Radioiodide imaging and radiovirotherapy of multiple myeloma using VSV(Delta51)-NIS, an attenuated vesicular stomatitis virus encoding the sodium iodide symporter gene.

Multiple myeloma is a radiosensitive malignancy that is currently incurable. Here, we generated a novel recombinant vesicular stomatitis virus [VSV(Delta51)-NIS] that has a deletion of methionine 51 in the matrix protein and expresses the human sodium iodide symporter (NIS) gene. VSV(Delta51)-NIS showed specific oncolytic activity against myeloma cell lines and primary myeloma cells and was able to replicate to high titers in myeloma cells in vitro.

Cell-based delivery of oncolytic viruses: a new strategic alliance for a biological strike against cancer.

Recent years have seen tremendous advances in the development of exquisitely targeted replicating virotherapeutics that can safely destroy malignant cells. Despite this promise, clinical advancement of this powerful and unique approach has been hindered by vulnerability to host defenses and inefficient systemic delivery. However, it now appears that delivery of oncolytic viruses within carrier cells may offer one solution to this critical problem.

Carrier cell-based delivery of an oncolytic virus circumvents antiviral immunity.

Oncolytic viruses capable of tumor-selective replication and cytolysis have shown early promise as cancer therapeutics. However, the host immune system remains a significant obstacle to effective systemic administration of virus in a clinical setting. Here, we demonstrate the severe negative impact of the adaptive immune response on the systemic delivery of oncolytic vesicular stomatitis virus (VSV) in an immune-competent murine tumor model, an effect mediated primarily by the neutralization of injected virions by circulating antibodies.

Vesicular stomatitis virus: re-inventing the bullet.

As our understanding of the molecular aspects of human disease increases, it is becoming possible to create designer therapeutics that are exquisitely targeted and have greater efficacy and fewer side effects. One class of targeted biological agents that has benefited from recent advances in molecular biology is designer viruses. Vesicular stomatitis virus (VSV) is normally relatively innocuous but can be engineered to target cancer cells or to stimulate immunity against diseases such as AIDS or influenza.

VSV strains with defects in their ability to shutdown innate immunity are potent systemic anti-cancer agents.

Ideally, an oncolytic virus will replicate preferentially in malignant cells, have the ability to treat disseminated metastases, and ultimately be cleared by the patient. Here we present evidence that the attenuated vesicular stomatitis strains, AV1 and AV2, embody all of these traits. We uncover the mechanism by which these mutants are selectively attenuated in interferon-responsive cells while remaining highly lytic in 80% of human tumor cell lines tested.