scholarly journals 211 SQZ™ eAPCs generated from PBMCs by delivery of multiple mRNAs encoding for antigens, costimulatory proteins, and engineered cytokines

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A224-A224
Author(s):  
Michael Maloney ◽  
Emrah Ilker Ozay ◽  
Amy Merino ◽  
Andrea Silva ◽  
Amber Martin ◽  
...  

BackgroundAntigen-specific CD8+ T cells are critical components of mounting an effective immune response against tumors. Generation of antigen-specific T cells require interactions with multiple signals produced by antigen presenting cells (APCs). These signals are comprised of three components: (signal 1) the peptide-MHC complex binding to the T cell receptor, (signal 2) costimulatory molecules on the surface of APCs, and (signal 3) inflammatory cytokines binding to cognate receptors on T cells.MethodsTo engineer all major cell subsets of human peripheral blood mononuclear cells (PBMCs) to become enhanced APCs (eAPCs), we used Cell Squeeze® technology to deliver multiple mRNA encoding for non-self-antigens (signal 1), CD86 (signal 2), and/or membrane-bound cytokines (signal 3). The signal 3 molecules, membrane-bound IL-12 (mbIL-12) and membrane-bound IL-2 (mbIL-2), are chimeric proteins designed to increase the localized concentration of the cytokines and limit off-target effects. Flow cytometry and western blots were used to confirm the translation of each of the delivered mRNA. The increased capabilities of these enhanced APCs were assessed in vitro by culturing the APCs with antigen-specific T cells for multiple days before measuring the functionality of antigen-specific T cells via intracellular cytokine staining or ELISA.ResultsWe demonstrate that Cell Squeeze® processing of PBMCs with mRNA encoding for signals 1, 2, and 3 results in highly effective enhanced APCs in vitro. In a single squeeze process, efficient delivery and translation of up to five mRNA is observed in all major PBMC cell subsets including T cells, B cells, NK cells, and monocytes. Once translated, the chimeric mbIL-2 and mbIL-12 can bind to their cognate receptors and exhibit minimal shedding from the surface. We show that enhanced APCs can present antigenic peptides derived from mRNA encoding for a foreign antigen on MHC complexes in an HLA agnostic manner, which drives antigen-specific T cell responses. The addition of CD86, mbIL-2, and mbIL-12 further enhance the activation and potency of antigen-specific T cells, as measured by an increase in the secretion of inflammatory cytokines upon restimulation (i.e. IFNγ).ConclusionsCell squeezing of human PBMCs with mRNA encoding for signals 1, 2, and 3 has the potential to generate enhanced APCs that drive robust CD8+ T cell response against multiple targets across several disease areas. The versatility of the Cell Squeeze® technology potentially enables rapid exchange of mRNA to other antigens or T cell activation signals.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4057-4057 ◽  
Author(s):  
Kirsten Marie Boughan ◽  
Xiaohua Chen ◽  
Paul Szabolcs

Abstract Background: AML remains a disease diagnosed in the aging population with chemotherapy followed by bone marrow transplant in some cases being the standard of care. Although response rates remain around 50-60%, treatment related mortality and disease relapse remain high. Adoptive immunotherapy, especially those targeting T cell co-inhibitory receptors, has proven successful in solid malignancies however, AML remains less explored. Our laboratory has previously demonstrated the feasibility to generate autologous AML reactive T cells in vitro (Mehta/Szabolcs; Immunotherapy 2016). It was noted that "resistant" AML blasts over expressed a number of genes associated with immunosuppressive characteristics. Over expression of these genes may induce T cell functional exhaustion. Therefore, we hypothesized that blocking PD-1 and/or CTLA-4 during co-culture with IFNg activated AML blasts, may enhance T cell activation and cytotoxicity. To test this hypothesis, we tested CTL responses against AML blasts and IFNg ELISpot formation after blocking with PD-1, CTLA-4 or both receptors, and compared the response in untreated T cells. Gene expression profiles of co-stimulatory/co-inhibitory receptors were also monitored to test for correlation. Methods: We evaluated 12 patients with newly diagnosed AML under an IRB approved protocol with written informed consent of patients. Mononuclear cell preparation was generated from fresh marrow samples or drawn from a biorepository of previously cryopreserved leukophereses. T cells were then purified using immunomagnetic CD3/CD28 beads (Life technologies) and cultivated in media with IL-2 and IL-7 for 2 weeks. AML blasts were cultured over a supporting layer of mesenchymal stromal cells (MSCs) derived from healthy BM donors for 1 week and then cryopreserved. T cells were then co-cultured with restored and irradiated autologous AML cells at an effector: target (E: T) ratio of 5:1 to 40:1. AML and T cells were co-cultured in the presence of Ipilimumab (anti-CTLA-4), or Nivolumab (anti-PD-1), or a combination of both drugs. T cells and AML were re stimulated in X-vivo 15 with IL-12, IL-15 and IL-2 weekly x 3weeks. T cell response to AML was quantitated by IFNg ELISpot assay and Europium TDA (EuTDA) CTL assays independently. Co-stimulatory/co-inhibitory expression on T cells was examined with RT-q PCR assay. Paired-sample student t test was used for statistical analysis with p<0.05. Results and Discussion: Out of 12 samples, 10 (83%) yielded viable AML cells available for cytotoxicity assay. One third (33%) of co-cultures exhibited a positive T cell response in CTL assays ("killers"). There was no difference in CTL activity by blockade of either PD-1 or CTL-4 (Fig 1). IFN-ɣ spot formation in ELISpot was observed in 4/10 samples (40%) with statistical significance noted in cells blocked with PD-1 as compared to all other blockade types (Fig 2). The results indicated that in vitro priming with autologous AML blasts or together with blocking PD-1 can enhance T cell response in 33-40%. By gene expression analysis, the ratio of co-stimulatory to co-inhibitory genes was calculated. In PD-1 blocked cells, the ratio of activation/inhibition was not impacted in T cells from "killers" (0.9; p=0.1), however, T cells from "non-killer cells" had a diminished ratio due to higher expression of co-inhibitory molecules (0.4; p=0.04) (Fig 3). This trend was also present in CTLA-4 blocked cells (0.85; p=0.4 in killers vs 0.54; p=0.03 in non-killers) (data not shown). Interestingly, dual blockage failed to influence gene expression ratio, data not shown. Conclusion: The above studies demonstrate that cytotoxicity can be achieved in T cells when primed against autologous AML. PD-1 blockade can enhance IFNg production and cytotoxic responses, but CTLA-4 and dual blockade failed to enhance T cell function. The upregulation of an inhibitory pattern of genes in T cells that did not express cytotoxicity (non-killers) could allude to an "inhibitory phenotype" that may be resistant to immunotherapy drug blockade and requires further study. Disclosures No relevant conflicts of interest to declare.


2011 ◽  
Vol 79 (11) ◽  
pp. 4493-4502 ◽  
Author(s):  
Shih-Hung Hsieh ◽  
Jr-Shiuan Lin ◽  
Juin-Hua Huang ◽  
Shang-Yang Wu ◽  
Ching-Liang Chu ◽  
...  

ABSTRACTWe have previously revealed the protective role of CD8+T cells in host defense againstHistoplasma capsulatumin animals with CD4+T cell deficiency and demonstrated that sensitized CD8+T cells are restimulatedin vitroby dendritic cells that have ingested apoptotic macrophage-associatedHistoplasmaantigen. Here we show that immunization with apoptotic phagocytes containing heat-killedHistoplasmaefficiently activated functional CD8+T cells whose contribution was equal to that of CD4+T cells in protection againstHistoplasmachallenge. Inhibition of macrophage apoptosis due to inducible nitric oxide synthase (iNOS) deficiency or by caspase inhibitor treatment dampened the CD8+T cell but not the CD4+T cell response to pulmonaryHistoplasmainfection. In mice subcutaneously immunized with viableHistoplasmayeasts whose CD8+T cells are protective againstHistoplasmachallenge, there was heavy granulocyte and macrophage infiltration and the infiltrating cells became apoptotic. In mice subcutaneously immunized with carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled apoptotic macrophages containing heat-killedHistoplasma, the CFSE-labeled macrophage material was found to localize within dendritic cells in the draining lymph node. Moreover, depleting dendritic cells in immunized CD11c-DTR mice significantly reduced CD8+T cell activation. Taken together, our results revealed that phagocyte apoptosis in theHistoplasma-infected host is associated with CD8+T cell activation and that immunization with apoptotic phagocytes containing heat-killedHistoplasmaefficiently evokes a protective CD8+T cell response. These results suggest that employing apoptotic phagocytes as antigen donor cells is a viable approach for the development of efficacious vaccines to elicit strong CD8+T cell as well as CD4+T cell responses toHistoplasmainfection.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana Colado ◽  
Esteban Enrique Elías ◽  
Valeria Judith Sarapura Martínez ◽  
Gregorio Cordini ◽  
Pablo Morande ◽  
...  

AbstractHypogammaglobulinemia is the most frequently observed immune defect in chronic lymphocytic leukemia (CLL). Although CLL patients usually have low serum levels of all isotypes (IgG, IgM and IgA), standard immunoglobulin (Ig) preparations for replacement therapy administrated to these patients contain more than 95% of IgG. Pentaglobin is an Ig preparation of intravenous application (IVIg) enriched with IgM and IgA (IVIgGMA), with the potential benefit to restore the Ig levels of all isotypes. Because IVIg preparations at high doses have well-documented anti-inflammatory and immunomodulatory effects, we aimed to evaluate the capacity of Pentaglobin and a standard IVIg preparation to affect leukemic and T cells from CLL patients. In contrast to standard IVIg, we found that IVIgGMA did not modify T cell activation and had a lower inhibitory effect on T cell proliferation. Regarding the activation of leukemic B cells through BCR, it was similarly reduced by both IVIgGMA and IVIgG. None of these IVIg preparations modified spontaneous apoptosis of T or leukemic B cells. However, the addition of IVIgGMA on in vitro cultures decreased the apoptosis of T cells induced by the BCL-2 inhibitor, venetoclax. Importantly, IVIgGMA did not impair venetoclax-induced apoptosis of leukemic B cells. Overall, our results add new data on the effects of different preparations of IVIg in CLL, and show that the IgM/IgA enriched preparation not only affects relevant mechanisms involved in CLL pathogenesis but also has a particular profile of immunomodulatory effects on T cells that deserves further investigation.


2021 ◽  
pp. annrheumdis-2020-219335
Author(s):  
Emma Garcia-Melchor ◽  
Giacomo Cafaro ◽  
Lucy MacDonald ◽  
Lindsay A N Crowe ◽  
Shatakshi Sood ◽  
...  

ObjectivesIncreasing evidence suggests that inflammatory mechanisms play a key role in chronic tendon disease. After observing T cell signatures in human tendinopathy, we explored the interaction between T cells and tendon stromal cells or tenocytes to define their functional contribution to tissue remodelling and inflammation amplification and hence disease perpetuation.MethodsT cells were quantified and characterised in healthy and tendinopathic tissues by flow cytometry (FACS), imaging mass cytometry (IMC) and single cell RNA-seq. Tenocyte activation induced by conditioned media from primary damaged tendon or interleukin-1β was evaluated by qPCR. The role of tenocytes in regulating T cell migration was interrogated in a standard transwell membrane system. T cell activation (cell surface markers by FACS and cytokine release by ELISA) and changes in gene expression in tenocytes (qPCR) were assessed in cocultures of T cells and explanted tenocytes.ResultsSignificant quantitative differences were observed in healthy compared with tendinopathic tissues. IMC showed T cells in close proximity to tenocytes, suggesting tenocyte–T cell interactions. On activation, tenocytes upregulated inflammatory cytokines, chemokines and adhesion molecules implicated in T cell recruitment and activation. Conditioned media from activated tenocytes induced T cell migration and coculture of tenocytes with T cells resulted in reciprocal activation of T cells. In turn, these activated T cells upregulated production of inflammatory mediators in tenocytes, while increasing the pathogenic collagen 3/collagen 1 ratio.ConclusionsInteraction between T cells and tenocytes induces the expression of inflammatory cytokines/chemokines in tenocytes, alters collagen composition favouring collagen 3 and self-amplifies T cell activation via an auto-regulatory feedback loop. Selectively targeting this adaptive/stromal interface may provide novel translational strategies in the management of human tendon disorders.


Blood ◽  
1999 ◽  
Vol 94 (7) ◽  
pp. 2396-2402 ◽  
Author(s):  
Anna Cambiaggi ◽  
Sylvie Darche ◽  
Sophie Guia ◽  
Philippe Kourilsky ◽  
Jean-Pierre Abastado ◽  
...  

In humans, a minor subset of T cells express killer cell Ig-like receptors (KIRs) at their surface. In vitro data obtained with KIR+ β and γδ T-cell clones showed that engagement of KIR molecules can extinguish T-cell activation signals induced via the CD3/T-cell receptor (TCR) complex. We analyzed the T-cell compartment in mice transgenic for KIR2DL3 (Tg-KIR2DL3), an inhibitory receptor for HLA-Cw3. As expected, mixed lymphocyte reaction and anti-CD3 monoclonal antibody (MoAb)-redirected cytotoxicity exerted by freshly isolated splenocytes can be inhibited by engagement of transgenic KIR2DL3 molecules. In contrast, antigen and anti-CD3 MoAb-induced cytotoxicity exerted by alloreactive cytotoxic T lymphocytes cannot be inhibited by KIR2DL3 engagement. In double transgenic mice, Tg-KIR2DL3 × Tg-HLA-Cw3, no alteration of thymic differentiation could be documented. Immunization of double transgenic mice with Hen egg white lysozime (HEL) or Pigeon Cytochrome-C (PCC) was indistinguishable from immunization of control mice, as judged by recall antigen-induced in vitro proliferation and TCR repertoire analysis. These results indicate that KIR effect on T cells varies upon cell activation stage and show unexpected complexity in the biological function of KIRs in vivo.


1993 ◽  
Vol 178 (6) ◽  
pp. 2107-2113 ◽  
Author(s):  
A J da Silva ◽  
O Janssen ◽  
C E Rudd

Intracellular signaling from the T cell receptor (TCR)zeta/CD3 complex is likely to be mediated by associated protein tyrosine kinases such as p59fyn(T), ZAP-70, and the CD4:p56lck and CD8:p56lck coreceptors. The nature of the signaling cascade initiated by these kinases, their specificities, and downstream targets remain to be elucidated. The TCR-zeta/CD3:p59fyn(T) complex has previously been noted to coprecipitate a 120/130-kD doublet (p120/130). This intracellular protein of unknown identity associates directly with p59fyn(T) within the receptor complex. In this study, we have shown that this interaction with p120/130 is specifically mediated by the SH2 domain (not the fyn-SH3 domain) of p59fyn(T). Further, based on the results of in vitro kinase assays, p120/130 appears to be preferentially associated with p59fyn(T) in T cells, and not with p56lck. Antibody reprecipitation studies identified p120/130 as a previously described 130-kD substrate of pp60v-src whose function and structure is unknown. TCR-zeta/CD3 induced activation of T cells augmented the tyrosine phosphorylation of p120/130 in vivo as detected by antibody and GST:fyn-SH2 fusion proteins. p120/130 represents the first identified p59fyn(T):SH2 binding substrate in T cells, and as such is likely to play a key role in the early events of T cell activation.


Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.


1990 ◽  
Vol 110 (5) ◽  
pp. 1757-1766 ◽  
Author(s):  
W Risau ◽  
B Engelhardt ◽  
H Wekerle

The endothelial blood-brain barrier (BBB) has a critical role in controlling lymphocyte traffic into the central nervous system (CNS), both in physiological immunosurveillance, and in its pathological aberrations. The intercellular signals that possibly could induce lymphocytes to cross the BBB include immunogenic presentation of protein (auto-)antigens by BBB endothelia to circulating T lymphocytes. This concept has raised much, though controversial, attention. We approached this problem by analyzing in vitro immunospecific interactions between clonal rat T lymphocyte lines with syngeneic, stringently purified endothelial monolayer cultures from adult brain micro-vessels. The rat brain endothelia (RBE) were established from rat brain capillaries using double collagenase digestion, density gradient fractionation and selective cytolysis of contaminating pericytes by anti-Thy 1.1 antibodies and complement. Incubation with interferon-gamma in most of the brain-derived endothelial cells induced Ia-antigens in the cytoplasm and on the cell surface in some of the cells. Before the treatment, the cells were completely Ia-negative. Pericytes were unresponsive to IFN-gamma treatment. When confronted with syngeneic T cell lines specific for protein (auto-)antigens (e.g., ovalbumin and myelin basic protein, MBP), RBE were completely unable to induce antigen-specific proliferation of syngeneic T lymphocytes irrespective of pretreatment with IFN-gamma and of cell density. RBE were inert towards the T cells, and did not suppress T cell activation induced by other "professional" antigen presenting cells (APC) such as thymus-derived dendritic cells or macrophages. IFN-gamma-treated RBE were, however, susceptible to immunospecific T cell killing. They were lysed by MBP-specific T cells in the presence of the specific antigen or Con A. Antigen dependent lysis was restricted by the appropriate (MHC) class II product. We conclude that the interaction of brain endothelial cells with encephalitogenic T lymphocytes may involve recognition of antigen in the molecular context of relevant MHC products, but that this interaction per se is insufficient to initiate the full T cell activation program.


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