Human car-NK therapy for pathological fibrosis in the heart

The National Heart, Lung, and Blood Institute awarded Yale University $444,015 under the Cardiovascular Diseases Research program (CFDA 93.837) on August 1, 2026, to develop human chimeric antigen receptor natural killer (CAR-NK) cells targeting cardiac fibrosis. The project, funded as an R21 Project Grant, will engineer universal CAR-NK cells derived from hypoimmunogenic human induced pluripotent stem cells with inactivated HLA class I/II and CD47 overexpression to enable off-the-shelf, allogeneic use without lymphodepletion or immunosuppression. These cells will be engineered with a CAR construct targeting fibroblast activation protein to selectively eliminate activated cardiac fibroblasts. The research will evaluate therapeutic efficacy in vitro and in vivo using an NSG-SGM3-IL15 mice model, with outcomes including fibroblast ablation, fibrosis regression, and recovery of cardiac function. The award addresses the limitation that current heart failure therapies primarily manage symptoms and do not reverse fibrotic burden, while offering a more favorable safety profile than CAR-T cell alternatives by avoiding cytokine release syndrome, neurotoxicity, and long-term persistence concerns. Work is performed in New Haven, Connecticut, with a period of performance through July 31, 2028.

Abstract

Cardiac fibrosis is a key pathological process contributing to heart failure, characterized by excessive deposition of extracellular matrix (ECM) that leads to increased ventricular stiffness, reduced compliance, and impaired cardiac function. Despite its central role in heart failure progression, current therapies primarily manage symptoms and do not reverse or eliminate the fibrotic burden. Targeting the activated fibroblasts responsible for ECM overproduction represents a promising therapeutic strategy. Recent advances have demonstrated that chimeric antigen receptor (car)-engineered immune cells can be redirected to target fibroblast activation protein (FAP), a marker of activated fibroblasts. However, the clinical application of car-t cells for fibrosis has been limited by significant safety concerns, including cytokine release syndrome, neurotoxicity, and long-term persistence. As an alternative, car natural killer (car-NK) cells offer a more favorable safety profile and have not been associated with these adverse effects, especially when derived from allogeneic sources. This project aims to develop universal car-NK cells derived from hypoimmunogenic human induced pluripotent stem cells (hipscs). These cells are engineered with inactivated HLA class i/II and overexpress CD47 to evade host immune recognition, allowing for off-the-shelf, allogeneic use without the need for lymphodepletion or immunosuppression. In this study, the car construct targets mouse FAP to enable selective elimination of activated cardiac fibroblasts. We will evaluate the therapeutic efficacy of these engineered car-NK cells in vitro and in vivo by cardiac fibrosis induction in NSG-SGM3-IL15 mice model. Outcomes will include fibroblast ablation, fibrosis regression, and recovery of cardiac function. This study has the potential to establish a new class of regenerative immunotherapies for cardiac fibrosis and heart failure.