scholarly journals Aged CAR T Cells Exhibit Enhanced Cytotoxicity and Effector Function but Shorter Persistence and Less Memory-like Phenotypes

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2047-2047 ◽  
Author(s):  
Hiroshi Kotani ◽  
Gongbo Li ◽  
Jiqiang Yao ◽  
Tania E. Mesa ◽  
Jon Chen ◽  
...  

Abstract [Introduction] CD19 chimeric antigen receptor (CAR) T cell therapies have been approved by the FDA for children and young adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL) and adults with r/r large B-cell lymphoma. Recent reports about long-term follow-up of CD19 CAR T cell therapy in B-ALL (Maude et. al. NEJM 2018, Park et. al. NEJM 2018) suggest that the median event-free survival of children and young adult patients is longer than that of adult patients (Over 11 months versus 6.1 months). The reason for the difference between survival of pediatric and adult patient is unclear, but we hypothesize it is due to age-related changes in the T cells collected from patients. Therefore, we compared the function of CAR T cells derived from young or aged mice. [Methods] Young C57BL/6J (B6) mice (6-12 weeks) and aged B6 mice (³ 72 weeks) were used as donors for CAR T cell preparation. Four types of mouse specific CD19 CAR encoded GFP fusion proteins were evaluated with all having the same anti-CD19 scFv and CD8 hinge and transmembrane domains but differing in their intracellular domain (m19Δz: lacks the CD3ξ signaling domain, m19z: CD3ξ signaling domain only, m1928z: CD28 and CD3ξ signaling domains, m19-humBBz: 4-1BB and CD3ξ signaling domains). [Results] T cells isolated from the spleen of aged B6 mice were significantly fewer than those of young B6 mice. However, CAR transduction efficiency, viability and yield were similar between young and aged CAR T cells for each CAR group. All groups of aged CAR T cells predominate with CD8+ and effector-like phenotypes at the expense of CD4+ and memory-like phenotypes after CD19+ artificial antigen presenting cell (aAPC) stimulation (Fig. 1A-1B). Furthermore, compared to CAR T cells derived from young mice, aged CAR T cells (m19z, m1928z and m19BBz) exhibited superior cytotoxicity in a real-time cell analysis for CD19+ aAPC killing (Fig. 1C). Using our immune competent in vivo murine model, aged CAR T cells were short-lived and expanded poorly despite their superior in vitro cytotoxicity. To evaluate for potential mechanisms involving preferential production of effector-like CAR T cells from aged mice we performed gene-expression, as well as single cell secretory polyfunctional analyses. While the polyfunctional strength index (PSI) of CD8+ aged CAR T cells was higher for aged CAR T cells, the increased score was due mostly to abundant secretion of a chemokine (Fig. 1D). Furthermore, the RNA-DESeq analysis demonstrated increased expression of chemokines and perturbation of the EOMES/TBET transcription factor axis. RNA-DESeq also suggested that young CAR T cells were highly active in cell proliferation and cell differentiation whereas aged CAR T cells upregulated gene expression pathways that regulated responses to stimulus and exocytosis. [Conclusions] CAR T cells derived from aged mice exhibited enhanced cytotoxicity but shorter persistence and less memory-like phenotypes. Our results suggest that the difference of clinical outcome between younger patients and older patients may be due to an age-dependent CAR T cell phenotype that is reflected by its unique gene expression pattern, secretory profile, and/or transcription factor balance. In our future directions we are extending these observations to human CAR T cells and identifying potential methods to improve the function of aged CAR T cells. Disclosures Davila: Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees.

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A152-A153
Author(s):  
Shihong Zhang ◽  
Karan Kohli ◽  
R Graeme Black ◽  
Brian Hayes ◽  
Cassandra Miller ◽  
...  

BackgroundChimeric antigen receptor (CAR) T cell therapy has transformed therapy for hematological malignancies but has not yet been established as standard of care for any solid tumors. One obstacle for human solid tumor immunotherapy research is the lack of clinically relevant, immunocompetent animal models. In this study, we sought to establish CAR T cells for naturally occurring canine sarcomas in client owned animals as a model for human CAR T cell therapy.MethodsArchived FFPE, freshly isolated canine solid tumor samples as well as tumor lines were tested for B7H3 expression by immunohistochemistry (IHC) and flow cytometry analysis. We designed CARs using the scFv from the human B7H3-specific antibody MGA271 and confirmed the cross-reactivity to canine B7H3 (construct information see figure 1A). A truncated EGFR (tEGFR) was included in the construct to allow for IHC and flow cytometry testing for the presence of CAR T cells. Killing efficiency was evaluated using 3D tumor spheroid killing assays to monitor dynamics. Safety of the CAR products following lymphodepletion was confirmed in two healthy dogs (figure 1B).ResultsCanine solid tumors were confirmed to be B7H3 positive in almost all cases. Using the GALV-pseudotyped retrovirus system, transduction was efficient with up to 70% CAR+ cells. Post-transduction expansion was over 100 folds. B7H3 CAR transduced canine T cells were able to eliminate B7H3+ canine tumor spheroids effectively (figure 2). Safety of the CAR T cells (dose: 1 × 109/m2) were confirmed in both healthy animals following cyclophosphamide lymphodepletion. After week 6, cetuximab was given to the subjects to deplete EGFR+ cells. Subject 2 experienced fever after CAR T cell administration. Both dogs showed elevated serum ALP and ALT levels and returned to normal (figure 3). No other treatment-related adverse events were observed. Information of the CAR T cell products can be found in table 1.Abstract 139 Figure 1Construct information and safety trial design(A) Four 2nd generation CAR constructs were generated. Two B7H3 CARs were candidates for the treatment, and two HER2 CARs served as controls, as they have been shown to kill canine cancer cells. The CARs are consisted of a single chain variable fragment (scFv, either B7H3-specific MGA271 or HER2-specific FRP5), a short hinge, a transmembrane domain (tm), a canine costimulatory signaling domain (either canine CD28 or 4-1BB) and canine CD3? signaling domain. Truncated EGFR is added in the construct for CAR+ T cell detection and facilitate the depletion of CAR T cells in vivo as a safety measure. (B) Blood from the subjects were drawn 3 weeks prior to the treatment for CAR T cell production. Cyclophosphamide (Cy, 400 mg/m2) and Fludarabine (Flu, 10 mg/m2) were given to the subjects for 2 days for lymphodepletion. CAR T cells (1 × 109/m2) and cetuximab (200 mg/m2) were given to the subjects as indicated. Blood, lymph node (LN) and bone marrow (BM) aspirates were collected for CAR T cell homing and persistence analysisAbstract 139 Figure 2Killing of canine OSA spheroids by canine CAR T ce(A) Scheme of tumor cell spheroid forming and killing. The loss of GFP can be measured for cytotoxicity readout (B) FRP5 and MGA271 CAR T cells can effectively kill canine cancer spheroids. Experiments were done in triplicates and error bars indicate SDAbstract 139 Figure 3Dynamics of peripheral lymphocytes, serum ALP and Current treatment regimen effectively decreased peripheral lymphocytes number after cyclophosphamide and fludarabine administration (D-4 and D-3) and increased serum ALP and ALT level after CAR T cell infusion (D0). Dashed line in both graphs show the upper limit of ALP and ALT levels, which are both 68U/LAbstract 139 Table 1Infused CAR T cell product informationBoth subjects are adult male beagle mixConclusionsWe demonstrated that, similar to human cancers, B7H3 is a target in canine solid tumors. We successfully generated canine B7H3 specific CAR T cell products that are highly efficient at killing canine 3D tumor spheroids using a production protocol that closely models human CAR T cell production procedure and confirmed the safety in vivo. We plan to test and optimize various approaches to enhance CAR T cell efficacy for solid tumor treatment both in vitro and in canine sarcoma patients.Ethics ApprovalThe study was approved by Fred Hutchinson Cancer Research Center‘s Institutional Animal Care and Use Committee (IACUC), approval number PROTO201900860


2021 ◽  
Vol 12 ◽  
Author(s):  
Camilla M. Grunewald ◽  
Corinna Haist ◽  
Carolin König ◽  
Patrick Petzsch ◽  
Arthur Bister ◽  
...  

BackgroundTreatment of B-cell malignancies with CD19-directed chimeric antigen receptor (CAR) T-cells marked a new era in immunotherapy, which yet has to be successfully adopted to solid cancers. Epigenetic inhibitors of DNA methyltransferases (DNMTi) and histone deacetylases (HDACi) can induce broad changes in gene expression of malignant cells, thus making these inhibitors interesting combination partners for immunotherapeutic approaches.MethodsUrothelial carcinoma cell lines (UCC) and benign uroepithelial HBLAK cells pretreated with the DNMTi decitabine or the HDACi romidepsin were co-incubated with CAR T-cells directed against EGFR or CD44v6, and subsequent cytotoxicity assays were performed. Effects on T-cell cytotoxicity and surface antigen expression on UCC were determined by flow cytometry. We also performed next-generation mRNA sequencing of inhibitor-treated UCC and siRNA-mediated knockdown of potential regulators of CAR T-cell killing.ResultsExposure to decitabine but not romidepsin enhanced CAR T-cell cytotoxicity towards all UCC lines, but not towards the benign HBLAK cells. Increased killing could neither be attributed to enhanced target antigen expression (EGFR and CD44v6) nor fully explained by changes in the T-cell ligands PD-L1, PD-L2, ICAM-1, or CD95. Instead, gene expression analysis suggested that regulators of cell survival and apoptosis were differentially induced by the treatment. Decitabine altered the balance between survival and apoptosis factors towards an apoptosis-sensitive state associated with increased CAR T-cell killing, while romidepsin, at least partially, tilted this balance in the opposite direction. Knockdown experiments with siRNA in UCC confirmed BID and BCL2L1/BCLX as two key factors for the altered susceptibility of the UCC.ConclusionOur data suggest that the combination of decitabine with CAR T-cell therapy is an attractive novel therapeutic approach to enhance tumor-specific killing of bladder cancer. Since BID and BCL2L1 are essential determinants for the susceptibility of a wide variety of malignant cells, their targeting might be additionally suitable for combination with immunotherapies, e.g., CAR T-cells or checkpoint inhibitors in other malignancies.


2021 ◽  
Author(s):  
Raphael B. Di Roberto ◽  
Rocio Castellanos-Rueda ◽  
Fabrice S. Schlatter ◽  
Darya Palianina ◽  
Oanh T.P. Nguyen ◽  
...  

Chimeric antigen receptors (CARs) consist of an extracellular antigen-binding region fused to intracellular signaling domains, thus enabling customized T cell responses against target cells. Due to the low-throughput process of systematically designing and functionally testing CARs, only a small set of immune signaling domains have been thoroughly explored, despite their major role in T cell activation, effector function and persistence. Here, we present speedingCARs, an integrated method for engineering CAR T cells by signaling domain shuffling and functional screening by single-cell sequencing. Leveraging the inherent modularity of natural signaling domains, we generated a diverse library of 180 unique CAR variants, which were genomically integrated into primary human T cells by CRISPR-Cas9. Functional and pooled screening of the CAR T cell library was performed by co-culture with tumor cells, followed by single-cell RNA sequencing (scRNA-seq) and single-cell CAR sequencing (scCAR-seq), thus enabling high-throughput profiling of multi-dimensional cellular responses. This led to the discovery of several CAR variants that retained the ability to kill tumor cells, while also displaying diverse transcriptional signatures and T cell phenotypes. In summary, speedingCARs substantially expands and characterizes the signaling domain combinations suited for CAR design and supports the engineering of next-generation T cell therapies.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nicola Tumino ◽  
Gerrit Weber ◽  
Francesca Besi ◽  
Francesca Del Bufalo ◽  
Valentina Bertaina ◽  
...  

AbstractThe outcome of patients affected by high-risk or metastatic neuroblastoma (NB) remains grim, with ≥ 50% of the children experiencing relapse or progression of the disease despite multimodal, intensive treatment. In order to identify new strategies to improve the overall survival and the quality of life of these children, we recently developed and optimized a third-generation GD2-specific chimeric antigen receptor (CAR) construct, which is currently under evaluation in our Institution in a phase I/II clinical trial (NCT03373097) enrolling patients with relapsed/refractory NB. We observed that our CAR T-cells are able to induce marked tumor reduction and even achieve complete remission with a higher efficiency than that of other CAR T-cells reported in previous studies. However, often responses are not sustained and relapses occur. Here, we demonstrate for the first time a mechanism of resistance to GD2.CAR T-cell treatment, showing how polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) increase in the peripheral blood (PB) of NB patients after GD2.CAR T-cell treatment in case of relapse and loss of response. In vitro, isolated PMN-MDSC demonstrate to inhibit the anti-tumor cytotoxicity of different generations of GD2.CAR T-cells. Gene-expression profiling of GD2.CAR T-cells “conditioned” with PMN-MDSC shows downregulation of genes involved in cell activation, signal transduction, inflammation and cytokine/chemokine secretion. Analysis of NB gene-expression dataset confirms a correlation between expression of these genes and patient outcome. Moreover, in patients treated with GD2.CAR T-cells, the frequency of circulating PMN-MDSC inversely correlates with the levels of GD2.CAR T-cells, resulting more elevated in patients who did not respond or lost response to the treatment. The presence and the frequency of PMN-MDSC in PB of high-risk and metastatic NB represents a useful prognostic marker to predict the response to GD2.CAR T-cells and other adoptive immunotherapy. This study underlines the importance of further optimization of both CAR T-cells and clinical trial in order to target elements of the tumor microenvironment.


2020 ◽  
Vol 14 (4) ◽  
pp. 312-323
Author(s):  
Romeo G. Mihăilă

Background: Patients with refractory or relapsed diffuse large B-cell lymphoma have a poor prognosis with the current standard of care. Objective: Chimeric Antigen Receptor T-cells (CAR T-cells) are functionally reprogrammed lymphocytes, which are able to recognize and kill tumor cells. The aim of this study is to make progress in this area. Method: A mini-review was achieved using the articles published in Web of Science and PubMed in the last year and the new patents were made in this field. Results: The responses to CAR T-cell products axicabtagene ciloleucel and tisagenlecleucel are promising; the objective response rate can reach up to 83%, and the complete response rate ranges between 40 and 58%. About half of the patients may have serious side effects, such as cytokine release syndrome and neurotoxicity. Current and future developments include the improvement of CAR T-cell expansion and polyfunctionality, the combined use of CAR T-cells with a fusion protein between interferon and an anti-CD20 monoclonal antibody, with checkpoint inhibitors or small molecule sensitizers that have apoptotic-regulatory effects. Furthermore, the use of IL-12-expressing CAR T-cells, an improved technology for the production of CAR T-cells based on targeted nucleases, the widespread use of allogeneic CAR T-cells or universal CAR T-cells obtained from genetically engineered healthy donor T-cells are future developments actively considered. Conclusion: CAR T-cell therapy significantly improved the outcome of patients with relapsed or refractory diffuse large B-cell lymphoma. The advances in CAR T-cells production technology will improve the results and enable the expansion of this new immunotherapy.


2021 ◽  
Vol 22 (5) ◽  
pp. 2476
Author(s):  
Kento Fujiwara ◽  
Masaki Kitaura ◽  
Ayaka Tsunei ◽  
Hotaka Kusabuka ◽  
Erika Ogaki ◽  
...  

T cells that are genetically engineered to express chimeric antigen receptor (CAR) have a strong potential to eliminate tumor cells, yet the CAR-T cells may also induce severe side effects due to an excessive immune response. Although optimization of the CAR structure is expected to improve the efficacy and toxicity of CAR-T cells, the relationship between CAR structure and CAR-T cell functions remains unclear. Here, we constructed second-generation CARs incorporating a signal transduction domain (STD) derived from CD3ζ and a 2nd STD derived from CD28, CD278, CD27, CD134, or CD137, and investigated the impact of the STD structure and signaling on CAR-T cell functions. Cytokine secretion of CAR-T cells was enhanced by 2nd STD signaling. T cells expressing CAR with CD278-STD or CD137-STD proliferated in an antigen-independent manner by their STD tonic signaling. CAR-T cells incorporating CD28-STD or CD278-STD between TMD and CD3ζ-STD showed higher cytotoxicity than first-generation CAR or second-generation CARs with other 2nd STDs. The potent cytotoxicity of these CAR-T cells was not affected by inhibiting the 2nd STD signals, but was eliminated by placing the STDs after the CD3ζ-STD. Our data highlighted that CAR activity was affected by STD structure as well as by 2nd STD signaling.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura Castelletti ◽  
Dannel Yeo ◽  
Nico van Zandwijk ◽  
John E. J. Rasko

AbstractMalignant mesothelioma (MM) is a treatment-resistant tumor originating in the mesothelial lining of the pleura or the abdominal cavity with very limited treatment options. More effective therapeutic approaches are urgently needed to improve the poor prognosis of MM patients. Chimeric Antigen Receptor (CAR) T cell therapy has emerged as a novel potential treatment for this incurable solid tumor. The tumor-associated antigen mesothelin (MSLN) is an attractive target for cell therapy in MM, as this antigen is expressed at high levels in the diseased pleura or peritoneum in the majority of MM patients and not (or very modestly) present in healthy tissues. Clinical trials using anti-MSLN CAR T cells in MM have shown that this potential therapeutic is relatively safe. However, efficacy remains modest, likely due to the MM tumor microenvironment (TME), which creates strong immunosuppressive conditions and thus reduces anti-MSLN CAR T cell tumor infiltration, efficacy and persistence. Various approaches to overcome these challenges are reviewed here. They include local (intratumoral) delivery of anti-MSLN CAR T cells, improved CAR design and co-stimulation, and measures to avoid T cell exhaustion. Combination therapies with checkpoint inhibitors as well as oncolytic viruses are also discussed. Preclinical studies have confirmed that increased efficacy of anti-MSLN CAR T cells is within reach and offer hope that this form of cellular immunotherapy may soon improve the prognosis of MM patients.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2941
Author(s):  
Luciana R. C. Barros ◽  
Emanuelle A. Paixão ◽  
Andrea M. P. Valli ◽  
Gustavo T. Naozuka ◽  
Artur C. Fassoni ◽  
...  

Immunotherapy has gained great momentum with chimeric antigen receptor T cell (CAR-T) therapy, in which patient’s T lymphocytes are genetically manipulated to recognize tumor-specific antigens, increasing tumor elimination efficiency. In recent years, CAR-T cell immunotherapy for hematological malignancies achieved a great response rate in patients and is a very promising therapy for several other malignancies. Each new CAR design requires a preclinical proof-of-concept experiment using immunodeficient mouse models. The absence of a functional immune system in these mice makes them simple and suitable for use as mathematical models. In this work, we develop a three-population mathematical model to describe tumor response to CAR-T cell immunotherapy in immunodeficient mouse models, encompassing interactions between a non-solid tumor and CAR-T cells (effector and long-term memory). We account for several phenomena, such as tumor-induced immunosuppression, memory pool formation, and conversion of memory into effector CAR-T cells in the presence of new tumor cells. Individual donor and tumor specificities are considered uncertainties in the model parameters. Our model is able to reproduce several CAR-T cell immunotherapy scenarios, with different CAR receptors and tumor targets reported in the literature. We found that therapy effectiveness mostly depends on specific parameters such as the differentiation of effector to memory CAR-T cells, CAR-T cytotoxic capacity, tumor growth rate, and tumor-induced immunosuppression. In summary, our model can contribute to reducing and optimizing the number of in vivo experiments with in silico tests to select specific scenarios that could be tested in experimental research. Such an in silico laboratory is an easy-to-run open-source simulator, built on a Shiny R-based platform called CARTmath. It contains the results of this manuscript as examples and documentation. The developed model together with the CARTmath platform have potential use in assessing different CAR-T cell immunotherapy protocols and its associated efficacy, becoming an accessory for in silico trials.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 743
Author(s):  
Aleksei Titov ◽  
Ekaterina Zmievskaya ◽  
Irina Ganeeva ◽  
Aygul Valiullina ◽  
Alexey Petukhov ◽  
...  

Adoptive cell immunotherapy (ACT) is a vibrant field of cancer treatment that began progressive development in the 1980s. One of the most prominent and promising examples is chimeric antigen receptor (CAR) T-cell immunotherapy for the treatment of B-cell hematologic malignancies. Despite success in the treatment of B-cell lymphomas and leukemia, CAR T-cell therapy remains mostly ineffective for solid tumors. This is due to several reasons, such as the heterogeneity of the cellular composition in solid tumors, the need for directed migration and penetration of CAR T-cells against the pressure gradient in the tumor stroma, and the immunosuppressive microenvironment. To substantially improve the clinical efficacy of ACT against solid tumors, researchers might need to look closer into recent developments in the other branches of adoptive immunotherapy, both traditional and innovative. In this review, we describe the variety of adoptive cell therapies beyond CAR T-cell technology, i.e., exploitation of alternative cell sources with a high therapeutic potential against solid tumors (e.g., CAR M-cells) or aiming to be universal allogeneic (e.g., CAR NK-cells, γδ T-cells), tumor-infiltrating lymphocytes (TILs), and transgenic T-cell receptor (TCR) T-cell immunotherapies. In addition, we discuss the strategies for selection and validation of neoantigens to achieve efficiency and safety. We provide an overview of non-conventional TCRs and CARs, and address the problem of mispairing between the cognate and transgenic TCRs. Finally, we summarize existing and emerging approaches for manufacturing of the therapeutic cell products in traditional, semi-automated and fully automated Point-of-Care (PoC) systems.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1229
Author(s):  
Ali Hosseini Rad S. M. ◽  
Joshua Colin Halpin ◽  
Mojtaba Mollaei ◽  
Samuel W. J. Smith Bell ◽  
Nattiya Hirankarn ◽  
...  

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized adoptive cell therapy with impressive therapeutic outcomes of >80% complete remission (CR) rates in some haematological malignancies. Despite this, CAR T cell therapy for the treatment of solid tumours has invariably been unsuccessful in the clinic. Immunosuppressive factors and metabolic stresses in the tumour microenvironment (TME) result in the dysfunction and exhaustion of CAR T cells. A growing body of evidence demonstrates the importance of the mitochondrial and metabolic state of CAR T cells prior to infusion into patients. The different T cell subtypes utilise distinct metabolic pathways to fulfil their energy demands associated with their function. The reprogramming of CAR T cell metabolism is a viable approach to manufacture CAR T cells with superior antitumour functions and increased longevity, whilst also facilitating their adaptation to the nutrient restricted TME. This review discusses the mitochondrial and metabolic state of T cells, and describes the potential of the latest metabolic interventions to maximise CAR T cell efficacy for solid tumours.


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