Project description:Although CD19 CAR T therapy has attained encouraging clinical outcomes worldwide, leukemia relapse after this therapy is associated with particular poor prognosis and has become an urgent problem to be solved. In consideration of the possible genetic or transcriptomic mechanisms underlying relapse, leukemia samples before CAR T cell infusion and after relapse were subjected to transcriptome sequencing
Project description:T cell-engaging therapies involving bispecific T cell engager (BiTE) and chimeric antigen receptor T (CAR-T) cells have achieved great success in the treatment of hematological tumors. However, the paucity of ideal cell surface molecules that can be targeted on glioblastoma (GBM) partially reduces the immunotherapeutic efficacy. Recently, high expression of Fn14 has been reported in several solid tumors, so the strategy of exploiting this specific antigen for GBM immunotherapy is worth studying. Consequently, we constructed Fn14× CD3 BiTE and Fn14-specific CAR-T cells and investigated their cytotoxic activity against GBM in vitro and in vivo. First, expression of Fn14 was confirmed in glioma tissues and GBM cells. Then, we designed Fn14-specific BiTE and CAR-T cells and tested their cytotoxicity in GBM cell cultures and mouse models of GBM. Fn14 was highly expressed in GBM tissues and cell lines, while it was undetectable in normal brain samples. Fn14× CD3 BiTE, Fn14 CAR-T cells and Fn14 CAR-T/IL-15 cells were antigen-specific and highly cytotoxic, showing good antitumor activity in vitro and causing significant regression of established solid tumors in xenograft models. However, the xenografts treated with Fn14 CAR-T cells regrew, whereas xenografts treated with Fn14 CAR-T/IL-15 cells did not. IL-15 engineering augmented the antitumor activity of Fn14 CAR-T cells and resulted in significant antitumor effects similar to those of Fn14× CD3 BiTE. Our results suggest that Fn14 is an appropriate target for GBM. Anti-Fn14 BiTE and Fn14-specific CAR-T/IL-15 cells may be exciting immunotherapeutic options for malignant brain cancer.
Project description:BackgroundCD19 chimeric antigen receptor (CAR) therapy has achieved impressive success in relapsed or refractory (R/R) B-cell malignancies, but relapse due to antigen escape is increasingly appearing reported. As the expression profile of CD22 is similar to that of CD19, CD22 has become a candidate target when CD19 CAR-T therapy fails.MethodsA novel CD22 CAR incorporating scFv derived from an HIB22 hybridoma which bound the first and second Ig-like extracellular domains of CD22 antigen was constructed. Preclinical investigation of the CD22 CAR-T therapy against B-cell malignancies was evaluated by coculturing CD22 CAR-T cells with tumor cell lines or primary blasts from patients in vitro and using a xenograft mouse model in vivo. Further clinical study of CD22/CD19 CAR-T sequential therapy was conducted in 4 R/R adult B-cell acute lymphoblastic leukemia (B-ALL) patients.ResultsThe novel CD22 CAR-T treatment had specific cytotoxicity to CD22 + target cells, and the survival time of mice in the CD22 CAR-T treatment group was significantly prolonged. Furthermore, it's validated that sequential CD22/CD19 CAR-T therapy was significantly superior than single CD19 or CD22 CAR-T treatment in a relapse xenograft model. All 4 patients achieved complete remission (CR) with negative minimal residual disease (MRD), including 3 patients who had received prior CD19-related immunotherapy. The proliferation of CD19 and CD22 CAR-T cells was observed respectively in vivo, and 3 of the 4 patients experienced cytokine release syndrome (CRS); 2 of these patients had grade 1 CRS and 1 had grade 3 CRS. Long term follow-up showed that 3 of the 4 (75%) patients had sustained CR for up to 1 year. Analysis of antigen expression in the relapsed patients demonstrated that loss or diminution of CD19 and CD22 expression might cause antigen escape from CAR-T surveillance.ConclusionsIn summary, the novel CD22 CAR-T therapy was validated with antitumor effects both in vitro and in vivo. Furthermore, our study demonstrated the safety and robust efficacy of sequential CD22/CD19 CAR-T therapy in xenograft models and clinical trials, especially as the salvage treatment for R/R B-ALL patients with antigen loss or in whom anti-CD19 related immunotherapy failure failed.Trial registrationChinese Clinical Trial Registry (ChiCTR): ChiCTR1900025419, Supplementarily registered 26 August, 2019.
Project description:Vδ1T cells, a rare subset of γδT cells, hold promise for treating solid tumors. Unlike conventional T cells, they recognize tumor antigens independently of the MHC antigen-presentation pathway, making them a potential “off-the-shelf” cell therapy product. However, isolation and activation of Vδ1T cells is challenging, which has limited their clinical investigation. Here, we developed a large-scale clinical-grade manufacturing process for Vδ1T cells and validated the therapeutic potential of B7-H3-CAR-modified Vδ1T cells in treating solid tumors. Co-expression of interleukin-2 with the B7-H3-CAR led to durable anti-tumor activity of Vδ1T cells in vitro and in vivo. In multiple subcutaneous and orthotopic mouse xenograft tumor models, a single intravenous administration of the CAR-Vδ1T cells resulted in complete tumor regression. These modified cells demonstrated significant in vivo expansion and robust homing ability to tumors, akin to natural tissue-resident immune cells.Additionally, the B7-H3-CAR-Vδ1T cells exhibited a favorable safety profile. In conclusion, B7-H3-CAR-modified Vδ1T cells represent a promising strategy for treating solid tumors.
Project description:CD39, expressed by tumor-infiltrating lymphocytes (TILs), is a marker to identify tumor-reactive T cells, which is frequently associated with stronger antitumor activity than bystander T cells in a variety of malignancies. Therefore, CD39 could be a promising marker for identifying the active antitumor immune cells used for cellular immunotherapy. To test this possibility, we constructed the hepatitis B virus (HBV) surface protein-specific chimeric antigen receptor T cells (HBVs-CAR-T cells) and generated the personalized tumor-reactive CD8+ T cells. We subsequently assessed their antitumor efficiency mainly with a co-culture system for autologous HBVs+ HCC organoid and T cells. We found that both CD39+ HBVs-CAR-T and CD39+ personalized tumor-reactive CD8+ T cells induced much more apoptosis in HCC organoids. Although the exhaustion status of CAR-T cells increased in CD39+ CAR-T cells, triple knockdown of PD-1, Tim-3, and Lag-3 with shRNAs further enhanced antitumor activity in CD39+ CAR-T cells. Furthermore, these CD39+ CAR-T cells exerted an increased secretion of interferon-γ and stronger antitumor effect in a patient-derived xenograft mouse model. Our findings demonstrated that CD39 could be a promising biomarker to enrich active immune cells and become an indicator marker for evaluating the prognosis of immunotherapy for HCC patients.
Project description:The prognosis of patients with acute myeloid leukemia (AML) remains dismal, highlighting the need for novel innovative treatment strategies. The application of chimeric antigen receptor (CAR) T-cell therapy to patients with AML has been limited, in particular by the lack of a tumor-specific target antigen. CD70 is a promising antigen to target AML, as it is expressed on most leukemic blasts, whereas little or no expression is detectable in normal bone marrow samples. To target CD70 on AML cells, we generated a panel of CD70-CAR T cells that contained a common single-chain variable fragment (scFv) for antigen detection, but differed in size and flexibility of the extracellular spacer and in the transmembrane and the costimulatory domains. These CD70scFv CAR T cells were compared with a CAR construct that contained human CD27, the ligand of CD70 fused to the CD3ζ chain (CD27z). The structural composition of the CAR strongly influenced expression levels, viability, expansion, and cytotoxic capacities of CD70scFv-based CAR T cells, but CD27z-CAR T cells demonstrated superior proliferation and antitumor activity in vitro and in vivo, compared with all CD70scFv-CAR T cells. Although CD70-CAR T cells recognized activated virus-specific T cells (VSTs) that expressed CD70, they did not prevent colony formation by normal hematopoietic stem cells. Thus, CD70-targeted immunotherapy is a promising new treatment strategy for patients with CD70-positive AML that does not affect normal hematopoiesis but will require monitoring of virus-specific T-cell responses.
Project description:BackgroundChimeric antigen receptor NK (CAR-NK) cell therapy is one of the most promising immunotherapies. Although it has shown a significant therapeutic effect in hematologic malignancies, few successes have been obtained in solid tumors including esophageal squamous cell carcinoma (ESCC). The major reasons are lack of specific cell surface antigens and complex tumor microenvironment. Here we identify CD22, a well-known tumor surface marker in hematologic malignancies, is expressed in ESCC, possibly serving as a potential target of CAR-NK cell therapy.MethodsThe expression of 13 tumor cell surface antigens used clinically was analyzed in patients from The Cancer Genome Atlas (TCGA) database. Also, mRNA expression were detected in 2 ESCC cell lines and 2 patients samples by qCPR. Then according to Venn diagram, CD22 was selected for further investigation. Following this, the expression of CD22 by immunofluorescence (IF) in ESCC cell lines and by immunohistochemistry (IHC) in 87 cases of human ESCC samples was detected respectively. On the basis of H-score results, the correlation between CD22 expression and clinical parameters was analyzed. As a proof, the efficacy of CD22-targeted CAR-NK cells against ESCC cell lines was performed by a real-time cell analyzer (RTCA) platform.ResultsKYSE-140 and KYSE-150 cell lines displayed surface expression of CD22. IHC showed an 80.46% (70/87) positive rate in ESCC patient samples. Among these, cell membranous expression of CD22 was observed in 27.59% (24/87) patient samples. Through chi-square test, expression of CD22 in ESCC was associated with lymph node metastasis while it was no related to the depth of tumor invasion and clinical stage. Engineered CD22-targeted CAR-NK cells exhibited inhibitory growth capability against ESCC cell lines (p < 0.0001).ConclusionsCD22 is a potential tumor surface antigen capable of being targeted by CAR-NK cells in ESCC. And potential therapeutics for ESCC may be developed based on immune cells expressing anti-CD22 CAR. The study also indicates that CD22 CAR-NK cells could be used in other cancers and more in vivo experiments are needed.
Project description:This study characterizes aminoindole molecules that are analogs of Genz-644442. Genz-644442 was identified as a hit in a screen of ~70,000 compounds in the Broad Institute's small-molecule library and the ICCB-L compound collection at Harvard Medical School. Genz-644442 is a potent inhibitor of Plasmodium falciparum in vitro (50% inhibitory concentrations [IC??s], 200 to 285 nM) and inhibits P. berghei in vivo with an efficacy of > 99% in an adapted version of Peters' 4-day suppressive test (W. Peters, Ann. Trop. Med. Parasitol. 69:155-171, 1975). Genz-644442 became the focus of medicinal chemistry optimization; 321 analogs were synthesized and were tested for in vitro potency against P. falciparum and for in vitro absorption, distribution, metabolism, and excretion (ADME) properties. This yielded compounds with IC??s of approximately 30 nM. The lead compound, Genz-668764, has been characterized in more detail. It is a single enantiomer with IC??s of 28 to 65 nM against P. falciparum in vitro. In the 4-day P. berghei model, when it was dosed at 100 mg/kg of body weight/day, no parasites were detected on day 4 postinfection. However, parasites recrudesced by day 9. Dosing at 200 mg/kg/day twice a day resulted in cures of 3/5 animals. The compound had comparable activity against P. falciparum blood stages in a human-engrafted NOD-scid mouse model. Genz-668764 had a terminal half-life of 2.8 h and plasma trough levels of 41 ng/ml when it was dosed twice a day orally at 55 mg/kg/day. Seven-day rat safety studies showed a no-observable-adverse-effect level (NOAEL) at 200 mg/kg/day; the compound was not mutagenic in Ames tests, did not inhibit the hERG channel, and did not have potent activity against a broad panel of receptors and enzymes. Employing allometric scaling and using in vitro ADME data, the predicted human minimum efficacious dose of Genz-668764 in a 3-day once-daily dosing regimen was 421 mg/day/70 kg, which would maintain plasma trough levels above the IC?? against P. falciparum for at least 96 h after the last dose. The predicted human therapeutic index was approximately 3, on the basis of the exposure in rats at the NOAEL. We were unable to select for parasites with >2-fold decreased sensitivity to the parent compound, Genz-644442, over 270 days of in vitro culture under drug pressure. These characteristics make Genz-668764 a good candidate for preclinical development.
Project description:Genetically engineered T cells expressing a chimeric antigen receptor (CAR) are rapidly emerging a promising new treatment for haematological and non-haematological malignancies. CAR-T therapy can induce rapid and durable clinical responses but is associated with unique acute toxicities. Moreover, CAR-T cells are vulnerable to immunosuppressive mechanisms. Here, we report that CAR-T cells release extracellular vesicles, mostly in the form of exosomes that carry CAR on their surface. The CAR-containing exosomes express a high level of cytotoxic molecules and inhibit tumour growth. Compared with CAR-T cells, CAR exosomes do not express Programmed cell Death protein 1 (PD1), and their antitumour effect cannot be weakened by recombinant PD-L1 treatment. In a preclinical in vivo model of cytokine release syndrome, the administration of CAR exosomes is relatively safe compared with CAR-T therapy. This study supports the use of exosomes as biomimetic nanovesicles that may be useful in future therapeutic approaches against tumours.