T cell-nanodrug conjugates synchronize vascular normalization and immune activation for solid tumor therapy.

Abstract

Adoptive T cell therapy requires T cells to infiltrate vascular tissues and preserve immune function. In solid tumor treatment, however, the surrounding microenvironment produces abnormal vasculature that impedes T cell infiltration. An approach that enables vascular normalization and enhances adoptive T cell function in parallel is essential for effective therapy but has not been reported. Here, we report the use of lenvatinib (LEN) to induce transient vascular normalization, thereby facilitating T cell infiltration. Moreover, LEN enhances T cell persistence by promoting the differentiation of T cells toward a memory phenotype. Our results indicate that the differentiation is by suppressing the PI3K-AKT-mTOR pathway, which drives effector differentiation, and by activating FOXO1, a transcription factor that promotes memory formation. To coordinate the transient vascular normalization and T cell enhancement, we link LEN-loaded, PD-L1-blocking micelles to T cells through acid-labile click chemistry, forming pH-responsive T cell-nanodrug conjugates. The conjugates synchronize the intratumoral release of LEN and the PD-L1 antagonist peptide OPBP-1, thereby coordinating vascular normalization, T cell differentiation, and checkpoint blockade. In vivo, the conjugates increased intratumoral CD8⁺ T cells and splenic memory T cells by over sixfold in B16-OVA tumors and achieved complete regression in a subset of MC38-OVA tumors without systemic toxicity, providing a promising strategy for solid tumor immunotherapy.