T Cells Demonstrate Enhanced Specificity for CD19+ Malignancies When Stimulated with IL-21.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1539-1539
Author(s):  
Harjeet Singh ◽  
Mary Helen Huls ◽  
Margaret J. Dawson ◽  
Tiejuan Mi ◽  
Gianpietro Dotti ◽  
...  
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Genetically Modified ◽  
Sleeping Beauty ◽  
Antigen Receptors ◽  
Therapeutic Success ◽  
Car T Cells ◽  
Car T ◽  
Early Phase Clinical Trials ◽  
Quiescent T Cells

Abstract T cells genetically modified to express CD19-specific chimeric antigen receptors (CARs) are being evaluated in early-phase clinical trials in patients with B-lineage malignancies. Therapeutic success is predicted by ability of infused CAR+ T cells to both persist and kill in an antigen-dependent fashion. The first of these dual goals can be achieved by altering the CAR molecule to provide T-cell survival signals through a chimeric CD28 endodomain (designated CD19RCD28). We now report that altering the culturing microenvironment with IL-21 improves antigen-dependent cytolysis of T cells when propagated on CD19+ artificial antigen presenting cells (aAPC) derived from K562. To test whether IL-21 acts in conjunction with CD28 signaling to support acquisition of redirected effector functions we electro-transferred quiescent T cells from peripheral blood with Sleeping Beauty system DNA plasmids to introduce CD19RCD28 CAR transposon. Selective outgrowth of CAR+ T cells was achieved on CD19+ aAPC that provide co-stimulation with the addition of exogenous IL-2 and/or IL-21. When IL-21 was present there was preferential numeric expansion of CD19-specific CD8+ T cells which lysed and produced IFN-g in response to CD19 (Figure). Furthermore, the CD8+CAR+ T cells displayed a central memory (CM) cell surface phenotype characterized as CD62L+ and CD28+. In contrast, genetically modified T cells propagated with exogenous IL-2 resulted in predominately CD19-specific CM CD4+ T cells. Thus, cytokines can be used to tailor the CD8/CD4 ratio of CAR+ T cells derived from peripheral blood. These data demonstrate that the dual goals of persistence and lysis can be achieved by altering CAR and the cytokine milieu and have implications for infusing CAR+ T cells in next-generation immunotherapy trials. Figure Figure

scholarly journals Mitochondrial Biomass As a Measure of Fitness for T Cells Expressing Chimeric Antigen Receptors

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3242-3242 ◽  
Author(s):  
Bipulendu Jena ◽  
David Rushworth ◽  
George T McNamara ◽  
Laurence JN Cooper
Keyword(s):  
T Cells ◽  
Research Funding ◽  
Genetically Modified ◽  
Sleeping Beauty ◽  
Mitochondrial Mass ◽  
Car T Cells ◽  
Mitochondrial Structure ◽  
Car T ◽  
Multiple Variables ◽  
Equity Ownership

Abstract Anti-tumor efficacy of genetically modified T cells depends on in vivo expansion and durable persistence of infused cells. Multiple variables including the structure of the CAR and characteristics of the recipient impact the anti-tumor effect of CAR+ T cells. However, a code for an optimal CAR design that would deliver clinically relevant result is yet to emerge. Here we propose a new measure of "fitness" for CAR+ T cells based on mitochondrial biomass that is quantifiable and could be translated to clinical settings. Spare respiratory capacity (SRC) is defined as the extra mitochondrial capacity available in a cell to produce energy under conditions of increased work or stress. Memory T cells capable of responding to infection has been shown to possess extra SRC (Windt et al., Immunity 2012). We therefore investigated whether subsets of CD19-specific CAR+ T cells after electro-transfer of Sleeping Beauty (SB) plasmids and propagation on activating and propagating cells (AaPC) could be identified based on SRC. Transmission electron microscopy revealed that genetically modified T cells revert to a condensed state of mitochondria after 2 weeks of activation through a second-generation CD19-specific CAR. However, mock-electroporated T cells activated by cross-linking CD3 (using AaPC loaded with OKT3) retain a classic mitochondrial structure. Moreover, antigen-driven numeric expansion in presence of membrane bound IL-15 led to an increase in mitochondrial biomass in CAR+ T cells. We extended these observations to various CAR+ T cells with unique specificity for tumor antigens and found similar changes in mitochondrial structure and distribution. Next, we examined if an increase in mitochondrial biomass influences functionality of genetically modified T cells. By SB mediated transposition CARs were co-expressed along with a fluorescence reporter protein (EYFP-GRX2) constituting yellow fluorescent protein fused to the mitochondrial localization sequence of GRX2 to track mitochondrial distribution in live cells. The genetically modified T cells were selectively propagated by stimulating the CARs using a proprietary monoclonal antibody that binds to a common extracellular stalk motif in CAR construct. CAR+ T cells that signaled through chimeric CD137z exhibited a high mitochondrial mass (EYFPhigh) and had superior rates of expansion ex vivo. In contrast, CAR+ T cells that signaled through chimeric CD28z had a low mitochondrial mass (EYFPdim), elevated levels of apoptosis, and inferior rates of numeric expansion. Confocal microscopy showed EYFP counts were higher for CAR+ T cells that signaled through CD137 signaling domain. We hypothesize that increased survival of CD137z-CAR T cells in a challenging cell culture environment could be due to reserve bio-energetic potential concomitant with the ability to meet metabolic demand of activated T cells. Further, SRC could be quantified using a fluorescent probe for mitochondrial mass pre-infusion which may be a defining criterion attesting to the fitness of CAR+ T cells for human applications. Disclosures Jena: Intrexon: Equity Ownership, Patents & Royalties: Potential royalties (Patent submitted); Ziopharm Oncology: Equity Ownership, Patents & Royalties: Potential roylaties (Patent submitted). Rushworth:Intrexon: Other: Potential Equity ownership; Ziopharam Oncology: Other: Potential Equity Ownership. McNamara:Ziopharm Oncology: Equity Ownership, Patents & Royalties: Potential royalties, Research Funding; Intrexon: Equity Ownership, Patents & Royalties: Potential royalties, Research Funding. Cooper:Ziopharm Oncology: Employment, Equity Ownership, Patents & Royalties, Research Funding; Intrexon: Equity Ownership, Patents & Royalties.

First Clinical Trials Employing Sleeping Beauty Gene Transfer System and Artificial Antigen Presenting Cells To Generate and Infuse T Cells Expressing CD19-Specific Chimeric Antigen Receptor

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 166-166 ◽  
Author(s):  
Partow Kebriaei ◽  
Helen Huls ◽  
Harjeet Singh ◽  
Simon Olivares ◽  
Matthew Figliola ◽  
...  
Keyword(s):  
T Cells ◽  
Gene Transfer ◽  
Chimeric Antigen Receptor ◽  
Genetically Modified ◽  
Sleeping Beauty ◽  
Clinical Grade ◽  
Car T Cells ◽  
Artificial Antigen ◽  
Car T ◽  
Antigen Presenting

Abstract Background T cells can be genetically modified ex vivo to redirect specificity upon enforced expression of a chimeric antigen receptor (CAR) that recognizes tumor-associated antigen (TAA) independent of human leukocyte antigen. We report a new approach to non-viral gene transfer using the Sleeping Beauty (SB) transposon/transposase system to stably express a 2nd generation CD19-specific CAR- (designated CD19RCD28 that activates via CD3z/CD28) in autologous and allogeneic T cells manufactured in compliance with current good manufacturing practice (cGMP) for Phase I/II trials. Methods T cells were electroporated using a Nucleofector device to synchronously introduce DNA plasmids coding for SB transposon (CD19RCD28) and hyperactive SB transposase (SB11). T cells stably expressing the CAR were retrieved over 28 days of co-culture by recursive additions of g-irradiated artificial antigen presenting cells (aAPC) in presence of soluble recombinant interleukin (IL)-2 and IL-21. The aAPC (designated clone #4) were derived from K562 cells and genetically modified to co-express the TAA CD19 as well as the co-stimulatory molecules CD86, CD137L, and a membrane-bound protein of IL-15. The dual platforms of the SB system and aAPC are illustrated in figure below. Results To date we have enrolled and manufactured product for 25 patients with multiply-relapsed ALL (n=12) or B-cell lymphoma (n=13) on three investigator-initiated trials at MD Anderson Cancer Center to administer thawed patient- and donor-derived CD19-specific T cells as planned infusions in the adjuvant setting after autologous (n=7), allogeneic adult (n=14) or umbilical cord (n=4) hematopoietic stem-cell transplantation (HSCT). Each clinical-grade T-cell product was subjected to a battery of in-process testing to complement release testing under CLIA. Currently, five patients have been infused with the CAR+ T cells following allogeneic HSCT, including one patient with cord blood-derived T cells (ALL, n=4; NHL, n=1), beginning at a dose of 106 and escalating to 107 modified T cells/m2. Three patients treated at the first dose level of 106 T cells/m2 have progressed; the patient treated at the next dose level with 107 T cells/m2 remains in remission at 5 months following HSCT. Assessment for response too early for patient treated with UCB T cells. Four patients with non-Hodgkin’s lymphoma have been treated with patient-derived modified T cells following autologous HSCT at a dose of 5x107 T cells/m2, and all patients remain in remission at 3 months following HSCT. No acute or late toxicities have been noted to date. PCR testing for persistence of CAR-modified T cells is underway. Conclusion We report the first human application of the SB and aAPC systems to genetically modify clinical-grade cells. Importantly, infusing CD19-specific CAR+ T cells in the adjuvant HSCT setting and thus targeting minimal residual disease is feasible and safe, and may provide an effective approach for maintaining remission in patients with high risk, CD19+ lymphoid malignancies. Clinical data is accruing and will be updated at the meeting. This nimble manufacturing approach can be readily modified in a cost-effective manner to improve the availability, persistence and therapeutic potential of genetically modified T cells, as well as target tumor–associated antigens other than CD19. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Very Rapid Production of CAR+ T-Cells upon Non-Viral Gene Transfer Using the Sleeping Beauty System

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2807-2807 ◽  
Author(s):  
Lenka V. Hurton ◽  
Harjeet Singh ◽  
Kirsten C. Switzer ◽  
Tiejuan Mi ◽  
Leo G. Flores ◽  
...  
Keyword(s):  
Tissue Culture ◽  
T Cells ◽  
T Cell ◽  
Gene Transfer ◽  
Ex Vivo ◽  
Genetically Modified ◽  
Sleeping Beauty ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

Abstract T cells are genetically modified ex vivo to express chimeric antigen receptors (CARs) for in vivo clinical applications. CAR-modified T cells have demonstrated redirected specificity and, in several clinical trials, potent anti-tumor activity. Manufacture, to date, is based upon gene transfer in cycling T cells followed by a period of tissue culture to achieve stable expression of introduced CARs. In contrast, we have adapted the non-viral-based Sleeping Beauty (SB) system to avoid the need for (i) T-cell activation and (ii) extended ex vivo tissue culture; thereby developing an approach whereby T cells can be both manufactured and delivered at multiple points-of-care (POC). This shortened culture decreases the time frame for manufacturing CAR+ T cells compared with current protocols for viral- or non-viral-based methodologies and is a foundation of our POC technology. Furthermore, reducing the ex vivo culture time preserves the memory and sustained persistence of CAR+ T cells by avoiding the differentiation programming induced by activation events typically required before or after gene transfer. We have previously demonstrated that co-expressing a membrane-bound version of interleukin-15 (mbIL15) significantly enhances the in vivo persistence of CAR+ T cells that are generated following 28-day culture after electro-transfer of SB derived DNA plasmids. Herein, we incorporated mbIL15 to generate POC CD19-specific CAR+ T cells. Peripheral blood mononuclear cells were genetically modified with mbIL15 and 2nd generation CAR coded from individual SB DNA plasmids and placed in culture for less than 2 days prior to adoptive transfer. NSG mice burdened by established and disseminated CD19+ leukemia were intravenously injected with just 7.5 x 105 CAR+ T cells, or an equivalent total T-cell dose of CARneg (unmodified or mock-treated) T cells. The mbIL15-CAR T-cell infusion yielded excellent disease-free survival, anti-tumor activity (Figure), and T-cell persistence. This approach to expediting the generation of genetically modified T cells enables the administration of CAR-modified naïve T cells and demonstrates that POC T cells have potent anti-tumor effects, even at a reduced CAR+ T-cell dose. This improvement to non-viral gene transfer and T-cell production reduces the requirement for tissue culture and thus time to manufacture within a GMP facility which translates to improvements in scalability and reduced costs. In summary, these data provide a translational pathway to undertake clinical trials by rapidly infusing T cells after genetic modification using the SB system. Disclosures Hurton: Intrexon: Equity Ownership, Patents & Royalties; Ziopharm Oncology: Equity Ownership, Patents & Royalties. Singh:Immatics: Equity Ownership, Patents & Royalties; Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Switzer:Intrexon: Equity Ownership, Patents & Royalties; Ziopharm Oncology: Equity Ownership, Patents & Royalties. Mi:Intrexon: Equity Ownership, Patents & Royalties; Ziopharm Oncology: Equity Ownership, Patents & Royalties. Maiti:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Su:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Huls:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Employment, Equity Ownership, Patents & Royalties. Champlin:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Cooper:Immatics: Equity Ownership; City of Hope: Patents & Royalties; Targazyme, Inc.: Equity Ownership; Sangamo BioSciences: Patents & Royalties; Intrexon: Equity Ownership; Ziopharm Oncology: Employment, Equity Ownership, Patents & Royalties; MD Anderson Cancer Center: Employment; Miltenyi Biotec: Honoraria.

scholarly journals CAR-T cells and BiTEs in solid tumors: challenges and perspectives

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Julien Edeline ◽  
Roch Houot ◽  
Aurélien Marabelle ◽  
Marion Alcantara
Keyword(s):  
T Cells ◽  
Solid Tumors ◽  
Specific Antigen ◽  
Hematologic Malignancies ◽  
Antibody Fragments ◽  
New Drugs ◽  
Car T Cells ◽  
Cell Specificity ◽  
Car T ◽  
Early Phase Clinical Trials

AbstractChimeric antigen receptor (CAR)-modified T cells and BiTEs are both immunotherapies which redirect T cell specificity against a tumor-specific antigen through the use of antibody fragments. They demonstrated remarkable efficacy in B cell hematologic malignancies, thus paving the way for their development in solid tumors. Nonetheless, the use of such new drugs to treat solid tumors is not straightforward. So far, the results from early phase clinical trials are not as impressive as expected but many improvements are under way. In this review we present an overview of the clinical development of CAR-T cells and BiTEs targeting the main antigens expressed by solid tumors. We emphasize the most frequent hurdles encountered by either CAR-T cells or BiTEs, or both, and summarize the strategies that have been proposed to overcome these obstacles.

scholarly journals Engineering Next-Generation CAR-T Cells for Better Toxicity Management

2020 ◽  
Vol 21 (22) ◽  
pp. 8620
Author(s):  
Alain E. Andrea ◽  
Andrada Chiron ◽  
Stéphanie Bessoles ◽  
Salima Hacein-Bey-Abina
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antigen Receptors ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Safety Strategies ◽  
Life Threatening ◽  
Preclinical And Clinical Studies

Immunoadoptive therapy with genetically modified T lymphocytes expressing chimeric antigen receptors (CARs) has revolutionized the treatment of patients with hematologic cancers. Although clinical outcomes in B-cell malignancies are impressive, researchers are seeking to enhance the activity, persistence, and also safety of CAR-T cell therapy—notably with a view to mitigating potentially serious or even life-threatening adverse events like on-target/off-tumor toxicity and (in particular) cytokine release syndrome. A variety of safety strategies have been developed by replacing or adding various components (such as OFF- and ON-switch CARs) or by combining multi-antigen-targeting OR-, AND- and NOT-gate CAR-T cells. This research has laid the foundations for a whole new generation of therapeutic CAR-T cells. Here, we review the most promising CAR-T cell safety strategies and the corresponding preclinical and clinical studies.

scholarly journals 8 Multiparameter characterization of CAR T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A8-A8
Author(s):  
Xueting Wang ◽  
Christina Pitzka ◽  
Daniela Rheindorf ◽  
Nadine Mockel-Tenbrinck ◽  
Tatjana Holzer ◽  
...  
Keyword(s):  
T Cells ◽  
Effector Function ◽  
Adoptive Cell Transfer ◽  
Intrinsic Variability ◽  
Freezing And Thawing ◽  
Therapeutic Success ◽  
Car T Cells ◽  
Number Of Patients ◽  
Car T

BackgroundAdoptive cell transfer of chimeric antigen receptor (CAR) modified T cells has demonstrated great therapeutic success against certain hematological malignancies. However, a substantial number of patients experienced relapse at some point after treatment with the underlying mechanisms not fully understood. Emerging data suggest that the undesired clinical outcome is related to different aspects, which include: the tumor heterogeneity, the tumor microenvironment, as well as intrinsic characteristics of the CAR T cells. In this work, we aimed to understand the diversity of CAR T cells generated from different donors, using multiparameter in vitro characterization.MethodsLeukapheresis from healthy donors were collected to generate CAR T cells using the GMP-compliant CliniMACS Prodigy® platform, enabling an automated and closed engineering of CAR T cells in a highly reproducible manner. We performed an in-depth characterization of the resulting CAR T cells by exploring differences in the immunophenotype, cell fitness and effector function of the freshly prepared as compared to frozen CAR T cell samples. Specifically, we designed several flow cytometry panels for the extensive characterization of immunophenotypes of interest such as: proliferative capacity, differentiation, activation and exhaustion. Cell fitness status was determined by the rate at which cells undergo apoptosis following stress. Finally, effector function was determined by the ability of the activated CAR T cells to secrete proinflammatory cytokines including IFN-g, TNF-a and IL-2. The associations between these different parameters were analyzed using comprehensive statistical approaches.ResultsWith our established workflow, over 20 healthy-donor derived CAR T cells were generated and characterized. We have observed donor-dependent variations and responses for most of the explored parameters. In general, the freezing and thawing process negatively affected cell fitness and effector function of the CAR T cells and resulted in altered immunophenotypes. Additionally, correlations between certain immunophenotypes and cell fitness/effector function were identified.ConclusionsCollectively, we established a workflow for multiparameter characterization of CAR T cells and assessed the intrinsic variability of CAR T cells for both research and clinical application.

Efficacy and Long Term Survival of Genetically Modified T Cells Targeting CD19 in a Syngeneic Immune Competent Transgenic Murine Tumor Model Is Dependent on Prior Lymphodepleting Chemotherapy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2754-2754
Author(s):  
James Lee ◽  
Yan Nikhamin ◽  
Gavin Imperato ◽  
Adam Cohen ◽  
Michel Sadelain ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Clinical Setting ◽  
Peripheral Blood ◽  
Tumor Model ◽  
B Cell Malignancies ◽  
Car T Cells ◽  
Human T Cells ◽  
Car T

Abstract T cells may be genetically modified ex vivo to target specific antigens by retroviral transduction of genes encoding chimeric antigen receptors (CARs). We have previously constructed a CAR, termed 19z1, specific for the CD19 antigen expressed on most B cell malignancies. Human T cells modified to express the 19z1 CAR specifically eradicate systemic human CD19+ tumors in SCID-Beige mice. However, these models are limited by the xenogeneic nature of the human T cells and tumor cells and the immune compromised state of the host. Here, we studied the biology of adoptively transferred 19z1+ T cells in a syngeneic immune competent murine model designed to better mimic the clinical setting of patients with B cell malignancies. We utilized transgenic C57BL6 mice which lack expression of mouse CD19 (mCD19−/−) and have a single copy of the human CD19 (hCD19+/−) gene (C57BL6(mCD19−/− hCD19+/−)) kindly provided by Dr. T. Tedder, Duke University. These mice are functionally immune-competent with hCD19 expression restricted to the B cell population. To assess whether syngeneic 19z1+ T cells were capable of eradicating normal hCD19+ B cells, we infused C57BL6(mCD19−/− hCD19+/−) mice with either 19z1+ or control prostate specific membrane antigen-targeted (Pz1+) T cells. As assessed by flow cytometric analysis of peripheral blood, we neither found evidence of hCD19+ B cell aplasias in 19z1+ T cell treated mice nor were able to demonstrate the persistence of infused CAR+ T cells. To investigate whether the lack of 19z1+ T cell efficacy and persistence was due to an absence of homeostatic drive, we next lymphodepleted C57BL6(mCD19−/− hCD19+/−) mice with cyclophosphamide prior to T cell infusion. Mice lymphodepleted prior to 19z1+ T cell infusion demonstrated marked and sustained B cell aplasias when compared to lymphodepleted Pz1+ T cell and non-lymphodepleted T cell treated controls. Furthermore, while no CAR+ T cells were identifiable in the Pz1 and non-lymphodepleted control groups, 19z1+ T cells were consistently present in the peripheral blood of the cyclophosphamide pre-treated, 19z1+ T cell treated mice (3–5% of white blood cells). To assess the anti-tumor efficacy of the 19z1+ T cells, we next established a systemic tumor model utilizing mouse EL4 thymoma cells retrovirally modified to express hCD19 (EL4(hCD19)). C57BL6(mCD19−/− hCD19+/−) mice pre-treated with cyclophosphamide, subsequently infused systemically with EL4(hCD19) tumor, followed by systemic 19z1+ T cell infusion, had a significant survival advantage (80% survival at >120 days) over untreated controls or controls treated with Pz1+ T cells or 19z1+ T cells in the absence of lymphodepletion (0% survival). In conclusion, we have developed a syngeneic immune competent tumor model of hCD19 disease that is highly relevant to the clinical setting. Using this model, we demonstrate the significance of lymphodepletion on the prolonged in vivo persistence and anti-tumor efficacy of 19z1+ T cells. Data derived from this model will be correlated to findings obtained from a recently initiated clinical trial for patients with chronic lymphocytic leukemia, and will significantly impact the design of subsequent trials in the future.

Targeting An Ancient Retrovirus In Tumor Using Engineered T Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4206-4206
Author(s):  
Janani Krishnamurthy ◽  
Brian Rabinovich ◽  
Simon Olivares ◽  
Mi Teijuan ◽  
Kirsten Switzer ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Tumor Cells ◽  
Treatment Strategy ◽  
Conflicts Of Interest ◽  
Sleeping Beauty ◽  
Normal Organ ◽  
Car T Cells ◽  
Car T ◽  
Env Protein

Abstract Human endogenous retroviruses (HERVs) are ancient viruses forming 8% of human genome. One subset of HERVs, the HERV-K has recently been found to be expressed on tumor cells including melanoma, breast cancer and lymphoma but not on normal body cells. Thus, targeting HERV-K protein as a tumor associated antigen (TAA) may be a potential treatment strategy for tumors that are resistant to conventional therapies. One approach to improve therapeutic outcome is by infusing T cells rendered specific for such TAAs preferentially expressed on tumor cells. Recognition of cell-surface TAAs independent of major histocompatibility complex can be achieved by introducing a chimeric antigen receptor (CAR) on T cells using gene therapy. This approach is currently being used in our clinical trials adoptively transferring CD19-specific CAR+ T cells into patients with B-lineage malignancies. Preliminary analysis of HERV-K env protein expression in 268 melanoma samples and 139 normal organ donor tissues using immunohistochemistry demonstrated antigen expression in tumor cells and absence of expression in normal organ tissues. The scFv region from a mouse monoclonal antibody to target HERV-K env was used to generate a CAR and cloned into Sleeping Beauty (SB) plasmid for stable expression in T cells. HERV-K-specific CAR+T cells were selectively propagated ex vivo on artificial antigen presenting cells (aAPC) using an approach already in our clinical trials. Indeed, after genetic modification of T cells and selection on HERV-K+ aAPC, over 95% of propagated T cells stably expressed the introduced HERV-K-specific CAR and exhibited redirected specificity for HERV-K+ melanoma (Figure 1). Further, the adoptive transfer of HERV-K-specific CAR+T cells killed metastatic melanoma in a mouse xenograph model. While we have chosen melanoma as our tumor model, this study has the potential to be applied to other malignancies, including lymphoma and myeloma due to restricted expression of HERV-K envelope (env) protein on these tumor cells. These data demonstrate that it is feasible to generate T cells expressing a HERV-K-specific CAR using a clinically-appealing approach as a treatment strategy for HERV-K env+ tumors. Disclosures: No relevant conflicts of interest to declare.

Adoptive Therapy Using Sleeping Beauty Gene Transfer System and Artificial Antigen Presenting Cells to Manufacture T Cells Expressing CD19-Specific Chimeric Antigen Receptor

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 311-311 ◽  
Author(s):  
Partow Kebriaei ◽  
Helen Huls ◽  
Harjeet Singh ◽  
Simon Olivares ◽  
Matthew Figliola ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Mononuclear Cells ◽  
Sleeping Beauty ◽  
Car T Cells ◽  
Car T ◽  
Cord Blood Mononuclear Cells ◽  
Active Disease

Abstract Objectives: T cells can be genetically modified ex vivo to redirect specificity upon expression of a chimeric antigen receptor (CAR) that recognizes tumor-associated antigen (TAA) independent of human leukocyte antigen. We employ non-viral gene transfer using the Sleeping Beauty (SB) transposon/transposase system to stably express a 2nd generation CD19-specific CAR- (designated CD19RCD28 that activates via CD3z/CD28) in patient (pt)- or donor-derived T cells for patients with advanced B-cell malignancies. Methods: T cells were electroporated using a Nucleofector device to synchronously introduce two DNA plasmids coding for SB transposon (CD19RCD28) and hyperactive SB transposase (SB11). T cells stably expressing the CAR were retrieved over 28 days of co-culture by recursive additions of designer g-irradiated activating and propagating cells (AaPC) in presence of soluble recombinant interleukin (IL)-2 and IL-21. The aAPC were derived from K562 cells and genetically modified to co-express the TAA CD19 as well as the co-stimulatory molecules CD86, CD137L, and a membrane-bound protein of IL-15. The dual platforms of the SB system and aAPC are illustrated in figure below. Results: To date we have successfully manufactured product for 42 pts with multiply-relapsed ALL (n=19), NHL (n=17), or CLL (n=5) on 4 investigator-initiated trials at MD Anderson Cancer Center to administer thawed pt- and donor-derived CD19-specific T cells as planned infusions in the adjuvant setting after autologous (n=5), allogeneic (n=21) or umbilical cord (n=4) hematopoietic cell transplantation (HCT), or for the treatment of active disease (n=12). Each clinical-grade T-cell product was subjected to a battery of in-process and final release testing. Adjuvant trials: Twelve pts have been infused with donor-derived CAR+ T cells following allogeneic HCT, including 2 pts with cord blood-derived T cells (ALL, n=10; NHL, n=2), beginning at a dose of 106 and escalating to 5x107 modified T cells/m2. Three pts, all with ALL, remain alive and in remission at median 5 months following T cell infusion. Five pts with NHL have been treated with pt-derived modified T cells following autologous HCT at a dose of 5x108 T cells/m2, and 4 pts remain in remission at median 12 months following T-cell infusions. Relapse trials: Thirteen pts have been treated for active disease (ALL, n=8; NHL, n=3; CLL, n=2) with pt or donor-derived (if prior allo-HCT) modified T cells at doses 106-5x107/m2, and 3 remain alive and in remission at median 3 months following T-cell infusions. No acute or late toxicities, including excess GVHD, have been noted. Conclusion: We report the first human application of the SB and AaPC systems to genetically modify clinical-grade cells. Furthermore, infusing CD19-specific CAR+ T cells in the adjuvant HCT setting and thus targeting minimal residual disease may provide an effective and safe approach for maintaining remission in pts at high risk for relapse. Next steps: The SB system serves as a nimble and cost-effective platform for genetic engineering of T cells. We are implementing next-generation clinical T-cell trials targeting ROR1, releasing T cells for infusion within days after electro-transfer of SB DNA plasmid coding for CAR and mRNA coding for transposase, and infusing T cells modified with CAR designs with improved therapeutic potential. Figure: Manufacture of CD19-specific T cells from peripheral and umbilical cord blood mononuclear cells by electro-transfer of SB plasmids and selective propagation of CAR+ T cells on AaPC/IL-2/IL-21. Figure:. Manufacture of CD19-specific T cells from peripheral and umbilical cord blood mononuclear cells by electro-transfer of SB plasmids and selective propagation of CAR+ T cells on AaPC/IL-2/IL-21. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document