scholarly journals Enhancing adoptive CD8 T cell therapy by systemic delivery of tumor associated antigens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ditte E. Jæhger ◽  
Mie L. Hübbe ◽  
Martin K. Kræmer ◽  
Gael Clergeaud ◽  
André V. Olsen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Subsets ◽  
Proliferative Potential ◽  
Systemic Delivery ◽  
Activated T Cells ◽  
T Cell Therapy ◽  
Tumor Associated Antigens ◽  
Post Infusion

AbstractAdoptive T-cell transfer (ACT) offers a curative therapeutic option for subsets of melanoma and hematological cancer patients. To increase response rates and broaden the applicability of ACT, it is necessary to improve the post-infusion performance of the transferred T cells. The design of improved treatment strategies includes transfer of cells with a less differentiated phenotype. Such T cell subsets have high proliferative potential but require stimulatory signals in vivo to differentiate into tumor-reactive effector T cells. Thus, combination strategies are needed to support the therapeutic implementation of less differentiated T cells. Here we show that systemic delivery of tumor-associated antigens (TAAs) facilitates in vivo priming and expansion of previously non-activated T cells and enhance the cytotoxicity of activated T cells. To achieve this in vivo priming, we use flexible delivery vehicles of TAAs and a TLR7/8 agonist. Contrasting subcutaneous delivery systems, these vehicles accumulate TAAs in the spleen, thereby achieving close proximity to both cross-presenting dendritic cells and transferred T cells, resulting in robust T-cell expansion and anti-tumor reactivity. This TAA delivery platform offers a strategy to safely potentiate the post-infusion performance of T cells using low doses of antigen and TLR7/8 agonist, and thereby enhance the effect of ACT.

scholarly journals Direct comparison of target-reactivity and cross-reactivity induced by CAR- and BiTE-redirected T cells for the development of antibody-based T-cell therapy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Masaki Maruta ◽  
Toshiki Ochi ◽  
Kazushi Tanimoto ◽  
Hiroaki Asai ◽  
Takashi Saitou ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Treatment Options ◽  
Cross Reactivity ◽  
Single Chain ◽  
Activated T Cells ◽  
T Cell Therapy ◽  
Myeloma Cells

Abstract The development of chimeric antigen receptor (CAR) and bispecific T-cell engager (BiTE) has led to the successful application of cancer immunotherapy. The potential reactivity mediated by CAR- and BiTE-redirected T cells needs to be assessed to facilitate the application of these treatment options to a broader range of patients. Here, we have generated CAR and BiTE possessing the same single chain fragment variable (scFv) specific for the HLA-A2/NY-ESO-1157-165 complex (A2/NY-ESO-1157). Using HLA-A2+NY-ESO-1+ myeloma cells and peptides presented by HLA-A2 molecules as a model, both sets of redirected T cells recognized and killed HLA-A2+NY-ESO-1+ myeloma cells in an A2/NY-ESO-1157-specific manner in vitro. Moreover, CAR- and BiTE-activated T cells showed similar functional avidity, as assessed by cytokine production and killing activity, both displaying antitumor reactivity against HLA-A2+NY-ESO-1+ myeloma cells in vivo. Interestingly, cross-reactivity for homologous peptides presented by HLA-A*02:01 and NY-ESO-1157 peptide presented by HLA-A2 alleles was not identical between CAR- and BiTE-redirected T cells, probably due to structural differences of modified antibodies. These results have demonstrated that both antitumor CAR- and BiTE-activated T cells have comparable potential to recognize tumors, while paying attention to unknown off-target reactivity that would differ for each antibody-based modality even if the same scFv was employed.

98 ATA3271: an armored, next-generation off-the-shelf, allogeneic, mesothelin-CAR T cell therapy for solid tumors

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A109-A109
Author(s):  
Jiangyue Liu ◽  
Xianhui Chen ◽  
Jason Karlen ◽  
Alfonso Brito ◽  
Tiffany Jheng ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Next Generation ◽  
Phase 3 ◽  
T Cell Therapy ◽  
Cell Therapies ◽  
Car T Cells ◽  
Car T

BackgroundMesothelin (MSLN) is a glycosylphosphatidylinositol (GPI)-anchored membrane protein with high expression levels in an array of malignancies including mesothelioma, ovaria, non-small cell lung cancer, and pancreatic cancers and is an attractive target antigen for immune-based therapies. Early clinical evaluation of autologous MSLN-targeted chimeric antigen receptor (CAR)-T cell therapies for malignant pleural mesothelioma has shown promising acceptable safety1 and have recently evolved with incorporation of next-generation CAR co-stimulatory domains and armoring with intrinsic checkpoint inhibition via expression of a PD-1 dominant negative receptor (PD1DNR).2 Despite the promise that MSLN CAR-T therapies hold, manufacturing and commercial challenges using an autologous approach may prove difficult for widespread application. EBV T cells represent a unique, non-gene edited approach toward an off-the-shelf, allogeneic T cell platform. EBV-specific T cells are currently being evaluated in phase 3 trials [NCT03394365] and, to-date, have demonstrated a favorable safety profile including limited risks for GvHD and cytokine release syndrome.3 4 Clinical proof-of-principle studies for CAR transduced allogeneic EBV T cell therapies have also been associated with acceptable safety and durable response in association with CD19 targeting.5 Here we describe the first preclinical evaluation of ATA3271, a next-generation allogeneic CAR EBV T cell therapy targeting MSLN and incorporating PD1DNR, designed for the treatment of solid tumor indications.MethodsWe generated allogeneic MSLN CAR+ EBV T cells (ATA3271) using retroviral transduction of EBV T cells. ATA3271 includes a novel 1XX CAR signaling domain, previously associated with improved signaling and decreased CAR-mediated exhaustion. It is also armored with PD1DNR to provide intrinsic checkpoint blockade and is designed to retain functional persistence.ResultsIn this study, we characterized ATA3271 both in vitro and in vivo. ATA3271 show stable and proportional CAR and PD1DNR expression. Functional studies show potent antitumor activity of ATA3271 against MSLN-expressing cell lines, including PD-L1-high expressors. In an orthotopic mouse model of pleural mesothelioma, ATA3271 demonstrates potent antitumor activity and significant survival benefit (100% survival exceeding 50 days vs. 25 day median for control), without evident toxicities. ATA3271 maintains persistence and retains central memory phenotype in vivo through end-of-study. Additionally, ATA3271 retains endogenous EBV TCR function and reduced allotoxicity in the context of HLA mismatched targets. ConclusionsOverall, ATA3271 shows potent anti-tumor activity without evidence of allotoxicity, both in vitro and in vivo, suggesting that allogeneic MSLN-CAR-engineered EBV T cells are a promising approach for the treatment of MSLN-positive cancers and warrant further clinical investigation.ReferencesAdusumilli PS, Zauderer MG, Rusch VW, et al. Abstract CT036: A phase I clinical trial of malignant pleural disease treated with regionally delivered autologous mesothelin-targeted CAR T cells: Safety and efficacy. Cancer Research 2019;79:CT036-CT036.Kiesgen S, Linot C, Quach HT, et al. Abstract LB-378: Regional delivery of clinical-grade mesothelin-targeted CAR T cells with cell-intrinsic PD-1 checkpoint blockade: Translation to a phase I trial. Cancer Research 2020;80:LB-378-LB-378.Prockop S, Doubrovina E, Suser S, et al. Off-the-shelf EBV-specific T cell immunotherapy for rituximab-refractory EBV-associated lymphoma following transplantation. J Clin Invest 2020;130:733–747.Prockop S, Hiremath M, Ye W, et al. A Multicenter, Open Label, Phase 3 Study of Tabelecleucel for Solid Organ Transplant Subjects with Epstein-Barr Virus-Driven Post-Transplant Lymphoproliferative Disease (EBV+PTLD) after Failure of Rituximab or Rituximab and Chemotherapy. Blood 2019; 134: 5326–5326.Curran KJ, Sauter CS, Kernan NA, et al. Durable remission following ‘Off-the-Shelf’ chimeric antigen receptor (CAR) T-Cells in patients with relapse/refractory (R/R) B-Cell malignancies. Biology of Blood and Marrow Transplantation 2020;26:S89.

696 Brentuximab vedotin, a CD30-directed antibody-drug conjugate, selectively depletes activated Tregs in vitro and in vivo

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A738-A738
Author(s):  
Bryan Grogan ◽  
Reice James ◽  
Michelle Ulrich ◽  
Shyra Gardai ◽  
Ryan Heiser ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Efflux Pump ◽  
Apoptotic Cell ◽  
T Cell Subsets ◽  
Memory Cells ◽  
Antibody Drug Conjugate ◽  
Selective Depletion

BackgroundRegulatory T cells (Tregs) play an important role in maintaining immune homeostasis, preventing excessive inflammation in normal tissues. In cancer, Tregs hamper anti-tumor immunosurveillance and facilitate immune evasion. Selective targeting of intratumoral Tregs is a potentially promising treatment approach. Orthogonal evaluation of tumor-infiltrating lymphocytes (TILs) in solid tumors in mice and humans have identified CCR8, and several tumor necrosis family receptors (TNFRs), including TNFSFR8 (CD30), as receptors differentially upregulated on intratumoral Tregs compared to normal tissue Tregs and other intratumoral T cells, making these intriguing therapeutic targets.Brentuximab vedotin (BV) is approved for classical Hodgkin lymphoma (cHL) across multiple lines of therapy including frontline use in stage III/IV cHL in combination with doxorubicin, vinblastine, and dacarbazine. BV is also approved for certain CD30-expressing T-cell lymphomas. BV is comprised of a CD30-directed monoclonal antibody conjugated to the highly potent microtubule-disrupting agent monomethyl auristatin E (MMAE).The activity of BV in lymphomas is thought to primarily result from tumor directed intracellular MMAE release, leading to mitotic arrest and apoptotic cell death.The role CD30 plays in normal immune function is unclear, with both costimulatory and proapoptotic roles described. CD30 is transiently upregulated following activation of memory T cells and expression has been linked to highly activated/suppressive IRF4+ effector Tregs.MethodsHere we evaluated the activity of BV on CD30-expressing T cell subsets in vitro and in vivo.ResultsTreatment of enriched T cell subsets with clinically relevant concentrations of BV drove selective depletion of CD30-expressing Tregs > CD30-expressingCD4+ T memory cells, with minimal effects on CD30-expressing CD8+ T memory cells. In a humanized xeno-GVHD model, treatment with BV selectively depleted Tregs resulting in accelerated wasting and robust T cell expansion. The observed differential activity on Tregs is likely attributable to significant increases in CD30 expression and reduced efflux pump activity relative to other T cell subsets. Interestingly, blockade of CD25 signaling prevents CD30 expression on T cell subsets without impacting proliferation, suggesting a link between CD25, the high affinity IL-2 receptor, and CD30 expression.ConclusionsTogether, these data suggest that BV may have an immunomodulatory effect through selective depletion of highly suppressive CD30-expressing Tregs.AcknowledgementsThe authors would like to thank Michael Harrison, PharmD for their assistance in abstract preparation.Ethics ApprovalAnimals studies were approved by and conducted in accordance with Seattle Genetics Institutional Care and Use Committee protocol #SGE-024.

scholarly journals IMMU-31. QUANTITATIVE EVALUATION OF ROUTES OF ADMINISTRATION OF IMMUNOTHERAPEUTIC T CELLS TO ORTHOTOPIC GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii111-ii111
Author(s):  
Lan Hoang-Minh ◽  
Angelie Rivera-Rodriguez ◽  
Fernanda Pohl-Guimarães ◽  
Seth Currlin ◽  
Christina Von Roemeling ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Ex Vivo ◽  
Adoptive T Cell Therapy ◽  
Whole Body ◽  
T Cell Therapy ◽  
Clinical Responses

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.

NFATc3 regulates the transcription of genes involved in T-cell activation and angiogenesis

Blood ◽  
2011 ◽  
Vol 118 (3) ◽  
pp. 795-803 ◽  
Author(s):  
Katia Urso ◽  
Arantzazu Alfranca ◽  
Sara Martínez-Martínez ◽  
Amelia Escolano ◽  
Inmaculada Ortega ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Genes ◽  
Gene Knockout ◽  
Activated T Cells ◽  
Knock Down ◽  
And Function

Abstract The nuclear factor of activated T cells (NFAT) family of transcription factors plays important roles in many biologic processes, including the development and function of the immune and vascular systems. Cells usually express more than one NFAT member, raising the question of whether NFATs play overlapping roles or if each member has selective functions. Using mRNA knock-down, we show that NFATc3 is specifically required for IL2 and cyclooxygenase-2 (COX2) gene expression in transformed and primary T cells and for T-cell proliferation. We also show that NFATc3 regulates COX2 in endothelial cells, where it is required for COX2, dependent migration and angiogenesis in vivo. These results indicate that individual NFAT members mediate specific functions through the differential regulation of the transcription of target genes. These effects, observed on short-term suppression by mRNA knock-down, are likely to have been masked by compensatory effects in gene-knockout studies.

scholarly journals Oligoclonal T Cells Transiently Expand and Express Tim-3 and PD-1 Following Anti-CD19 CAR T Cell Therapy: A Case Report

2018 ◽  
Vol 19 (12) ◽  
pp. 4118 ◽  
Author(s):  
Christopher Funk ◽  
Christopher Petersen ◽  
Neera Jagirdar ◽  
Sruthi Ravindranathan ◽  
David Jaye ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hematologic Malignancy ◽  
Drug Application ◽  
B Cell Lymphoma ◽  
T Cell Subsets ◽  
Phenotypic Analysis ◽  
T Cell Therapy ◽  
Car T Cell ◽  
Car T

Clinical trials of chimeric antigen receptor (CAR) T cells in hematologic malignancy associate remissions with two profiles of CAR T cell proliferation kinetics, which differ based upon costimulatory domain. Additional T cell intrinsic factors that influence or predict clinical response remain unclear. To address this gap, we report the case of a 68-year-old woman with refractory/relapsed diffuse large B cell lymphoma (DLBCL), treated with tisagenlecleucel (anti-CD19), with a CD137 costimulatory domain (4-1BB) on an investigational new drug application (#16944). For two months post-infusion, the patient experienced dramatic regression of subcutaneous nodules of DLBCL. Unfortunately, her CAR T exhibited kinetics unassociated with remission, and she died of DLBCL-related sequelae. Serial phenotypic analysis of peripheral blood alongside sequencing of the β-peptide variable region of the T cell receptor (TCRβ) revealed distinct waves of oligoclonal T cell expansion with dynamic expression of immune checkpoint molecules. One week prior to CAR T cell contraction, T cell immunoglobulin mucin domain 3 (Tim-3) and programmed cell death protein 1 (PD-1) exhibited peak expressions on both the CD8 T cell (Tim-3 ≈ 50%; PD-1 ≈ 17%) and CAR T cell subsets (Tim-3 ≈ 78%; PD-1 ≈ 40%). These correlative observations draw attention to Tim-3 and PD-1 signaling pathways in context of CAR T cell exhaustion.

scholarly journals First-in-Human Study of ET019003, a Next Generation Anti-CD19 T-Cell Therapy, in Patients with Relapsed/Refractory Diffuse Large B Cell Lymphoma (r/r DLBCL)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2870-2870 ◽  
Author(s):  
Pengcheng He ◽  
Hong Liu ◽  
Haibo Liu ◽  
Mina Luo ◽  
Hui Feng ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Cell Expansion ◽  
T Cell Therapy ◽  
Car T ◽  
Equity Ownership ◽  
T Cell Expansion ◽  
The Absolute

Background : CD19-targeted CAR-T therapies have shown promising efficacy in treating B-cell malignancies. However, treatment-related toxicities, such as cytokine-release syndrome (CRS) and CAR T-cell-related encephalopathy syndrome (CRES), have been one of the major obstacles limiting the use of CAR-T therapies. How to minimize occurrence and severity of toxicity while maintaining efficacy is a major focus for T-cell therapies in development. ET019003 is a next generation CD19-targeted T-cell therapy developed by Eureka Therapeutics, built on the proprietary ARTEMISTM T-cell platform. The ET019003 construct is optimized with the co-expression of an ET190L1 Antibody-TCR (Xu et al, 2018) and novel co-stimulation molecule. We are conducting a First-in-human (FIH) study of ET019003 T cells in CD19+ r/r DLBCL patients. Methods: This FIH study aims to evaluate the safety and efficacy of ET019003 T-cell therapy in CD19+ patients with r/r DLBCL. As of July 2019, six subjects were administered ET019003 T cells. These subjects were pathologically confirmed with DLBCL that is CD19+ (by immunohistochemistry), whose disease have progressed or relapsed after 2-5 lines of prior therapies. All were high-risk patients with rapid tumor progression and heavy tumor burden. Each subject had a Ki67 proliferative index over 60%, 2/6 of the subjects had a Ki67 proliferative index over 90%. Moreover, 5/6 of the subjects had extra-nodal involvement. Following a 3-day preconditioning treatment with Fludarabine (25mg/m2/day)/ Cyclophosphamide (250mg/m2/day), patients received i.v. infusions of ET019003 T cells at an initial dose of 2-3×106 cells/kg. Additional doses at 3×106 cells/kg were administered at 14 to 30-day intervals. Adverse events were monitored and assessed based on CTCAE 5.0. Clinical responses were assessed based on Lugano 2014 criteria. Results: As of July 2019, six subjects have received at least one ET019003 T-cell infusion, and four subjects have received two or more ET019003 T-cell infusions. No Grade 2 or higher CRS was observed in the six subjects. One subject developed convulsions and cognitive disturbance. This subject had lymphoma invasion in the central nervous system before ET019003 T-cell therapy. The subject was treated with glucocorticoid and the symptoms resolved within 24 hours. Other adverse events included fever (6/6, 100%), fatigue (3/6, 50%), thrombocytopenia (3/6, 50%), diarrhea (2/6, 33%), and herpes zoster (1/6, 17%). ET019003 T-cell expansion in vivo (monitored by flow cytometry and qPCR) was observed in all six subjects after first infusion. The absolute peak value of detected ET019003 T cells ranged between 26,000 - 348,240 (median 235,500) per ml of peripheral blood. Tmax (time to reach the absolute peak value) was 6 - 14 days (median 7.5 days). For the four subjects who received multiple ET019003 T-cell infusions, the absolute peak values of detected ET019003 T cells after the second infusion were significantly lower than the absolute peak values achieved after the first infusion. For the two subjects who received three or more infusions of ET019003 T cells, no significant ET019003 T-cell expansion in vivo was observed after the third infusion. All six subjects completed the evaluation of clinical responses at 1 month after ET019003 T-cell therapy. All subjects responded to ET019003 T cells and achieved either a partial remission (PR) or complete response (CR). Conclusions: Preliminary results from six CD19+ r/r DLBCL patients in a FIH study show that ET019003 T-cell therapy is safe with robust in vivo T-cell expansion. The clinical study is on-going and we are monitoring safety as well as duration of response in longer follow-up. Reference: Xu et al. Nature Cell Discovery, 2018 Disclosures Liu: Eureka Therapeutics: Employment, Equity Ownership. Chang:Eureka Therapeutics: Equity Ownership. Liu:Eureka Therapeutics: Employment, Equity Ownership.

scholarly journals 708 Novel ways to exploit IL-21 to augment adoptive T cell transfer therapy against tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Anna Cole ◽  
Guillermo Rangel RIvera ◽  
Aubrey Smith ◽  
Megan Wyatt ◽  
Brandon Ware ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Cells ◽  
Striking Difference ◽  
T Cell Therapy ◽  
Cell Immunity ◽  
Emory University

BackgroundIL-21 enhances the anti-tumor capacity of adoptively transferred CD8+ T cells, while IL-2 and IL-15 impair T cell immunity by driving their expansion to a more differentiated status. Yet, these cytokines can act on many different immune cells. Given the potency of IL-21, we tested if this cytokine directly augments T cells or rather if it enhances other immune cells in the culture that indirectly improves T cell therapy.MethodsTo test this question, splenocytes from pmel-1 transgenic mice were used, as all CD8+ T cells express a transgenic TCR specific for tumor-antigen gp10025–33 overexpressed on melanoma. We then peptide activated naïve CD8+ T cells enriched or not from the spleen of pmel-1 mice and expanded them in the presence of IL-21 or IL-2 (10 ng/mL) for four days. Expanded pmel-1 from these various cultures were then restimulated with irradiated splenocytes pulsed with gp10025–33 and grown an additional seven days with IL-2 (10 ng/mL), irrespective of their initial cytokine condition. The in vitro memory phenotype, exhaustion profile, and cytokine secretion of these cultures were then assayed. Furthermore, mice bearing B16KVP melanoma tumors were infused with pmel-1 T cells expanded via these various approaches and compared for their relative capacity to engraft, persist, and regress tumor in vivo.ResultsInterestingly, we discovered that IL-21-treated T cells generated from bulk splenocytes are phenotypically and functionally distinct from IL-21-treated isolated T cells. Upon restimulation, IL-21-treated T cells from bulk splenocytes exhibited an exhausted phenotype that was like anergic IL-2-treated T cells. Moreover, few cells expressed CD62L but expressed heightened markers of suppression, including TIM3, PD-1, and EOMES. Moreover, they produced more effector molecules, including granzyme B and IFN-gamma. In vivo IL-21-treated T cells expanded from bulk splenocytes engrafted and persisted poorly, in turn mediating suboptimal regression of melanoma. Conversely, IL-21 dramatically bolstered the engraftment and antitumor activity of T cells only if they were first isolated from the spleen prior to their expansion and infusion into the animal.ConclusionsCollectively, our data shows that IL-21 may improve ACT therapy best when used directly on antitumor CD8+ T cells. Further studies will illuminate the mechanism behind this striking difference and determine whether other cell subsets reactive to IL-21 cause T cell dysfunction and/or reduced bioavailability. These findings are important for defining the best culture conditions in which to use IL-21 for ACT.AcknowledgementsWe would like to acknowledge Emory University, The Winship Cancer Institute, and the Pediatrics/Winship Flow Cytometry Core.Ethics ApprovalAll animal procedures were approved by the Institutional Animal Care and Use Committee of Emory University, protocol number 201900225.

scholarly journals 124 Functionalizing CAR T cells for selective proliferation and dual-targeting using the meditope technology

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

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.

scholarly journals A Correlation Between Differentiation Phenotypes of Infused T Cells and Anti-Cancer Immunotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Ren ◽  
Kunkun Cao ◽  
Mingjun Wang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antitumor Immunity ◽  
Ex Vivo ◽  
T Cell Therapy ◽  
Production Methods ◽  
Anti Cancer ◽  
Status Differentiation ◽  
Differentiation Status

T-cell therapy, usually with ex-vivo expansion, is very promising to treat cancer. Differentiation status of infused T cells is a crucial parameter for their persistence and antitumor immunity. Key phenotypic molecules are effective and efficient to analyze differentiation status. Differentiation status is crucial for T cell exhaustion, in-vivo lifespan, antitumor immunity, and even antitumor pharmacological interventions. Strategies including cytokines, Akt, Wnt and Notch signaling, epigenetics, and metabolites have been developed to produce less differentiated T cells. Clinical trials have shown better clinical outcomes from infusion of T cells with less differentiated phenotypes. CD27+, CCR7+ and CD62L+ have been the most clinically relevant phenotypic molecules, while Tscm and Tcm the most clinically relevant subtypes. Currently, CD27+, CD62L+ and CCR7+ are recommended in the differentiation phenotype to evaluate strategies of enhancing stemness. Future studies may discover highly clinically relevant differentiation phenotypes for specific T-cell production methods or specific subtypes of cancer patients, with the advantages of precision medicine.

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