Retargeting vesicular stomatitis virus using measles virus envelope glycoproteins

Oncolytic vesicular stomatitis virus (VSV) has potent antitumor activity, but infects a broad range of cell types. Here, we used the measles virus (MV) hemagglutinin (H) and fusion (F) envelope glycoproteins to redirect VSV entry and infection specifically to tumor-associated receptors. Replication-defective VSV, deleted of its glycoprotein gene (VSVΔG), was pseudotyped with MV-F and MV-H displaying single-chain antibodies (scFv) specific for epidermal growth factor receptor (EGFR), folate receptor (FR), or prostate membrane-specific antigen (PSMA). Viral titers were ∼10⁵ PFU/ml, but could be concentrated to 10⁷ PFU/ml. Immunoblotting confirmed incorporation of the MV-H-scFv and MV-F into functional VSV virions. Although VSV-G was able to infect all tumor cell lines tested, the retargeted VSV infected only cells that expressed the targeted receptor. In vivo specificities of the EGFR-, FR-, and PSMA-retargeted VSV were assessed by intratumoral injection into human tumor xenografts. Analysis of green fluorescent protein reporter gene expression indicated that VSV infection was restricted to receptor-positive tumors. In summary, we have demonstrated for the first time that VSV can be efficiently retargeted to different cellular receptors using the measles display technology, yielding retargeted VSV vectors that are highly specific for tumors that express the relevant receptor.