T cell immunotherapy mediated by dual-affinity aptamer targeted liposome

Redirecting immune cells to the tumor cells and enhancing its anti-tumor immune response is a very promising cancer treatment strategy. AS1411 aptamers have high affinity for malignant tumors with high nucleolin expression, and cytotoxic T lymphocyte associated protein 4 (CTLA-4) aptamers can specifically bind to CTLA-4, which is expressed by T cells. In this study, a dual-affinity aptamer targeted liposome (Dat. Lipo) was constructed based on AS1411 aptamer and CTLA-4 aptamer, and its immunotherapeutic effect on T cells was studied. After the aptamer was modified with cholesterol, Dat. Lipo was prepared by instillation method; its effect of redirecting T cells was determined by confocal micrographs; its T cell immunotherapy effect was evaluated by cell counting kit-8 (CCK8) and T cell penetration was evaluated by tumor spheroids. The results showed that compared with liposomes loaded with one type aptamer, Dat. Lipo could effectively promote the redirection of T cells to tumor cells; Dat. Lipo had good biosafety and immunotherapeutic effect on MCF-7 and HepG2 cells in a concentration-dependent manner; Dat. Lipo could also promote T cells to infiltrate into the tumor spheroids and enhance the immunotherapy effect of T cells in different dimensions. In summary, Dat. Lipo can use the high affinity of aptamers to redirect T cells to tumor cells, enhance the effect of immunotherapy, and has a promising application prospect in tumor therapy. This study was approved by the Examination Committee of Cancer Hospital of Xiangya School of Medicine, Central South University, Hunan Cancer Hospital.