Tumor Antigen–Specific T-Cell Expansion Is Greatly Facilitated by In vivo Priming

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.

Download Full-text

Tissue Parenchymal Cell Expression of B7-H1 Inhibits Infiltrating T Cell Expansion and Prevents Persistence of Graft-Versus-Host Disease

Blood ◽

10.1182/blood.v118.21.2974.2974 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2974-2974

Author(s):

Xiaofan Li ◽

Wei He ◽

Ruishu Deng ◽

Can Liu ◽

Miao Wang ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Expansion ◽

Cd8 T Cell ◽

Target Tissue ◽

T Cell Expansion ◽

Parenchymal Cells

Abstract Abstract 2974 Alloreactive donor CD8+ T cells facilitate engraftment and mediate graft versus leukemia (GVL) effects but also cause graft versus host disease (GVHD) in murine and human recipients after allogeneic hematopoietic cell transplantation (HCT). B7-H1 (PD-L1) expression by antigen-presenting cells has an important role in tolerizing activated T cells by binding to PD-1. We and others previously reported that disruption of binding between B7-H1 and PD-1 augments acute GVHD. Parenchymal cells do not usually express B7-H1 but can be induced by inflammatory cytokines (i.e. IFN-g) to express B7-H1. The role of B7-H1 expression by parenchymal tissue cells in regulating the expansion and persistence of donor CD8+ cells in tissues of mice with GVHD has not yet been evaluated. In the current studies, we evaluated the role of B7-H1 expression by GVHD target tissues in regulating donor CD8+ T cell function in 3 different experimental GVHD systems, using in vivo bioluminescent imaging (BLI), in vivo BrdU-labeling, and in vitro proliferation assays. The first system evaluated the role of B7-H1 expression in TBI-conditioned recipients. In these recipients, injected donor CD8+ T cells showed two waves of expansion that correlated with two phases of clinical GVHD. The first wave of donor CD8+ T cell expansion was associated with upregulated expression of B7-H1 in GVHD target tissues and only weak clinical GVHD. The second wave of donor CD8+ T cell expansion was associated with loss of B7-H1 expression, vigorous donor CD8+ T proliferation and expansion in the GVHD target tissues, and lethal GVHD. In a gain-of-function experiment, B7-H1 expression was induced in hepatocytes by hydrodynamic injection of B7-H1 cDNA during the second wave of T cell expansion in mice with GVHD; this subsequently decreased T cell expansion in the liver and ameliorated GVHD. The second system evaluated the role of B7-H1 expression in anti-CD3-conditioned recipients. In wild-type recipients, injected donor CD8+ T cells had only a single wave of expansion, and the mice had no signs of GVHD. B7-H1 expression by tissue cells (i.e. hepatocytes) was up-regulated, and the tissue infiltrating donor CD8+ T cells were anergic. In B7-H1−/− recipients, injected donor CD8+ T cells proliferated vigorously in GVHD target tissues and caused lethal GVHD.The third system evaluated the role of B7-H1 in unconditioned Rag-2−/− recipients after administration of blocking anti-B7-H1 and in the B7-H1−/−Rag-2−/− chimeras with B7-H1 sufficient Rag-2−/− bone marrow cells, in which B7-H1 deficiency was only in tissue parenchymal cells. Both blockade of B7-H1 and B7-H1 deficiency in parenchymal cells resulted in vigorous donor CD8+ T proliferation in GVHD target tissues and caused lethal GVHD. Taken together, these results show that expression of B7-H1 in GVHD target tissue parenchymal cells plays an important role in regulating the proliferation of infiltrating donor CD8+ T cells and preventing the persistence of GVHD. Our studies also indicate that TBI but not anti-CD3 conditioning can lead to loss of GVHD target tissue cell expression of B7-H1 and persistence of GVHD. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

IL-7 increases both thymic-dependent and thymic-independent T-cell regeneration after bone marrow transplantation

Blood ◽

10.1182/blood.v97.5.1491 ◽

2001 ◽

Vol 97 (5) ◽

pp. 1491-1497 ◽

Cited By ~ 223

Author(s):

Crystal L. Mackall ◽

Terry J. Fry ◽

Cathy Bare ◽

Paul Morgan ◽

Anne Galbraith ◽

...

Keyword(s):

Bone Marrow ◽

Bone Marrow Transplantation ◽

T Cell ◽

Marrow Transplantation ◽

Cell Expansion ◽

Immune Reconstitution ◽

Cell Regeneration ◽

T Cell Expansion ◽

Peripheral Expansion

Thymic-dependent differentiation of bone marrow (BM)-derived progenitors and thymic-independent antigen-driven peripheral expansion of mature T cells represent the 2 primary pathways for T-cell regeneration. These pathways are interregulated such that peripheral T-cell expansion is increased in thymectomized versus thymus-bearing hosts after bone marrow transplantation (BMT). This study shows that this interregulation is due to competition between progeny of these 2 pathways because depletion of thymic progeny leads to increased peripheral expansion in thymus-bearing hosts. To test the hypothesis that competition for growth factors modulates the magnitude of antigen-driven peripheral expansion during immune reconstitution in vivo, a variety of T-cell active cytokines were administered after BMT. Of the cytokines (interleukins) tested (IL-3, IL-12, IL-6, IL-2, and IL-7), IL-2 modestly increased peripheral expansion in the face of increasing numbers of thymic emigrants, whereas IL-7 potently accomplished this. This report also demonstrates that the beneficial effect of IL-7 on immune reconstitution is related to both increases in thymopoiesis as well as a direct increase in the magnitude of antigen-driven peripheral expansion. Therefore, the administration of exogenous IL-7, and to a lesser extent IL-2, abrogates the down-regulation in antigen-driven peripheral expansion that occurs in thymus-bearing hosts after BMT. These results suggest that one mechanism by which T-cell–depleted hosts may support antigen-driven T-cell expansion in vivo is via an increased availability of T-cell–active cytokines to support clonal expansion.

Download Full-text

Locally produced C5a binds to T cell–expressed C5aR to enhance effector T-cell expansion by limiting antigen-induced apoptosis

Blood ◽

10.1182/blood-2008-04-151068 ◽

2008 ◽

Vol 112 (5) ◽

pp. 1759-1766 ◽

Cited By ~ 163

Author(s):

Peter N. Lalli ◽

Michael G. Strainic ◽

Min Yang ◽

Feng Lin ◽

M. Edward Medof ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Apoptosis ◽

Cell Expansion ◽

Immune Cell ◽

Regulatory Protein ◽

T Cell Apoptosis ◽

T Cell Expansion

Abstract Our recent studies have shown that immune cell–produced complement provides costimulatory and survival signals to naive CD4+ T cells. Whether these signals are similarly required during effector cell expansion and what molecular pathways link locally produced complement to T-cell survival were not clarified. To address this, we stimulated monoclonal and polyclonal T cells in vitro and in vivo with antigen-presenting cells (APCs) deficient in the complement regulatory protein, decay accelerating factor (DAF), and/or the complement component C3. We found that T-cell expansion induced by DAF-deficient APCs was augmented with diminished T-cell apoptosis, whereas T-cell expansion induced by C3−/− APCs was reduced because of enhanced T-cell apoptosis. These effects were traced to locally produced C5a, which through binding to T cell–expressed C5aR, enhanced expression of Bcl-2 and prevented Fas up-regulation. The results show that C5aR signal transduction in T cells is important to allow optimal T-cell expansion, as well as to maintain naive cell viability, and does so by suppressing programmed cell death.

Download Full-text

Functionalized microcarriers improve T cell manufacturing by facilitating migratory memory T cell production and increasing CD4/CD8 ratio

10.1101/646760 ◽

2019 ◽

Cited By ~ 1

Author(s):

Nathan J. Dwarshuis ◽

Hannah W. Song ◽

Anokhi Patel ◽

Theresa Kotanchek ◽

Krishnendu Roy

Keyword(s):

T Cells ◽

T Cell ◽

Cell Expansion ◽

Magnetic Beads ◽

Memory Cell ◽

Cell Yield ◽

Cell Therapies ◽

T Cell Expansion ◽

Multiple Donors

AbstractAdoptive cell therapies (ACT) using chimeric antigen receptor (CAR) T cells have shown promise in treating cancer, but manufacturing large numbers of high quality cells remains challenging. Critically, current T cell expansion technologies only partially recapitulate thein vivomicroenvironment found in the human lymph nodes. In these organs, T cells expand at high cell density with autocrine/paracrine signaling, as well as signals from the extracellular matrix (ECM). Here we describe a T cell expansion system using degradable gelatin microcarriers functionalized with anti-CD3 and anti-CD28 monoclonal antibodies (mAbs), which address several of these shortcomings. We show that using this system, we can achieve approximately 2-fold greater expansion compared to functionalized magnetic beads, the current industry standard. Furthermore, carriers generated higher numbers of CCR7+CD62L+ migratory, central memory T cells and CD4+ T cells across multiple donors. Both these phenotypes have emerged as important for establishing durable and effective responses in patients receiving T cell immunotherapies. We further demonstrate that carriers can achieve greater memory cell yield compared to beads across a range of IL2 concentrations from 20 U/mL to 100 U/mL. These differences were greater at lower IL2 concentrations, indicating that the carriers are more efficient. We optimized this system using a design of experiments (DOE) approach and found that the carrier concentration affects the memory cell yield in a quadratic manner, where high or low concentrations are detrimental to memory formation. Finally, we show that carriers do not hinder CAR transduction and can maintain the CD4 and memory phenotype advantages in CAR-transduced T cells.

Download Full-text

Faculty Opinions recommendation of Primary T cell expansion and differentiation in vivo requires antigen presentation by B cells.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1031583.368750 ◽

2006 ◽

Author(s):

Laurence Eisenlohr

Keyword(s):

T Cell ◽

B Cells ◽

Antigen Presentation ◽

Cell Expansion ◽

T Cell Expansion

Download Full-text

MHC class II-independent and -dependent T cell expansion and B cell hyperactivity in vivo in mice deficient in CD152 (CTLA-4)

International Immunology ◽

10.1093/intimm/dxh091 ◽

2004 ◽

Vol 16 (7) ◽

pp. 895-904 ◽

Cited By ~ 7

Author(s):

W. Stohl

Keyword(s):

T Cell ◽

B Cell ◽

Mhc Class Ii ◽

Cell Expansion ◽

Class Ii ◽

T Cell Expansion

Download Full-text

Synergy of IL-21 and IL-15 in regulating CD8+ T cell expansion and function

Journal of Experimental Medicine ◽

10.1084/jem.20041057 ◽

2005 ◽

Vol 201 (1) ◽

pp. 139-148 ◽

Cited By ~ 502

Author(s):

Rong Zeng ◽

Rosanne Spolski ◽

Steven E. Finkelstein ◽

SangKon Oh ◽

Panu E. Kovanen ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Expansion ◽

Tumor Regression ◽

Severe Combined Immunodeficiency ◽

Cd8 T Cell ◽

T Cell Expansion

Interleukin (IL)-21 is the most recently recognized of the cytokines that share the common cytokine receptor γ chain (γc), which is mutated in humans with X-linked severe combined immunodeficiency. We now report that IL-21 synergistically acts with IL-15 to potently promote the proliferation of both memory (CD44high) and naive (CD44low) phenotype CD8+ T cells and augment interferon-γ production in vitro. IL-21 also cooperated, albeit more weakly, with IL-7, but not with IL-2. Correspondingly, the expansion and cytotoxicity of CD8+ T cells were impaired in IL-21R−/− mice. Moreover, in vivo administration of IL-21 in combination with IL-15 boosted antigen-specific CD8+ T cell numbers and resulted in a cooperative effect on tumor regression, with apparent cures of large, established B16 melanomas. Thus, our studies reveal that IL-21 potently regulates CD8+ T cell expansion and effector function, primarily in a synergistic context with IL-15.

Download Full-text