Biology subjects

Zamat, A.

Publications and source records attributed to Zamat, A..

4 recordsLinked to original sources

bioRxiv2025

Closed-loop sonothermogenetic control of CAR T cells for metronomic brain cancer therapy

Achieving durable CAR T cell responses against primary brain tumors and metastases requires strategies that enable intracranial control of therapy to overcome the barriers of solid tumor treatment without compromising safety. Here, we show that closed-loop sonothermogenetics enables remote regulation of CAR T cell therapeutic activity through the intact skull. Using MR-guided focused ultrasound with closed-loop temperature feedback, we modulate CAR T cells engineered with a genetically encoded thermal bioswitch to achieve metronomic activation in the brain without lasting adverse effects on healthy brain tissue. In murine models of brain cancer, metronomic production of NKG2D T cell engagers by intratumoral CAR T cells overcomes antigen heterogeneity in breast cancer brain metastasis and myeloid-derived immunosuppression in glioblastoma to drive antitumor responses. Our findings support the use of closed-loop sonothermogenetics for spatial and temporal control of CAR T cell therapies targeting solid brain tumors.

bioengineering↗

bioRxiv2024

Tumor Priming by Ultrasound Mechanogenetics for with SynNotch CAR T Therapy

Cell-based cancer immunotherapy holds potential as a therapeutic approach, yet its application for solid tumor treatment remains challenging. We created a system where focused ultrasound (FUS) is able to remotely stimulate gene expressions in a specific tissue area through mechanical induction, gated by a chemical inducer to minimize the background noise. This system, known as CaDox, integrates FUS-triggered mechanical and calcium stimulation with doxycycline-responsive genetic circuits, which allows the localized expression of the clinically validated and specific antigen CD19 within a subpopulation of cancer cells upon FUS stimulation. These CD19-expressing cells can then function as "training centers" that activate synNotch chimeric antigen receptor (CAR) T cells to generate CARs that recognize a less specific but widespread antigen in cancer cells, thereby attacking and suppress the whole cancer cell population nearby at the tumor site. We validated the functionality of this CaDox system in vitro, in organoids, and in vivo, demonstrating its potential for various cell types and as a versatile platform for precisely controllable immunotherapy. Our combinatorial approach thus offers a FUS-controlled remote and non-invasive priming of solid tumors for effective and safe CAR T immunotherapy via the induced production of clinically validated antigens.

synthetic biology↗

bioRxiv2021

In vivo mRNA delivery to virus-specific T cells by light-induced ligand exchange of MHC class I antigen-presenting nanoparticles

Simultaneous delivery of mRNA to multiple populations of antigen (Ag)-specific CD8+ T cells is challenging given the diversity of peptide epitopes and polymorphism of class I major histocompatibility complexes (MHCI). We developed Ag-presenting nanoparticles (APNs) for mRNA delivery using pMHCI molecules that were refolded with photocleavable peptides to allow rapid ligand exchange by UV light and site-specifically conjugated with a lipid tail for post-insertion into preformed mRNA lipid nanoparticles. Across different TCR transgenic mouse models (P14, OT-1, Pmel), UV-exchanged APNs bound and transfected their cognate Ag-specific CD8+ T cells equivalent to APNs produced using conventionally refolded pMHCI molecules. In mice infected with PR8 influenza, multiplexed delivery of UV-exchanged APNs against three immunodominant epitopes led to ~50% transfection of a VHH mRNA reporter in cognate Ag-specific CD8+ T cells. Our data shows that UV-mediated peptide exchange can be used to rapidly produce APNs for mRNA delivery to multiple populations of Ag-specific T cells in vivo. TeaserLight-induced rapid production of antigen-presenting nanoparticles for mRNA delivery to multiple virus-specific T cell populations.

bioengineering↗

bioRxiv2020

Remote control of CAR T cell therapies by thermal targeting

The limited ability to control anti-tumor activity within tumor sites contributes to poor CAR T cell responses against solid malignancies. Systemic delivery of biologic drugs such as cytokines can augment CAR T cell activity despite off-target toxicity in healthy tissues that narrows their therapeutic window. Here we develop a platform for remote control of CAR T therapies by thermal targeting. To enable CAR T cells to respond to heat, we construct synthetic thermal gene switches that trigger expression of transgenes in response to mild elevations in local temperature (40-42 {degrees}C) but not to orthogonal cellular stresses such as hypoxia. We show that short pulses of heat (15-30 min) lead to more than 60-fold increases in gene expression without affecting key T cell functions including proliferation, migration, and cytotoxicity. We demonstrate thermal control of broad classes of immunostimulatory agents including CARs, Bispecific T cell Engagers (BiTEs), and cytokine superagonists to enhance proliferation and cell targeting. In mouse models of adoptive transfer, photothermal targeting of intratumoral CAR T cells to control the production of an IL-15 superagonist significantly enhances anti-tumor activity and overall survival. We envision that thermal targeting could improve the safety and efficacy of next-generation therapies by allowing remote control of CAR T cell activity.

bioengineering↗