scholarly journals Augmented expansion of Treg cells from healthy and autoimmune subjects via adult progenitor cell co-culture

2020 ◽  
Author(s):  
JL Reading ◽  
VD Roobrouck ◽  
CM Hull ◽  
PD Becker ◽  
J Beyens ◽  
...  

AbstractRecent clinical experience has demonstrated that adoptive regulatory T cell therapy is a safe and feasible strategy to suppress immunopathology via induction of host tolerance to allo- and autoantigens. However, clinical trials continue to be compromised due to an inability to manufacture a sufficient Treg cell dose. Multipotent adult progenitor cells (MAPCⓇ) promote regulatory T cell differentiation in vitro, suggesting they may be repurposed to enhance ex vivo expansion of Tregs for adoptive cellular therapy. Here, we use a GMP compatible Treg expansion platform to demonstrate that MAPC cell-co-cultured Tregs (MulTreg) exhibit a log-fold increase in yield across two independent cohorts, reducing time to target dose by an average of 30%. Enhanced expansion is linked with a distinct Treg cell-intrinsic transcriptional program, characterized by diminished levels of core exhaustion (BATF, ID2, PRDM1, LAYN, DUSP1), and quiescence (TOB1, TSC22D3) related genes, coupled to elevated expression of cell-cycle and proliferation loci (MKI67, CDK1, AURKA, AURKB). In addition, MulTreg display a unique gut homing (CCR7lo β7hi) phenotype and importantly, are more readily expanded from patients with autoimmune disease compared to matched Treg lines, suggesting clinical utility in gut and/or Th1-driven pathology associated with autoimmunity or transplantation. Relative to expanded Tregs, MulTreg retain equivalent and robust purity, FoxP3 TSDR demethylation, nominal effector cytokine production and potent suppression of Th1-driven antigen specific and polyclonal responses in vitro and xeno graft vs host disease (xGvHD) in vivo. These data support the use of MAPC cell co-culture in adoptive Treg therapy platforms as a means to rescue expansion failure and reduce the time required to manufacture a stable, potently suppressive product.

2021 ◽  
Vol 12 ◽  
Author(s):  
James L. Reading ◽  
Valerie D. Roobrouck ◽  
Caroline M. Hull ◽  
Pablo Daniel Becker ◽  
Jelle Beyens ◽  
...  

Recent clinical experience has demonstrated that adoptive regulatory T (Treg) cell therapy is a safe and feasible strategy to suppress immunopathology via induction of host tolerance to allo- and autoantigens. However, clinical trials continue to be compromised due to an inability to manufacture a sufficient Treg cell dose. Multipotent adult progenitor cells (MAPCⓇ) promote Treg cell differentiation in vitro, suggesting they may be repurposed to enhance ex vivo expansion of Tregs for adoptive cellular therapy. Here, we use a Good Manufacturing Practice (GMP) compatible Treg expansion platform to demonstrate that MAPC cell-co-cultured Tregs (MulTreg) exhibit a log-fold increase in yield across two independent cohorts, reducing time to target dose by an average of 30%. Enhanced expansion is coupled to a distinct Treg cell-intrinsic transcriptional program characterized by elevated expression of replication-related genes (CDK1, PLK1, CDC20), downregulation of progenitor and lymph node-homing molecules (LEF1 CCR7, SELL) and induction of intestinal and inflammatory tissue migratory markers (ITGA4, CXCR1) consistent with expression of a gut homing (CCR7lo β7hi) phenotype. Importantly, we find that MulTreg are more readily expanded from patients with autoimmune disease compared to matched Treg lines, suggesting clinical utility in gut and/or T helper type1 (Th1)-driven pathology associated with autoimmunity or transplantation. Relative to expanded Tregs, MulTreg retain equivalent and robust purity, FoxP3 Treg-Specific Demethylated Region (TSDR) demethylation, nominal effector cytokine production and potent suppression of Th1-driven antigen specific and polyclonal responses in vitro and xeno Graft vs Host Disease (xGvHD) in vivo. These data support the use of MAPC cell co-culture in adoptive Treg therapy platforms as a means to rescue expansion failure and reduce the time required to manufacture a stable, potently suppressive product.


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.


2020 ◽  
Author(s):  
Caroline Lamarche ◽  
German E. Novakovsky ◽  
Christopher N. Qi ◽  
Evan W. Weber ◽  
Crystal L. Mackall ◽  
...  

AbstractRegulatory T cell (Treg) therapy is a promising approach to improve outcomes in transplantation and autoimmunity. In conventional T cell therapy, chronic stimulation can result in poor in vivo function, a phenomenon termed exhaustion. Whether or not Tregs are also susceptible to exhaustion, and if so, if this would limit their therapeutic effect, was unknown. We studied how two methods which induce conventional T cell exhaustion – repetitive stimulation or expression of a tonic-signaling chimeric antigen receptor (CAR) – affect human Tregs. With each repetitive polyclonal stimulation Tregs progressively acquired an exhausted phenotype, and became less suppressive in vitro. Tregs expressing a tonic-signaling CAR rapidly acquired an exhausted phenotype and had major changes in their transcriptome and metabolism. Although tonic-signaling CAR-Tregs remained stable and suppressive in vitro, they lost in vivo function, as tested in a model of xenogeneic graft-versus-host disease. The finding that human Tregs are susceptible to exhaustion has important implications for the design of Treg adoptive immunotherapy strategies.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3086-3086
Author(s):  
Ryan Urak ◽  
ChingLam Wong ◽  
Wen-Chung Chang ◽  
Elizabeth E. Budde ◽  
Christine Brown ◽  
...  

Abstract Insufficient persistence and effector function of Chimeric Antigen Receptor (CAR) re-directed T cells in vivo has been a challenge for adoptive T cell therapy. Generation of long-lived potent CAR T cells is an increasing demand in the field. AKT activation triggered by convergent extracellular signals evokes a transcription program that enhances effector functions. However, sustained AKT activation severely impairs T cell memory and protective immunity because AKT drives differentiation of effectors, therefore diminishing T cell potential to survive and differentiate into memory cells. We now investigate whether inhibition of AKT signaling during ex vivo expansion can prevent terminal differentiation of CD19- chimeric antigen receptor (CD19 CAR) engineered T cells and increase the number of memory CD19 CAR T cells, which would enhance the antitumor activity following adoptive therapy. CD8+ T cells from healthy donors were isolated, activated with CD3/CD28 beads, and then transduced with a lentiviral vector encoding a second-generation CD19CAR containing a CD28 co-stimulatory domain and two mutations (L235E; N297Q) within the CH2 region on the IgG4-Fc spacers which enhances potency and persistence by blocking Fc receptor binding. In addition, the lentiviral construct also expresses a truncated human epidermal growth factor receptor (huEGFRt) which allows us to use as a selectable marker and a mechanism to ablate the CAR T cells if necessary. IL-2 (50U/mL) and AKT inhibitor (1uM/mL) were supplemented every other day. Transduced CD19CAR T cells without AKT inhibitor treatment were used as controls. The engineered CD19CAR T cells were expanded in vitro for 21 days before in vitro and in vivo analyses. We found that AKT inhibitor did not compromise the CD19CAR T cell proliferation and survival in vitro. There was a comparable CD19CAR T cell expansion after culturing in the presence or absence AKT inhibitor. Functionally, AKT inhibitor did not dampen the effector function of CD19CAR T cells as indicated by equivalent levels of interferon gamma production and CD107a expression upon CD19 antigen stimulation. Memory-like phenotype such as CD62L and CD28 expression on CAR T cells is associated with better antitumor activity in vivo. We therefore characterized the CD19CAR T cells after ex vivo expansion. We found that 40% of AKT-inhibited CD19CAR T cells expressed CD62L and co-expressed CD28. More importantly, no exhaustion markers such as KRLG and PD-1 were induced on the AKT inhibitor treated cells. In contrast, only 10% of control untreated CD19CAR T cells expressed CD62L and they were CD28 negative, indicating that AKT-inhibited CD19CAR T cells with higher levels of CD62L and CD28 expression may have superior anti-tumor activity following adoptive transfer. To test the potency of the AKT inhibitor treated CAR T cells, 0.5x106 CD19+ acute lymphoid leukemic cells (SupB15) engineered to express firefly luciferase were inoculated intravenously into NOD/Scid IL-2RgammaCnull (NSG) mice. Five days post tumor engraftment, 2x106 CD8+ CD19CAR T cells were intravenously injected into tumor bearing mice. Control mice received either no T cells, non-transduced T cells (Mock), or CD19CAR T cells that were not treated with AKT inhibitor during in vitro expansion. Tumor signals post T cell infusion were monitored by biophotonic imaging. Compared to the untreated CD19CAR T cells, which exhibited lower and transient anti-tumor activity, AKT inhibitor treated CD19CAR T cells completely eradicated the CD19+ tumor in all mice (Figure 1) 21 days post CD19CAR T cell infusion. In conclusion, our results demonstrate that inhibition of AKT signaling during the ex vivo priming and expansion gives rise to a CD19CAR T cell population that possesses superior antitumor activity. These findings suggest that ex vivo therapeutic modulation of AKT might be a strategy to augment antitumor immunity for adoptive CAR T cell therapy, which could easily be transitioned into the clinic with the availability of pharmaceutical grade AKT inhibitor. Disclosures Forman: Amgen: Consultancy; Mustang: Research Funding.


Author(s):  
Adham S. Bear ◽  
Joseph A. Fraietta ◽  
Vivek K. Narayan ◽  
Mark O’Hara ◽  
Naomi B. Haas

Cancer immunotherapy tools include antibodies, vaccines, cytokines, oncolytic viruses, bispecific molecules, and cellular therapies. This review will focus on adoptive cellular therapy, which involves the isolation of a patient’s own immune cells followed by their ex vivo expansion and reinfusion. The majority of adoptive cellular therapy strategies utilize T cells isolated from tumor or peripheral blood, but may utilize other immune cell subsets. T-cell therapies in the form of tumor-infiltrating lymphocytes, T-cell receptor T cells, and CAR T cells may act as “living drugs” as these infused cells expand, engraft, and persist in vivo, allowing adaptability over time and enabling durable remissions in subsets of patients. Adoptive cellular therapy has been less successful in the management of solid tumors because of poor homing, proliferation, and survival of transferred cells. Strategies are discussed, including expression of transgenes to address these hurdles. Additionally, advances in gene editing using CRISPR/Cas9 and similar technologies are described, which allow for clinically translatable gene-editing strategies to enhance the antitumor activity and to surmount the hostilities advanced by the host and the tumor. Finally, the common toxicities and approaches to mitigate these are reviewed.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A109-A109
Author(s):  
Jiangyue Liu ◽  
Xianhui Chen ◽  
Jason Karlen ◽  
Alfonso Brito ◽  
Tiffany Jheng ◽  
...  

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.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Anna Cole ◽  
Guillermo Rangel RIvera ◽  
Aubrey Smith ◽  
Megan Wyatt ◽  
Brandon Ware ◽  
...  

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.


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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Ren ◽  
Kunkun Cao ◽  
Mingjun Wang

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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