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 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.

Chimeric Antigen Receptor T Cell Immunotherapy for Tumor: A Review of Patent Literatures

2019 ◽  
Vol 14 (1) ◽  
pp. 60-69
Author(s):  
Manxue Fu ◽  
Liling Tang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Limiting Factors ◽  
Car T Cells ◽  
Car T Cell ◽  
Cell Immunotherapy ◽  
Car T ◽  
T Cell Immunotherapy

Background: Chimeric Antigen Receptor (CAR) T cell immunotherapy, as an innovative method for tumor immunotherapy, acquires unprecedented clinical outcomes. Genetic modification not only provides T cells with the antigen-binding function but also endows T cells with better immunological functions both in solid and hematological cancer. However, the CAR T cell therapy is not perfect because of several reasons, such as tumor immune microenvironment, and autologous limiting factors of CAR T cells. Moreover, the safety of CAR T cells should be improved.Objective:Recently many patents and publications have reported the importance of CAR T cell immunotherapy. Based on the patents about CAR T cell immunotherapy, we conclude some methods for designing the CAR which can provide information to readers.Methods:In this review, we collect recent patents and publications, summarize some specific antigens for oncotherapy from patents and enumerate some approaches to conquering immunosuppression and reinforcing the immune response of CAR T cells. We also sum up some strategies for improving the safety of CAR T cell immunotherapy.Results:CAR T cell immunotherapy as a neotype cellular immunotherapy has been proved effective in oncotherapy and authorized by FDA. Improvements in CAR designing enhance functions of CAR T cells.Conclusion:This review, summarizing antigens and approaches to overcome defects of CAR T cell immunotherapy from patents and publications, might contribute to a broad readership.

scholarly journals Chimeric Antigen Receptor T Cell Exhaustion during Treatment for Hematological Malignancies

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chunyi Shen ◽  
Zhen Zhang ◽  
Yi Zhang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Hematological Malignancies ◽  
Antigen Receptor ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Immunotherapy, especially based on chimeric antigen receptor (CAR) T cells, has achieved prominent success in the treatment of hematological malignancies. However, approximately 30-50% of patients will have disease relapse following remission after receiving CD19-targeting CAR-T cells, with failure of maintaining a long-term effect. Mechanisms underlying CAR-T therapy inefficiency consist of loss or modulation of target antigen and CAR-T cell poor persistence which mostly results from T cell exhaustion. The unique features and restoration strategies of exhausted T cells (Tex) have been well described in solid tumors. However, the overview associated with CAR-T cell exhaustion is relatively rare in hematological malignancies. In this review, we summarize the characteristics, cellular, and molecular mechanisms of Tex cells as well as approaches to reverse CAR-T cell exhaustion in hematological malignancies, providing novel strategies for immunotherapies.

scholarly journals Clinical Development and Manufacture of Chimeric Antigen Receptor T cells and the Role of Leukapheresis

2017 ◽  
Vol 13 (01) ◽  
pp. 28 ◽  
Author(s):  
Andrew Fesnak ◽  
Una O’Doherty ◽  
◽  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Large Scale ◽  
Mononuclear Cells ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Adoptive transfer of chimeric antigen receptor (CAR) T cells is a powerful targeted immunotherapeutic technique. CAR T cells are manufactured by harvesting mononuclear cells, typically via leukapheresis from a patient’s blood, then activating, modifying the T cells to express a transgene encoding a tumour-specific CAR, and infusing the CAR T cells into the patient. Gene transfer is achieved through the use of retroviral or lentiviral vectors, although non-viral delivery systems are being investigated. This article discusses the challenges associated with each stage of this process. Despite the need for a consistent end product, there is inherent variability in cellular material obtained from critically ill patients who have been exposed to cytotoxic therapy. It is important to carefully select target antigens to maximise effect and minimise toxicity. Various types of CAR T cell toxicity have been documented: this includes “on target, on tumour”, “on target, off tumour” and “off target” toxicity. A growing body of clinical evidence supports the efficacy and safety of CAR T cell therapy; CAR T cells targeting CD19 in B cell leukemias are the best-studied therapy to date. However, providing personalised therapy on a large scale remains challenging; a future aim is to produce a universal “off the shelf” CAR T cell.

scholarly journals The roles of T cell competition and stochastic extinction events in chimeric antigen receptor T cell therapy

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Gregory J. Kimmel ◽  
Frederick L. Locke ◽  
Philipp M. Altrock
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Chimeric antigen receptor (CAR) T cell therapy is a remarkably effective immunotherapy that relies on in vivo expansion of engineered CAR T cells, after lymphodepletion (LD) by chemotherapy. The quantitative laws underlying this expansion and subsequent tumour eradication remain unknown. We develop a mathematical model of T cell–tumour cell interactions and demonstrate that expansion can be explained by immune reconstitution dynamics after LD and competition among T cells. CAR T cells rapidly grow and engage tumour cells but experience an emerging growth rate disadvantage compared to normal T cells. Since tumour eradication is deterministically unstable in our model, we define cure as a stochastic event, which, even when likely, can occur at variable times. However, we show that variability in timing is largely determined by patient variability. While cure events impacted by these fluctuations occur early and are narrowly distributed, progression events occur late and are more widely distributed in time. We parameterized our model using population-level CAR T cell and tumour data over time and compare our predictions with progression-free survival rates. We find that therapy could be improved by optimizing the tumour-killing rate and the CAR T cells' ability to adapt, as quantified by their carrying capacity. Our tumour extinction model can be leveraged to examine why therapy works in some patients but not others, and to better understand the interplay of deterministic and stochastic effects on outcomes. For example, our model implies that LD before a second CAR T injection is necessary.

scholarly journals Development of molecular and pharmacological switches for chimeric antigen receptor T cells

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Bill X. Wu ◽  
No-Joon Song ◽  
Brian P. Riesenberg ◽  
Zihai Li
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Intervention Strategy ◽  
Antigen Receptor ◽  
Cytokine Release ◽  
Cytokine Release Syndrome ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract The use of chimeric antigen receptor (CAR) T cell technology as a therapeutic strategy for the treatment blood-born human cancers has delivered outstanding clinical efficacy. However, this treatment modality can also be associated with serious adverse events in the form of cytokine release syndrome. While several avenues are being pursued to limit the off-target effects, it is critically important that any intervention strategy has minimal consequences on long term efficacy. A recent study published in Science Translational Medicine by Dr. Hudecek’s group proved that dasatinib, a tyrosine kinase inhibitor, can serve as an on/off switch for CD19-CAR-T cells in preclinical models by limiting toxicities while maintaining therapeutic efficacy. In this editorial, we discuss the recent strategies for generating safer CAR-T cells, and also important questions surrounding the use of dasatinib for emergency intervention of CAR-T cell mediated cytokine release syndrome.

136 Targeting MET with chimeric antigen receptor T cells in hepatocellular carcinoma

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A149-A149
Author(s):  
Yuan Qin ◽  
Anna Qin ◽  
Anna Musket ◽  
Joseph Lee ◽  
Zhi Yao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Confocal Imaging ◽  
Dependent Manner ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

BackgroundHepatocellular carcinoma (HCC) is the leading cause of cancer mortality worldwide. While HBV/HCV infection is the primary cause of HCC, overexpression of MET, the receptor of hepatocyte growth factor (HGF), occurs in 50% HCC patients, and is an indicator of poor prognosis. Although the multi-target MET tyrosine kinase inhibitor cabozantinib is FDA approved for treating advanced HCC, the long-term efficacy versus toxicity remains unknown. Our study is to develop specific MET-targeting chimeric antigen receptor T (CAR-T) cells for treating HCC with MET overexpression.MethodsBased on a well-established anti-MET monoclonal antibody, we synthesized and cloned the single-chain variable fragment (ScFv) sequence into two retroviral based 2nd generation CAR vectors (MET-CAR.CD28.ζ. and MET-CAR.4-1BB.ζ.). A MET-CAR without CD3ζ domain (MET-CARΔ) served as a negative control. To produce MET-CAR-T cells, healthy PBMCs were stimulated with anti-CD3/CD28 antibodies in the presence of IL-7/IL-15 followed by transduction with MET-CAR viral particles. T cell transduction efficacy was determined using flow cytometry. HCC cell lines with variable MET expression from high/positive (MHCC97H, C3A, and JHH5) to MET low/negative (SNU398) were used to determine MET-specific CAR T cells specificity and effector function using MTS assay. We also collected media from the tumor-T cell co-cultures and determined IL-2 and IFNγ secretion using ELISA. Finally, real-time confocal imaging (24 h) was performed to record the progress of MET-CAR T cell mediated killing activity against MHCC97H/mCherry cells.ResultsWe show that both MET-CAR.CD28.ζ and MET-CAR.4-1BB.ζ -T cells significantly killed MHCC97H, C3A, and JHH5 cells in antigen dependent manner. MET-CAR T cell killing is MET dependent as we observed no killing of MET-negative SNU398 cells. In addition, MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells secreted IL-2 and IFNγ when co-cultured with MHCC97H, C3A, JHH5 cells, but not SNU398. Confocal imaging studies showed that both MET-specific CAR T cells migrated toward MHCC97H/mCherry cells, formed aggregations, and induced tumor cell death, while MET-CARΔ T cells failed to do so.ConclusionsHere we demonstrate that MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells specifically recognize and kill MET-positive HCC cells in vitro. While animal studies are required to validate the efficacy in vivo, our study has produced a novel therapeutic CAR T cell target for treating malignant HCC and other type of cancers with MET overexpression.AcknowledgementsThis independent research was supported by the Gilead Sciences Research Scholars Program in Liver Disease- The Americas, and Department of Defense (DoD) Ideal Award (to QX)Ethics ApprovalThe study was approved by East Tennessee State University’s Ethics Board, approval number #0619.3s.

scholarly journals A CAR RNA FISH assay reveals functional and spatial heterogeneity of chimeric antigen receptor T cells in tissue

2020 ◽  
Author(s):  
Karsten Eichholz ◽  
Alvason Zhenhua Li ◽  
Kurt Diem ◽  
Semih U. Tareen ◽  
Michael C. Jensen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Car T Cells ◽  
Car T Cell ◽  
Rna Fish ◽  
Car T

AbstractChimeric antigen receptor (CAR) T cells are engineered cells used in cancer therapy and are studied to treat infectious diseases. Trafficking and persistence of CAR T cells is an important requirement for efficacy to target cancer and HIV sanctuary sites. Here, we describe a CAR RNA FISH histocytometry platform combined with a dnnRRS image analysis algorithm to quantitate spatial distribution and in vivo functional ability of a CAR T cell population at a single cell resolution. In situ, CAR T cell exhibited a heterogenous effector gene expression and this was related to the distance from tumor cells, allowing a quantitative assessment of the potential in vivo effectiveness. The platform offers the potential to study immune functions engineered cells in situ with their target cells in tissues with high statistical power and thus, as an important tool for preclinical and potentially clinical assessment of CAR T cell effectiveness.One Sentence SummaryWe developed a CAR RNA FISH assay to study chimeric antigen receptor T cell trafficking and function in human and mouse tissue.Impact statementWe developed an imaging platform and analysis pipeline to study large populations of engineered cells on a single cell level in situ.

scholarly journals High-Affinity Chimeric Antigen Receptor With Cross-Reactive scFv to Clinically Relevant EGFR Oncogenic Isoforms

2021 ◽  
Vol 11 ◽  
Author(s):  
Radhika Thokala ◽  
Zev A. Binder ◽  
Yibo Yin ◽  
Logan Zhang ◽  
Jiasi Vicky Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Tumor Escape ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Tumor heterogeneity is a key reason for therapeutic failure and tumor recurrence in glioblastoma (GBM). Our chimeric antigen receptor (CAR) T cell (2173 CAR T cells) clinical trial (NCT02209376) against epidermal growth factor receptor (EGFR) variant III (EGFRvIII) demonstrated successful trafficking of T cells across the blood–brain barrier into GBM active tumor sites. However, CAR T cell infiltration was associated only with a selective loss of EGFRvIII+ tumor, demonstrating little to no effect on EGFRvIII- tumor cells. Post-CAR T-treated tumor specimens showed continued presence of EGFR amplification and oncogenic EGFR extracellular domain (ECD) missense mutations, despite loss of EGFRvIII. To address tumor escape, we generated an EGFR-specific CAR by fusing monoclonal antibody (mAb) 806 to a 4-1BB co-stimulatory domain. The resulting construct was compared to 2173 CAR T cells in GBM, using in vitro and in vivo models. 806 CAR T cells specifically lysed tumor cells and secreted cytokines in response to amplified EGFR, EGFRvIII, and EGFR-ECD mutations in U87MG cells, GBM neurosphere-derived cell lines, and patient-derived GBM organoids. 806 CAR T cells did not lyse fetal brain astrocytes or primary keratinocytes to a significant degree. They also exhibited superior antitumor activity in vivo when compared to 2173 CAR T cells. The broad specificity of 806 CAR T cells to EGFR alterations gives us the potential to target multiple clones within a tumor and reduce opportunities for tumor escape via antigen loss.

Investigation of product derived lymphoma following infusion of piggyBac modified CD19 chimeric antigen receptor T-cells

Blood ◽  
2021 ◽  
Author(s):  
Kenneth Paul Micklethwaite ◽  
Kavitha Gowrishankar ◽  
Brian S Gloss ◽  
Ziduo Li ◽  
Janine A Street ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Copy Number ◽  
Antigen Receptor ◽  
Gene Copy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Insertion Sites

We performed a Phase I clinical trial of donor derived CD19-specific chimeric antigen receptor T-cells (CAR T-cells) for B-cell malignancy that relapsed or persisted after matched related allogeneic hemopoietic stem cell transplant. To overcome the cost and transgene capacity limitations of traditional viral vectors, CAR T-cells were produced using the piggyBac transposon system of genetic modification. Following CAR T-cell infusion, one patient developed a gradually enlarging retroperitoneal tumor due to a CAR expressing CD4+ T-cell lymphoma. Screening of other patients led to the detection of a second CAR T-cell tumor in thoracic para-aortic lymph nodes in an asymptomatic patient. Analysis of the first lymphoma showed a high transgene copy number, but no insertion into typical oncogenes. There were also structural changes such as altered genomic copy number and point mutations unrelated to the insertion sites. Transcriptome analysis showed transgene promoter driven upregulation of transcription of surrounding regions despite insulator sequences surrounding the transgene. However, marked global changes in transcription predominantly correlated with gene copy number rather than insertion sites. In both patients, the CAR T-cell derived lymphoma progressed and one patient died. We describe the first two cases of malignant lymphoma derived from CAR gene modified T-cells. Although CAR T-cells have an enviable record of safety to date, our results emphasize the need for caution and regular follow up of CAR T recipients, especially when novel methods of gene transfer are used to create genetically modified immune therapies. The trial was registered at www.anzctr.org.au as ACTRN12617001579381.

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