Oncolytic influenza A virus expressing interleukin-15 decreases tumor growth in vivo.

ABSTRACT

BACKGROUND: Interleukin-15 has become a promising molecule in the context of eliciting an effective, antitumor immune response because it is able to stimulate cells of the innate and adaptive immune system. METHODS: We generated an interleukin-15-expressing oncolytic influenza A virus for the treatment of an established murine tumor model. RESULTS: Our oncolytic influenza A virus produced large amounts of interleukin-15 and induced proliferation and activation of human T cells in vitro. Intraperitoneal administration increased the amount of mouse natural killer cells and effector memory T cells, as well as T cell reactivity in vivo. Moreover, intratumoral injection induced a profound decrease in growth of established tumors in mice and increased the amount of tumor-infiltrating T cells and natural killer cells. CONCLUSION: We established a stable, IL-15-producing oncolytic influenza A virus with promising immunostimulatory and antitumor attributes.