Buddy-CAR-NK cells: IL7/IL7R-engineered CAR-NK cells show enhanced proliferation and anti-tumor function while modulating the TME through paracrine T cell activation — ASN Events
  1. Schedule
  2. Poster Session Two
  3. Buddy-CAR-NK cells: IL7/IL7R-engineered CAR-NK cells show enhanced proliferation and anti-tumor function while modulating the TME through paracrine T cell activation

Buddy-CAR-NK cells: IL7/IL7R-engineered CAR-NK cells show enhanced proliferation and anti-tumor function while modulating the TME through paracrine T cell activation (#255)

Andreia Maia 1 , Mubin Tarannum 1 , Sara Piccinelli 1 , Grace Birch 1 , Mila Stanojevic 1 , Maily Nguyen 1 , Alaa Ali 1 , Rizwan Romee 1
  1. Dana-Farber Cancer Institute | Harvard Medical School, Cambridge, MA, United States

The effectiveness of CAR-T and CAR-NK cell therapies is limited by the immunosuppressive tumor microenvironment (TME), particularly in solid tumors. IL7 is a promising cytokine for TME modulation, promoting T cell proliferation and preventing exhaustion. However, mature NK cells are unresponsive to IL7 due to the IL7Rα absence. To address this, we engineered the Buddy-CAR system, comprising CAR-NK cells that express IL7Rα and secrete IL7, aiming to enhance both autocrine activation and paracrine stimulation of tumor-infiltrating T cells.

We developed three CAR constructs targeting Mesothelin (MSLN): MSLN-CAR (M), MSLN-CAR secreting IL7 (M7), and MSLN-CAR expressing IL7Rα and secreting IL7 (M7R). M7R exhibited a significantly enhanced metabolic fitness (Seahorse assay) and improved proliferation index (1.9 vs 1.1 for M, p=0.03) using a CTV assay. M7R showed increased cytotoxicity against MSLN+ ASPC1 cells (61.4% vs 52.3% for M7, p=0.712 and 49.8% for M, p=0.002) at a 2:1 ratio. M7R also showed a 3.9-fold increased IFN-γ production compared to M7 (0.9, p=0.0002) and M (1, p=0.0005). Additionally, CAR-T cells demonstrated higher proliferation capacity in a CTV assay, displaying more cells in later generations, when co-cultured with IL7-secreting CAR-NK cells (26.3% for M7, p=0.048 and 27.6% for M7R, p=0.035 compared to 2.72% for M) in a 1:1 ratio.

In NGS-Tg (Hu-L15) mice (n=5), M7R, intravenously injected, showed significantly higher %hCD45+ CAR-NK cells infiltration in various organs compared to M, including bone marrow (0.23% vs 0.05%, p=0.0039), liver (2.17% vs 0.04%, p=0.0477), spleen (1.40% vs 0.05%, p=0.0367), lungs (5.19% vs 0.31%, p=0.0021), and blood (1.38% vs 0.27%, p=0.0280), 2-weeks post-injection, indicating superior trafficking and proliferation in vivo. Ongoing in vivo experiments are evaluating the tumor control efficacy of M7R.

Our Buddy-CAR system represents a novel approach to enhancing CAR-NK cell functionality while simultaneously modulating the TME through IL7 signaling, holding promise across multiple cancer types.