen HPV16 E7 oncoprotein in a form of SigE7LAMP fusion molecule. The ability of soluble receptors to bind TGF-β in vitro was proved. Immunization of mice with double recombinant viruses and virus expressing SigE7LAMP only led to eliciting similar response of E7 specific CD8+ T cells as detected by IFN-γ ELISPOT.