# Dynamic magneto-mechanical force in lysosomes induces durable macrophage repolarization for antitumor immunity

## TL;DR

A new method using magnetic forces on lysosomes in macrophages boosts long-term antitumor immunity by altering immune cell behavior.

## Contribution

A magneto-mechanical strategy that dynamically manipulates lysosomes to induce durable macrophage repolarization for antitumor immunity.

## Key findings

- MagLMP activates the Gal9-AMPK-NF-κB pathway for sustained M1-like macrophage repolarization.
- Cyclic MagLMP extends survival in a mouse lung adenocarcinoma model, with one third surviving over 300 days.
- Single-cell RNA sequencing and macrophage models confirmed the essential role of the Gal9-AMPK-NF-κB axis.

## Abstract

Mechanical forces are emerging physical cues that regulate biochemical signals of immune cells for antitumor immunity. Owing to the lack of precise tools to impose intracellular forces, little is known about whether and how organelle-level forces trigger mechanotransduction for antitumor immunity. Here, we developed a magneto-mechanical force-triggered lysosomal membrane permeabilization (MagLMP) strategy to induce durable macrophage repolarization for in vivo applications. Self-assembled magnetic nanomotors are driven by rotational magnetic fields, facilitating dynamic damage to the lysosomal membrane by a finely tuned torque-induced vortex. Intriguingly, galectin 9 (Gal9) was found to be critical for sensing cyclic MagLMP, which dynamically activated AMP-activated protein kinase (AMPK), enhanced activation of nuclear factor kappa B (NF-κB), and induced metabolic alterations for sustained M1-like macrophage repolarization, followed by mounting of antitumor immunity. Through single-cell RNA sequencing of tumor tissues, as well as macrophage depletion-reconstitution models involving intratumoral transfer of Gal9-KO bone marrow-derived macrophages (BMDMs) and AMPK shRNA-transduced Gal9-KO BMDMs, we confirmed the Gal9-AMPK-NF-κB axis as the essential pathway by which MagLMP functions in antitumor therapy. In a mouse model of lung adenocarcinoma in situ, overall survival was extended after intravenous administration of nanomotors followed by cyclic MagLMP, and one third of mice survived for more than 300 days. Together, these results demonstrate an intracellular mechanical strategy that can dynamically manipulate innate immune responses in vivo, providing a tool for durable immunotherapy through organelle mechanotransduction.