Described herein are chimeric Newcastle disease viruses engineered to express an agonist of a co-stimulatory signal of an immune cell and compositions comprising such viruses. Also described herein are chimeric Newcastle disease viruses engineered to express an antagonist of an inhibitory signal of an immune cell and compositions comprising such viruses. The chimeric Newcastle disease viruses and compositions are useful in the treatment of cancer. In addition, described herein are methods for treating cancer comprising administering Newcastle disease viruses in combination with an agonist of a co-stimulatory signal of an immune and/or an antagonist of an inhibitory signal of an immune cell.

Described herein are chimeric Newcastle disease viruses engineered to express an agonist of a co-stimulatory signal of an immune cell and compositions comprising such viruses. Also described herein are chimeric Newcastle disease viruses engineered to express an antagonist of an inhibitory signal of an immune cell and compositions comprising such viruses. The chimeric Newcastle disease viruses and compositions are useful in the treatment of cancer. In addition, described herein are methods for treating cancer comprising administering Newcastle disease viruses in combination with an agonist of a co-stimulatory signal of an immune and/or an antagonist of an inhibitory signal of an immune cell.

The present disclosure provides a recombinant herpesvirus of turkeys (HVT) and a preparation method and use thereof. The present disclosure specifically provides a recombinant HVT, where an exogenous gene is inserted in a spacer region between an HVT005 region and an HVT006 region of an HVT genome; and the exogenous gene is selected from a gene derived from the group consisting of a Newcastle disease virus (NDV), an avian influenza virus (AIV), and an infectious bursal disease virus (IBDV); the spacer region between an HVT005 region and an HVT006 region of an HVT genome is located between 8,867 nt and 9,319 nt of the HVT genome, and has a nucleotide sequence set forth in SEQ ID NO: 1.