Researchers engineer inhalable CAR-T cell-derived exosomes as paclitaxel carriers for treating lung cancer

Non-small cell lung cancer (NSCLC) is a worldwide health threat with high annual morbidity and mortality. Chemotherapeutic drugs such as paclitaxel (PTX) have been widely applied clinically. However, systemic toxicity due to the non-specific circulation of PTX often leads to multi-organ damage, including to the liver and kidney. Thus, it is necessary to develop a novel strategy to enhance the targeted antitumor effects of PTX.

Researchers at Sun Yat-Sen University have engineered exosomes derived from T cells expressing the chimeric antigen receptor (CAR-Exos), which targeted mesothelin (MSLN)-expressing Lewis lung cancer (MSLN-LLC) through the anti-MSLN single-chain variable fragment (scFv) of CAR-Exos. PTX was encapsulated into CAR-Exos (PTX@CAR-Exos) and administered via inhalation to an orthotopic lung cancer mouse model. Inhaled PTX@CAR-Exos accumulated within the tumor area, reduced tumor size, and prolonged survival with little toxicity. In addition, PTX@CAR-Exos reprogrammed the tumor microenvironment and reversed the immunosuppression, which was attributed to infiltrating CD8⁺ T cells and elevated IFN-γ and TNF-α levels.

Schematic illustration of inhalable CAR exosomes derived from
CAR-T cells as PTX carriers for treating lung cancer

A Preparation process of PTX@CAR-Exo. B Antitumor effect of inhalable PTX@CAR-Exo against lung cancer. CAR-T cell-derived exosomes (CAR-Exos) inherited the targeted cytolytic effects from parental cells by releasing granzyme B and perforins. The loaded PTX was delivered into the tumor area to stimulate immune responses. In contrast to conventional CAR-T cell therapy and intravenous administration of PTX, the inhalable PTX@CAR-Exos used in an orthotopic lung cancer model exhibited superior antitumor effects and improved the bioavailability of both CAR-Exos and PTX, with decreased systemic toxicity

This study provides a nanovesicle-based delivery platform to promote the efficacy of chemotherapeutic drugs with fewer side effects. This novel strategy may ameliorate the present obstacles to the clinical treatment of lung cancer.