Abstract: A replication-competent recombinant virus includes an expression cassette encoding a protein associated with arginine biosynthesis. The protein associated with arginine biosynthesis may include argininosuccinate synthase 1 (ASS1), argininosuccinate lyase (ASL), or ornithine transcarboxylase (OTC). The recombinant virus may be derived from a myxoma virus. A method of treating a cell includes contacting a cell with a recombinant virus including an expression cassette encoding a protein associated with arginine biosynthesis. The protein associated with arginine biosynthesis may be ASS1, ASL, OTC.

Abstract: The present disclosure provides a recombinant oncolytic myxoma vims engineered to express a soluble form of an immune checkpoint protein in conjunction with a cytokine/chemokine and/or a tumor antigen. In certain aspects, the oncolytic myxoma virus is a replication competent virus such as myxoma vims. Methods of cancer treatment comprising administering the recombinant oncolytic myxoma virus expressing the soluble form of the immune checkpoint protein are also provided.

Abstract: The present disclosure provides a recombinant oncolytic virus engineered to express a soluble form of an immune checkpoint protein. In certain aspects, the oncolytic vims is a replication competent virus such as myxoma vims. Methods of cancer treatment comprising administering the recombinant oncolytic virus expressing the soluble form of the immune checkpoint protein are also provided.

Abstract: According to the present invention, eight human RING-CH-containing genes are human transmembrane ubiquitin ligase proteins, are homologues of the viral K3-family, and perform functions similar to their viral counterparts. One of these proteins, MARCH-IV, is able to downregulate MHC I and CD4 in a fashion similar to that afforded by the viral immune evasion proteins. This is the first cellular gene product identified that downregulates surface expression of MHC I. The MARCH-family of proteins regulates endocytosis of cell surface receptors (e.g., transferrin receptor, histocompatibility antigens and Fas; type I as well as type II transmembrane domains) via ubiquitination. Particular embodiments provide drug targets for inhibiting the internalization and degredation of various cell surface receptors. Further embodiments provide methods for treating or preventing cancer and other disorders (e.g.