Abstract LB144: Overexpression of CD47 protects hypoimmune CAR T cells from innate immune cell killing

2021 ◽  
Author(s):  
Xiaomeng Hu ◽  
Mo Dao ◽  
Kathy White ◽  
Ryan Clarke ◽  
Sam Landry ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Cell ◽  
Cell Killing ◽  
Innate Immune ◽  
Innate Immune Cell ◽  
Car T Cells ◽  
Car T

scholarly journals 114 Preclinical development of a novel iPSC-derived CAR-MICA/B NK cell immunotherapy to overcome solid tumor escape from NKG2D-mediated mechanisms of recognition and killing

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A126-A126
Author(s):  
John Goulding ◽  
Mochtar Pribadi ◽  
Robert Blum ◽  
Wen-I Yeh ◽  
Yijia Pan ◽  
...  
Keyword(s):  
T Cells ◽  
Cancer Immunotherapy ◽  
Tumor Immunity ◽  
Immune Cell ◽  
Nk Cell ◽  
Tumor Escape ◽  
Car T Cells ◽  
Car T

BackgroundMHC class I related proteins A (MICA) and B (MICB) are induced by cellular stress and transformation, and their expression has been reported for many cancer types. NKG2D, an activating receptor expressed on natural killer (NK) and T cells, targets the membrane-distal domains of MICA/B, activating a potent cytotoxic response. However, advanced cancer cells frequently evade immune cell recognition by proteolytic shedding of the α1 and α2 domains of MICA/B, which can significantly reduce NKG2D function and the cytolytic activity.MethodsRecent publications have shown that therapeutic antibodies targeting the membrane-proximal α3 domain inhibited MICA/B shedding, resulting in a substantial increase in the cell surface density of MICA/B and restoration of immune cell-mediated tumor immunity.1 We have developed a novel chimeric antigen receptor (CAR) targeting the conserved α3 domain of MICA/B (CAR-MICA/B). Additionally, utilizing our proprietary induced pluripotent stem cell (iPSC) product platform, we have developed multiplexed engineered, iPSC-derived CAR-MICA/B NK (iNK) cells for off-the-shelf cancer immunotherapy.ResultsA screen of CAR spacer and ScFv orientations in primary T cells delineated MICA-specific in vitro activation and cytotoxicity as well as in vivo tumor control against MICA+ cancer cells. The novel CAR-MICA/B design was used to compare efficacy against NKG2D CAR T cells, an alternative MICA/B targeting strategy. CAR-MICA/B T cells showed superior cytotoxicity against melanoma, breast cancer, renal cell carcinoma, and lung cancer lines in vitro compared to primary NKG2D CAR T cells (p<0.01). Additionally, using an in vivo xenograft metastasis model, CAR-MICA/B T cells eliminated A2058 human melanoma metastases in the majority of the mice treated. In contrast, NKG2D CAR T cells were unable to control tumor growth or metastases. To translate CAR-MICA/B functionality into an off-the-shelf cancer immunotherapy, CAR-MICA/B was introduced into a clonal master engineered iPSC line to derive a multiplexed engineered, CAR-MICA/B iNK cell product candidate. Using a panel of tumor cell lines expressing MICA/B, CAR-MICA/B iNK cells displayed MICA specificity, resulting in enhanced cytokine production, degranulation, and cytotoxicity. Furthermore, in vivo NK cell cytotoxicity was evaluated using the B16-F10 melanoma cell line, engineered to express MICA. In this model, CAR-MICA/B iNK cells significantly reduced liver and lung metastases, compared to untreated controls, by 93% and 87% respectively.ConclusionsOngoing work is focused on extending these preclinical studies to further support the clinical translation of an off-the-shelf, CAR-MICA/B iNK cell cancer immunotherapy with the potential to overcome solid tumor escape from NKG2D-mediated mechanisms of recognition and killing.ReferenceFerrari de Andrade L, Tay RE, Pan D, Luoma AM, Ito Y, Badrinath S, Tsoucas D, Franz B, May KF Jr, Harvey CJ, Kobold S, Pyrdol JW, Yoon C, Yuan GC, Hodi FS, Dranoff G, Wucherpfennig KW. Antibody-mediated inhibition of MICA and MICB shedding promotes NK cell-driven tumor immunity. Science 2018 Mar 30;359(6383):1537–1542.

scholarly journals Impact of T Helper Cell Subtype on CAR-T Cell Therapy Efficacy

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Ibrahim M. Khan, BS BA ◽  
Andrew S. Nelson, PhD ◽  
Mark H. Kaplan, PhD
Keyword(s):  
T Cells ◽  
B Cell ◽  
Culture Conditions ◽  
Cell Killing ◽  
T Helper ◽  
Th Cells ◽  
Car T Cells ◽  
Th9 Cells ◽  
Tnf Α ◽  
Car T

Background and Hypothesis: Chimeric antigen receptors (CARs) are recombinant receptors with high affinity for the target antigen. Used for tumor therapy, CARs are transduced into patient T cells. CAR-T cells specific for CD19 are used to treat B cell acute lymphoblastic leukemia (B-ALL). Cancerous B cells are destroyed by CAR-T cells in an antigen-specific manner. Currently being used in conjunction with radiation and other cancer therapies to prohibit relapse, Dr. Marco Davila of the Moffitt Cancer Center, has shown that CAR-T therapy induces long term remission and B cell aplasia. Experimental Design: In this experiment the CAR vector obtained from Dr. Davila was transduced into T helper cells cultured under varying conditions (Th0, Th9, and ThGranzyme A). B cell killing and longevity of transduced CAR-Th cells were monitored as part of the criteria for determining the most effective Th subtype for the CAR-T therapy. The target cell killing-mechanism was analyzed at the RNA level using quantitative polymerase chain reaction (qPCR) to analyze gene expression of cytotoxic molecules including granzymes A/B, perforins, Fas-FasL, and TNF-α. Th9 cells were expected to be among the most effective of the indicated subtypes due to their longevity and coordination of the immune response. Results: T cells in all conditions were effectively transduced for CAR expression, although Th9 cells demonstrated a greater proportion of cultured cells that were transduced with the CAR. QPCR results suggest that there is specification of cytotoxic programs among the culture conditions. In Th9 cells, qPCR results suggest their use of perforin and TNF-α. Ongoing studies will compare cytotoxic activity. Potential Impact: Further steps after determining the most effective culture conditions include injecting transduced Th cells of the optimized subtype into mice afflicted with BALL to assess cancer killing in vivo as well as the potential harm of the therapy to the patient.

scholarly journals Potent Anti-Tumor Activity of Bcma CAR-T Therapy Against Heavily Treated Multiple Myeloma and Dynamics of Immune Cell Subsets Using Single-Cell Mass Cytometry

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1859-1859 ◽  
Author(s):  
Yongxian Hu ◽  
Zhang Yanlei ◽  
Guoqing Wei ◽  
Chang alex Hong ◽  
He Huang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Single Cell ◽  
Immune Cell ◽  
Cell Mass ◽  
Mass Cytometry ◽  
Car T Cells ◽  
Car T Cell ◽  
Immune Cell Subsets ◽  
Car T

Background BCMA CAR-T cells have demonstrated substantial clinical activity against relapsed/refractory multiple myeloma (RRMM). In different clinical trials, the overall response rate (ORR) varied from 50% to 100%. Complete remission (CR) rate varied from 20% to 80%. Here we developed a BCMA CAR-T cell product manufactured via lentiviral vector-mediated transduction of activated T cells to express a second-generation CAR with 4-1BB costimulatory domain and evaluated the efficacy and safety, moreover, dynamics of immune cell subsets using single-cell mass cytometry during treatment were analyzed. Methods Our trial (ChiCTR1800017404) is a phase 1, single-arm, open-label single center study to evaluate the safety and efficacy of autologous BCMA CAR-T treatment for RRMM. Patients were subjected to a lymphodepleting regimen with Flu and Cy prior to CAR-T infusion. BCMA CAR-T cells were administered as a single infusion at a median dose of 3.5 (1 to 6) ×106/kg. MM response assessment was conducted according to the International Uniform Response Criteria. Cytokine-release syndrome (CRS) was graded as Lee DW et al described (Blood.2014;124(2):188-195). Phenotypic analysis of peripheral blood mononuclear cells (PBMCs), frozen BCMA CAR-T aliquots, phenotype and in vivo kinetics of immune cell subsets after CAR-T infusion were performed by single-cell mass cytometry. Results As of the data cut-off date (August 1st, 2019), 33 patients, median age 62.5 (49 to 75) years old were infused with BCMA CAR-T cells. The median observation period is 8.0 (0.7 to 18) months. ORR was 100% (The patient who died of infection at 20 days after CAR-T infusion were excluded). All the 32 patients achieved MRD negative in bone marrow by flow cytometry in 2 weeks after CAR-T infusion. Partial response (4 PR, 12.1%), VGPR (7 VGPR, 21.2%), and complete response (21 CR, 63.6%) within 12 weeks post CAR-T infusion were achieved. Durable responses from 4 weeks towards the data cut-off date were found in 28/33 patients (84.8%) (Figure 1a). All patients had detectable CAR-T expansion by flow cytometry from Day 3 post CAR-T cell infusion. The peak CAR-T cell expansion in CD3+ lymphocytes of peripheral blood (PB) varied from 35% to 95% with a median percentage of 82.9%. CRS was reported in all the 33 patients, including 4 with Grade 1, 13 with Grade 2 and 16 with Grade 3. During follow-up, 1-year progression-free survival (PFS) was 70.7% (Figure 1b) and overall survival (OS) was 71.7% (Figure 1c). Multivariate analysis of patients with PR and patients with CR+VGPR revealed that factors including extramedullary infiltration, age>60 years old, high-risk cytogenetics, late stage and CAR-T cell dose were not associated with clinical response (P>0.05). Single-cell mass cytometry revealed that the frequency of total T cells, CD8+ T cells, NK cells and CD3+CD56+ NKT cells in PB was not associated with BCM CAR-T expansion or clinical response. CD8+ Granzyme B+ Ki-67+ CAR-T cells expanded prominently in CRS period. As serum cytokines increased during CRS, non-CAR-T immune cell subsets including PD1+ NK cells, CD8+ Ki-67+ ICOS+ T cells expanded dominantly implying that non-CAR-T cells were also activated after CAR-T treatment. After CRS, stem cell like memory CAR-T cells (CD45RO+ CCR7- CD28- CD95+) remain the main subtype of CAR-T cells (Figure 1d). Conclusions Our data showed BCMA CAR-T treatment is safe with prominent efficacy which can overcome the traditional high-risk factors. We also observed high expansion level and long-term persistence of BCMA CAR-T cells contribute to potent anti-myeloma activity. Stem cell like memory CAR-T cells might be associated with long-term persistence of BCMA CAR-T cells. These initial data provide strong evidence to support the further development of this anti-myeloma cellular immunotherapy. Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals TMIC-49. ABROGATING CD70 EXPRESSION IN GBM RESULTS IN A REDUCED IMMUNOSUPPRESSIVE TUMOR MICROENVIRONMENT

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi258-vi258
Author(s):  
Haipeng Tao ◽  
Linchun Jin ◽  
Hector Mendez-Gomez ◽  
Yu Long ◽  
Meng Na ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Immune Cell ◽  
Critical Role ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T ◽  
Tumor Mouse Model ◽  
Immunosuppressive Microenvironment

Abstract BACKGROUND We found that CD70, as an immune modulator, in GBM plays a critical role in immunosuppression and tumor progression. Although CD70+ tumors recruit more CD3+ T cells than CD70— tumors do in patients with GBM, CD70 on GBM is also found to be involved in promoting CD8+ T cell death. The experiments by overexpressing or silencing CD70 in a primary tumor demonstrate that it can alter cell growth, survival, migration, and morphology of GBM cells. CD70 is negatively correlated with survival in patients with gliomas. These results suggest that CD70 is involved in immunosuppression in GBM. OBJECTIVE To determine if abrogating CD70 in tumor using CD70CAR-T cells could reverse the immunosuppressive microenvironment and enhance overall endogenous tumor immunity against both CD70+ and CD70— tumors, which might help to overcome a key obstacle— tumor-heterogeneity using single-targeted CAR-T cell therapy. METHODS CD70 was overexpressed (~75% positivity) in KR158 GBM line. Murine CD70CAR T cells were used to eliminate CD70+ tumors in an immunocompetent orthotopic tumor mouse model. Tumor-bearing mice were administered the CD70CAR T and vector-tranduced T cells, followed by IVIS imaging for tumor growth. The presentation and phenotype of CAR T cells and endogenous immune cell populations in tumors and spleens were measured. RESULTS Five weeks post treatment, CD4+ T cells were found to be the dominant T cell population in tumors for both CAR-T and endogenous T cells. While the CAR-T cells shrank the tumors, fewer PD-1 expressing endogenous T cells, as well as granulocytic MDSC, but not monocytic MDSC were observed in the tumor (not in spleen) for the CAR-T group, compared to the vector group. No significant changes were seen for NK cells and Tregs between the groups. CONCLUSION This study suggests that eliminating CD70+ tumor cells may reverse the immunosuppressive landscape of the tumor microenvironment.

scholarly journals From antibodies to living drugs: Quo vadis cancer immunotherapy?

2021 ◽  
Author(s):  
Árpád Szöőr ◽  
János Szöllősi ◽  
György Vereb
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Monoclonal Antibodies ◽  
Immune Cell ◽  
Wide Spectrum ◽  
Lessons Learned ◽  
Significant Advance ◽  
Preclinical Models ◽  
Car T Cells ◽  
Car T

AbstractIn the last few decades, monoclonal antibodies targeting various receptors and ligands have shown significant advance in cancer therapy. However, still a great percentage of patients experiences tumor relapse despite persistent antigen expression. Immune cell therapy with adoptively transferred modified T cells that express chimeric antigen receptors (CAR) is an engaging option to improve disease outcome. Designer T cells have been applied with remarkable success in the treatment for acute B cell leukemias, yielding unprecedented antitumor activity and significantly improved overall survival. Relying on the success of CAR T cells in leukemias, solid tumors are now emerging potential targets; however, their complexity represents a significant challenge. In preclinical models, CAR T cells recognized and efficiently killed the wide spectrum of tumor xenografts; however, in human clinical trials, limited antitumor efficacy and serious side effects, including cytokine release syndrome, have emerged as potential limitations. The next decade will be an exciting time to further optimize this novel cellular therapeutics to improve effector functions and, at the same time, keep adverse events in check. Moreover, we need to establish whether gene-modified T cells which are yet exclusively used for cancer patients could also be successful in the treatment for other diseases. Here, we provide a concise overview about the transition from monoclonal antibodies to the generation of chimeric antigen receptor T cells. We summarize lessons learned from preclinical models, including our own HER2-positive tumor models, as well as from clinical trials worldwide. We also discuss the challenges we are facing today and outline future prospects.

IL-7 and CCL19 expression in CAR-T cells improves immune cell infiltration and CAR-T cell survival in the tumor

2018 ◽  
Vol 36 (4) ◽  
pp. 346-351 ◽  
Author(s):  
Keishi Adachi ◽  
Yosuke Kano ◽  
Tomohiko Nagai ◽  
Namiko Okuyama ◽  
Yukimi Sakoda ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Survival ◽  
Immune Cell ◽  
Cell Infiltration ◽  
Immune Cell Infiltration ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
T Cell Survival

scholarly journals Novel Immune Cell-Based Therapies to Eradicate High-Risk Acute Myeloid Leukemia

2021 ◽  
Vol 12 ◽  
Author(s):  
Roberto Limongello ◽  
Andrea Marra ◽  
Antonella Mancusi ◽  
Samanta Bonato ◽  
Eni Hoxha ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
Nk Cells ◽  
Genetic Risk ◽  
Myeloid Leukemia ◽  
Immune Cell ◽  
Car T Cells ◽  
Wide Range ◽  
Car T ◽  
Acute Myeloid

Adverse genetic risk acute myeloid leukemia (AML) includes a wide range of clinical-pathological entities with extremely poor outcomes; thus, novel therapeutic approaches are needed. Promising results achieved by engineered chimeric antigen receptor (CAR) T cells in other blood neoplasms have paved the way for the development of immune cell-based therapies for adverse genetic risk AML. Among these, adoptive cell immunotherapies with single/multiple CAR-T cells, CAR-natural killer (NK) cells, cytokine-induced killer cells (CIK), and NK cells are subjects of ongoing clinical trials. On the other hand, allogeneic hematopoietic stem cell transplantation (allo-HSCT) still represents the only curative option for adverse genetic risk AML patients. Unfortunately, high relapse rates (above 50%) and associated dismal outcomes (reported survival ~10–20%) even question the role of current allo-HSCT protocols and emphasize the urgency of adopting novel effective transplant strategies. We have recently demonstrated that haploidentical allo-HSCT combined with regulatory and conventional T cells adoptive immunotherapy (Treg-Tcon haplo-HSCT) is able to overcome disease-intrinsic chemoresistance, prevent leukemia-relapse, and improve survival of adverse genetic risk AML patients. In this Perspective, we briefly review the recent advancements with immune cell-based strategies against adverse genetic risk AML and discuss how such approaches could favorably impact on patients’ outcomes.

scholarly journals G-CSF/Plerixafor Dual-Mobilized Donor Derived CD33CAR T-Cells As Potent and Effective AML Therapy in Pre-Clinical Models

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1716-1716
Author(s):  
Giacomo Canesin ◽  
Hillary Hoyt ◽  
Reid Williams ◽  
Mariana Silva ◽  
Melissa Chng ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Ex Vivo ◽  
Publicly Traded ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract There are currently no known acute myeloid leukemia (AML) specific antigens. Genetic ablation of CD33 using CRISPR/Cas9 engineering of the hematopoietic stem cell (HSC) transplant (VOR33) represents a synthetic biology approach to generating a leukemia-specific antigen in the transplant recipient. VOR33 enables anti-CD33 CAR-T cell killing of AML cells while sparing normal myeloid lineage development and function, thereby potentially avoiding myelosuppression and increasing the therapeutic index of anti-CD33 CAR-T therapy. Mobilized leukapheresis product represents an attractive starting material for the generation of both a CD33 null HSC transplant and a complementary CD33CAR T-cell product. In this study, we sought to determine the impact of dual mobilization with Granulocyte-Colony Stimulating Factor (G-CSF) and plerixafor (mozobil) on immune cell composition, T cell phenotype, and the functionality of these T cells to control AML tumor growth upon chimeric antigen receptor (CAR) transduction. Mobilized (mob) peripheral blood mononuclear cells (PBMCs) were collected from healthy donors injected with G-CSF (10µg/kg/day, 5 consecutive days) and plerixafor (240µg/kg, on day 4 and 5). Non-mobilized (non-mob) PBMCs, collected from the same donors, were used as controls. Cells were analyzed by flow cytometry for immunophenotyping and T cell characterization including differentiation and bone marrow homing markers, as well as responses to T cell activation with anti-CD3 (OKT3) and IL-2. Non-/mob PBMC populations were also analyzed by single-cell next generation sequencing (CITEseq) using 127 immune cell phenotypic markers in combination with extensive transcriptome and T cell receptor repertoire analysis. In addition, lentiviral transduction of anti-CD33 CAR constructs enabled functional comparisons of mob- and non-mob-CAR T-cells in AML cell co-cultures as well as AML mouse models. Ex vivo immunophenotyping of PBMC from a total of over 30 healthy donor samples showed that mobilization decreases the overall percentage of CD3 + T cells but increases that of naïve T cells (CD45RA +/CCR7 +), at the expense of T effector-memory (CD45RA -/CCR7 -) and central-memory (CD45RA -/CCR7 +) populations. Bone marrow homing factors (e.g.: CXCR4) were increased in mob compared to non-mob T cell samples. As expected, higher percentages of monocytes (CD14 +) were detected in mob compared to non-mob donor samples, but this difference disappeared after culture under T cell activation conditions. T cell activation also led to similar increases in CD25, CD69 and CD137 expression, and a decrease in CD62L expression. Single cell sequencing analyses confirmed mobilization-induced increases in naïve T cells as well as changes in monocytes/macrophages, CD4 + T cells and NK cells percentages. Notably, functional in vitro cytotoxic assays demonstrated that mob-CD33-CAR T-cells are as effective as non-mob-CD33-CAR T-cells in killing CD33 + AML cells, with reduced 'bystander' activation of non-transduced T cells. Furthermore, results from in vivo AML mouse models indicate that mob-CD33-CAR T-cells are equally effective in clearing CD33 + tumors as non-mob-CD33-CAR T-cells. Our analysis showed phenotypical ex vivo differences between mob and non-mob PBMCs, which disappeared upon activation, indicating similar responses to T cell-specific stimulation. These findings are corroborated by similar in vitro cytotoxicity profiles of non-/mob-CAR T-cells. Non-transduced T cells in the mob-CAR T-cell population showed limited 'bystander' activation, indicating a potentially favorable clinical toxicity profile. Additional in vivo assessment of mob-CAR T-cell function shows effective tumor clearance, which supports further efforts towards their clinical use in combination with engineered HSCs for the treatment of AML patients. Disclosures Canesin: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Hoyt: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Williams: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Silva: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Chng: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Cummins: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Ung: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Qiu: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Shin: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Hu: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Ge: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Scherer: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Chakraborty: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company. Kassim: Vor Biopharma: Current Employment, Current equity holder in publicly-traded company.

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