Effect of MMP9 inhibition on effector T-cell responses in a PD1-axis refractory model.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 104-104
Author(s):  
Victoria Smith ◽  
Vladi Juric ◽  
Amanda Mikels-Vigdal ◽  
Chris O'Sullivan ◽  
Maria Kovalenko ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Cell Activation ◽  
Immune Cell ◽  
Single Agent ◽  
Fold Increase ◽  
Cytotoxic T Cell

104 Background: Matrix metalloproteinase 9 (MMP9) acts via diverse mechanisms to promote tumor growth and metastasis, and is a key component of the immune-suppressive myeloid inflammatory milieu. We developed a monoclonal antibody (AB0046) that inhibits murine MMP9 and assessed its mechanism of action in immunocompetent mice as a single agent, or in combination with a murine anti-PDL1 antibody. Methods: An orthotopic, syngeneic tumor model (NeuT), which models MMP9-positive myeloid infiltrate, was utilized for efficacy and pharmacodynamic studies involving RNA and T cell receptor (TCR) sequencing, and flow cytometry. Enzymatic analyses were performed on T cell chemoattractant CXCR3 ligands (CXCL9, CXCL10, and CXCL11) which were subsequently evaluated in chemotaxis assays. Results: Anti-MMP9 treatment alone or in combination with an anti-PDL1 antibody decreased primary tumor growth as compared to IgG control-treated animals (56% vs 335% tumor growth increase, p = 0.0005) or anti-PDL1 alone. Profiling of tumors by RNA sequencing revealed that inhibition of MMP9 resulted in elevated expression of genes associated with immune cell activation pathways (Hallmark Interferon Gamma Response, FDR p < 0.001). Treatment with anti-MMP9 and anti-PDL1 antibodies decreased TCR clonality, with evidence of a more diverse TCR repertoire (p = 0.005). Immunophenotyping of tumor-associated T cells by flow cytometry showed that anti-MMP9 and anti-PDL1 co-treatment promoted a 2.8-fold increase in CD3+ cells in tumors (p = 0.01), which was associated with an increase in CD4+ T cells (3.2-fold increase; p = 0.006) and CD8+ T cells (2.8-fold increase; p = 0.013). In contrast, anti-MMP9 and combination treatment resulted in a decrease in tumor-associated regulatory T cells (CD25+ FoxP3+ cells, p = 0.04). MMP9 cleavage of T cell chemoattractant ligands in vitro rendered them functionally inactive for recruitment of activated primary human effector T cells. Conclusions: Inhibition of MMP9 reduces tumor burden and promotes cytotoxic T cell infiltration in a PD1-axis refractory mouse model. The combination of nivolumab and GS-5745, a humanized anti-MMP9 inhibitory antibody, is currently being evaluated in gastric cancer (NCT02864381).

Local activator and T cell engager (LocATE) selectively blocks PD-L1 at the cytolytic synapse for deeper responses in multiple myeloma.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 8045-8045 ◽  
Author(s):  
Christian Leisner ◽  
Leonardo Borras ◽  
Stephanie Jungmichel ◽  
Philipp Richle ◽  
Fabian Scheifele ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Fold Increase ◽  
Checkpoint Inhibition ◽  
Bone Marrow Biopsies ◽  
Immune Synapse

8045 Background: The BCMA-targeting bispecific T-cell engager AMG420 emerged as the first bispecific that achieved responses similar to CAR-T therapies in patients with relapsed/refractory (RR) multiple myeloma (MM). Despite improved ORR, the median duration until relapse is currently limited to approximately 12 months. Persistent minimal residual disease drives relapse and is characterized by increased expression of PD-1/PD-L1. Efficacy with checkpoint inhibitors is compromised by 1) their activity not been targeted specifically to the immune synapse between T cells and cancer cells, and 2) dose-limiting broadly distributed immune-related adverse events, which has halted several clinical trials. This underscores the need for localized checkpoint inhibition within the cytolytic synapse. We developed a Local Activator and T cell Engager (LocATE) antibody that combines binding to CD3 and BCMA with selective blockade of PD-L1 at the immune synapse in just one scaffold. Selectivity is achieved via low afffinity for PD-L1 and high affinity for BCMA. Methods: Antibody mediated Cytotoxicity (LDH assay) and T cell activation (IL-2 release) was measured in vitro using MM cell lines together with isolated human CD3+ T cells. Human ex vivo T cell activity and redirection was evaluated on fresh bone marrow biopsies from MM patients with different disease stages by automated microscopy (pharmacoscopy) and image analysis. Results: The LocATE antibody showed a 5-fold increase in T cell activation and MM cell killing in vitro compared to a BCMAxCD3 BiTE. Furthermore, patient-derived MM cells showed up to a 19-fold increase in T cell activation as compared to a BCMAxCD3 BiTE or a combination of BiTE and PD-L1 inhibitor, while no activity was observed on healthy cells. Conclusions: These results suggest that T cell redirection with simultaneous checkpoint inhibition in the synapse is highly potent while minimizing off-tumor toxicity, therefore, has high therapeutic potential for patients with relapsed MM.

A T Cell-Engaging CD3 Recruit-Tandab Potently Kills CD19+ Tumor B Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3721-3721
Author(s):  
Eugene Zhukovsky ◽  
Uwe Reusch ◽  
Carmen Burkhardt ◽  
Stefan Knackmuss ◽  
Ivica Fucek ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Cells ◽  
Cytotoxicity Assays

Abstract Abstract 3721 Background: CD19 is expressed from early B cell development through differentiation into plasma cells, and is an attractive alternative to CD20 as a target for the development of therapeutic antibodies to treat B cell malignancies. T cells are potent tumor-killing effector cells that cannot be recruited by native antibodies. The CD3 RECRUIT-TandAb AFM11, a humanized bispecific tetravalent antibody with two binding sites for both CD3 and CD19, is a novel therapeutic for the treatment of NHL that harnesses the cytotoxic nature of T cells. Methods: We engineered a bispecific anti-CD19/anti-CD3e tetravalent TandAb with humanized and affinity-matured variable domains. The TandAb's binding properties, T cell-mediated cytotoxic activity, and target-mediated T cell activation were characterized in a panel of in vitro assays. In vivo efficacy was evaluated in a murine NOD/scid xenograft model reconstituted with human PBMC. Results: AFM11 mediates highly potent CD19+ tumor cell lysis in cytotoxicity assays performed on a panel of cell lines (JOK-1, Raji, Nalm-6, MEC-1, VAL, Daudi) and primary B-CLL tumors: EC50 values are in the low- to sub-picomolar range and do not correlate with the expression density of CD19 on the target cell lines. The cytotoxic activity of tetravalent AFM11 is superior to that of alternative bivalent antibody formats possessing only a single binding site for both CD19 and CD3. High affinity binding of AFM11 to CD19 and to CD3 is essential for efficacious T cell recruitment. Both CD8+ and CD4+ T cells mediate cytotoxicity however the former exhibit much faster killing. We observe that AFM11 displays similar cytotoxic efficacy at different effector to target ratios (from 5:1 to 1:5) in cytotoxicity assays; this suggests that T cells are engaged in the serial killing of CD19+ target cells. In the absence of CD19+ target cells in vitro, AFM11 does not elicit T cell activation as manifested by cytokine release (from a panel of ten cytokines associated with T cell activation), their proliferation, or their expression of activation markers. AFM11 activates T cells exclusively in the presence of its targets and mediates lysis of CD19+ cells while sparing antigen-negative bystanders. In the absence of CD19+ target cells, AFM11 concentrations in excess of 500-fold over EC50 induce down-modulation of the CD3/TCR complex. Yet, AFM11-treated T cells can be re-engaged for target cell lysis. All of these features of AFM11-induced T cell activation may contribute additional safety without compromising its efficacy. In vivo AFM11 demonstrates a robust dose-dependent inhibition of subcutaneous Raji tumors in mice. At 5 mg/kg AFM11 demonstrates a complete suppression of tumor growth, and even at 5 ug/kg tumor growth is reduced by 60%. Moreover, we observe that a single administration of AFM11 produces inhibition of tumor growth similar to that of 5 consecutive administrations. Conclusions: In summary, our in vitro and in vivo experiments with AFM11 demonstrate the high potency and efficacy of its anti-tumor cytotoxicity. Thus, AFM11 is a novel highly efficacious drug candidate for the treatment of B cell malignancies with an advantageous safety profile. Disclosures: Zhukovsky: Affimed Therapeutics AG: Employment, Equity Ownership. Reusch:Affimed Therapeutics AG: Employment. Burkhardt:Affimed Therapeutics AG: Employment. Knackmuss:Affimed Therapeutics AG: Employment. Fucek:Affimed Therapeutics AG: Employment. Eser:Affimed Therapeutics AG: Employment. McAleese:Affimed Therapeutics AG: Employment. Ellwanger:Affimed Therapeutics AG: Employment.

500 P2RX7 agonist treatment boosts the ability of IL-12-activated CD8+ T cells to infiltrate and control murine melanoma

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A535-A535
Author(s):  
Kelsey Wanhainen ◽  
Stephen Jameson ◽  
Henrique Borges Da Silva
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Mitochondrial Respiration ◽  
Immune Cell ◽  
List Type ◽  
Memory Cd8 T Cells ◽  
And Control

BackgroundExtracellular adenosine triphosphate (eATP) is a ‘danger signal’ used to sense cellular damage, and recognized by purinergic receptors in mammals. Among those receptors, P2RX7 is preferentially expressed in immune cells. Notably, we recently discovered that P2RX7 is crucial for the generation and maintenance of long-lived tissue-resident and circulating memory CD8+ T cells.1 2 CD8+ T cell function is fundamental for tumor control, and therapies to harness protective CD8+ T cells that overcome exhaustion are currently in the limelight of anticancer strategies. Given our previous data, and the fact that eATP is abundantly present inside the melanoma microenvironment, we tested whether (a) P2RX7 is required for activated CD8+ T cells to infiltrate and control melanoma upon adoptive cell therapy, and (b) P2RX7 agonism can boost the anticancer capacity of CD8+ T cells.Methods(a) We in vitro-activated WT or P2rx7-/- CD8+ T cells (transgenic for the LCMV epitope gp33-P14 or for the ovalbumin SIINFEKL peptide-OTI) with anti-CD3/CD28/IL-2, ± IL-12, for 72h. Cells were adoptively transferred (single transfer of WT or P2rx7-/- cells) into mice with 7 days after subcutaneous transfer of B16 melanoma encoding gp33 or SIINFEKL. We tracked tumor growth until 60 days or at the appropriate endpoint. In some experiments, we sacrificed recipient mice 7 days after adoptive T cell transfer for immune cell phenotyping. Some parameters (cytokine production, mitochondrial respiration via Seahorse) were measured in in vitro-activated cells. (b) WT and P2rx7-/- cells were activated with anti-CD3/anti-CD28/IL-2, ± Bz-ATP, a P2RX7 agonist. Tumor growth was tracked over time until 60 days or at the appropriate endpoint.ResultsWT and P2RX7-deficient (P2rx7-/-) CD8+ T cells in the absence of IL-12 do not differ in tumor infiltration and/or control. However, P2rx7-/- CD8+ T cells activated in response to IL-12 tertiary stimulus do not control B16 melanomas as well as their WT counterparts. Phenotypically, IL-12-P2rx7-/- CD8+ T cells do not profoundly differ from IL-12-WT CD8+ T cells, except for diminished mitochondrial respiration levels in vitro, and diminished mitochondrial membrane potential (e.g. mitochondrial health) among tumor-infiltrating cells. Strikingly, Bz-ATP treatment increased the mitochondrial activity of WT CD8+ T cells in vitro and in vivo and led to increased B16 infiltration and control, in a P2RX7-dependent manner.ConclusionsWe are currently studying the mechanisms behind the ability of P2RX7 agonists to increase the antitumor function of CD8+ T cells; these are promising results that can lead to a new alternative in immune cell therapies against melanoma.AcknowledgementsWe would like to thank Jane Ding and Lily Qian for technical assistance, and Kristin Hogquist for scientific input.Ethics ApprovalThis study was approved by the IACUC board at the University of Minnesota (IACUC number A3456-01)ReferencesBorges da Silva H, Beura LK, Wang H, Hanse EA, Gore R, Scott MC, Walsh DA, Block KE, Fonseca R, Yan Y, Hippen KL, Blazar BR, Masopust D, Kelekar A, Vulchanova L, Hogquist KA, Jameson SC. The purinergic receptor P2RX7 directs metabolic fitness of long-lived memory CD8+ T cells. Nature. 2018; 559(7713):264–268.Borges da Silva H, Peng C, Wang H, Wanhainen KM, Ma C, Lopez S, Khoruts A, Zhang N, Jameson SC. Extracellular ATP sensing via P2RX7 promotes CD8+ tissue-resident memory T cells by enhancing TGF-β sensitivity. Immunity 2020;53(1):158–171.

Mechanism of Synergistic Effects on T Cell Activation By Avadomide (CC-122) and Nivolumab

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4133-4133
Author(s):  
Yumi Nakayama ◽  
Matthew E. Stokes ◽  
Michelle Waldman ◽  
Patrick R. Hagner ◽  
Anita K. Gandhi
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Synergistic Effects ◽  
Single Agent ◽  
Differentially Expressed ◽  
Cytotoxic T Cell ◽  
Employment Equity ◽  
Equity Ownership

Abstract Background: Avadomide (CC-122) is a cereblon modulator that promotes ubiquitination and degradation of the hematopoietic transcription factors Ikaros and Aiolos, leading to immunomodulation, such as T cell activation and increased interleukin-2 (IL-2) production in primary peripheral blood mononuclear cells (PBMCs). The immune checkpoint inhibitor nivolumab (nivo), an anti-PD-1 antibody, induces immune activation and can enhance immune response against various solid tumors. Previously, we have shown that the combination of avadomide and nivo synergistically enhance IL-2 production, T cell proliferation, and immune-mediated cytotoxicity, relative to single agent activity. To understand molecular mechanisms underlying these synergistic effects, we compared the effects of avadomide, nivo, or the combination on gene expression in primary human T cells using whole transcriptome RNA sequencing and differential pathway analysis. Methods: PBMCs were isolated from healthy donors (N=6), treated with DMSO/IgG, avadomide 50 nM, nivo 10 µg/mL, or avadomide and nivo for 1 hour, then stimulated with 0.5 ng/mL staphylococcus enterotoxin B for 48 hours. Culture supernatants were collected for cytokine analysis; T cells were isolated by magnetic cell separation for RNA extraction. RNA was sequenced by Illumina HiSeq v4; data was filtered to transcripts ≥10 counts across all samples and processed by DESeq2. Significantly differentially expressed genes (FDR-adj. P values <0.05) were computed for each treatment group relative to DMSO/IgG controls. Pathway analysis was performed with the GSEA Molecular Signatures Database (MSigDB) using the Hallmark and C2 curated gene sets, which comprise a diverse set of biological pathways, including KEGG and Reactome, to provide unbiased enrichment analysis. T cell-related pathways from the MSigDB C5 (Gene Ontology) collection were used to investigate specific effects on immune function. Synergy was defined by the fractional product method. Results: Avadomide, nivo, and the combination enhanced IL-2 production in SEB-stimulated PBMCs by 282%, 47%, and 586% respectively, compared with DMSO/IgG controls, confirming the synergistic effects on cytokine production. The top pathways upregulated in each treatment group included the following T cell related pathways: for avadomide - T cell receptor (TCR) signaling, JAK/STAT, cytokine/receptor interaction; for nivo - CD8 TCR pathway and HIF1A targets; and for the combination - TCR signaling, JAK/STAT, and HDAC3 targets which are required for T cell maturation and cytokine production. Combination treatment uniquely upregulated pathways including the Biocarta cytotoxic T cell pathway and calcium signaling in CD4+ T cells. Among the 7732 genes modified by any treatment, 1949 were uniquely differentially expressed by the combination. A targeted enrichment analysis using only T cell-related pathways from the C5 collection revealed that these uniquely differentially expressed genes represent processes such as T cell differentiation, proliferation, and activation. Conclusions: At the gene expression level, many T cell-related pathways were upregulated by one or more single agent and/or the combination. However, the presence of uniquely differentially regulated genes suggests that combination treatment induced broader effects in pathways involved in T cell differentiation, proliferation, and activation than either avadomide or nivo alone. Interestingly, the cytotoxic T cell pathway was uniquely upregulated by the combination, consistent with our previous finding of a significant increase in cytotoxicity with avadomide/nivo in combination. Calcium signaling in CD4+ T cell genes were also uniquely upregulated, suggesting that avadomide/nivo combination effects may involve nuclear factor of activated T cells (NFAT)-dependent T cell immune regulation. These data provide molecular support for the in vitro phenotypic activity of avadomide and checkpoint blockade on enhancing T cell activity. Avadomide is now under investigation in combination with checkpoint blockade in solid tumors (NCT02859324) and with CAR T therapy in lymphoma (NCT03310619). Disclosures Nakayama: Celgene Corporation: Employment, Equity Ownership. Stokes:Celgene Corporation: Employment, Equity Ownership. Waldman:Celgene Corporation: Employment, Equity Ownership. Hagner:Celgene Corporation: Employment, Equity Ownership. Gandhi:Celgene Corporation: Employment, Equity Ownership.

561 DuoBody®-PD-L1×4–1BB (GEN1046) induces superior immune-cell activation, cytokine production and cytotoxicity by combining PD-L1 blockade with conditional 4–1BB co-stimulation

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A595-A595
Author(s):  
Alexander Muik ◽  
Isil Altintas ◽  
Rachelle Kosoff ◽  
Friederike Gieseke ◽  
Kristina Schödel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cytokine Production ◽  
Immune Cell ◽  
Anti Tumor Activity

BackgroundCheckpoint inhibitors targeting the PD-1/PD-L1 axis (CPI) have changed the treatment paradigm and prognosis for patients with advanced solid tumors; however, many patients experience limited benefit due to treatment resistance. 4-1BB co-stimulation can activate cytotoxic T-cell- and NK-cell-mediated anti-tumor immunity and has been shown to synergize with CPI in preclinical models. DuoBody-PD­L1×4-1BB is a first-in-class, Fc-silenced, bispecific next-generation checkpoint immunotherapy that activates T cells through PD-L1 blockade and simultaneous PD-L1-dependent 4-1BB co-stimulation. Here we present preclinical evidence for the mechanism of action of DuoBody-PD-L1×4-1BB, and proof-of-concept using mouse-reactive mbsAb-PD-L1×4-1BB in vivo.MethodsRNA sequencing analyses was performed on primary human CD8+ T cells that were co-cultured with PD-L1+ monocytes in the presence of anti-CD3/anti-CD28 and test compounds. T-cell proliferation and cytokine production were analyzed in primary human T-cell and mixed lymphocyte reaction (MLR) assays in vitro, and using patient-derived tumor-infiltrating lymphocytes (TILs). Cytotoxic activity was assessed in co-cultures of CLDN6+PD-L1+ MDA-MB-231 tumor cells and CLDN6-TCR+CD8+ T cells. Anti-tumor activity of mbsAb-PD-L1×4-1BB was tested in vivo using the CT26 mouse tumor model. Immunophenotyping of the tumor microenvironment (TME), tumor-draining lymph nodes (tdLNs) and peripheral blood was performed by flow cytometry.ResultsDuoBody-PD-L1×4-1BB significantly induced expression of genes associated with immune cell proliferation, migration and cytokine production in activated CD8+ T cells, which were not altered by CPI. DuoBody-PD-L1×4-1BB dose-dependently enhanced expansion of human TILs ex vivo. DuoBody-PD-L1×4-1BB dose-dependently enhanced T-cell proliferation and pro-inflammatory cytokine production in vitro (e.g. IFNγ and TNFα; in polyclonal and antigen-specific T-cell proliferation assays and MLR), which was dependent on crosslinking to PD-L1+ cells and superior to CPI or the combination of Fc-silenced PD-L1- and 4-1BB-specific antibodies. DuoBody-PD-L1x4-1BB induced upregulation of degranulation marker CD107a and granzyme B in CD8+ T cells, resulting in antigen-specific T-cell-mediated cytotoxicity of MDA-MB-231 tumor cells in vitro, superior to CPI. In mice bearing subcutaneous CT26 tumors, a model that was insensitive to PD-L1 blockade, mbsAb-PD-L1×4-1BB elicited tumor rejection in the majority of the mice at active dose levels and significantly improved survival. Dose-dependent anti-tumor activity was associated with expansion of tumor antigen-specific T cells in the blood and enhanced immune-cell activation in tdLNs and TME.ConclusionsCombining PD-L1 blockade with conditional 4-1BB co-stimulation using bispecific antibodies induced T-cell activation, expansion, and cytotoxic activity in vitro and potent anti-tumor activity in vivo superior to CPI. DuoBody-PD-L1×4-1BB is currently being evaluated in patients with advanced solid tumors in a first-in-human trial (NCT03917381).Ethics ApprovalAll mice studies were performed by BioNTech SE at its research facilities in Germany, and the mice were housed in accordance with German federal and state policies on animal research. All experiments were approved by the regulatory authorities for animal welfare in Germany. The use of tumor tissue resections was approved by BioNTech SE‘s Ethics Board, approval number 837.309.12 (8410-F).

scholarly journals Reversing Epigenetic Gene Silencing to Overcome Immune Evasion in CNS Malignancies

2021 ◽  
Vol 11 ◽  
Author(s):  
Nivedita M. Ratnam ◽  
Heather M. Sonnemann ◽  
Stephen C. Frederico ◽  
Huanwen Chen ◽  
Marsha-Kay N. D. Hutchinson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Immune Evasion ◽  
Immune Cell ◽  
Single Agent ◽  
Cell Infiltration ◽  
Cell Trafficking ◽  
T Cell Infiltration ◽  
Dismal Prognosis

Glioblastoma (GBM) is an aggressive brain malignancy with a dismal prognosis. With emerging evidence to disprove brain-immune privilege, there has been much interest in examining immunotherapy strategies to treat central nervous system (CNS) cancers. Unfortunately, the limited success of clinical studies investigating immunotherapy regimens, has led to questions about the suitability of immunotherapy for these cancers. Inadequate inherent populations of tumor infiltrating lymphocytes (TILs) and limited trafficking of systemic, circulating T cells into the CNS likely contribute to the poor response to immunotherapy. This paucity of TILs is in concert with the finding of epigenetic silencing of genes that promote immune cell movement (chemotaxis) to the tumor. In this study we evaluated the ability of GSK126, a blood-brain barrier (BBB) permeable small molecule inhibitor of EZH2, to reverse GBM immune evasion by epigenetic suppression of T cell chemotaxis. We also evaluated the in vivo efficacy of this drug in combination with anti-PD-1 treatment on tumor growth, survival and T cell infiltration in syngeneic mouse models. GSK126 reversed H3K27me3 in murine and human GBM cell lines. When combined with anti-PD-1 treatment, a significant increase in activated T cell infiltration into the tumor was observed. This resulted in decreased tumor growth and enhanced survival both in sub-cutaneous and intracranial tumors of immunocompetent, syngeneic murine models of GBM. Additionally, a significant increase in CXCR3+ T cells was also seen in the draining lymph nodes, suggesting their readiness to migrate to the tumor. Closer examination of the mechanism of action of GSK126 revealed its ability to promote the expression of IFN-γ driven chemokines CXCL9 and CXCL10 from the tumor cells, that work to traffic T cells without directly affecting T maturation and/or proliferation. The loss of survival benefit either with single agent or combination in immunocompromised SCID mice, suggest that the therapeutic efficacy of GSK126 in GBM is primarily driven by lymphocytes. Taken together, our data suggests that in glioblastoma, epigenetic modulation using GSK126 could improve current immunotherapy strategies by reversing the epigenetic changes that enable immune cell evasion leading to enhanced immune cell trafficking to the tumor.

scholarly journals Bispecific CAR-T Cells Targeting Both BCMA and CD24: A Potentially Treatment Approach for Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2802-2802
Author(s):  
Fumou Sun ◽  
Yan Cheng ◽  
Bailu Peng ◽  
Hongwei Xu ◽  
Frits van Rhee ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Car T Cells ◽  
Co Activation ◽  
Car T

Abstract Introduction: Anti-myeloma BCMA-specific chimeric antigen receptor (CAR) T-cell therapies represent a promising new treatment strategy, with high response rates observed in the early stages of therapy. However, the responses are not durable. One known mechanism of relapse has been traced to the loss of BCMA expression following long-term CAR-T therapy. Another potential reason is that while BCMA CAR-T cells eliminate the bulk of BCMA-positive MM cells, a small subset of BCMA-negative, very drug-resistant MM cells, such as tumor-initiating cells (TICs) survive and seed relapses. There is a strong correlation between the presence of MM TICs with minimal residual disease, acquired drug resistance and relapse. This suggests that TIC-targeted therapies could improve outcomes. We have previously demonstrated that MM cells expressing CD24 also exhibit features of TICs, e.g. self-renewal, increased expression of embryonic stem cell genes and drug resistance. We have generated bispecific CAR-T cells which recognize both BCMA and CD24 antigens and have tested their therapeutic efficacy in MM cells in vitro and in vivo models. Methods: We constructed a bispecific BCMA-CD24 CAR vector, with 2 complete CAR units: BCMA CAR and CD24 CAR. P2A was inserted between these two CARs. The BCMA CAR contains a safety switch in the hinge region, and a CD28 co-activation domain with CD3ζ. The CD24 CAR contained a 4-1BB co-activation domain with CD3ζ. To decrease the risk of severe immunological side effects, we integrated RQR8, an immunological safety switch with epitopes for CD34 and CD20 as a suicide molecule into the hinge region. Lentivirus particles were used to transduce primary human T cells. CAR-T cells were detected on day 7 by flow cytometry using antibodies to CD34. We performed co-culture killing assays, detected the T cell activation marker CD69 and measured the cytokines in the supernatant. We determined whether BCMA-CD24 CAR-T cells targeted the TIC population by flow cytometry and microscopy. The NOD. Cg-Prkdc scidIl2rg tm1Wjl/SzJ (NSG) xenograft mouse model was used for in vivo studies. 8-week-old NSG mice were administered 2 × 10 6 MM cells by intravenous injection. On day 7 after MM cells injection, 1 × 10 6 CAR-T cells were administered. Mice were weighed and monitored for signs of distress every two days. Bioluminescence images were acquired 10 min after D-luciferin injection. Myeloma progression was monitored every 7 days until the mice develop hind limb paralysis or the bioluminescence signal (ROI) is more than 2 × 10 10. Results: CAR-T cells were detected by flow cytometry using the RQR8-specific CD34 antibody. The BCMA-CD24 CAR was found to be expressed on roughly 13% of T-cells. To determine the selective lysis by the CAR-T cells, we performed co-culture killing assays in which MM cell lines over-expressing CD24 (ARP-1 CD24OE or OCI CD24OE cells) were incubated with CAR-T cells. When the CAR-T: MM ratio was 5:1, the lysis percentage of target cells was 99% (ARP-1 CD24OE) and 89% (OCI CD24OE). CAR-T cell activation was determined by increased CD69 expression and IL-2 production. As expected, exposure to CD24 + MM cells resulted in strong activation of CAR-T cells, and CAR-T cells did target and kill the TIC population. Bioluminescence imaging showed CAR-T mediated antitumor activity, yielding near-complete tumor clearance. Additionally, mice treated with CAR-T cells exhibited increased survival compared with mice in the control groups. Conclusion and Significance: This study developed a BCMA-CD24 CAR-T, a novel MM immunotherapy. We have demonstrated strong cytotoxic activity and selectivity for MM cells in vitro and in vivo. Future studies will be aimed at determining if BCMA-CD24 CAR-T can target TIC-mediated relapses. Disclosures No relevant conflicts of interest to declare.

scholarly journals Prenatal Cadmium Exposure Alters Proliferation in Mouse CD4+ T Cells via LncRNA Snhg7

2022 ◽  
Vol 12 ◽  
Author(s):  
Jamie L. McCall ◽  
Melinda E. Varney ◽  
Emily Rice ◽  
Sebastian A. Dziadowicz ◽  
Casey Hall ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
Protein Levels ◽  
Cd Exposure

ObjectivePrenatal cadmium (Cd) exposure leads to immunotoxic phenotypes in the offspring affecting coding and non-coding genes. Recent studies have shown that long non-coding RNAs (lncRNAs) are integral to T cell regulation. Here, we investigated the role of long non-coding RNA small nucleolar RNA host gene 7 (lncSnhg7) in T cell proliferation.MethodsRNA sequencing was used to analyze the expression of lncRNAs in splenic CD4+ T cells with and without CD3/CD28 stimulation. Next, T cells isolated from offspring exposed to control or Cd water throughout mating and gestation were analyzed with and without stimulation with anti-CD3/CD28 beads. Quantitative qPCR and western blotting were used to detect RNA and protein levels of specific genes. Overexpression of a miR-34a mimic was achieved using nucleofection. Apoptosis was measured using flow cytometry and luminescence assays. Flow cytometry was also used to measure T cell proliferation in culture. Finally, lncSnhg7 was knocked down in splenic CD4+ T cells with lentivirus to assess its effect on proliferation.ResultsWe identified 23 lncRNAs that were differentially expressed in stimulated versus unstimulated T cells, including lncSnhg7. LncSnhg7 and a downstream protein, GALNT7, are upregulated in T cells from offspring exposed to Cd during gestation. Overexpression of miR-34a, a regulator of lncSnhg7 and GALNT7, suppresses GALNT7 protein levels in primary T cells, but not in a mouse T lymphocyte cell line. The T cells isolated from Cd-exposed offspring exhibit increased proliferation after activation in vitro, but Treg suppression and CD4+ T cell apoptosis are not affected by prenatal Cd exposure. Knockdown on lncSnhg7 inhibits proliferation of CD4+ T cells.ConclusionPrenatal Cd exposure alters the expression of lncRNAs during T cell activation. The induction of lncSnhg7 is enhanced in splenic T cells from Cd offspring resulting in the upregulation of GALNT7 protein and increased proliferation following activation. miR-34a overexpression decreased GALNT7 expression and knockdown of lncSnhg7 inhibited proliferation suggesting that the lncSnhg7/miR-34a/GALNT7 is an important pathway in primary CD4+ T cells. These data highlight the need to understand the consequences of environmental exposures on lncRNA functions in non-cancerous cells as well as the effects in utero.

Lenalidomide Decreases PD-1 Expression, Depletes Regulatory T-Cells and Improves Cellular Response to a Multiple Myeloma/Dendritic Cell Fusion Vaccine In Vitro

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 492-492 ◽  
Author(s):  
Katarina Luptakova ◽  
Brett Glotzbecker ◽  
Heidi Mills ◽  
Dina Stroopinsky ◽  
Baldev Vasir ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Fold Increase ◽  
Cellular Immunotherapy ◽  
Cd4 Cells

Abstract Abstract 492 Introduction: We have developed a cancer vaccine for multiple myeloma in which patient derived tumor cells are fused with dendritic cells (DCs) such that a broad array of tumor antigens are presented in the context of DC mediated costimulation. In clinical studies, we have demonstrated that vaccination results in the induction of anti-tumor immunity and disease response in a subset of patients. A fundamental challenge limiting the efficacy of cellular immunotherapy is the immunosuppressive milieu that characterizes patients with myeloma. We have previously reported that the PD-1/PDL-1 pathway plays an important role in suppressing T cell immunity in patients with myeloma, PD-1 expression is upregulated on T cells isolated from patients with multiple myeloma, and PD-1 blockade is associated with enhancement of T-cell response to the vaccine. Lenalidomide is a potent anti-myeloma agent whose activity may be linked, in part, to its immunomodulatory properties. We hypothesized that lenalidomide would augment the capacity to elicit anti-myeloma immunity. In our current study, we examined the effect of lenalidomide on T-cell activation and polarization, PD-1 signaling, and vaccine-induced responses in vitro. Methods and results: Peripheral blood mononuclear cells were cultured in media containing IL-2 with and without 1μM lenalidomide. The expression of cell surface molecules and intracellular cytokines was assessed using flow cytometry. Exposure of unstimulated T cells to lenalidomide resulted in a decrease in the percentage of CD4+ T cells expressing PD-1 (from 8.0% to 5.6%, p=0.04) and a 2 fold increase in T-cell proliferation as measured by incorporation of tritiated thymidine. We then examined the effect of lenalidomide on T cell activation by ligation of the costimulatory complex using antibodies directed against CD3 and anti CD28. Most notably, the upregulation of PD-1 by CD3/CD28 ligation was markedly decreased in the presence of lenalidomide as measured in CD4+ cells (from 26% to 15%, p<0.0001) and in CD8+ cells (from 16% to 10% p<0.01). Ligation of CD3/CD28 in the presence of lenalidomide resulted in greater degree of Th1 polarization as manifested by a 2 fold increase in the percentage of CD8+ T cells expressing IFNγ (p=0.02) and a decrease in the percentage of regulatory T-cells (CD4+CD25+FoxP3+) from 6.88% to 3.13% (p=0.02). In addition, the percentage of NK cells (CD3-CD56+) expressing IFNγ following CD3/CD28 ligation was 5-fold greater (p=0.03) in the presence of lenalidomide. Lastly, we studied the effect of lenalidomide on T-cells stimulated in vitro by the DC/myeloma fusion vaccine. DC/myeloma fusions were generated as previously described. Fusion mediated stimulation of autologous T cells in the presence of lenalidomide resulted in an increase in the percentage CD4+ and CD8+ T cells expressing IFNγ, (5.35% to 8.79%, p=0.06; and 6.37% to 9.85%, p=0.03, respectively). The proportion of regulatory T-cells decreased from 9.57% to 4.43% in the presence of lenalidomide (p<0.01). As with non-specific stimulation, PD-1 expression on CD4+ cells in the presence of lenalidomide decreased from 24% to 19%. In concert with these findings, exposure to lenalidomide resulted in increased cytotoxic T lymphocyte mediated lysis of autologous tumor targets (from 25% to 36%). Conclusions: In vitro exposure to lenalidomide results in enhanced T-cell activation in response to direct ligation of the co-stimulatory complex and stimulation by the DC/myeloma fusion vaccine. Exposure to lenalidomide suppresses T cell expression of PD-1 and expansion of regulatory T cells, 2 critical pathways responsible for tumor mediated immune suppression. To our knowledge, this is the first demonstration of an interaction between lenalidomide and the PD-1/PDL-1 pathway. These findings support the development of cellular immunotherapy in conjunction with lenalidomide, including its use with the DC/myeloma fusion vaccine. Disclosures: No relevant conflicts of interest to declare.

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.

Sign in / Sign up

Export Citation Format

Share Document