Understand T cells.
Rethink their possibilities.

Designing off-the-shelf allogeneic CAR-T therapies is critically important for pediatric cancers such as neuroblastoma and DIPG. While patients with low tumor burden receiving GD2-directed CAR-T cells have demonstrated impressive 3-year event-free survival rates approaching 60%, achieving this low burden typically requires intensive induction treatments, including high-dose chemotherapy or meta-iodobenzylguanidine (MIBG). These harsh regimens often induce severe lymphopenia, making autologous T cell collection for CAR-T manufacturing challenging or unfeasible.

To overcome this barrier, we propose locus-specific engineering of targets identified from our CRISPR knockout screen. This precision engineering strategy integrates synthetic rheostatic circuits that provide environmental sensing, converting negative immunosuppressive signals from the tumor microenvironment into positive outputs to enhance T cell fitness, while simultaneously providing crucial safety mechanisms for next-generation, off-the-shelf cell therapies.

Gain-of-function mutations in IDH1/2 generate the oncometabolite D-2-hydroxyglutarate (D-2HG), which drives immune evasion by suppressing CD8+ T cell function within the tumor microenvironment (TME). While pharmacological inhibition of IDH1 (e.g., AG120) provides initial metabolic rescue and promotes antitumor immunity, this approach is insufficient to sustain long-term T cell efficacy.

To identify genetic targets capable of overcoming D-2HG-mediated immunosuppression, we conducted a genome-wide CRISPR knockout screen in CD8+ T cells. This screen identified several D-2HG-specific negative regulators of T cell effector function, whose activity is being translated into human CAR-T cell models.

A major limitation of current adoptive T cell therapies is terminal differentiation and exhaustion, which curtail in vivo persistence and long-term antitumor functionality. To overcome these barriers, we conducted genome-wide CRISPR knockout screens to identify novel intrinsic targets that restrain T cell differentiation. We discovered that the specific inhibition of these regulatory nodes blocks terminal differentiation and confers profound resistance to exhaustion.

Mechanistically, targeting these nodes induces a durable "stem-like" epigenetic imprinting state that reprograms the T cell landscape, resulting in significantly enhanced persistence and sustained effector functionality under chronic antigen exposure and immunosuppressive microenvironmental stress.

To ensure the clinical safety and translatability of this approach, we have developed a transient strategy to deliver this epigenetic reprogramming. By avoiding permanent genomic editing, this transient modulation mitigates the risks of uncontrolled proliferation or permanent loss of key regulatory checkpoints, while establishing the beneficial epigenetic memory required for durable therapeutic efficacy. This approach provides a safe, next-generation platform for manufacturing persistent, exhaustion-resistant T cell therapies.

Research at Gustave Roussy has further demonstrated that host biological factors, notably the gut microbiota and tumor-associated macrophages (TAMs), can influence CAR-T response and contribute to resistance mechanisms.

The CELL-ATTACK program aims to strengthen academic cell therapy development at Gustave Roussy by establishing on-site CAR-T manufacturing capabilities to accelerate the translation from bench to clinical trial. The program pursues three complementary objectives: (1) improve CAR-T efficacy, persistence, and safety through T cell reprogramming strategies that enhance resistance to exhaustion; (2) understand and modulate patient-specific biological factors, including the intestinal microbiota and TAMs, to overcome resistance; and (3) identify novel tumor-specific antigens using high-resolution profiling to design next-generation CAR-T with reduced toxicity. Together, these approaches aim to expand the applicability of cellular therapies and provide precise, effective treatments for patients with refractory cancers.

Fibrosis is a severe, life-limiting complication in diseases such as Duchenne Muscular Dystrophy (DMD) and Systemic Sclerosis (SSc), for which no specific treatments currently exist. We propose repurposing Chimeric Antigen Receptor (CAR) cell therapy to target fibrosis. Preclinical models demonstrate that FAP-specific CAR-T cells can mitigate pathological extracellular matrix deposition and improve organ function, offering a promising therapeutic avenue in non-tumor environments.

To overcome the logistical complexity, high costs, and delays associated with conventional ex vivo CAR-T manufacturing, this project aims to develop an innovative in vivo reprogramming strategy. By using optimized lipid nanoparticle (LNP) technology to deliver CAR-encoding modified RNA directly to the host, we intend to generate transient, anti-fibrotic CAR-T cells directly within the patient, paving the way for a scalable, off-the-shelf solution for fibrotic diseases.