# Activation of FCGR2A enhances the antitumor efficacy of hPSC-derived CAR-M

## TL;DR

This study shows that activating FCGR2A in macrophages derived from stem cells improves their ability to kill tumor cells, offering a promising approach for cancer immunotherapy.

## Contribution

The study identifies FCGR2A as an optimal intracellular signaling domain for enhancing CAR-M antitumor efficacy and demonstrates the benefits of proinflammatory polarization.

## Key findings

- CAR-Ms derived from hPSCs effectively kill HER2-positive SKOV3 tumor cells.
- FCGR2A-based CAR-Ms show the strongest cytotoxic activity against tumor cells.
- Proinflammatory polarization significantly enhances the tumor-killing efficacy of FCGR2A CAR-Ms.

## Abstract

Chimeric antigen receptor macrophages (CAR‐Ms) represent a novel approach in cellular immunotherapy. Human pluripotent stem cells (hPSCs) provide an unlimited and renewable cell source, enabling scalable and standardized production of CAR‐Ms with consistent quality.

In this study, we established a robust differentiation protocol to generate CAR‐Ms from hPSCs. To evaluate HER2‐directed hPSC‐derived CAR-M functionality, we first profiled HER2 expression across multiple tumor cell lines and identified SKOV3 as the optimal target due to its high HER2 level. CAR constructs incorporating intracellular domains from CD3ɛ, FCGR1A, FCGR2A, FCGR2B, and FCGR3A were introduced into hPSCs via lentiviral transduction.

Importantly, CAR expression did not impair hPSCs differentiation into macrophages. Functional assays revealed that all CAR-Ms exerted cytotoxic effects on HER2‐positive SKOV3 cells, with FCGR2A‐based CAR-Ms demonstrating the strongest activity. Furthermore, polarization of CAR‐Ms into a proinflammatory state significantly enhanced tumor‐killing efficacy, particularly in FCGR2A CAR‐Ms.

These findings highlight the potential of FCGR2A as an optimal signaling domain for CAR‐M design and underscore the therapeutic promise of proinflammatory polarized CAR‐Ms in solid tumor immunotherapy.