Targeting CDK7 suppresses super enhancer-linked inflammatory genes and alleviates CAR T cell-induced cytokine release syndrome.

BACKGROUND: Cytokine release syndrome (CRS) is a systemic inflammatory response characterized by the overexpression of inflammatory genes. Controlling CRS is essential for improving the therapeutic effects of chimeric antigen receptor (CAR) engineered T cells. However, current treatment options are limited given the complexity of cytokine interactions so it is important to seek a mild strategy with broad-spectrum inhibition to overcome this challenge. METHODS: Using THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), we demonstrated the transcriptional suppression of inflammatory genes in activated macrophages. RNA sequencing and ChIP sequencing were conducted to identify the key target genes of the inflammatory response. Pathogen- and CAR T cell-induced CRS models were also established to assess the efficacy and safety of targeting CDK7. RESULTS: CDK7 blockade attenuated cytokine release, mitigated hyperinflammatory states and rescued mice from lethal CRS. Targeting CDK7 preferentially suppressed a set of inflammatory genes, of which STAT1 and IL1 were the key targets associated with super enhancers. Furthermore, we confirmed the potent efficacy of THZ1 in alleviating the CRS induced by CAR T cell infusion without causing tissue injury or impairing antitumor effects. CONCLUSIONS: Our work indicates the CDK7-dependent transcription addiction of inflammatory genes. Targeting CDK7 is a promising strategy for treating CRS by inhibiting multiple cytokines.

Improvement of in vitro potency assays by a resting step for clinical-grade chimeric antigen receptor engineered T cells.

BACKGROUND: Chimeric antigen receptor engineered T (CAR-T) cell therapy is a promising approach currently revolutionizing the field of cancer immunotherapy. However, data concerning clinical-grade CAR-T cell stability and functionality after months of cryopreservation have not been released by companies so far. To investigate the effect of cryopreservation on CAR-T cells and to further optimize the potency assays, we performed this study. METHODS: A third generation of CD19 CAR-T cells was manufactured according to Good Manufacturing Practice (GMP) requirements, which is applied to patients in an ongoing clinical phase 1 study. Quality control tests for sterility, endotoxin and mycoplasma were performed for each batch. Stability in terms of viability, recovery, transduction efficiency and functional capacity was determined using microscopy, multiparametric flow cytometry as well as chromium-51 release tests. RESULTS: Up to 90days of cryopreservation had no influence on viability, recovery and transduction efficiency of CAR-T cells. However, higher cell concentration for cryopreservation could alter the cell viability and recovery but not the transduction efficiency. Moreover, directly after thawing, both the quantity and quality of the functionality of CAR-T cells were transiently hampered by the negative effects of cryopreservation. Notably, the impaired functionality could be fully restored and even strengthened after an overnight resting process. DISCUSSION: Cryopreservation is a challenge for the functional activity of CAR-T cells. However, CAR-T cells regain their potency by overnight incubation at 37°C, which mimics the clinical application setting. Therefore, an overnight resting step should be included in in vitro potency assays.

T Cell-Associated Immunotherapy for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases worldwide with limited therapeutic options. Accumulating evidences suggest that immunotherapy could be a promising option for treating HCC. T cell-associated immunotherapy lights up the hope for the improvement of complementary approach to conventional HCC treatments, which needs further research to consummate the clinical consequences. The present work reviewed several T cells associated cellular immunotherapies for HCC, including immune checkpoint blockade, gene-engineered T cells, bispecific T cell engagers, and so on. We also analyzed how these immunotherapies can mediate tumor cell eradication and evaluated their superiority or insufficiency.

Single-cell RNA-Seq reveals the potential risk of anti-mesothelin CAR T Cell therapy toxicity to different organs in humans.

"On-target off-tumor" toxicity is a major challenge to the use of chimeric antigen receptor (CAR)-engineered T cells in the treatment of solid malignancies, because of the expression of target antigens in normal tissues. Mesothelin overexpression is associated with poor prognosis of multiple solid tumors, and would therefore appear to be a suitable antigen target. To understand the risk of toxicity to different organs on anti-mesothelin CAR T cell therapy, single-cell RNA sequencing (scRNA-seq) datasets derived from major human physiological systems were analyzed in this study, including the respiratory, cardiovascular, digestive, and urinary systems. According to scRNA-seq datasets, the organs were stratified into high or low risk based on the level of mesothelin expression. We report that the proportion of mesothelin-positive cells was 7.71%, 2.40% and 2.20% of myocardial cells, pulmonary cells and stomach cells, respectively, indicating that these organs could be at high risk of "on-target off-tumor" toxicity on anti-mesothelin CAR T cell therapy. By contrast, esophagus, ileum, liver, kidney and bladder exhibited low mesothelin expression (<1%). Therefore, these organs could be regarded as at low risk. Thus, the risk of toxicity to different organs and tissues in anti-mesothelin CAR T cell therapy may be predicted by these scRNA-seq data.

EGFR-specific CAR-T cells trigger cell lysis in EGFR-positive TNBC.

Triple-negative breast cancer (TNBC) is an aggressive cancer subtype for which effective therapies are lacking. Epidermal growth factor receptor (EGFR) is overexpressed in various types of TNBC cells, and several EGFR-specific immunotherapies have been used to treat cancer patients. Chimeric antigen receptor engineered T (CAR-T) cells have also been used as cancer therapies. In this study, we generated two types of EGFR-specific CAR-modified T cells using lentiviral vectors with DNA sequences encoding the scFv regions of two anti-EGFR antibodies. The cytotoxic and antitumor effects of these CAR-modified T cells were examined in cytokine release and cytotoxicity assays in vitro and in tumor growth assays in TNBC cell line- and patient-derived xenograft mouse models. Both types of EGFR-specific CAR-T cells were activated by high-EGFR-expressing TNBC cells and specifically triggered TNBC cell lysis in vitro. Additionally, the CAR-T cells inhibited growth of cell-line- and patient-derived xenograft TNBC tumors in mice. These results suggest that EGFR-specific CAR-T cells might be a promising therapeutic strategy in patients with high-EGFR-expressing TNBC.

Progress of the diagnosis and treatment of acute leukemia in China: work review of Institute of Hematology&Blood Diseases Hospital, Chinese Academy of Medical Sciences / 白血病·淋巴瘤

Acute leukemia is a kind of malignant proliferative disease originating from hematopoietic stem cells, which is characterized with molecular and clinical heterogeneity. Chemotherapy and hematopoietic stem cell transplantation are the major treatments for acute leukemia. In recent years, the development of targeted therapy has significantly improved the prognosis of acute leukemia patients. This article reviews the part of the work of Institute of Hematology&Blood Diseases Hospital, Chinese Academy of Medical Sciences on the research of pathogenesis, diagnosis and treatment of acute leukemia.

Progress of the diagnosis and treatment of acute leukemia in China: work review of Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences / 白血病·淋巴瘤

Acute leukemia is a kind of malignant proliferative disease originating from hematopoietic stem cells, which is characterized with molecular and clinical heterogeneity. Chemotherapy and hematopoietic stem cell transplantation are the major treatments for acute leukemia. In recent years, the development of targeted therapy has significantly improved the prognosis of acute leukemia patients. This article reviews the part of the work of Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences on the research of pathogenesis, diagnosis and treatment of acute leukemia.