Example 1: CCL5 Expressing Oncolytic Virus

The chemokine CCL5 is a RANTES, which is able to regulate upon activation and normal T cell expressed. It plays an important part in several human diseases and binds to three receptors: CCR1, CCR3, and CCR514, which are expressed on a variety of types of effector and regulatory T cells. It is formed by both activated T lymphocytes and antigen presenting cells, and is widely chemoattractive. Recently, researchers have demonstrated that vvCCL5 (an oncolytic vaccinia virus expressing CCL5) constitutively expressing CCL5, promotes immune infiltration of mouse colorectal tumors in vivo and improves therapeutic effects. Besides, CCL5 expression also induces prolonged persistence of the virus exclusively within the tumor. What's more, further improvement of antitumor effectiveness is observed when vvCCL5 is used together with type-1-polarized dendritic cells (DC1) vaccination, along with enhanced immune cell infiltration into the tumor and an obvious T1 skewing of the infiltrating T-cells.