Project description:Single-cell RNA sequencing of BM resident immune cells of patients undergoing CAR T-cell infusion and their Infusion Product (IP). Data in this study were generated from a patients enrolled in the FT01CARCIK Phase I/IIb clinical trial (NCT03389035) and two patients treated with autologous commercial CAR T cells (tisagenlecleucel). BM samples have been collected before CAR T treatment (pre) and at early time points (1-2 months) after treatment (post). CD45+CD3+ T cells, and CD45+/lowCD3-, encompassing the hematopoietic immune niche of the TME cells, have been separated by flow cytometry-based cell sorting and compared to cells of the corresponding patient’s BM before CAR T-cell treatment at the moment of relapse. In parallel, CAR T-cell infusion products (IP) have been sorted according to the surface CAR expression. Significance: This study highlights the critical role of the tumor microenvironment on CAR T-cell fate and endogenous immunity in B-cell acute lymphoblastic leukemia. We demonstrate that IFN response, hypoxia, and TGF-b signaling lead to general immune suppression, resulting in endogenous T-cell exhaustion and compromising CAR T-cell efficacy
Project description:Immunotherapy using CD19-directed chimeric antigen receptor (CAR)-T cells has shown excellent results for treatment of B-cell leukaemia and lymphoma. To produce CAR-T cells, the patient’s own T cells are isolated from the blood and modified in a laboratory with a genetic vector to express a tumor antigen-directed CAR on its surface. The CAR-T cells are then expanded in numbers and given back to the patient with the aim to eradicate the tumors. However, some patients display primary resistance to CAR-T treatment while others relapse quickly after CAR-T treatment. In this experiment, we seek to understand whether the quality of the individual CAR-T cell product the patients were given can predict outcome to the therapy. We investigate the transcriptional profile of the individual CAR-T infusion products using single-cell RNA sequencing. In this dataset, we identified a T cell subset correlating with response that could be used as an indicator for clinical outcome. Targeted RNA and protein single-cell libraries were obtained using the BD Rhapsody platform (BD Biosciences). In total four separate targeted libraries were produced with 6 patients per library. Sequencing was performed on NovaSeq 6000 S1 sequencer at the SNP&SEQ Technology Platform (Uppsala, Sweden). The raw scRNA-seq data was pre-processed by BD Biosciences using the Rhapsody Analysis pipeline to convert the raw reads into Unique Molecular Identifier (UMI) counts. UMIs are further adjusted within Rhapsody by applying BD’s Recursive Substitution Error Correction (RSEC) and Distribution-Based Error Correction (DBEC) in order to remove false UMIs caused by sequencing or library preparation errors. Pooled samples were deconvoluted using Sample-tag reads. The scRNA-seq and AbSeq counts were loaded, processed and used for clustering and differential gene expression with Seurat v. 4.0.0.
Project description:Chimeric antigen receptor (CAR) T cell therapies have revolutionized B cell malignancy treatment, but subsets of patients with large B cell lymphoma (LBCL) experience primary resistance or relapse after CAR T cell treatment. To uncover tumor microenvironment (TME)-induced resistance mechanisms, we examined patients’ intratumoral immune infiltrates and observed that elevated levels of immunoregulatory macrophages in pre-infusion tumor biopsies are correlated with poor clinical responses. In murine models, CAR T cell-produced interferon-gamma (IFN-g) promotes the expression of inducible nitric oxide synthase (iNOS, NOS2) in immunoregulatory macrophages, impairing CAR T cell function. Mechanistically, proteomics analysis of CAR T cells revealed that iNOS-expressing macrophages promote the upregulation of genes mediating apoptosis and cell cycle arrest in CAR T cells, while downregulating ribosome biogenesis and protein synthesis. Furthermore, CAR T cell metabolism is compromised by the depletion of glycolytic intermediates and rewiring of the TCA cycle. Pharmacological inhibition of iNOS enhances the CAR T cell treatment efficacy in B cell tumor-bearing mice. Notably, elevated levels of iNOS+CD14+ monocytes were observed in leukaphereses of patients with non-durable response to CAR T cell therapy. These findings suggest that mitigating iNOS in tumor-associated macrophages (TAMs), potentially by modulating IFN-g expression in CAR T cells, could improve outcomes for LBCL patients.
Project description:Chimeric antigen receptor (CAR) T cell therapies have revolutionized B cell malignancy treatment, but subsets of patients with large B cell lymphoma (LBCL) experience primary resistance or relapse after CAR T cell treatment. To uncover tumor microenvironment (TME)-induced resistance mechanisms, we examined patients’ intratumoral immune infiltrates and observed that elevated levels of immunoregulatory macrophages in pre-infusion tumor biopsies are correlated with poor clinical responses. In murine models, CAR T cell-produced interferon-gamma (IFN-g) promotes the expression of inducible nitric oxide synthase (iNOS, NOS2) in immunoregulatory macrophages, impairing CAR T cell function. Mechanistically, proteomics analysis of CAR T cells revealed that iNOS-expressing macrophages promote the upregulation of genes mediating apoptosis and cell cycle arrest in CAR T cells, while downregulating ribosome biogenesis and protein synthesis. Furthermore, CAR T cell metabolism is compromised by the depletion of glycolytic intermediates and rewiring of the TCA cycle. Pharmacological inhibition of iNOS enhances the CAR T cell treatment efficacy in B cell tumor-bearing mice. Notably, elevated levels of iNOS+CD14+ monocytes were observed in leukaphereses of patients with non-durable response to CAR T cell therapy. These findings suggest that mitigating iNOS in tumor-associated macrophages (TAMs), potentially by modulating IFN-g expression in CAR T cells, could improve outcomes for LBCL patients.
Project description:CEACAM5-specific CAR NK-92 cells were engineered to target CEACAM5-expressing lung tumor cells. To study their transcriptional response during tumor engagement, parental NK-92 cells, CEACAM5-CAR NK-92 cells, hydrocortisone-treated CAR NK-92 cells, NR3C1-knockout (cortisol-resistant) CAR NK-92 cells, and hydrocortisone-treated NR3C1-knockout CAR NK-92 cells were co-cultured with CEACAM5⁺ A549 lung cancer cells for 16 hours. Following co-culture, NK-92–derived effector cells were isolated by flow cytometry and processed for bulk RNA sequencing. This dataset captures transcriptional programs associated with CAR activation, hydrocortisone exposure, and glucocorticoid receptor deficiency in NK-92–based effector cells responding to CEACAM5⁺ tumor targets.
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:Purpose: To compare cell states amoung three populations of interest among circulating CAR T cells in patients with lymphoma. Methods: Nine patients with large B-cell lymphoma (LBCL) were treated with axicabtagene ciloleucel (axi-cel), a commercial CD19-targeted CAR T-cell therapy. On day 7, fresh peripheral blood mononuclear cells were stained with an antibody panel for fluorescence-activated cell sorting (FACS), a panel for cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq), and a viability dye. Single live CAR+ T cells were sorted from each patient, counted, processed for 5' single-cell RNA-sequencing with feature barcoding and TCR clonotype analysis on the 10X Genomics platform, and sequenced by the Stanford Genomics Facility (HighSeq 4000) or Novogene (NovaSeq 6000). Results: We found that circulating CD4+ and CD8+ CAR T cells that express CD57 and T-bet are clonally expanded and display features of effector T cells. In contrast, CD4+ CD57- CAR T cells that express Helios expand polyclonally and display features of T regulatory cells. Conclusions: This study provides insights into cell states of circulating CAR T cells on day 7 that associate with clinical response or toxicity in LBCL patients treated with axi-cel.
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:Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionized the treatment of blood cancers. Parsing the genetic underpinnings of T cell precursor quality and subsequent CAR-T efficacy is challenging. RNA-seq informs infused CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasizes effector and metabolism genes. We investigated whether analyses of transcriptionally repressive and permissive histone methylation marks reveal associations with CAR-T potential beyond what is seen by transcriptomic analysis. We assessed human CD8+ T cell naïve, central and effector memory subsets that form the substrate of CAR-T cell products, and CAR-T cells derived from these subsets. We extended these observations into the clinic, by examining CAR-T products from a clinical trial of lymphoma patients (NCT01865617). We report that histone marks provide a rich dataset for identification of genes not apparent by conventional transcriptomics. Histone marks improved identification of T cell subsets, CAR-T manufactured from these subsets, and CAR-T manufactured from central memory cells from healthy donors and patients. Using this discriminative approach, we controlled for clinical factors and identified a factor, KLF7, associated with CAR-T cell expansion in patients. Epigenomic methods are an orthogonal, robust and wide-reaching approach for the assessment of T cell immunotherapeutic quality.