scholarly journals lncRNA Mediated Hijacking of T-cell Hypoxia Response Pathway by Mycobacterium tuberculosis Predicts Latent to Active Progression in Humans

2020 ◽  
Author(s):  
Jyotsana Mehra ◽  
Vikram Kumar ◽  
Priyansh Srivastava ◽  
Tavpritesh Sethi
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mrna Level ◽  
Mrna Translation ◽  
Detailed Comparison ◽  
Hypoxia Response ◽  
Mechanistic Pathway ◽  
Cell Hypoxia ◽  
In Cis

AbstractCytosolic functions of Long non-coding RNAs including mRNA translation masking and sponging are major regulators of biological pathways. Formation of T cell-bounded hypoxic granuloma is a host immune defence for containing infected Mtb-macrophages. Our study exploits the mechanistic pathway of Mtb-induced HIF1A silencing by the antisense lncRNA-HIF1A-AS2 in T cells. Computational analysis of in-vitro T-cell stimulation assays in progressors (n=119) versus non-progressor (n=221) tuberculosis patients revealed the role of lncRNA mediated disruption of hypoxia adaptation pathways in progressors. We found 291 upregulated and 227 downregulated DE lncRNAs that were correlated at mRNA level with HIF1A and HILPDA which are major players in hypoxia response. We also report novel lncRNA-AC010655 (AC010655.4 and AC010655.2) in cis with HILPDA, both of which contain binding sites for the BARX2 transcription factor, thus indicating a mechanistic role. Detailed comparison of infection with antigenic stimulation showed a non-random enrichment of lncRNAs in the cytoplasmic fraction of the cell in TB progressors. The lack of this pattern in non-progressors replicates indicates the hijacking of the lncRNA dynamics by Mtb. The in-vitro manifestation of this response in the absence of granuloma indicates pre-programmed host-pathogen interaction between T-cells and Mtb regulated through lncRNAs, thus tipping this balance towards progression or containment of Mtb. Finally, we trained multiple machine learning classifiers for reliable prediction of latent to the active progression of patients, yielding a model to guide aggressive treatment.

627 The DLL3-targeted half-life extended bispecific T cell engager (HLE BiTE®) immune-oncology therapy AMG 757 has potent antitumor activity in neuroendocrine cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Mouse Models ◽  
T Cell Activation ◽  
Phase 1 ◽  
Phase 1 Study ◽  
Human T Cells

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.

scholarly journals DL4-μbeads induce T cell lineage differentiation from stem cells in a stromal cell-free system

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ashton C. Trotman-Grant ◽  
Mahmood Mohtashami ◽  
Joshua De Sousa Casal ◽  
Elisa C. Martinez ◽  
Dylan Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Cell ◽  
Stromal Cell ◽  
Hematopoietic Stem ◽  
Free System ◽  
Cell Therapies ◽  
Immunodeficient Mice ◽  
Human T Cell

AbstractT cells are pivotal effectors of the immune system and can be harnessed as therapeutics for regenerative medicine and cancer immunotherapy. An unmet challenge in the field is the development of a clinically relevant system that is readily scalable to generate large numbers of T-lineage cells from hematopoietic stem/progenitor cells (HSPCs). Here, we report a stromal cell-free, microbead-based approach that supports the efficient in vitro development of both human progenitor T (proT) cells and T-lineage cells from CD34+cells sourced from cord blood, GCSF-mobilized peripheral blood, and pluripotent stem cells (PSCs). DL4-μbeads, along with lymphopoietic cytokines, induce an ordered sequence of differentiation from CD34+ cells to CD34+CD7+CD5+ proT cells to CD3+αβ T cells. Single-cell RNA sequencing of human PSC-derived proT cells reveals a transcriptional profile similar to the earliest thymocytes found in the embryonic and fetal thymus. Furthermore, the adoptive transfer of CD34+CD7+ proT cells into immunodeficient mice demonstrates efficient thymic engraftment and functional maturation of peripheral T cells. DL4-μbeads provide a simple and robust platform to both study human T cell development and facilitate the development of engineered T cell therapies from renewable sources.

scholarly journals 764 Expansion with IL-15 increases cytotoxicity of Vγ9Vδ2 T cells and is associated with higher levels of cytotoxic molecules and T-bet

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A812-A812
Author(s):  
Pia Aehnlich ◽  
Per Thor Straten ◽  
Ana Micaela Carnaz Simoes ◽  
Signe Skadborg ◽  
Gitte Olofsson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Expansion ◽  
Ex Vivo ◽  
Adoptive Cell Therapy ◽  
Hematological Cancers ◽  
Cytotoxic Molecules ◽  
Vγ9vδ2 T Cells ◽  
T Cell Expansion

BackgroundAdoptive cell therapy (ACT) is an approved treatment option for certain hematological cancers and has also shown success for some solid cancers. Still, benefit and eligibility do not extend to all patients. ACT with Vγ9Vδ2 T cells is a promising approach to overcome this hurdle.MethodsIn this study, we explored the effect of different cytokine conditions on the expansion of Vγ9Vδ2 T cells in vitro.ResultsWe could show that Vγ9Vδ2 T cell expansion is feasible with two different cytokine conditions: (a) 1000U/ml interleukin (IL)-2 and (b) 100U/ml IL-2+100U/ml IL-15. We did not observe differences in expansion rate or Vγ9Vδ2 T cell purity between the conditions; however, IL-2/IL-15-expanded Vγ9Vδ2 T cells displayed enhanced cytotoxicity against tumor cells, also in hypoxia. While this increase in killing capacity was not reflected in phenotype, we demonstrated that IL-2/IL-15-expanded Vγ9Vδ2 T cells harbor increased amounts of perforin, granzyme B and granulysin in a resting state and release more upon activation. IL-2/IL-15-expanded Vγ9Vδ2 T cells also showed higher levels of transcription factor T-bet, which could indicate that T-bet and cytotoxic molecule levels confer the increased cytotoxicity.ConclusionsThese results advocate the inclusion of IL-15 into ex vivo Vγ9Vδ2 T cell expansion protocols in future clinical studies.

12 Development of an in vitro assay to assess bispecific T cell engager using T cells from CD3e humanized mice

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A12-A12
Author(s):  
Jun Zhou ◽  
Shuang Zhu ◽  
Hongjuan Zhang ◽  
Lei Zheng ◽  
Mingfa Zang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Lymphoblastic Leukemia ◽  
Humanized Mice ◽  
Activation Markers ◽  
In Vivo Models ◽  
Vitro Assay ◽  
Bite Antibody

BackgroundBispecific T cell engagers (BiTE) is a fast-growing class of immunotherapies. They are bispecific antibody that bind to T cell-surface protein (for example, CD3e) and a specific tumor associate antigen (TAA) on tumor cells, by which to redirect T cells against tumor cells in a MHC-independent manner. A successful example in the clinical is Blinatumomab, a BiTE antibody against CD3/CD19 approved in 2014 to treat acute lymphoblastic leukemia. Currently, many CD3-based BiTE are in clinical trials, including BCMAxCD3, Her2xCD3, CEAxCD3, and PSMAxCD3. To evaluate the efficacy of BiTE in vitro, human peripheral blood monocyte cells (hPBMC) are commonly being used as a source of T cells to co-culture with tumor cells. The disadvantage of using hPBMC is donor-to-donor variability and the availability of the original donor if a study needs to be repeated.MethodsTo overcome this, we proposed to replace hPBMC with T cells from human CD3e (hCD3) genetically engineered mouse models mice (GEMM) for in in vitro coculture assay. T cells were isolated from hCD3 GEMM mice using negative selection mouse T cell isolation kit. Conventional tumor cell lines or luciferase-engineered patient-derived-xenograft (PDX)-derived organoids (PDXO) expressing specific antigens are co-cultured with hCD3 T cells in 96-well plates in the presence of BiTE antibody.ResultsWe measured the killing of tumor cells using either flow cytometry or luciferase activity as readouts. To analyze tumor-reactivity of T cells to cancer cell line or organoids, IFN-gamma in the culture medium was measured and activation markers on T cells was assessed.ConclusionsOur data showed the feasibility of using humanized mice T cells as a replacement for hPBMCs to assess BiTE antibody in vitro. We are further validating the application of murine hCD3 T cells for in vivo models to test bispecific T cell engagers.

scholarly journals Targeting human Acyl-CoA:cholesterol acyltransferase as a dual viral and T cell metabolic checkpoint

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathalie M. Schmidt ◽  
Peter A. C. Wing ◽  
Mariana O. Diniz ◽  
Laura J. Pallett ◽  
Leo Swadling ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Human Liver ◽  
Lipid Droplets ◽  
Ex Vivo ◽  
Functional Cure ◽  
Carcinogenic Activity ◽  
Attractive Therapeutic Target ◽  
Tcr Signalling

AbstractDetermining divergent metabolic requirements of T cells, and the viruses and tumours they fail to combat, could provide new therapeutic checkpoints. Inhibition of acyl-CoA:cholesterol acyltransferase (ACAT) has direct anti-carcinogenic activity. Here, we show that ACAT inhibition has antiviral activity against hepatitis B (HBV), as well as boosting protective anti-HBV and anti-hepatocellular carcinoma (HCC) T cells. ACAT inhibition reduces CD8+ T cell neutral lipid droplets and promotes lipid microdomains, enhancing TCR signalling and TCR-independent bioenergetics. Dysfunctional HBV- and HCC-specific T cells are rescued by ACAT inhibitors directly ex vivo from human liver and tumour tissue respectively, including tissue-resident responses. ACAT inhibition enhances in vitro responsiveness of HBV-specific CD8+ T cells to PD-1 blockade and increases the functional avidity of TCR-gene-modified T cells. Finally, ACAT regulates HBV particle genesis in vitro, with inhibitors reducing both virions and subviral particles. Thus, ACAT inhibition provides a paradigm of a metabolic checkpoint able to constrain tumours and viruses but rescue exhausted T cells, rendering it an attractive therapeutic target for the functional cure of HBV and HBV-related HCC.

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.

scholarly journals THU0046 A PIPELINE TO STUDY ANTIGEN-SPECIFIC CD4+ T CELLS IN RHEUMATOID ARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 235.1-236
Author(s):  
R. Kumar ◽  
N. Yoosuf ◽  
C. Gerstner ◽  
S. Turcinov ◽  
K. Chemin ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Tenascin C ◽  
Tetramer Staining ◽  
Tcr Repertoire ◽  
Citrullinated Antigen

Background:Autoimmunity to citrullinated autoantigens forms a critical component of disease pathogenesis in rheumatoid arthritis (RA). Presence of anti-citrullinated protein antibodies (ACPAs) in patients has high diagnostic value. Recently, several citrullinated antigen specific CD4+T cells have been described. However, detailed studies of their T-cell receptor usage and in-vivo profile suffer from the disadvantage that these cells are present at very low frequencies. In this context, we here present a pipeline for TCR repertoire analysis of antigen-specific CD4+T cells from RA patients, including both citrulline and influenza (control) specificities using in-vitro peptide challenge induced-cell expansion.Objectives:To enable studies of the T cell repertoire of citrullinated antigen-specific CD4+T cells in rheumatoid arthritisMethods:Peripheral blood mononuclear cells (PBMCs) (n=7) and synovial fluid mononuclear cells (SFMCs) (n=5) from HLA-DR*0401-postive RA patients were cultured in the presence of citrullinated Tenascin C peptide cocktails or influenza peptides (positive control). Citrulline reactive cells were further supplemented with recombinant human IL-15 and IL-7 on day 2. All cultures were replenished with fresh medium on day 6 and rIL-2 was added every 2 days from then. Assessment of proportion of peptide-HLA-tetramer positive cells was performed using flow cytometry whereby individual antigen-specific CD4+T cells were sorted into 96-well plates containing cell lysis buffer, followed by PCR-based alpha/beta TCR sequencing. TCR sequencing data was demultiplexed and aligned for TCR gene usage using MiXCR. Some tetramer positive cells were sorted into complete medium containing human IL-2 and PHA for expansion of antigen-specific cells. Cells were supplemented with irradiated allogenic PBMCs (30 times number of antigen specific cells). Clones of antigen specific CD4+T cells were further subjected to tetramer staining to confirm expansion of cells.Results:As evidenced by increase in frequency of tetramer positive CD4+T cells, in vitro peptide stimulation resulted in expansion of both influenza specific (Fig. 1a) and citrullinated antigen specific (Fig. 1b) CD4+T cells. Polyclonal in-vitro expansion of tenascin C tetramer positive sorted cells followed by tetramer staining further confirmed antigen specificity and enrichment for antigen specific CD4+T cells after polyclonal stimulation (Fig.1c). TCR repertoire analysis in PB and SF dataset from the first patient showed clonal expansion of influenza specific cells in both sites. Synovial fluid had more diversity of expanding clones as compared to paired PB, with few expanded clones being shared among SF and PB. We observed a more diverse TCR repertoire in citrulline specific CD4+T cells. We also observed sharing of TCR alpha chains among different citrulline specific CD4+T cell clones.Fig. 1In-vitroexpansion of antigen specific CD4+T cells:Conclusion:This method provides a highly suitable approach for investigating TCR specificities of antigen specific CD4+T cells under conditions of low cell yields. Building on this dataset will allow us to assess specific features of TCR usage of autoreactive T cells in RA.PBMCs were cultured in presence of (a) influenza (HA, MP54) and (b) citrullinated tenascin peptides. The proportion of antigen specific CD4+T cells was assessed using HLA-class II tetramer staining. We observed an increase in frequency of (a) Infleunza specific cells (red dots in upper left and lower right quadrants) and (b) citrullinated tenascin C specific cells (red dots in lower right quadrant), at day 13 post culture as compared to day 3. (c) Sorting of citrullinated tenascin specific CD4+T cells, followed by PHA expansion resulted in visible increase in proportion of citrullinated tenascin specific CD4+T cells.Disclosure of Interests:Ravi kumar: None declared, Niyaz Yoosuf: None declared, Christina Gerstner: None declared, Sara Turcinov: None declared, Karine Chemin: None declared, Vivianne Malmström Grant/research support from: VM has had research grants from Janssen Pharmaceutica

scholarly journals Nanoparticle T-cell engagers as a modular platform for cancer immunotherapy

Leukemia ◽  
2021 ◽  
Author(s):  
Kinan Alhallak ◽  
Jennifer Sun ◽  
Katherine Wasden ◽  
Nicole Guenthner ◽  
Julie O’Neal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Escape ◽  
Multiple Cancer ◽  
Cancer Antigen ◽  
Cancer Antigens ◽  
Car T ◽  
Modular Platform

AbstractT-cell-based immunotherapy, such as CAR-T cells and bispecific T-cell engagers (BiTEs), has shown promising clinical outcomes in many cancers; however, these therapies have significant limitations, such as poor pharmacokinetics and the ability to target only one antigen on the cancer cells. In multiclonal diseases, these therapies confer the development of antigen-less clones, causing tumor escape and relapse. In this study, we developed nanoparticle-based bispecific T-cell engagers (nanoBiTEs), which are liposomes decorated with anti-CD3 monoclonal antibodies (mAbs) targeting T cells, and mAbs targeting the cancer antigen. We also developed a nanoparticle that targets multiple cancer antigens by conjugating multiple mAbs against multiple cancer antigens for T-cell engagement (nanoMuTEs). NanoBiTEs and nanoMuTEs have a long half-life of about 60 h, which enables once-a-week administration instead of continuous infusion, while maintaining efficacy in vitro and in vivo. NanoMuTEs targeting multiple cancer antigens showed greater efficacy in myeloma cells in vitro and in vivo, compared to nanoBiTEs targeting only one cancer antigen. Unlike nanoBiTEs, treatment with nanoMuTEs did not cause downregulation (or loss) of a single antigen, and prevented the development of antigen-less tumor escape. Our nanoparticle-based immuno-engaging technology provides a solution for the major limitations of current immunotherapy technologies.

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 Immunotherapy using IgE or CAR T cells for cancers expressing the tumor antigen SLC3A2

2021 ◽  
Vol 9 (6) ◽  
pp. e002140
Author(s):  
Giulia Pellizzari ◽  
Olivier Martinez ◽  
Silvia Crescioli ◽  
Robert Page ◽  
Ashley Di Meo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
T Cells ◽  
T Cell ◽  
Type I ◽  
Cell Therapies ◽  
Car T Cells ◽  
Car T Cell ◽  
Tumor Associated Antigen ◽  
Car T

BackgroundCancer immunotherapy with monoclonal antibodies and chimeric antigen receptor (CAR) T cell therapies can benefit from selection of new targets with high levels of tumor specificity and from early assessments of efficacy and safety to derisk potential therapies.MethodsEmploying mass spectrometry, bioinformatics, immuno-mass spectrometry and CRISPR/Cas9 we identified the target of the tumor-specific SF-25 antibody. We engineered IgE and CAR T cell immunotherapies derived from the SF-25 clone and evaluated potential for cancer therapy.ResultsWe identified the target of the SF-25 clone as the tumor-associated antigen SLC3A2, a cell surface protein with key roles in cancer metabolism. We generated IgE monoclonal antibody, and CAR T cell immunotherapies each recognizing SLC3A2. In concordance with preclinical and, more recently, clinical findings with the first-in-class IgE antibody MOv18 (recognizing the tumor-associated antigen Folate Receptor alpha), SF-25 IgE potentiated Fc-mediated effector functions against cancer cells in vitro and restricted human tumor xenograft growth in mice engrafted with human effector cells. The antibody did not trigger basophil activation in cancer patient blood ex vivo, suggesting failure to induce type I hypersensitivity, and supporting safe therapeutic administration. SLC3A2-specific CAR T cells demonstrated cytotoxicity against tumor cells, stimulated interferon-γ and interleukin-2 production in vitro. In vivo SLC3A2-specific CAR T cells significantly increased overall survival and reduced growth of subcutaneous PC3-LN3-luciferase xenografts. No weight loss, manifestations of cytokine release syndrome or graft-versus-host disease, were detected.ConclusionsThese findings identify efficacious and potentially safe tumor-targeting of SLC3A2 with novel immune-activating antibody and genetically modified cell therapies.

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