Mutant Myxoma viruses are provided herein and methods of using these viruses to treat cancer or elicit an interferon response in a subject are also provided. The mutant Myxoma virus is modified to reduce or eliminate the activity or expression of Myxoma virus protein M62 as compared to a control virus. The mutant virus is capable of stimulating an interferon response in subjects after administration and can also lead to inhibition, reduction or elimination of the CD14+ tumor associated macrophage inhibition of CD4+ T cells in a subject having cancer and lead to a change in the tumor microenvironment to treat the cancer or work in combination with other cancer therapeutics to treat the cancer as described herein.
1. A method of treating cancer in a subject comprising administering a therapeutically effective amount of a mutant myxoma virus modified to eliminate or reduce activity or expression of Myxoma virus protein M62R as compared to a control myxoma virus to the subject.