Biology subjects

Paruzzo, L.

Publications and source records attributed to Paruzzo, L..

4 recordsLinked to original sources

bioRxiv2026

SPTBN2 promotes an immunosuppressive tumor microenvironment and cross-resistance to anti-cancer therapies

Immunosuppressive tumor microenvironment (TME) inactivates CD8+ cytotoxic lymphocytes (CTLs). Here, we identify SPTBN2 spectrin as a key immunosuppressive regulator induced in CTLs in response to nutritional deficit. In human pancreatic and colorectal cancers, SPTBN2 expression negatively correlated with CTL infiltration and patients survival. In TME of mouse pancreatic and colorectal adenocarcinomas, SPTBN2 inactivated intratumoral CTLs, stimulated tumor growth and conferred cross-resistance to anti-cancer therapies. SPTBN2 knockout protected CAR T-cells from trogocytosis and increased their memory state. SPTBN2 maintained levels of cell surface proteins such as BTLA that undermine CAR T-cell cytotoxicity and promote exhaustion. Re-expression of BTLA largely reversed phenotypes in SPTBN2-deficient CAR T-cells. In manufactured CAR T cells, SPTBN2 was associated with their clinical failure in pediatric patients with leukemia. Accordingly, ablation of SPTBN2 in CAR T-cells increased their cytotoxicity, in vivo persistence and therapeutic effects indicating that SPTBN2 can be targeted to increase the efficacy of anti-cancer therapies.

cancer biology↗

bioRxiv2026

An ancestral haplotype of P2RX5 yields a B-cell surface marker and a promising multi-lineage immunotherapy target

While CD19- and BCMA-directed immunotherapies have improved outcomes for B-lymphoid and plasma cell malignancies, frequent relapses with antigen loss/downregulation highlight the need for new targets. Here, using transcriptomic datasets and newly-developed monoclonal antibodies, we show that P2RX5, long considered a pseudogene in humans, encodes a stable protein in 80% of individuals of African descent carrying the ancestral haplotype. Like CD19, P2RX5 displays B-cell lineage-restricted expression in normal tissues. Unlike CD19, P2RX5 is expressed not only in B-cell neoplasms, but also in T-cell leukemia (T-ALL) and multiple myeloma (MM). We developed P2RX5-directed bispecific T-cell engagers and CAR T cells, which killed T-ALL cells with no evidence of T-cell fratricide. These agents were non-inferior to FDA-approved CD19- and BCMA-directed immunotherapeutics in cell culture and xenograft models of Burkitt lymphoma and MM, while maintaining potency against CD19- and BCMA-negative variants. Hence, P2RX5 is a unique multi-lineage target for frontline or salvage immunotherapy.

cancer biology↗

bioRxiv2025

Harnessing the CD2 axis to broaden and enhance the efficacy of CAR T cell therapies

Patients with T-cell lymphomas and leukemias have overall poor outcomes due to the lack of targeted and effective treatments, particularly in the relapsed and refractory settings. Development of chimeric antigen receptor (CAR) T-cells against T-cell neoplasms is limited by a lack of discriminating T-cell antigens that allow for effective anti-tumor responses while preventing CAR T-cell fratricide. We hypothesized that targeting CD2, a pan-T-cell antigen, using anti-CD2 CAR T-cells engineered without CD2 expression (CART2), would support CAR T-cell manufacturability and preclinical efficacy. Optimized CD2-knockout CART2, generated using CRISPR-Cas9, eradicated primary patient-derived CD2+ hematological neoplasms in vitro and in vivo, secreted effector cytokines, and exhibited adequate proliferative capacity. Nevertheless, CD2 has a key costimulatory function, and its deletion could lead to CAR T-cell dysfunction. Therefore, we tested the role of the CD2:CD58 axis in CAR T-cells, using the anti-CD19 CART models. We demonstrate that CD2 loss attenuates CART19 efficacy by reducing avidity for tumor antigen, co-stimulation, and ultimately in vivo activity. Analogously, we show that tumor CD58 loss reduces CART19 efficacy. To overcome this issue, we developed a novel PD-1:CD2 switch receptor that rescues intracellular CD2 signaling, particularly when PD-L1 is engaged, resulting in improved in vivo outcomes. Collectively, we studied the role of CD2 both as a target for CAR T cell therapy and as a critical costimulatory protein, whose signaling can be rescued using the PD-1:CD2 switch receptor. This receptor can be incorporated into CAR T-cells and provides an effective strategy to overcome CD2-signaling deficiencies.

cancer biology↗

bioRxiv2024

Directed evolution-based discovery of ligands for in vivo restimulation of CAR-T cells

Chimeric antigen receptor (CAR) T cell therapy targeting CD19 elicits remarkable clinical efficacy in B-cell malignancies, but many patients relapse due to failed expansion and/or progressive loss of CAR-T cells. We recently reported a strategy to potently restimulate CAR-T cells in vivo, enhancing their functionality by administration of a vaccine-like stimulus comprised of surrogate peptide ligands for a CAR linked to a lymph node-targeting amphiphilic PEG-lipid (termed CAR-T-vax). Here, we demonstrate a general strategy to generate and optimize peptide mimotopes enabling CAR-T-vax generation for any CAR. Using the clinical CD19 CAR (FMC63) as a test case, we employed yeast surface display to identify peptide binders to soluble IgG versions of FMC63, which were subsequently affinity matured by directed evolution. CAR-T vaccines using these optimized mimotopes triggered marked expansion and memory development of CD19 CAR-T cells in both syngeneic and humanized mouse models of B-ALL/Lymphoma, and enhanced control of disease progression. This approach thus enables vaccine boosting to be applied to any clinically relevant CAR-T cell product.

bioengineering↗