The invention discloses a recombinant oncolytic
vaccinia virus and a preparation method and application thereof. The
thymidine kinase (TK) region of the
virus comprises a coding sequence of a PD1 full-length
antibody shown in the formula of SEQ ID NO.1. Through effective combination of the anti-tumor effect of
gene therapy and the oncolytic effect of
virus treatment, the oncolytic
vaccinia virus for efficiently expressing the PD1 full-length
antibody gene is prepared. When the oncolytic
vaccinia virus produces the oncolytic effect of splitting
tumor cells, the PD1 full-length
antibody is efficiently expressed, the activity of PD1 on the surfaces of T cells is inhibited, the
T cell immune response is activated and the dual antitumor effects are produced. Compared with the
single gene therapy or
viral therapy, the method using the recombinant oncolytic vaccinia virus improves the effects of killing malignant
B cell lymphoma. Through virus replication-
related gene deletion, the TK regionof the vaccinia virus
genome is deleted so that specific replication of the viruses in the abnormally proliferating
tumor cells is ensured and the viruses can not replicate in normal cells, so that the safety of the oncolytic vaccinia virus vector is greatly improved.