Inhibition of CD38 enzymatic activity enhances CAR-T cell immune-therapeutic efficacy by repressing glycolytic metabolism.

Chimeric antigen receptor (CAR)-T therapy has shown superior efficacy against hematopoietic malignancies. However, many patients failed to achieve sustainable tumor control partially due to CAR-T cell exhaustion and limited persistence. In this study, by performing single-cell multi-omics data analysis on patient-derived CAR-T cells, we identify CD38 as a potential hallmark of exhausted CAR-T cells, which is positively correlated with exhaustion-related transcription factors and further confirmed with in vitro exhaustion models. Moreover, inhibiting CD38 activity reverses tonic signaling- or tumor antigen-induced exhaustion independent of single-chain variable fragment design or costimulatory domain, resulting in improved CAR-T cell cytotoxicity and antitumor response. Mechanistically, CD38 inhibition synergizes the downregulation of CD38-cADPR -Ca2+ signaling and activation of the CD38-NAD+-SIRT1 axis to suppress glycolysis. Collectively, our findings shed light on the role of CD38 in CAR-T cell exhaustion and suggest potential clinical applications of CD38 inhibition in enhancing the efficacy and persistence of CAR-T cell therapy.

Mitochondrial isocitrate dehydrogenase impedes CAR T cell function by restraining antioxidant metabolism and histone acetylation.

The efficacy of chimeric antigen receptor (CAR) T cell therapy is hampered by relapse in hematologic malignancies and by hyporesponsiveness in solid tumors. Long-lived memory CAR T cells are critical for improving tumor clearance and long-term protection. However, during rapid ex vivo expansion or in vivo tumor eradication, metabolic shifts and inhibitory signals lead to terminal differentiation and exhaustion of CAR T cells. Through a mitochondria-related compound screening, we find that the FDA-approved isocitrate dehydrogenase 2 (IDH2) inhibitor enasidenib enhances memory CAR T cell formation and sustains anti-leukemic cytotoxicity in vivo. Mechanistically, IDH2 impedes metabolic fitness of CAR T cells by restraining glucose utilization via the pentose phosphate pathway, which alleviates oxidative stress, particularly in nutrient-restricted conditions. In addition, IDH2 limits cytosolic acetyl-CoA levels to prevent histone acetylation that promotes memory cell formation. In combination with pharmacological IDH2 inhibition, CAR T cell therapy is demonstrated to have superior efficacy in a pre-clinical model.

Rewiring mitochondrial metabolism to counteract exhaustion of CAR-T cells.

Short persistence and early exhaustion of T cells are major limits to the efficacy and broad application of immunotherapy. Exhausted T and chimeric antigen receptor (CAR)-T cells upregulate expression of genes associated with terminated T cell differentiation, aerobic glycolysis and apoptosis. Among cell exhaustion characteristics, impaired mitochondrial function and dynamics are considered hallmarks. Here, we review the mitochondrial characteristics of exhausted T cells and particularly discuss different aspects of mitochondrial metabolism and plasticity. Furthermore, we propose a novel strategy of rewiring mitochondrial metabolism to emancipate T cells from exhaustion and of targeting mitochondrial plasticity to boost CAR-T cell therapy efficacy.

Inhibition of Calcium Signaling Prevents Exhaustion and Enhances Anti-Leukemia Efficacy of CAR-T Cells via SOCE-Calcineurin-NFAT and Glycolysis Pathways.

Chimeric antigen receptor (CAR) T cells are potent agents for recognizing and eliminating tumors, and have achieved remarkable success in the treatment of patients with refractory leukemia and lymphoma. However, dysfunction of T cells, including exhaustion, is an inevitable obstacle for persistent curative effects. Here, the authors initially found that calcium signaling is hyperactivated via sustained tonic signaling in CAR-T cells. Next, it is revealed that the store-operated calcium entry (SOCE) inhibitor BTP-2, but not the calcium chelator BAPTA-AM, markedly diminishes CAR-T cell exhaustion and terminal differentiation of CAR-T cells in both tonic signaling and tumor antigen exposure models. Furthermore, BTP-2 pretreated CAR-T cells show improved antitumor potency and prolonged survival in vivo. Mechanistically, transcriptome and metabolite analyses reveal that treatment with BTP-2 significantly downregulate SOCE-calcineurin-nuclear factor of activated T-cells (NFAT) and glycolysis pathways. Together, the results indicate that modulating the SOCE-calcineurin-NFAT pathway in CAR-T cells renders them resistant to exhaustion, thereby yielding CAR products with enhanced antitumor potency.

BCMA CAR-T Therapy Is Safe and Effective for Refractory/Relapsed Multiple Myeloma With Central Nervous System Involvement.

Central nervous system (CNS) involvement is a rare complication of multiple myeloma (MM) that portends an extremely poor prognosis. Although chimeric antigen receptor (CAR)-T cell therapy is considered a promising strategy for patients with MM, the role of CAR-T cell therapy in MM involving the CNS has not been fully elucidated. In this study, we retrospectively analyzed 4 cases of B-cell maturation antigen CAR-T cell therapy for patients with relapsed/refractory MM involving the CNS. Patients received a range of 2-7 lines of prior therapy, including 1 autologous hematopoietic stem cell transplant. The most common adverse event was cytokine release syndrome, which was observed in all 4 patients, including 2 with grade 1 and 2 with grade 2. No patient was complicated with immune effector cell-associated neurotoxicity syndrome. Within the follow-up (median: 257 d, range: 116-392 d), 3 of 4 patients reached complete remission (CR), and 1 patient reached partial response. At the data cutoff, 1 patient continued to remain in CR at day 220, and the patient with partial response died at day 116. The other 2 patients relapsed at 317 and 111 days with CR durations of 287 and 81 days, respectively. Our results show promising effectiveness and acceptable safety of CAR-T cell therapy for heavily pretreated patients with CNS MM.

Dasatinib enhances anti-leukemia efficacy of chimeric antigen receptor T cells by inhibiting cell differentiation and exhaustion.

Relapses of CD19-expressing leukemia in patients who achieved initial remission after CART cell treatment have been reported to correlate with poor CART cells persistence. Sustained tonic signaling or strong activation drives CART cell differentiation and exhaustion, which limit the therapeutic efficacy and persistence of CART cells. Here, we identified dasatinib as the optimal candidate to prevent or reverse both CD28/CART and 4-1BB/CART cell differentiation and exhaustion during ex vivo expansion, which profoundly enhanced the therapeutic efficacy and in vivo persistence. Moreover, strong activation-induced CART cells differentiation, exhaustion and apoptosis driven by CD3/CD28 stimulation or antigen exposure were dramatically prevented or reversed by dasatinib treatment. Mechanistically, dasatinib markedly reduced the phosphorylation of Src and Lck, and downregulated the expression of genes involved in CAR signaling pathways, which resulted in the optimization of cell differentiation, exhaustion and apoptosis-related gene expression. Our study proposes a promising pharmacological approach for optimizing CART cells manufacture, and provides an experimental basis for reinvigorating CART cells in clinical application.

CRS-related coagulopathy in BCMA targeted CAR-T therapy: a retrospective analysis in a phase I/II clinical trial.

Chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA) has shown promising effects in the treatment of patients with refractory/relapsed multiple myeloma (R/R MM) patients. In this retrospective analysis of phase I/II clinical trial (ChiCTR1800017404), 37 patients with R/R MM received their first BCMA-targeted CAR T-cells following lymphodepletion chemotherapy. The response rate was high (97%), while accompanied by a high incidence of adverse events including coagulation dysfunction. Of 37 patients, all (100%) had cytokine release syndrome (CRS) and 34 (91%) developed at least one abnormal coagulation parameter. The values of coagulation parameters were positively correlated with the severity of CRS as well as with the levels of some cytokines, such as interleukin (IL)-6, IL-10, and interferon (IFN)-γ, etc. Furthermore, levels of the plasma tissue factor (TF), Factor X (FX), Factor XII (FXII), and P-selectin also showed a positive correlation with severity of CRS as well as some specific cytokines, which indicates that these factors are likely to play important roles in CRS-related coagulopathy. Our study suggests that there exists relationship in some extent between coagulation disorder and CRS. Moreover, coagulation dysfunction can be managed with daily monitoring and early intervention despite high incidence.

Single-Cell Transcriptomic Analysis Reveals BCMA CAR-T Cell Dynamics in a Patient with Refractory Primary Plasma Cell Leukemia.

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 clinical patients remains unexplored. Here, we longitudinally profiled the transcriptomes of 55,488 T cells including CAR-T products, CAR-T cells, and endogenous T cells at the peak and remission phases in a plasma cell leukemia (PCL) patient treated with BCMA CAR-T cells by single-cell transcriptomic analysis. Our results showed distinct CAR-T and endogenous T cell subsets indicating stage-specific expression in proliferation, cytotoxicity, and intercellular signaling pathways. Furthermore, we found that CAR-T cells at peak phase gradually convert to a highly cytotoxic state from a highly proliferative state along a development trajectory. Moreover, re-analysis of a single cell study from CD8+ CD19 CAR-T confirmed our findings. These commonalities suggest conserved mechanisms for CAR-T treatment across hematological malignancies. Taken together, our current study provides insight into CAR-T cell dynamics during CAR-T therapy and proves that both BCMA CAR-T and CD19 CAR-T have similar transcriptional characteristics, especially at the CAR-T peak phase.

A novel mutation of SERPINC1 in a patient presenting as recurrent cerebral sinus venous and portal vein thrombosis.

: Inherited antithrombin deficiency (OMIM 107300) is a rare autosomal dominant disorder that could increase the risk of venous thromboembolism and is usually caused by mutations of SERPINC1. Herein, we present a case of a novel mutation in the SERPINC1 gene in a Chinese patient. The patient was a 54-year-old man who presented with recurrent venous thromboembolism and was without a recent history of any precipitating factors. Whole exome sequencing and Sanger sequencing identified a novel heterozygous variant on exon 2 of SERPINC1 gene (c.142G>A, p.P48S).

Application of postoperative autotransfusion in total joint arthroplasty reduces allogeneic blood requirements: a meta-analysis of randomized controlled trials.

BACKGROUND: Total joint arthroplasty is associated with significant blood loss and often requires blood transfusion. However, allogeneic blood transfusion (ABT) may lead to severe problems, such as immunoreaction and infection. Postoperative autotransfusion, an alternative to ABT, is controversial. We conducted a meta-analysis to evaluate the ability of postoperative autotransfusion to reduce the need for ABT following total knee arthroplasty (TKA) and total hip arthroplasty (THA). METHODS: Systematic literature searches for randomized controlled trials were performed using PubMed, Embase, and the Cochrane Library until February 2016. Relative risks (RRs) and weighted mean differences with 95% confidence intervals (CIs) were calculated using fixed-effect or random-effect models; we also evaluated publication bias and heterogeneity. RESULTS: Seventeen trials with a total of 2314 patients were included in the meta-analysis. The pooled RRs of ABT rate between autotransfusion and the regular drainage/no drainage groups for TKA and THA were 0.446 (95% CI = 0.287, 0.693; p < 0.001) and 0.757 (95% CI = 0.599, 0.958; p = 0.020), respectively. In the subgroup analysis performed in TKA patients according to control interventions, the pooled RRs were 0.377 (95% CI = 0.224, 0.634; p < 0.001) (compared with regular drainage) and 0.804 (95% CI = 0.453, 1.426, p = 0.456) (compared with no drainage). In the subgroup analysis performed for THA, the pooled RRs were 0.536 (95% CI = 0.379, 0.757, p < 0.001) (compared with regular drainage) and 1.020 (95% CI = 0.740, 1.405, p = 0.904) (compared with no drainage). CONCLUSIONS: Compared to regular drainage, autotransfusion reduces the need for ABT following TKA and THA. This reduction is not present when comparing autotransfusion to no drainage. However, the reliability of the meta-analytic results concerning TKA was limited by significant heterogeneity in methods among the included studies.