Described herein are chimeric Newcastle disease viruses engineered to express a heterologous interferon antagonist and compositions comprising such viruses. The chimeric Newcastle disease viruses and compositions are useful in the treatment of cancer.

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.

Provided are an oncolytic heterologous recombinant Newcastle disease virus (NDV), preparation method and application thereof. The heterologous recombinant NDV can express alpha (1,3) galactosyltransferase (1,3GT). The 1,3GT is the protein represented by the flowing B1) and B2): B1) the protein has an amino acid sequence of SEQ ID No.1; and B2) the protein is derived from B1) and has a function of 1,3GT obtained by substituting and/or deleting and/or adding one or more amino acid residue(s) in the amino acid sequence represented by SEQ ID No.1. The recombination NDV can be used for tumor treatment.