Viral vector and application thereof

A group of viral vectors, comprising:

• a first viral vector, wherein the first viral vector carries a first nucleic acid molecule, and the first nucleic acid molecule encodes an envelope protein;
• at least a second viral vector, wherein the second viral vector carries a second nucleic acid molecule, the second nucleic acid molecule encodes at least one fusion protein, the fusion protein includes at least one single chain antibody and the C-terminal domain of the envelope protein;
• the single chain antibody is capable of binding to CD28 or CD3, the C-terminal domain of the envelope protein includes a transmembrane region and a intracellular region of the envelope protein, the C-terminal of the at least one single chain antibody is connected to the N-terminal of the C-terminal domain of the envelope protein;
• the first nucleic acid molecule and the second nucleic acid molecule are arranged to express the envelope protein and the fusion protein, and the envelope protein and the fusion protein are in a non-fusion form.

A lentivirus, wherein the lentivirus expresses an envelope protein and a fusion protein, wherein the fusion protein comprises at least one single chain antibody and a C-terminal domain of the envelope protein, the single chain antibody is capable of binding to CD28 or CD3, the C-terminal domain of the envelope protein comprises transmembrane and intracellular regions of the envelope protein, the C-terminal of the at least one single chain antibody is connected to the N-terminal of the C-terminal domain of the envelope protein,

• optionally, the envelope protein is an envelope G glycoprotein or a mutant of envelope G glycoprotein of vesicular stomatitis virus;
• preferably, the lentivirus expresses an envelope protein and a fusion protein, wherein the fusion protein comprises a first single chain antibody, a second single chain antibody and a C-terminal domain of the envelope protein, the first single chain antibody is capable of binding to CD28, the second single chain antibody is capable of binding to CD3, the C-terminal domain of the envelope protein comprises a transmembrane region and a intracellular region of the envelope protein, the C-terminal of the first single chain antibody is connected to the N-terminal of the second single chain antibody, and the C-terminal of the second single chain antibody is connected to the N-terminal of the C-terminal domain of the envelope protein;
• or, the C-terminal of the second single chain antibody is connected to the N-terminal of the first single chain antibody, and the C-terminal of the first single chain antibody is connected to the N-terminal of the C-terminal domain of the envelope protein, optionally, the envelope protein is an envelope G glycoprotein or a mutant of envelope G glycoprotein of vesicular stomatitis virus.