Targeting T-cell malignancies using allogeneic double-negative CD4-CAR-T cells.

Area of Science:

• Immunotherapy
• Cellular Therapy
• Oncology

Background:

• Relapsed/refractory T-cell malignancies have limited therapeutic options.
• Chimeric antigen receptor (CAR)-T cell therapy faces challenges in T-cell malignancies due to potential contamination and fratricide.
• Allogeneic double-negative T cells (DNTs) are a safe, off-the-shelf cell therapy candidate amenable to CAR transduction.

Purpose of the Study:

• To explore the antitumor activity of allogeneic DNTs against T-cell malignancies.
• To evaluate the potential of anti-CD4-CAR (CAR4)-DNTs for adoptive cell therapy in T-cell malignancies.

Main Methods:

• Ex vivo expansion and CAR4 transduction of healthy donor-derived allogeneic DNTs.
• Assessment of DNT and CAR4-DNT antitumor activity against T-cell acute lymphoblastic leukemia (T-ALL) and peripheral T-cell lymphoma (PTCL) using cytotoxicity assays and xenograft models.
• Investigation of mechanisms of action via transwell and blocking assays.

Main Results:

• Allogeneic DNTs demonstrated endogenous cytotoxicity against T-ALL and PTCL in vitro, requiring high doses in vivo.
• CAR4 transduction significantly enhanced DNT potency, with CAR4-DNTs showing superior cytotoxicity against CD4+ T-ALL and PTCL.
• CAR4-DNTs effectively eliminated T-ALL and PTCL cell lines and primary blasts, infiltrated tumors, delayed progression, and prolonged survival in xenograft models. Pretreatment with idelalisib enhanced CAR4-DNT persistence and efficacy.
• Mechanisms involved LFA-1, NKG2D, and perforin/granzyme B pathways.

Conclusions:

• Allogeneic CAR4-DNTs demonstrate effective targeting of T-cell malignancies.
• CAR4-DNTs represent a viable adoptive cell therapy for T-cell malignancies like T-ALL and PTCL.