scholarly journals An inducible caspase 9 safety switch for T-cell therapy

Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4247-4254 ◽  
Author(s):  
Karin C. Straathof ◽  
Martin A. Pulè ◽  
Patricia Yotnda ◽  
Gianpietro Dotti ◽  
Elio F. Vanin ◽  
...  

Abstract The efficacy of adoptive T-cell therapy as treatment for malignancies may be enhanced by genetic modification of infused cells. However, oncogenic events due to vector/transgene integration, and toxicities due to the infused cells themselves, have tempered enthusiasm. A safe and efficient means of removing aberrant cells in vivo would ameliorate these concerns. We describe a “safety switch” that can be stably and efficiently expressed in human T cells without impairing phenotype, function, or antigen specificity. This reagent is based on a modified human caspase 9 fused to a human FK506 binding protein (FKBP) to allow conditional dimerization using a small molecule pharmaceutical. A single 10-nM dose of synthetic dimerizer drug induces apoptosis in 99% of transduced cells selected for high transgene expression in vitro and in vivo. This system has several advantages over currently available suicide genes. First, it consists of human gene products with low potential immunogenicity. Second, administration of dimerizer drug has no effects other than the selective elimination of transduced T cells. Third, inducible caspase 9 maintains function in T cells overexpressing antiapoptotic molecules. These characteristics favor incorporation of inducible caspase 9 as a safety feature in human T-cell therapies.

2020 ◽  
Vol 217 (12) ◽  
Author(s):  
Shannon K. Oda ◽  
Kristin G. Anderson ◽  
Pranali Ravikumar ◽  
Patrick Bonson ◽  
Nicolas M. Garcia ◽  
...  

Adoptive T cell therapy (ACT) with genetically modified T cells has shown impressive results against some hematologic cancers, but efficacy in solid tumors can be limited by restrictive tumor microenvironments (TMEs). For example, Fas ligand is commonly overexpressed in TMEs and induces apoptosis in tumor-infiltrating, Fas receptor–positive lymphocytes. We engineered immunomodulatory fusion proteins (IFPs) to enhance ACT efficacy, combining an inhibitory receptor ectodomain with a costimulatory endodomain to convert negative into positive signals. We developed a Fas-4-1BB IFP that replaces the Fas intracellular tail with costimulatory 4-1BB. Fas-4-1BB IFP-engineered murine T cells exhibited increased pro-survival signaling, proliferation, antitumor function, and altered metabolism in vitro. In vivo, Fas-4-1BB ACT eradicated leukemia and significantly improved survival in the aggressive KPC pancreatic cancer model. Fas-4-1BB IFP expression also enhanced primary human T cell function in vitro. Thus, Fas-4-1BB IFP expression is a novel strategy to improve multiple T cell functions and enhance ACT against solid tumors and hematologic malignancies.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii111-ii111
Author(s):  
Lan Hoang-Minh ◽  
Angelie Rivera-Rodriguez ◽  
Fernanda Pohl-Guimarães ◽  
Seth Currlin ◽  
Christina Von Roemeling ◽  
...  

Abstract SIGNIFICANCE Adoptive T cell therapy (ACT) has emerged as the most effective treatment against advanced malignant melanoma, eliciting remarkable objective clinical responses in up to 75% of patients with refractory metastatic disease, including within the central nervous system. Immunologic surrogate endpoints correlating with treatment outcome have been identified in these patients, with clinical responses being dependent on the migration of transferred T cells to sites of tumor growth. OBJECTIVE We investigated the biodistribution of intravenously or intraventricularly administered T cells in a murine model of glioblastoma at whole body, organ, and cellular levels. METHODS gp100-specific T cells were isolated from the spleens of pmel DsRed transgenic C57BL/6 mice and injected intravenously or intraventricularly, after in vitro expansion and activation, in murine KR158B-Luc-gp100 glioma-bearing mice. To determine transferred T cell spatial distribution, the brain, lymph nodes, heart, lungs, spleen, liver, and kidneys of mice were processed for 3D imaging using light-sheet and multiphoton imaging. ACT T cell quantification in various organs was performed ex vivo using flow cytometry, 2D optical imaging (IVIS), and magnetic particle imaging (MPI) after ferucarbotran nanoparticle transfection of T cells. T cell biodistribution was also assessed in vivo using MPI. RESULTS Following T cell intravenous injection, the spleen, liver, and lungs accounted for more than 90% of transferred T cells; the proportion of DsRed T cells in the brains was found to be very low, hovering below 1%. In contrast, most ACT T cells persisted in the tumor-bearing brains following intraventricular injections. ACT T cells mostly concentrated at the periphery of tumor masses and in proximity to blood vessels. CONCLUSIONS The success of ACT immunotherapy for brain tumors requires optimization of delivery route, dosing regimen, and enhancement of tumor-specific lymphocyte trafficking and effector functions to achieve maximal penetration and persistence at sites of invasive tumor growth.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A133-A133
Author(s):  
Cheng-Fu Kuo ◽  
Yi-Chiu Kuo ◽  
Miso Park ◽  
Zhen Tong ◽  
Brenda Aguilar ◽  
...  

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.


2020 ◽  
Vol 8 (2) ◽  
pp. e000896
Author(s):  
Talia Velasco-Hernandez ◽  
Samanta Romina Zanetti ◽  
Heleia Roca-Ho ◽  
Francisco Gutierrez-Aguera ◽  
Paolo Petazzi ◽  
...  

BackgroundThere are few therapeutic options available for patients with B-cell acute lymphoblastic leukemia (B-ALL) relapsing as CD19– either after chemotherapy or CD19-targeted immunotherapies. CD22-chimeric antigen receptor (CAR) T cells represent an attractive addition to CD19-CAR T cell therapy because they will target both CD22+CD19– B-ALL relapses and CD19– preleukemic cells. However, the immune escape mechanisms from CD22-CAR T cells, and the potential contribution of the epitope binding of the anti-CD22 single-chain variable fragment (scFv) remain understudied.MethodsHere, we have developed and comprehensively characterized a novel CD22-CAR (clone hCD22.7) targeting a membrane-distal CD22 epitope and tested its cytotoxic effects against B-ALL cells both in in vitro and in vivo assays.ResultsConformational epitope mapping, cross-blocking, and molecular docking assays revealed that the hCD22.7 scFv is a high-affinity binding antibody which specifically binds to the ESTKDGKVP sequence, located in the Ig-like V-type domain, the most distal domain of CD22. We observed efficient killing of B-ALL cells in vitro, although the kinetics were dependent on the level of CD22 expression. Importantly, we show an efficient in vivo control of patients with B-ALL derived xenografts with diverse aggressiveness, coupled to long-term hCD22.7-CAR T cell persistence. Remaining leukemic cells at sacrifice maintained full expression of CD22, ruling out CAR pressure-mediated antigen loss. Finally, the immunogenicity capacity of this hCD22.7-scFv was very similar to that of other CD22 scFv previously used in adoptive T cell therapy.ConclusionsWe report a novel, high-affinity hCD22.7 scFv which targets a membrane-distal epitope of CD22. 4-1BB-based hCD22.7-CAR T cells efficiently eliminate clinically relevant B- CD22high and CD22low ALL primary samples in vitro and in vivo. Our study supports the clinical translation of this hCD22.7-CAR as either single or tandem CD22–CD19-CAR for both naive and anti-CD19-resistant patients with B-ALL.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2162-2162
Author(s):  
Martin Szyska ◽  
Stefanie Herda ◽  
Stefanie Althoff ◽  
Andreas Heimann ◽  
Tra My Dang ◽  
...  

Abstract Adoptive T cell therapy (ATT) is a promising option for the treatment of solid cancers. However, various defense mechanisms acquired by the tumor during evolution prevent transferred T cells (TC) to unfold their full potential. A combination of ATT with accessory therapeutic approaches including checkpoint inhibition and targeted therapy could lift TC inhibition and efficiently shift the immune balance towards tumor rejection. An in-vivo analysis of the impact of combination strategies on the outcome of ATT would greatly enhance the search for an optimal accessory to ATT therapy. We generated the transgenic mouse line BLITC (bioluminescence imaging of T cells) expressing an NFAT (nuclear factor of activated T cell)-dependent Click-beetle luciferase (Na et. al, 2010) and a constitutive Renilla Luciferase, allowing us to monitor migration and activation of transferred TCs in vivo. In order to analyze crucial ATT parameters in a clinically relevant tumor model, BLITC mice were crossed to the two HY-TCR transgenic mice Marilyn (CD4: H-2Ab-Dby) and MataHari (CD8: H-2Db-Uty) to generate TCs that could be monitored for in-vivo infiltration, local activation and rejection of established (> 0,5 cm x 0,5 cm / ≥10 days growth) H-Y expressing MB49 tumors. In order to better reflect the clinical situation, we lymphodepleted tumor-bearing immunocompetent albino B6 mice with fludarabine (FLu) and/or cyclophosphamide (CTX) prior to ATT. Transferred TCs were FACSorted and injected after an optional culture expansion phase. As shown before for freshly injected tumor cells (Perez-Diez, 2007), we observed a superior response of tumor-antigen specific CD4+ TCs compared to CD8+ TCs against established tumors. Whereas 5*106 CD8+ T cells hardly attenuated tumor growth, even as few as 5000 H-Y TCR-transgenic CD4+ T cells rejected tumors in most mice, depending on the lymphodepleting treatment (Figure A - remission rates in parentheses). Tumor infiltration and activation of adoptively transferred TCs was monitored in-vivo by the respective bioluminescent reporters. Around day 4 and 6, CD4+ TCs migrated from tumor-draining lymph nodes into the tumor environment and persisted until rejection. Interestingly, activation of CD4+ TCs was only transient (between days 4 and 7) in all mice, independent of therapy outcome (in Figure B shown for refractory tumor). Whereas loss of activation signal during remission was correlated with tumor clearance and decline of effector function, in refractory tumors it suggests a rapid inactivation of infiltrating TCs by the tumor microenvironment. Our data indicate that the failure of tumor rejection is not caused by impaired peripheral expansion or tumor homing but rather by inhibition of TC effector function. Responsible mechanisms and counter-acting therapeutic interventions are the focus of ongoing studies. In summary, the BLITC reporter system facilitates analysis of therapeutic parameters for ATT in a well-established solid tumor model. Using BLITC mice for transduction with TCR or CAR expression cassettes could allow rapid monitoring of on-target as well as undesired off-target effects in virtually any tumor setting. Future experiments will focus on the beneficial effects of combination treatments on the activation of adoptively transferred TCs. Figure. Figure. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Siao-Yi Wang ◽  
Tamson V. Moore ◽  
Annika V. Dalheim ◽  
Gina M. Scurti ◽  
Michael I. Nishimura

AbstractAdoptive T cell therapy with T cell receptor (TCR)-modified T cells has shown promise in treating metastatic melanoma and other malignancies. However, studies are needed to improve the efficacy and durability of responses of TCR-modified T cells. Standard protocols for generating TCR-modified T cells involve activating T cells through CD3 stimulation to allow for the efficient transfer of tumor-reactive receptors with viral vectors. T cell activation results in terminal differentiation and shortening of telomeres, which are likely suboptimal for therapy. In these studies, we demonstrate efficient T cell transduction with the melanoma-reactive TIL1383I TCR through culturing with interleukin 7 (IL-7) in the absence of CD3 activation. The TIL1383I TCR-modified T cells generated following IL-7 culture were enriched with naïve (TN) and memory stem cell populations (TSCM) while maintaining longer telomere lengths. Furthermore, we demonstrated melanoma-reactivity of TIL1383I TCR-modified cells generated following IL-7 culture using in vitro assays and a superior response in an in vivo melanoma model. These results suggest that utilizing IL-7 to generate TCR-modified T cells in the absence of activation is a feasible strategy to improve adoptive T cell therapies for melanoma and other malignancies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yamin Jie ◽  
Guijun Liu ◽  
Lina Feng ◽  
Ying Li ◽  
Mingyan E ◽  
...  

In spite of impressive success in treating hematologic malignancies, adoptive therapy with chimeric antigen receptor modified T cells (CAR T) has not yet been effective in solid tumors, where identification of suitable tumor-specific antigens remains a major obstacle for CAR T-cell therapy due to the “on target off tumor” toxicity. Protein tyrosine kinase 7 (PTK7) is a member of the Wnt-related pseudokinases and identified as a highly expressed antigen enriched in cancer stem cells (CSCs) from multiple solid tumors, including but not limited to triple-negative breast cancer, non-small-cell lung cancer, and ovarian cancer, suggesting it may serve as a promising tumor-specific target for CAR T-cell therapy. In this study, we constructed three different PTK7-specific CAR (PTK7-CAR1/2/3), each comprising a humanized PTK7-specific single-chain variable fragment (scFv), hinge and transmembrane (TM) regions of the human CD8α molecule, 4-1BB intracellular co-stimulatory domain (BB-ICD), and CD3ζ intracellular domain (CD3ζ-ICD) sequence, and then prepared the CAR T cells by lentivirus-mediated transduction of human activated T cells accordingly, and we sequentially evaluated their antigen-specific recognition and killing activity in vitro and in vivo. T cells transduced with all three PTK7-CAR candidates exhibited antigen-specific cytokine production and potent cytotoxicity against naturally expressing PTK7-positive tumor cells of multiple cancer types without mediating cytotoxicity of a panel of normal primary human cells; meanwhile, in vitro recursive cytotoxicity assays demonstrated that only PTK7-CAR2 modified T cells retained effective through multiple rounds of tumor challenge. Using in vivo xenograft models of lung cancers with different expression levels of PTK7, systemic delivery of PTK7-CAR2 modified T cells significantly prevented tumor growth and prolonged overall survival of mice. Altogether, our results support PTK7 as a therapeutic target suitable for CAR T-cell therapy that could be applied for lung cancers and many other solid cancers with PTK7 overexpression.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2533-2533
Author(s):  
Angela Orcurto ◽  
Johanna Chiffelle ◽  
Eleonora Ghisoni ◽  
David Barras ◽  
Isaac Crespo ◽  
...  

2533 Background: Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) has demonstrated a curative potential for patients with metastatic melanoma (MM). Nevertheless, activity remains unsatisfactory in many patients, requiring development of biomarkers that predict therapeutic efficacy. We report results of a single-center phase I study to assess feasibility, safety and efficacy of TIL-ACT in MM patients (NCT03475134). Methods: Patients with MM refractory to at least one prior line of therapy received TIL therapy with lymphodepleting chemotherapy before T-cell infusion, followed by high-dose interleukin-2. RDG- and FDG-PET imaging was performed before and after TIL infusion. Multispectral immuno-fluorescence (mIF) imaging and bulk-RNA sequencing (Seq) were performed on tumor samples pre-ACT and post-ACT (day+30 and upon progression). Single-cell RNA-Seq and TCR-Seq were performed on pre-ACT tumor and ACT product, as well as on tumor-reactive and neoantigen-specific TILs and on longitudinal blood samples. Results: As of 02/02/2021, thirteen patients (enrolled between March 2018 and December 2020) have successfully completed TIL-ACT therapy, with a median follow-up of 9.5 months (IQR 3.0 -24.6). Median age was 53 years (range 20-69) and all were previously treated with PD-1 based blockade. Median number of TILs infused was 55.0 x109 cells (range 12.8-84.7). The best overall response rate by RECIST 1.1 and disease control rate in evaluable patients was 41.7% (5/12) and 50% (6/12) respectively at 3 months. Two patients have an ongoing near-complete response at 3 years. Up to data cut-off, 10 patients have progressed by RECIST v1.1, with median PFS of 4.8 months (95% CI 1.5 - 9.6), while median OS is not reached. mIF revealed biomarkers of response, which may allow proper identification of patients in subsequent studies. In addition, deep sequencing of bulk and neoepitope-specific TIL clonotypes highlighted transcriptomic signatures revealing cell programs regulating in vitro expansion, in vivo blood persistence as well as tumor infiltration post-ACT. RGD-PET data will also be presented. Conclusions: We demonstrate reproducibility of TIL-ACT in our center, consistently with previous reports. Comprehensive translational studies reveal immune correlates of clinical responses that contribute to the understanding of mechanisms of TIL potency and will guide the development of next-generation cell products. Clinical trial information: NCT03475134.


2020 ◽  
Author(s):  
Yamin Jie ◽  
Guijun Liu ◽  
Lina Feng ◽  
Ying Li ◽  
Mingyan E ◽  
...  

Abstract Background: In spite of impressive success in treating hematologic malignancies, adoptive therapy with chimeric antigen receptor modified T cells (CAR T) has not yet been effective in solid tumors, where identification of suitable tumor-specific antigens remains a major obstacle for CAR T-cell therapy due to the “on target off tumor” toxicity. Protein tyrosine kinase 7 (PTK7) is a member of the Wnt-related pseudokinases and identified as a highly expressed antigen enriched in cancer stem cells (CSCs) from multiple solid tumors, including but not limited to triple-negative breast cancer, non-small cell lung cancer, and ovarian cancer, suggesting it may serve as a promising tumor-specific target for CAR T-cell therapy. Methods: In this study, we constructed 3 different PTK7-specific CAR (PTK7-CAR1/2/3) each comprising a humanized PTK7-specific single chain variable fragment (scFv), hinge and transmembrane (TM) regions of the human CD8α molecule, 4-1BB intracellular co-stimulatory domain (BB-ICD), and CD3ζ intracellular domain (CD3ζ-ICD) sequence, and then prepared the CAR T cells by lentivirus mediated transduction of human activated T cells accordingly, and sequentially evaluated their antigen-specific recognition and killing activity in vitro and in vivo.Results: T cells transduced with all 3 PTK7-CAR candidates exhibited antigen-specific cytokine production and potent cytotoxicity against naturally expressing PTK7-positive tumor cells of multiple cancer types without mediating cytotoxicity of a panel of normal primary human cells; meanwhile, in vitro recursive cytotoxicity assays demonstrated that only PTK7-CAR2 modified T cells retained effective through multiple rounds of tumor challenge. Using in vivo xenograft models of lung cancers with different expression level of PTK7, systemic delivery of PTK7-CAR2 modified T cells significantly prevented tumor growth and prolonged overall survival of mice. Conclusion: Altogether, our results support PTK7 as a therapeutic target suitable for CAR T-cell therapy that could be applied for lung cancers and many other solid cancers with PTK7 overexpression.


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