Conditional Control of Universal CAR T Cells by Cleavable OFF-Switch Adaptors

Skin-Resident γδ T Cells Mediate Potent and Selective Antitumor Cytotoxicity through Directed Chemotactic Migration and Mobilization of Cytotoxic Granules

Dendritic epidermal T cells (DETCs) are a unique subset of γδ T cells that reside predominantly in mouse epidermis; yet, their antitumor functions remain enigmatic. In this study, we report that DETCs mediate potent and exquisitely selective cytotoxicity against diverse tumor types while sparing healthy cells. In vitro, DETCs induced apoptosis in melanoma, hepatoma, colon carcinoma, and lymphoma lines in a dose- and time-dependent manner that required direct cell-cell contact. In vivo, adoptive DETC transfer significantly suppressed melanoma growth and metastasis while prolonging survival. Mechanistically, DETCs upregulated perforin/granzyme B expression upon tumor recognition, and inhibition of this pathway ablated cytotoxicity. DETCs selectively homed to and formed intimate contacts with tumor cells in vivo through directed chemotaxis and aggregation. Tumor engagement triggered proinflammatory DETC activation while dampening immunosuppressive factors in the microenvironment. Notably, mTOR signaling coupled tumor recognition to DETC trafficking, cytotoxicity, and inflammatory programs because rapamycin treatment impaired effector functions and therapeutic efficacy. Collectively, these findings establish DETCs as multidimensional antitumor effectors and provide insights for harnessing their unique biology for cancer immunotherapy.

Chimeric antigen receptor T cell immunotherapy for gynecological malignancies

Gynecologic malignancies pose a serious threat to women's health worldwide. Although immunotherapy has significantly revolutionized cancer treatment strategies, effective therapeutic options for recurrent or advanced gynecologic malignancies are still deficient, posing significant challenges to clinical therapy. Chimeric antigen receptor (CAR) T cell therapy has achieved remarkable efficacy in treating hematologic malignancies, marking a significant change in the oncology treatment paradigm. However, despite the gradual increase in CAR T cell therapy used in treating solid tumors in recent years, its efficacy in treating gynecologic malignancies still needs further validation. This review will thoroughly examine CAR-T cell engineering and its mechanism of action on specific antigens associated with gynecologic malignancies, systematically assess the current application of CAR T cell therapy in gynecologic tumors and the advancements in clinical trials, and discuss the significant challenges and corresponding strategies, thereby offering a scientific foundation and guidance for future research in this area.

Conditional Control of Benzylguanine Reaction with the Self-Labeling SNAP-tag Protein

SNAP-tag, a mutant of the O6-alkylguanine-DNA-alkyltransferase, self-labels by reacting with benzylguanine (BG) substrates, thereby forming a thioether bond. SNAP-tag has been genetically fused to a wide range of proteins of interest in order to covalently modify them. In the context of both diagnostic and therapeutic applications, as well as use as a biological recording device, precise control in a spatial and temporal fashion over the covalent bond-forming reaction is desired to direct inputs, readouts, or therapeutic actions to specific locations, at specific time points, in cells and organisms. Here, we introduce a comprehensive suite of six caged BG molecules: one light-triggered and five others that can be activated through various chemical and biochemical stimuli, such as small molecules, transition metal catalysts, reactive oxygen species, and enzymes. These molecules are unable to react with SNAP-tag until the trigger is present, which leads to near complete SNAP-tag conjugation, as illustrated both in biochemical assays and on human cell surfaces. This approach holds promise for targeted therapeutic assembly at disease sites, offering the potential to reduce off-target effects and toxicity through precise trigger titration.

Molecular Matchmakers: Bioconjugation Techniques Enhance Prodrug Potency for Immunotherapy

Cancer patients suffer greatly from the severe off-target side effects of small molecule drugs, chemotherapy, and radiotherapy─therapies that offer little protection following remission. Engineered immunotherapies─including cytokines, immune checkpoint blockade, monoclonal antibodies, and CAR-T cells─provide better targeting and future tumor growth prevention. Still, issues such as ineffective activation, immunogenicity, and off-target effects remain primary concerns. "Prodrug" therapies─classified as therapies administered as inactive and then selectively activated to control the time and area of release─hold significant promise in overcoming these concerns. Bioconjugation techniques (e.g., natural linker conjugation, bioorthogonal reactions, and noncanonical amino acid incorporation) enable the rapid and homogeneous synthesis of prodrugs and offer selective loading of immunotherapeutic agents to carrier molecules and protecting groups to prevent off-target effects after administration. Several prodrug activation mechanisms have been highlighted for cancer therapeutics, including endogenous activation by hypoxic or acidic conditions common in tumors, exogenous activation by targeted bioorthogonal cleavage, or stimuli-responsive light activation, and dual-stimuli activation, which adds specificity by combining these mechanisms. This review will explore modern prodrug conjugation and activation options, focusing on how these strategies can enhance immunotherapy responses and improve patient outcomes. We will also discuss the implications of computational methodology for therapy design and recommend procedures to determine how and where to conjugate carrier systems and "prodrug" groups onto therapeutic agents to enhance the safety and control of these delivery platforms.

Revolutionizing Immunotherapy: Unveiling New Horizons, Confronting Challenges, and Navigating Therapeutic Frontiers in CAR-T Cell-Based Gene Therapies

The CAR-T cell therapy has marked the dawn of new era in the cancer therapeutics and cell engineering techniques. The review emphasizes on the challenges that obstruct the therapeutic efficiency caused by cell toxicities, immunosuppressive tumor environment, and decreased T cell infiltration. In the interest of achieving the overall survival (OS) and event-free survival (EFS) of patients, the conceptual background of potential target selection and various CAR-T cell design techniques are described which can minimize the off-target effects, reduce toxicity, and thus increase the resilience of CAR-T cell treatment in the haematological malignancies as well as in solid tumors. Furthermore, it delves into cutting-edge technologies like gene editing and synthetic biology, providing new opportunities to enhance the functionality of CAR-T cells and overcome mechanisms of immune evasion. This review provides a comprehensive understanding of the complex and diverse aspects of CAR-T cell-based gene treatments, including both scientific and clinical aspects. By effectively addressing the obstacles and utilizing the capabilities of cutting-edge technology, CAR-T cell therapy shows potential in fundamentally changing immunotherapy and reshaping the approach to cancer treatment.

Rationalizing Diverse Binding Mechanisms to the Same Protein Fold: Insights for Ligand Recognition and Biosensor Design

The engineering of novel protein-ligand binding interactions, particularly for complex drug-like molecules, is an unsolved problem, which could enable many practical applications of protein biosensors. In this work, we analyzed two engineered biosensors, derived from the plant hormone sensor PYR1, to recognize either the agrochemical mandipropamid or the synthetic cannabinoid WIN55,212-2. Using a combination of quantitative deep mutational scanning experiments and molecular dynamics simulations, we demonstrated that mutations at common positions can promote protein-ligand shape complementarity and revealed prominent differences in the electrostatic networks needed to complement diverse ligands. MD simulations indicate that both PYR1 protein-ligand complexes bind a single conformer of their target ligand that is close to the lowest free-energy conformer. Computational design using a fixed conformer and rigid body orientation led to new WIN55,212-2 sensors with nanomolar limits of detection. This work reveals mechanisms by which the versatile PYR1 biosensor scaffold can bind diverse ligands. This work also provides computational methods to sample realistic ligand conformers and rigid body alignments that simplify the computational design of biosensors for novel ligands of interest.

Indolent CD4+ CAR T-Cell Lymphoma after Cilta-cel CAR T-Cell Therapy

Indolent CD4+ cytotoxic chimeric antigen receptor (CAR) T-cell lymphoma involving the small intestine was diagnosed in a patient who had previously received ciltacabtagene autoleucel (cilta-cel) CAR T-cell therapy for treatment of myeloma. Targeted messenger RNA sequencing revealed the presence of CAR gene product in tumor cells. Whole-genome sequencing of samples of tumor and peripheral blood identified a single lentiviral insertion site within the second intron of the SSU72 gene. In addition, numerous genetic alterations that may have contributed to malignant transformation were identified in the tumor sample. (Funded by MedStar Georgetown University Hospital.).

Rationalizing diverse binding mechanisms to the same protein fold: insights for ligand recognition and biosensor design

The engineering of novel protein-ligand binding interactions, particularly for complex drug-like molecules, is an unsolved problem which could enable many practical applications of protein biosensors. In this work, we analyzed two engineer ed biosensors, derived from the plant hormone sensor PYR1, to recognize either the agrochemical mandipropamid or the synthetic cannabinoid WIN55,212-2. Using a combination of quantitative deep mutational scanning experiments and molecular dynamics simulations, we demonstrated that mutations at common positions can promote protein-ligand shape complementarity and revealed prominent differences in the electrostatic networks needed to complement diverse ligands. MD simulations indicate that both PYR1 protein-ligand complexes bind a single conformer of their target ligand that is close to the lowest free energy conformer. Computational design using a fixed conformer and rigid body orientation led to new WIN55,212-2 sensors with nanomolar limits of detection. This work reveals mechanisms by which the versatile PYR1 biosensor scaffold can bind diverse ligands. This work also provides computational methods to sample realistic ligand conformers and rigid body alignments that simplify the computational design of biosensors for novel ligands of interest.

Enhancing the safety of CAR-T cell therapy: Synthetic genetic switch for spatiotemporal control

Chimeric antigen receptor T (CAR-T) cell therapy is a promising and precise targeted therapy for cancer that has demonstrated notable potential in clinical applications. However, severe adverse effects limit the clinical application of this therapy and are mainly caused by uncontrollable activation of CAR-T cells, including excessive immune response activation due to unregulated CAR-T cell action time, as well as toxicity resulting from improper spatial localization. Therefore, to enhance controllability and safety, a control module for CAR-T cells is proposed. Synthetic biology based on genetic engineering techniques is being used to construct artificial cells or organisms for specific purposes. This approach has been explored in recent years as a means of achieving controllability in CAR-T cell therapy. In this review, we summarize the recent advances in synthetic biology methods used to address the major adverse effects of CAR-T cell therapy in both the temporal and spatial dimensions.