摘要
Interleukin 2 (IL-2) is widely used as an active immunotherapeutic agent in clinical metastatic cancers. However, its therapeutic concentrations do not last long due to its short half-life. Thus, only a transient proliferation of the anti-cancer CD8+ T cells can be achieved, resulting in poor efficacy. Therefore, the aim of this work was to create a system that promotes CD8+ T cell proliferation at the tumor site using IL-2 persistently present and activates an anti-cancer immune response. This goal was achieved by the design of the IL-2-loaded polypeptide nanoparticles (P-IL-2) where methoxy poly(ethylene glycol) block poly-[(N-2-hydroxyethyl)-aspartamide] phenylboronic acid was used to encapsulate IL-2 through boron-nitrogen coordination with poly(L-lysine). P-IL-2 significantly prolonged the circulation time of IL-2 and achieved a selective drug release at the tumor site in the presence of high levels of reactive oxygen species, thus activating an anti-cancer immune response and exerting a better anti-cancer effect. The half-life of P-IL-2 was 3.15-fold higher than that of IL-2, and the quantity of CD8+ T cells after using P-IL-2 was 1.89-fold higher than that after using IL-2. In addition, the combination of P-IL-2 and anti-CTLA-4 monoclonal antibody resulted in an enhanced immune activation. Hence, this work provides a new approach to improve the efficacy of IL-2 in anti-cancer immunotherapy.
基金
supported by the National Natural Science Foundation of China(Nos.52025035,51873206 and 52203198)
the Project of Health research talents Project of Jilin Province(No.2020SCZ06)
the Project of Jilin Province Development and Reform Commission(No.2021C043-6)
the Jilin Provincial International Cooperation Key Laboratory of Biomedical Polymers(No.20210504001GH).