Project description:We here applied single-cell RNA sequencing of circulating T-cells from primary MM patients to perform transcriptional profiling and assess T-cell fitness in the context of emerging resistance to CAR-T cell therapy. Response to PD-1 inhibition after CAR-T was dictated by the fitness state of non-CAR T cells
Project description:Success of chimeric antigen receptor (CAR) T-cell therapy in lymphoid malignancies has not yet been recapitulated in acute myeloid leukemia (AML). We developed CAR T-cells targeting CD371 with a mutated CD28 costimulatory domain to limit T-cell exhaustion, and constitutive interleukin-18 secretion to enhance immune function (CD371/SAVVY/IL-18 CAR). We initiated a phase I trial (NCT06017258), successfully manufactured and administered CD371/SAVVY/IL-18 CAR T-cells in 5 patients with relapsed/refractory AML, and observed expansion following a single infusion of 3x104 or 3x105 CAR T-cells/kg; three patients refractory to ≥5 lines of therapy and post-allogeneic transplant exhibited AML clearance. Single-cell analyses revealed that circulating CAR T-cells in responders included predominantly cytotoxic CD8+ effector T-cells 2 weeks post-infusion while co-existing NK-cells expressed markers of activation. This pilot study highlights the activity of low-dose IL-18 “armored” CAR T-cells against refractory AML and their potential to promote CAR T-cell cytotoxicity and innate endogenous anti-tumor immunity.
Project description:Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B-cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in a patient remains largely unexplored. Single-cell RNA sequencing samples were collected at three phases: CAR-T products before infusion, CAR-T on day 8 after infusion, and CAR-T on day 15 after infusion. After obtaining the PBMCs for each phase, CAR-T and endogenous T cells were collected by fluorescence-activated cell sorting with anti-Mouse IgG Biotin, FITC Streptavidin, and anti-human CD3 APC.
Project description:<p>Small cell lung cancer (SCLC) exhibits profound immunometabolic suppression that impairs antigen presentation and constrains immunotherapy efficacy. Through integrated multi-omics analyses of primary human SCLC tumors, we identified midkine (MDK) as a dominant tumor-secreted driver of immune evasion. Mechanistically, MDK activates STAT3 to induce indoleamine 2,3-dioxygenase 1 (IDO1), driving tryptophan-kynurenine metabolic reprogramming. This axis suppresses myeloid antigen presentation, reduces HLA class I expression, and impairs CD8+ T cell function, establishing a immunosuppressive tumor microenvironment (TME). We engineered DLL3-targeted CAR T cells secreting anti-MDK scFv. These dual-functional CAR T cells neutralize MDK within the TME, restore antigen presentation, alleviate metabolic suppression, and reinvigorate CD8+ T cell responses. In SCLC models, they exhibited markedly enhanced antitumor activity, improved metabolic fitness, and durable immune activation without systemic toxicity. Collectively, our findings identify MDK as a key immunometabolic regulator and support sMDK-DLL3 CAR T cells as a targeted immunotherapy for SCLC.</p>
Project description:Insufficient functional T cell persistence impedes therapeutic success of chimeric antigen receptor (“CAR”) therapies. Here, we performed a CAR-adapted base editing screen of PIK3CD, a key regulator of T cell function, metabolism, and fate. We identified point mutations that beneficially modulate CAR T cell profiles in 4-1BBz and 28z CAR T cells, respectively. Remarkably, point mutations with differing effects on PI3Kδ signaling activity were advantageous in distinct CAR contexts: The PI3Kδ-activating mutation E81K enhanced proliferation, metabolic fitness and effector function in 4-1BBz CARs, promoting long-term functional persistence and enhanced therapeutic efficacy in vivo. Conversely, the PI3Kδ-attenuating mutation L32P improved T cell memory formation and functionality in 28z CAR T cells. Together, our approach of Rational Optimization of Activation-dependent Signaling via Targeted Allelic Reprogramming (ROADSTAR) illustrates the importance of CAR design-specific fine-tuning of tailoring intrinsic T cell signaling and demonstrates the potential of base editing for next-generation cellular therapies.
Project description:Chimeric antigen receptor (CAR) T-cells induce responses in patients with relapsed/refractory leukemia; however, long-term efficacy is frequently limited by post-CAR relapses. The inability to target antigen-low cells is an intrinsic vulnerability of second-generation CAR T-cells and underlies the majority of relapses following CD22BBz CAR T-cell therapy. We interrogated CD22BBz CAR signaling in response to low antigen and found inefficient phosphorylation of LAT, limiting downstream signaling. To overcome this, we designed the Adjunctive LAT-Activating CAR T-cell (ALA-CART) platform, pairing a second-generation CAR with a LAT-CAR incorporating the intracellular domain of LAT. ALA-CART cells demonstrated reduced differentiation during manufacturing and increased LAT phosphorylation, MAPK signaling and AP-1 activity. Consequently, ALA-CART cells showed improved cytotoxicity, proliferation, persistence and efficacy against antigen-low leukemias that were refractory to clinically-active CD22BBz CAR T-cells. These data suggest restoration of LAT signaling through the ALA-CART platform represents a promising strategy for overcoming multiple mechanisms of CAR T-cell failure.
Project description:Insufficient functional T cell persistence impedes therapeutic success of chimeric antigen receptor (“CAR”) therapies. Here, we performed a CAR-adapted base editing screen of PIK3CD, a key regulator of T cell function, metabolism, and fate. We identified point mutations that beneficially modulate CAR T cell profiles in 4-1BBz and 28z CAR T cells, respectively. Remarkably, point mutations with differing effects on PI3Kδ signaling activity were advantageous in distinct CAR contexts: The PI3Kδ-activating mutation E81K enhanced proliferation, metabolic fitness and effector function in 4-1BBz CARs, promoting long-term functional persistence and enhanced therapeutic efficacy in vivo. Conversely, the PI3Kδ-attenuating mutation L32P improved T cell memory formation and functionality in 28z CAR T cells. Together, our approach of Rational Optimization of Activation-dependent Signaling via Targeted Allelic Reprogramming (ROADSTAR) illustrates the importance of CAR design-specific fine-tuning of tailoring intrinsic T cell signaling and demonstrates the potential of base editing for next-generation cellular therapies. Raw data files not provided due to data sensitivity and privacy concerns.
Project description:Single cell RNA sequencing (scRNA-seq) was performed with peripheral blood cells before (Day 0, T0), during nivolumab treatment (Day 7, T1; Day 21, T2), and when plasma EBV turned negative (Day 76, T3) in 1 patient (patient 7). scRNA-seq libraries were generated following the recommended protocol of the 3’ scRNA-seq 10X genomics platform and using v2 chemistry, and sequenced data was collected by illumina NovaSeq 6000 sequencing.