scholarly journals Natural Flt3Lg-Based Chimeric Antigen Receptor (Flt3-CAR) T Cells Successfully Target Flt3 on AML Cell Lines

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1238
Author(s):  
Varvara Maiorova ◽  
Murad D. Mollaev ◽  
Polina Vikhreva ◽  
Elena Kulakovskaya ◽  
Dmitry Pershin ◽  
...  
Keyword(s):  
T Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Flt3 Ligand ◽  
Antitumor Effects ◽  
Car T Cells ◽  
Car T ◽  
Dependent Inhibition ◽  
Functional Equivalent

Relapsed/refractory acute myeloid leukemia (AML) cannot be cured with chemotherapy alone, as the blasts survive the treatment. Chimeric antigen receptor (CAR) approaches for AML are being actively developed. CARs promote immune reactions through recognition of the target molecular epitopes at the surface of cancer cells. The recognition involves the extracellular portion of the CAR protein, which corresponds to either the antibody or the physiological binding partner of the targeted antigen. Here, we design a chimeric receptor with a full-length natural Flt3-ligand recognition module that targets Flt3 tyrosine kinase, known as an adverse marker in AML. We demonstrate specific killing of Flt3-positive THP-1 cells by Flt3-CAR T cells and the lack of cytotoxicity towards Flt3-negative U937 cells. We prove that the inherent cytolytic capacity of T cells is essential for the killing. Finally, we confirm the authenticity of targeting by its competitive dose-dependent inhibition with a soluble Flt3-ligand. The developed system can be viewed as a non-immunogenic functional equivalent of scFv-mediated targeting. The robust in vitro antitumor effects of Flt3-CAR T cells, combined with their low off-target cytotoxicity, hold promise for AML treatment.

scholarly journals Evaluation of chimeric antigen receptor T cell therapy in non-human primates infected with SHIV or SIV

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248973
Author(s):  
Nami Iwamoto ◽  
Bhavik Patel ◽  
Kaimei Song ◽  
Rosemarie Mason ◽  
Sara Bolivar-Wagers ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Chimeric Antigen Receptor ◽  
Viral Suppression ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T

Achieving a functional cure is an important goal in the development of HIV therapy. Eliciting HIV-specific cellular immune responses has not been sufficient to achieve durable removal of HIV-infected cells due to the restriction on effective immune responses by mutation and establishment of latent reservoirs. Chimeric antigen receptor (CAR) T cells are an avenue to potentially develop more potent redirected cellular responses against infected T cells. We developed and tested a range of HIV- and SIV-specific chimeric antigen receptor (CAR) T cell reagents based on Env-binding proteins. In general, SHIV/SIV CAR T cells showed potent viral suppression in vitro, and adding additional CAR molecules in the same transduction resulted in more potent viral suppression than single CAR transduction. Importantly, the primary determinant of virus suppression potency by CAR was the accessibility to the Env epitope, and not the neutralization potency of the binding moiety. However, upon transduction of autologous T cells followed by infusion in vivo, none of these CAR T cells impacted either acquisition as a test of prevention, or viremia as a test of treatment. Our study illustrates limitations of the CAR T cells as possible antiviral therapeutics.

scholarly journals HIV-1-Specific Chimeric Antigen Receptor T Cells Fail To Recognize and Eliminate the Follicular Dendritic Cell HIV Reservoir In Vitro

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Matthew T. Ollerton ◽  
Edward A. Berger ◽  
Elizabeth Connick ◽  
Gregory F. Burton
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Follicular Dendritic

ABSTRACT The major obstacle to a cure for HIV infection is the persistence of replication-competent viral reservoirs during antiretroviral therapy. HIV-specific chimeric antigen receptor (CAR) T cells have been developed to target latently infected CD4+ T cells that express virus either spontaneously or after intentional latency reversal. Whether HIV-specific CAR-T cells can recognize and eliminate the follicular dendritic cell (FDC) reservoir of HIV-bound immune complexes (ICs) is unknown. We created HIV-specific CAR-T cells using human peripheral blood mononuclear cells (PBMCs) and a CAR construct that enables the expression of CD4 (domains 1 and 2) and the carbohydrate recognition domain of mannose binding lectin (MBL) to target native HIV Env (CD4-MBL CAR). We assessed CAR-T cell cytotoxicity using a carboxyfluorescein succinimidyl ester (CFSE) release assay and evaluated CAR-T cell activation through interferon gamma (IFN-γ) production and CD107a membrane accumulation by flow cytometry. CD4-MBL CAR-T cells displayed potent lytic and functional responses to Env-expressing cell lines and HIV-infected CD4+ T cells but were ineffective at targeting FDC bearing HIV-ICs. CD4-MBL CAR-T cells were unresponsive to cell-free HIV or concentrated, immobilized HIV-ICs in cell-free experiments. Blocking intercellular adhesion molecule-1 (ICAM-1) inhibited the cytolytic response of CD4-MBL CAR-T cells to Env-expressing cell lines and HIV-infected CD4+ T cells, suggesting that factors such as adhesion molecules are necessary for the stabilization of the CAR-Env interaction to elicit a cytotoxic response. Thus, CD4-MBL CAR-T cells are unable to eliminate the FDC-associated HIV reservoir, and alternative strategies to eradicate this reservoir must be sought. IMPORTANCE Efforts to cure HIV infection have focused primarily on the elimination of latently infected CD4+ T cells. Few studies have addressed the unique reservoir of infectious HIV that exists on follicular dendritic cells (FDCs), persists in vivo during antiretroviral therapy, and likely contributes to viral rebound upon cessation of antiretroviral therapy. We assessed the efficacy of a novel HIV-specific chimeric antigen receptor (CAR) T cell to target both HIV-infected CD4+ T cells and the FDC reservoir in vitro. Although CAR-T cells eliminated CD4+ T cells that express HIV, they did not respond to or eliminate FDC bound to HIV. These findings reveal a fundamental limitation to CAR-T cell therapy to eradicate HIV.

scholarly journals CRISPR-mediated insertion of a chimeric antigen receptor produces nonviral T cell products capable of inducing solid tumor regression

2021 ◽  
Author(s):  
Katherine Mueller ◽  
Nicole Piscopo ◽  
Matthew Forsberg ◽  
Louise Saraspe ◽  
Amritava Das ◽  
...  
Keyword(s):  
T Cells ◽  
Chimeric Antigen Receptor ◽  
Viral Vectors ◽  
Viral Vector ◽  
Tumor Regression ◽  
Antigen Receptor ◽  
Car T Cells ◽  
Car T

Chimeric antigen receptor (CAR) T cells traditionally harbor viral vectors that encode the CAR transgene in the genome. However, viral vector manufacturing typically is resource intensive, suffers from batch-to-batch variability, and includes several animal components, adding regulatory and supply chain pressures. Here, CAR T cells were generated within nine days using recombinant SpCas9 protein and nucleic acids, without any viral vectors or animal components. In comparison to traditional retroviral CAR T cells, nonviral CRISPR CAR T cells exhibit TRAC-targeted genomic integration of the CAR transgene, higher frequency of gene expression signatures associated with a memory phenotype, low receptor signaling prior to infusion, and potent cytotoxicity against GD2+ neuroblastoma in vitro and in vivo. This proof-of-principle study eliminating viral vectors and animal components during CAR gene transfer could enable more flexible and scalable manufacturing of clinically-relevant, high-quality CAR T cells to treat cancers, including solid tumors.

scholarly journals Chimeric antigen receptor T (CAR-T) cells expanded with IL-7/IL-15 mediate superior antitumor effects

2019 ◽  
Vol 10 (10) ◽  
pp. 764-769 ◽  
Author(s):  
Jianxia Zhou ◽  
Liyuan Jin ◽  
Fuping Wang ◽  
Yuan Zhang ◽  
Bing Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Antitumor Effects ◽  
Car T Cells ◽  
Car T

scholarly journals Characterization of novel dual tandem CD19/BCMA chimeric antigen receptor T cells to potentially treat multiple myeloma

2020 ◽  
Author(s):  
Liqing Kang ◽  
Jian Zhang ◽  
Minghao Li ◽  
Nan Xu ◽  
Wei Qi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Tumor Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Cytokine Release ◽  
Car T Cells ◽  
Car T

Abstract Background: Treatment with chimeric antigen receptor (CAR)-engineered T cells directed against the B-cell maturation antigen (BCMA) promoted transient recovery from multiple myeloma (MM). However, the absence of this antigen on immature plasma cells may limit the efficacy of this modality and facilitate relapse. The purpose of this study is to characterize a novel CAR that includes both a single-chain variable fragment (scFv)-BCMA and an scFv-CD19 in tandem orientation (tan-CAR) in an attempt to target both BCMA and CD19 expression on MM cells. Method: The scFv sequences from the anti-CD19 antibody FMC63 and the anti-BCMA antibody C11D5.3 were ligated in tandem with transmembrane and T-cell signaling domains to generate the tan-CAR construct. Specificity and efficacy of activated tan-CAR T cells were analyzed using in vitro proliferation, cytokine release, and cytolysis assays. We also evaluated the in vivo efficacy with a xenograft mouse model that included target tumor cells that expressed CD19 or BCMA and compared the results to those obtained with conventional CAR T cells. Results: The in vitro studies revealed specific activation of tan-CAR T cells by K562 cells that overexpressed CD19 and/or BCMA. Cell proliferation, cytokine release, and cytolytic activity were all comparable to the responses of single scFv CAR T cells. Importantly, in vivo studies of tan-CAR T cells revealed specific inhibition of tumor growth in the mouse xenograft model that included cells expressing both CD19 and BCMA. Systemic administration of tan-CAR T cells resulted in complete tumor remission, in contrast to the reduced efficacies of BCMA-CAR T and CD19-CAR T alone in this setting. Conclusion: We report the successful design and execution of novel tan-CAR T cells that promote significant anti-tumor efficacy against both CD19 and BCMA antigen-positive tumor cells in vitro and in vivo . The data from this study reveal a novel strategy that may help to reduce the rate of relapse in the treatment with single scFv-CAR T cells.

scholarly journals CAR T Cells Equipped With a Fully Human scFv Targeting Trop2 Can Be Used to Treat Pancreatic Cancer

2021 ◽  
Author(s):  
Hong Jia Zhu ◽  
Yujie Jia ◽  
Jingwen Tan ◽  
Xiaoyan Fang ◽  
Jing Ye ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
T Cells ◽  
Cancer Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Car T Cells ◽  
Pancreatic Cancer Cells ◽  
Car T

Abstract Purpose: Chimeric antigen receptor (CAR) T cell therapy has demonstrated clinical success in treating haematologic malignancies but has not been effective against solid tumours thus far. Trop2 is a tumour-related antigen broadly overexpressed on a variety of tumours and has been reported as a promising target for pancreatic cancers. Our study aimed to determine whether CAR T cells designed with a fully human Trop2-specific single-chain fragment variable (scFv) can be used in the treatment of Trop2-positive pancreatic tumours.Methods: We designed Trop2-targeted chimeric antigen receptor engineered T cells with a novel human anti-Trop2 scFv (2F11) and then investigated the cytotoxicity, degranulation, and cytokine secretion profiles of the anti-Trop2 CAR T cells when they were exposed to Trop2+ cancer cells in vitro. We also studied the antitumour efficacy and toxicity of Trop2-specific CAR T cells in vivo using a BxPC-3 pancreatic xenograft model.Results: Trop2-targeted CAR T cells designed with 2F11 effectively killed Trop2-positive pancreatic cancer cells and produced high levels of cytotoxic cytokines in vitro. In addition, Trop2-targeted CAR T cells, which persistently circulate in vivo and efficiently infiltrate into tumour tissues, significantly blocked and even eliminated BxPC-3 pancreatic xenograft tumour growth without obvious deleterious effects observed after intravenous injection into NSG mice. Moreover, disease-free survival was efficiently prolonged.Conclusion: These results show that Trop2-targeted CAR T cells equipped with a fully human anti-Trop2 scFv could be a potential treatment strategy for pancreatic cancer and could be useful for clinical evaluation.

Synergistic Antitumor Effects of Chimeric Antigen Receptor-Modified T Cells and Oncolytic Virotherapy

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5808-5808 ◽  
Author(s):  
Xingbing Wang ◽  
Stephen Gottschalk ◽  
Xiao-Tong Song
Keyword(s):  
T Cells ◽  
Vaccinia Virus ◽  
Tumor Cells ◽  
Chimeric Antigen Receptor ◽  
Conflicts Of Interest ◽  
Synergistic Effects ◽  
Antigen Receptor ◽  
Antitumor Effects ◽  
Car T Cells ◽  
Car T

Abstract Oncolytic vaccinia virus (VV) therapy has shown promise in preclinical models and in clinical studies. However their use has been limited by constraints on delivery and effective tumor targeting. The combination of VV therapy with Chimeric Antigen Receptor-modified T cells (CAR-T cells) might overcome these limitations, since CAR-T cells can direct VV to the tumors. In our previous studies, we have developed a novel T-cell Engager Armed Vaccinia Virus (TEA-VVs) strategy that expresses secretory bispecific antibodies that bind both to CD3 and a tumor cell surface antigen EphA2. We demonstrated that EphA2-TEA-VV displays significantly enhanced antitumor activity by inducing bystander killing of tumor cells that are not infected with virus, compared to non-modified VV. In this study, we aimed to evaluate the efficacy of combination therapy of HER2-CAR-T cells with EphA2-TEA-VV. This combinational therapy should exerts its anti-tumor activity through three mechanisms: i) HER2-CAR-T cells recognize and lyse HER2-positive tumor cells, ii) VV infect, replicate in, and lyse tumor cells, and iii) bi-specific antibody expressed by EphA2-TEA-VV directs T cells to recognize EphA2 and kill tumor cells, overcoming tumor heterogeneity. In our preliminary studies, we demonstrated that EphA2-TEA-VV can effectively infect and replicated in HER2-CAR-T cells. In coculture assays, preinfectin of HER2-CAR-T cells with EphA2-TEA-VV resulted in strongly enhanced killing of HER2+EphA2+ A549 tumor cells. These results illustrate the potential of combining CAR-T cells and TEA-VV for synergistic effects that more effectively treat cancer.  Disclosures No relevant conflicts of interest to declare.

scholarly journals Engineering T cells with hypoxia-inducible chimeric antigen receptor (HiCAR) for selective tumor killing

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Qibin Liao ◽  
Huan He ◽  
Yunyu Mao ◽  
Xiangqing Ding ◽  
Xiaoyan Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
Solid Tumors ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Normal Tissues ◽  
Car T Cells ◽  
Car T ◽  
Tumor Killing

Abstract Chimeric antigen receptor-modified T cells (CAR-T cells) have shown good effects in the treatment of hematologic cancers; however, they may cause on-target off-tumor toxicity because of minimal expression of tumor-associated antigens (TAAs) on normal tissues, particularly in the context of treating solid tumors. Hypoxia is a common hallmark of solid tumors because of the Warburg effect. To minimize side effects, we designed a hypoxia-inducible CAR (HiCAR), which is driven by a hypoxia response element (HRE), and consists of a conventional CAR and an oxygen-dependent degradation domain (ODD) that is actively degraded under normoxia but stabilized under hypoxia. HiCAR-T cells showed enhanced cytotoxicity against tumor cells under hypoxia compared to normoxia in vitro and antitumor efficacy comparable to that of conventional CAR-T cells in vivo. Overall, our study demonstrates the potential of the HiCAR for improving the safety of CAR-T cells to promote the clinical application of CAR-T immunotherapy.

scholarly journals Chlorotoxin Redirects Chimeric Antigen Receptor T Cells for Specific and Effective Targeting of Glioblastoma

2020 ◽  
Author(s):  
Dongrui Wang ◽  
Renate Starr ◽  
Wen-Chung Chang ◽  
Brenda Aguilar ◽  
Darya Alizadeh ◽  
...  
Keyword(s):  
T Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Matrix Metalloproteinase 2 ◽  
Cell Surface Expression ◽  
Binding Potential ◽  
Car T Cells ◽  
Car T

AbstractWhile chimeric antigen receptor (CAR) T cells have demonstrated antitumor activity against glioblastoma (GBM), tumor heterogeneity remains a critical challenge. To more effectively target heterogeneous GBMs, we report the development of a novel peptide-based CAR exploiting the GBM-binding potential of chlorotoxin (CLTX). CLTX bound a greater proportion of tumor cells than GBM-associated antigens EGFR, HER2 and IL13Rα2. CAR T cells bearing CLTX as the targeting domain (CLTX-CAR), mediated potent in vitro and in vivo anti-GBM activity, and efficiently targeted tumors lacking expression of other GBM-associated antigens. Importantly, CLTX-CAR T cells exhibited no observable off-target effector activity against normal cells, or when adoptively transferred into mice. Effective targeting by CLTX-CAR T cells required cell surface expression of matrix metalloproteinase-2 (MMP-2). Our results are the first demonstration of a peptide toxin utilized as a CAR targeting domain, expanding the repertoire of tumor-selective CAR T cells with the potential to reduce antigen escape.One Sentence SummaryChimeric antigen receptors incorporating chlorotoxin as the tumor targeting domain recognize and kill glioblastoma with high specificity and potency.

Sign in / Sign up

Export Citation Format

Share Document