Project description:Purpose: To compare cell states between CD19-28z and GD2-28z human CAR T cells on day 10 of cell culture. Methods: Human T cells were activated and lentivirally transduced with CD19-28z or GD2-28z CAR constructs and maintained in culture for 10 days, and then delivered to the Stanford Functional Genomics Facility for 3' single-cell RNA-sequencing on the 10X Genomics platform. Results: Comparison of transcription factor profiles by single cell RNA-seq analysis of CD8+ T cells expressing CD19-28z vs. GD2-28z CAR confirmed that the bZIP family members JUN, JUNB, JUND, and ATF4 were among the most differentially expressed and broadly connected in exhausted GD2-28z CAR T cells. Conclusions: This study provides insights into cell states that could explain the underlying differences between highly functional CD19-28z CAR T cells and exhaustion-prone GD2-28z CAR T cells on day 10 in culture.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized the systems-based analysis of cellular pathways. The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) between two generations of CAR-T cells aimed at integrating their fitness to overcome exhaustion and stress in tumor microenvironments Methods: mRNA profiles of CAR-T cells co-cultured with target cells for 48 hours were generated by deep sequencing. Human CD45 enrichment was performed to decrease tumor contamination. Results: Gene Set Enrichment Analysis (GSEA) of the RNA expression profile of T cells obtained 48 hours post co-culture with target cells demonstrated the enrichment of genes with memory T cell phenotype in B7H3 CAR-T compared to GD2-B7H3 T cells. However, B7H3 CAR-T cells were enriched in genes associated with glycolysis and apoptosis pathways suggesting a committed terminal fate for these T cells. There was significantly greater expression of genes attributed to exhaustion in B7H3 CAR-T cells than GD2-B7H3 T cells. In particular, B7H3 CAR-T cells showed higher expression of inhibitory receptors LAG3, HAVCR2 (TIM3), and BTLA genes, along with exhaustion-related transcription factor genes TBX21 (T-bet), PRDM1 (Blimp-1), and IKZF2 (Helios). B7H3 CAR-T cells also expressed genes that encode transcription factors reported to be associated with activated and memory T cells, such as KLF6, JUN, and JUNB. Conclusions: Our study represents the first analysis of transcriptome comparing SynNotch gated GD2-B7H3 CAR-T cells versus the conventional B7H3 CAR-T cells. GD2-B7H3 T cells exhibited superior resistance to exhaustion and greater metabolic fitness in comparison to conventional CAR-T cells. Metabolic preference (glycolytic versus oxidative) has an enormous impact on T cell fate. After eradicating NBL cells, GD2-B7H3 T cells had an oxygen consumption rate similar to UT cells, suggesting that the gated T cells can revert to their naïve metabolic state. Improved metabolic plasticity and reprogramming in favor of oxidative rather than glycolytic phosphorylation supports the hypothesis that the gated CAR-T cells likely have intact expansion potential, similar to unmanipulated naïve T cells. We observed significant enrichment of glycolytic genes in conventional B7H3 CAR-T cells compared to GD2-B7H3 T cells, supporting our metabolic studies. Our data suggest that SynNotch gated CAR-T cells have a more favorable oxidative metabolic profile than 4-1BB CAR-T cells.
Project description:The purpose of the experiment was to compare the transcriptional profile of T-cells expressing a GD2-CAR construct or a GD2-CAR.C7R construct (where the GD2-CAR and the C7R construct are co-expressed), after the T-cells had been exposed to two serial tumor cell co-cultures. C7R is an engineered IL-7 receptor that has been rendered constitutively active. The sample replicates were generated using peripheral blood mononuclear cells (PBMCs) obtained from healthy human donors.
Project description:Long-lived, self-renewing, multipotent T memory stem cells (TSCM) can trigger profound and sustained tumor regression but their rareness poses a major hurdle to their clinical application. Presently, clinically compliant procedures to generate relevant numbers of this T cell population are undefined. Here, we provide a strategy for deriving large numbers of clinical grade tumor-redirected TSCM cells starting from naïve precursors. CD8+CD62L+CD45RA+ naïve T cells enriched by streptamer-based serial positive selection were activated by CD3/CD28 engagement in the presence of IL-7, IL-21 and the glycogen synthase-3β inhibitor TWS119, and genetically engineered to express a CD19-specific chimeric antigen receptor (CD19-CAR). These conditions allowed for the generation of CD19-CAR modified TSCM cells that were phenotypically, functionally and transcriptomically equivalent to their naturally occurring counterpart. Compared with T cell products currently under clinical investigation, CD19-CAR modified TSCM cells exhibit enhanced metabolic fitness, persistence and anti-tumor activity against systemic acute lymphoblastic leukemia xenografts. Based on these findings, we have initiated a phase 1 clinical study to evaluate the activity of CD19-CAR modified TSCM in patients with B-cell malignancies refractory to prior allogeneic hematopoietic stem cell transplantation. Three healthy human blood donors provided lymphocyte-enriched apheresis blood for this study after informed consent. From all samples, total RNA was isolated using an miRNeasy Mini Kit (Qiagen), processed by Ambionâ??s WT expression kit, fragmented and labeled with a WT Terminal Labeling Kit (Affymetrix), hybridized to WT Human Gene 1.0 ST arrays (Affymetrix) and stained on a Genechip Fluidics Station 450 (Affymetrix), all according to the respective manufacturer's instructions. Samples represent exon-level and gene-level analyses.
Project description:Diffuse intrinsic pontine glioma (DIPG) and other H3K27M-mutated diffuse midline gliomas (DMGs) are universally lethal central nervous system (CNS) tumors that occur most commonly in children and young adults1. Average life expectancy is ten months from diagnosis, and 5-year survival is less than 1%2. Palliative radiotherapy is the only established treatment3, and neither cytotoxic nor targeted pharmacological approaches have demonstrated anti-tumor responses or improved prognosis to date3,4. We previously discovered that the disialoganglioside GD2 is highly and uniformly expressed on H3K27M+ DMG cells and demonstrated that intravenously (IV) administered GD2.4-1BB.z chimeric antigen receptor (CAR) T-cells eradicated established DMGs in patient-derived orthotopic murine models5, thereby providing the rationale for a first-in-human/first-in-child Phase 1 clinical trial (NCT04196413). Because CAR T-cell-induced inflammation and edema of the brainstem can result in obstructive hydrocephalus, increased intracranial pressure, and dangerous tissue shifts, a number of neurocritical care precautions were incorporated in the clinical trial design and management plan. Here we present the clinical experience from the first four patients with H3K27M+ DMG treated with GD2-CAR T-cells at dose level 1 (DL1; 1e6 GD2-CAR T-cells/kg administered IV). Patients who exhibited clinical benefit were eligible for subsequent administrations of GD2-CAR T-cells. Given preclinical evidence for increased CAR T-cell potency6, and the potential for diminished immunogenicity with locoregional administration, second doses were administered intracerebroventricularly (ICV) through an Ommaya catheter to three patients. As predicted from preclinical models, toxicity was largely related to the neuroanatomical location of the tumors and was reversible with intensive supportive care. Although GD2 is expressed at low levels in normal neural tissue, no evidence of on-target, off-tumor toxicity was observed. Three of four patients exhibited clinical and radiographic improvement, underscoring the promise of this approach for H3K27M+ DMG therapy. Correlative studies of serum and CSF revealed marked proinflammatory cytokine production following GD2 CAR T cell administration and single cell transcriptomic analysis of 65,598 single cells from CAR T cell products and patient CSF has begun to reveal differences that correlate with the heterogeneity between subjects and routes of administration.
Project description:Vα24-invariant natural killer T cells (NKTs) have antitumor properties that can be enhanced by transgenic expression of tumor-specific receptors. Here, we report the results of the first-in-human clinical evaluation of autologous NKTs co-expressing a GD2-specific chimeric antigen receptor with interleukin (IL)15 (GD2-CAR.15) in 12 children with neuroblastoma (NB) treated on four dose levels (NCT03294954). Objectives included assessing safety, antitumor activity, and immune response. No dose-limiting toxicities occurred, and one patient had grade 2 cytokine release syndrome resolved by tocilizumab. The overall response rate was 25% (3/12) and disease control rate was 58% (7/12) including four patients with stable disease, two partial responses, and one complete response. CD62L+ NKT frequency in infused products correlated with CAR-NKT expansion in patients and was higher in responders than non-responders (71% vs 35.3%, p=0.002). Singe-cell RNA sequencing analysis identified B cell translocation gene 1 (BTG1) as one of the top upregulated genes in GD2-CAR.15-NKTs after in vitro serial tumor challenge. Genetic gain- and loss-of-function experiments revealed that BTG1 is a key driver of hyporesponsiveness in exhausted NKT and T cells. Crucially, NKTs co-expressing GD2-CAR.15 and BTG1-specific shRNA eradicated metastatic NB in mice. These results indicate that CAR-NKTs are safe, produce objective responses in NB patients, and that targeting BTG1 can enhance their therapeutic potency.
Project description:We generate macrophages from pluripotent stem cells (PSCs) with GD2 CARs integrated into AAVS1 locus. To produce CAR macrophages (CAR-M) we established a serum- and feeder-free differentiation protocol which generates macrophages through arterialized hemogenic endothelium.
Project description:Vα24-invariant natural killer T cells (NKTs) have antitumor properties that can be enhanced by transgenic expression of tumor-specific receptors. Here, we report the results of the first-in-human clinical evaluation of autologous NKTs co-expressing a GD2-specific chimeric antigen receptor with interleukin (IL)15 (GD2-CAR.15) in 12 children with neuroblastoma (NB) treated on four dose levels (NCT03294954). Objectives included assessing safety, antitumor activity, and immune response. No dose-limiting toxicities occurred, and one patient had grade 2 cytokine release syndrome resolved by tocilizumab. The overall response rate was 25% (3/12) and disease control rate was 58% (7/12) including four patients with stable disease, two partial responses, and one complete response. CD62L+ NKT frequency in infused products correlated with CAR-NKT expansion in patients and was higher in responders than non-responders (71% vs 35.3%, p=0.002). Singe-cell RNA sequencing analysis identified B cell translocation gene 1 (BTG1) as one of the top upregulated genes in GD2-CAR.15-NKTs after in vitro serial tumor challenge. Genetic gain- and loss-of-function experiments revealed that BTG1 is a key driver of hyporesponsiveness in exhausted NKT and T cells. Crucially, NKTs co-expressing GD2-CAR.15 and BTG1-specific shRNA eradicated metastatic NB in mice. These results indicate that CAR-NKTs are safe, produce objective responses in NB patients, and that targeting BTG1 can enhance their therapeutic potency.
Project description:Long-lived, self-renewing, multipotent T memory stem cells (TSCM) can trigger profound and sustained tumor regression but their rareness poses a major hurdle to their clinical application. Presently, clinically compliant procedures to generate relevant numbers of this T cell population are undefined. Here, we provide a strategy for deriving large numbers of clinical grade tumor-redirected TSCM cells starting from naïve precursors. CD8+CD62L+CD45RA+ naïve T cells enriched by streptamer-based serial positive selection were activated by CD3/CD28 engagement in the presence of IL-7, IL-21 and the glycogen synthase-3β inhibitor TWS119, and genetically engineered to express a CD19-specific chimeric antigen receptor (CD19-CAR). These conditions allowed for the generation of CD19-CAR modified TSCM cells that were phenotypically, functionally and transcriptomically equivalent to their naturally occurring counterpart. Compared with T cell products currently under clinical investigation, CD19-CAR modified TSCM cells exhibit enhanced metabolic fitness, persistence and anti-tumor activity against systemic acute lymphoblastic leukemia xenografts. Based on these findings, we have initiated a phase 1 clinical study to evaluate the activity of CD19-CAR modified TSCM in patients with B-cell malignancies refractory to prior allogeneic hematopoietic stem cell transplantation.
Project description:To characterize transfer of molecules from target cells into CAR T cells via trogocytosis we cultured NALM-6 leukemia cell line expressing a CD19-mCherry fusion protein with CAR T cells. NALM6-CD19-mCherry were loaded with heavy amino acid and cocultured with CAR T cells for 1 hour. CAR T cells were next sorted into two fractions, mCherry-positive (TrogPos), and -negative (TrogNeg). Proteomics analysis revealed the presence of targeted antigen (CD19) in the TrogPos only.