682 Antibody-mediated blockade of interleukin-10 receptor-alpha promotes the activation of immune cells from in vitro dissociated tumor samples

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A721-A721
Author(s):  
Alexey Berezhnoy ◽  
Kalpana Shah ◽  
Daorong Liu ◽  
Peter Lung ◽  
Vatana Long ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Interferon Gamma ◽  
Expression Profiles ◽  
Interleukin 10 ◽  
Biologically Active ◽  
List Type ◽  
Receptor Alpha

BackgroundInterleukin-10 (IL-10) is a multifunctional cytokine that can mediate immune suppression or activation depending on the immunological context. Mouse studies have demonstrated that blockade of IL-10 enhances immune response against tumors and chronic viral infections;1 2 intriguingly, high concentrations of long-acting, pegylated IL-10 have also shown anti-tumor activity.3 Here we investigated IL-10 and IL-10 receptor-alpha (IL-10RA) expression profiles in normal and tumor tissues as well as the immunological effects of modulating the IL-10 pathway via antibody-mediated blockade of IL-10RA.MethodsIL-10 and IL-10RA mRNA are expressed by several tumors, including renal, lung, breast, and colon cancers. Fluorescent in-situ hybridization revealed that the majority of IL-10RA was expressed by CD3-negative tumor-infiltrating cells, localized in close proximity to T cells in the tumor microenvironment (TME). Immunohistochemistry studies confirmed expression of IL-10RA in the TME, while no expression was detected in healthy tissues. Furthermore, dissociated tumor cells produced biologically active levels of IL-10 in culture.ResultsMonoclonal antibodies (mAbs) against IL-10RA prevented IL-10 signaling and enhanced release of IL-12 by monocyte-derived dendritic cells activated with suboptimal LPS concentrations. The effect of IL-10RA blockade was greater than that observed with IL-10 neutralizing mAbs. In mixed lymphocyte reactions and superantigen-driven T-cell activation, IL-10RA blockade enhanced IL-2 secretion by T lymphocytes. Consistent with earlier observations in mouse models,4 the effect of IL-10RA blockade was nonredundant with blockade of the PD-1/PD-L1 axis, resulting in enhanced IL-2 and interferon-gamma secretion by T cells when both pathways were inhibited. Blockade of IL-10RA during CD3-redirected in vitro killing of tumor cells by PBMC induced IL-12 release as well as upregulation of CD86 and HLA-DR by CD3-negative cells. In in vitro dissociated tumor cells, IL-10RA blockade induced release of IL-2, interferon-gamma and other proinflammatory cytokines; additional PD-1/PD-L1 axis blockade further enhanced cytokine release.ConclusionsIn summary, antibody-mediated IL-10RA blockade can potentiate immune activation in the dissociated tumor cells and may be a valuable addition to cancer immunotherapies, including redirected T-cell killing and checkpoint blockade.ReferencesVicari A, et al. J. Exp. Med 2002;196:541–549.Ejrnaes M, et al. J Exp Med 2006;203:2461–72.Emmerich J, et al. Cancer Res 2012. 72:3570–3581.Brooks D, et al. Proc Natl Acad Sci U S A 2008;105:20428–33.

scholarly journals 122 A powerful, precise targeting system controlled by tumor deletions transforms CEA and MSLN CAR-T cells into tumor-selective agents

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A131-A131
Author(s):  
Agnes Hamburger ◽  
Han Xu ◽  
Yuta Ando ◽  
Grace Asuelime ◽  
Kristian Bolanos-Ibarra ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Loss Of Heterozygosity ◽  
Tumor Antigens ◽  
Allelic Loss ◽  
List Type ◽  
Mixed Cell ◽  
Normal Cells

BackgroundMesothelin (MSLN) and carcinoembryonic antigen (CEA) are classic tumor-associated antigens that are expressed in many solid tumors including the majority of lung, colorectal and pancreatic cancers. However, both MSLN and CEA are also expressed in vital normal organs. This normal expression creates risk of serious inflammation for CEA- or MSLN-directed therapeutics. To date all active CEA- or MSLN-targeted investigational therapeutics have been toxic when administered systemically.MethodsWe have developed a safety mechanism to protect normal tissues without abrogating sensitivity of cytotoxic T cells directed at MLSN(+) or CEA(+) tumors in a subset of patients with defined loss of heterozygosity (LOH) in their tumors (figure 1). This dual-receptor (Tmod< sup >TM</sup >) system exploits common LOH at the HLA locus in cancer cells, allowing T cells to recognize the difference between tumor and normal tissue.1 2 T cells engineered with specific Tmod constructs contain: (i) a MSLN- or CEA-activated CAR; and, (ii) an inhibitory receptor gated by HLA-A*02. HLA-A*02 binding blocks T cell cytotoxicity, even in the presence of MSLN or CEA. The Tmod system is designed to treat heterozygous HLA class I patients, selected for HLA LOH. When HLA-A*02 is absent from tumors selected for LOH, the CARs are predicted to mediate potent killing of the A*02(-) malignant cells.ResultsThe Tmod system robustly protects surrogate normal cells even in mixed-cell populations in vitro while mediating robust cytotoxicity of tumor cells in xenograft models (see example in figure 2). The MSLN CAR can also be paired with other blockers, supporting scalability of the approach to patients beyond HLA-A*02 heterozygotes.Abstract 122 Figure 1Illustration of the Tmod T cell engaging with tumor cells with somatic loss of HLA-A*02 and with normal cells.Abstract 122 Figure 2Bioluminescence measurements show the average difference between the size of the MSLN(+)A*02(+) ‘normal’ graft compared to the MSLN(+)A*02(-) tumor graft on the two flanks of mice after T cell infusion. Both tumor and normal grafts are destroyed by CAR-Ts (CAR-3 and M5 benchmark) while the MSLN Tmod cells kill the tumor but not the normal graft.ConclusionsThe Tmod mechanism may provide an alternative route to leverage solid-tumor antigens such as MSLN and CEA in safer, more effective ways than previously possible.ReferencesHamburger AE, DiAndreth B, Cui J, et al. Engineered T cells directed at tumors with defined allelic loss. Mol Immunol 2020;128:298–310.Hwang MS, Mog BJ, Douglass J, et al. Targeting loss of heterozygosity for cancer-specific immunotherapy. Proc Natl Acad Sci U S A 2021;118(12):e2022410118.

scholarly journals 154 Context-dependent reversible modulation of cJUN expression by CAR T cells for cancer treatment

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A164-A164
Author(s):  
Zhifen Yang ◽  
Francesco Marincola
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
List Type ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Context Dependent ◽  
Fadu Cells

BackgroundOverexpression of canonical AP-1 factor cJUN was shown to prevent CAR T cell exhaustion and improve anti-tumor potency in vivo (1). However, its clinical utilization is limited by potential for transformation and oncogenic risk. Here, we present a conditional, antigen-dependent, non-editing CRISPR-activation (CRISPRa) circuit (RB-339) that delivers context-dependent upregulation of endogenous cJUN increasing CAR-T cell resistance to exhaustion.MethodsRB-339 is a CAR T cell engineered to conditionally turn on the transcription of the cJUN endogenous gene. The circuit includes a lentiviral construct encoding an anti-HER2 (4D5) single chain variable fragment, with CD28 and CD3ζ co-stimulatory domains linked to a tobacco etch virus (TEV) protease and a single guide RNA (sgRNA) targeting the promoter region of cJUN. A second construct encodes linker for activation of T cells, complexed to nuclease-deactivated/dead Cas9 (dCas9)-VP64-p65-Rta transcriptional activator (VPR) via a TEV-cleavable linker (LdCV). Activation of CAR allows the release of dCas9 for nuclear localization and conditionally and reversibly induces the expression of cJUN. RB-339 was compared in vitro to control (cRB-339, lacking the cJUN sgRNA) and CAR-T cells engineered to constitutively express cJun.ResultsRB-339 induced cJUN upregulation upon stimulation with HER2-coated beads and this resulted in significantly elevated expression over a 6-day time course compared to the control cRB-339 (figure 1A-B). When HER2-coated beads were removed at day 3, cJUN expression returned to baseline parallel to cRB-339. The conditional upregulation of cJUN in RB-339 contrasted with the constitutive overexpression in the transgene carrying cells that was irrespective of antigen stimulation (figure 1C). Upon exposure to HER2+ FaDu cancer cells, RB-339 peaked at day 2 and declined afterwards when FaDu cells were killed at day 3; cJUN increased again at day 4 upon restimulation with FaDu cells at day 3 (figure 2). Such a dynamic induction of cJUN resulted in significantly enhanced CAR-T cells proliferation in RB-339 compared to the respective conventional CAR-T cells or cRB-339 (figure 3).Abstract 154 Figure 1Conditional upregulation of cJUN by RB-339 in vitro. RB-339 and its control cRB-339 were stimulated by HER2-coated or BSA-coated beads for either six days or three days followed by removal of beads at day 3 (figure 1A-B). Intracellular expression of cJUN was detected at indicated time points. Intracellular cJUN expression in overexpressed cJUN-CAR (figure 1C)Abstract 154 Figure 2Kinetics of cJUN upregulation in RB-339 upon exposure to HER2+ FaDu tumor cells. RB-339 and its control cRB-339 were stimulated by FaDu tumor cells for six days with or without restimulation at day 3Abstract 154 Figure 3Conditional upregulation of cJUN resulted in enhanced CAR-T proliferation in RB-339 in vitro after 6-day co-culture with FaDu tumor cells, compared to conventional HER2 CAR or cRB-339ConclusionsWe conclude that CAR-T engineered to conditionally express the canonical AP-1 factor cJUN increases expansion potential similarly to CAR-T cells engineered to constitutively express the cJun transgene. However, the context-dependent upregulation of cJUN limits the risk of oncogenic transformation. We are currently combining inducible and reversible cJUN and IL-12 upregulation for the generation of the next RB-339 product.ReferenceLynn RC, Weber EW, et al. c-Jun overexpression in CAR T cells induces exhaustion resistance. Nature 2019; 576(7786):293–300.

scholarly journals 796 ALG.APV-527: a 5T4 tumor directed bispecific approach utilizing ADAPTIRTM technology designed for conditional 4-1BB T cell/NK agonism against solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A831-A831
Author(s):  
Michelle Nelson ◽  
Anette Sundstedt ◽  
Yago Pico de Coaña ◽  
Ashly Lucas ◽  
Anneli Nilsson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Solid Tumors ◽  
Tumor Cells ◽  
Immune Cell ◽  
Expression Profiles ◽  
Transcriptional Profiling ◽  
Sequencing Data ◽  
Multiple Tumor

Background4-1BB (CD137) is an activation-induced co-stimulatory receptor that regulates immune responses of activated CD8+ T cells and NK cells. Leveraging the therapeutic benefit of 1st generation 4-1BB monospecifics has been challenging due to dose limiting hepatotoxicity. To minimize systemic immune toxicities and enhance activity at the tumor site, we have developed a novel 4-1BB x 5T4 bispecific antibody that stimulates 4-1BB function only when co-engaged with 5T4, a highly selective tumor-associated antigen. The combined preclinical dataset presented here provides an overview of the potential indication landscape, mechanism of action and the efficacy and safety profile of ALG.APV-527, supporting its advancement into the clinic.MethodsGenevestigator Software was used to analyze curated transcriptomic data from bulk tumor mRNA-sequencing data libraries and from single cell RNA-seq libraries for the expression profiles of CD8, 4-1BB and 5T4 across selected human solid tumor datasets. ADCC and ADCP reporter bioassays were utilized to assess Fc engagement by ALG.APV-527. For in vitro tumor lysis studies, human T cells were co-cultured with labelled tumor cells and sub-optimally activated with anti-CD3. Cytotoxicity of tumor cells were continually assessed using a Live-Cell Analysis System.ResultsDual expression of CD8 and 5T4 occurred in many tumor types and correlated well with indications that are pursued in the clinical development of ALG.APV-527. 4-1BB expression was observed in tumor-derived lymphoid subpopulations, especially in those with an exhausted phenotype. Since ALG.APV-527 is designed with a non-Fcγ receptor binding Fc, minimal ADCC & ADCP was induced in vitro. Additionally, ALG.APV-527 enhanced primary immune cell-mediated killing of 5T4-expressing tumor cells when compared to anti-CD3 alone, demonstrating the potential benefit of 4-1BB agonism for enhancing cytotoxic anti-tumor responses in the clinic.ConclusionsALG.APV-527 is designed to elicit safe and efficacious 4-1BB-mediated antitumor activity in a range of 5T4-expressing tumor indications. Transcriptional profiling of patient tumor samples demonstrates 4-1BB expression in multiple tumor-infiltrating lymphocyte subsets and identifies potential indications with 5T4 expression and CD8+ T cell infiltration. The unique design of the molecule minimizes systemic immune activation and hepatotoxicity, allowing for highly efficacious tumor-specific responses as demonstrated by potent activity in in vitro models. Based on these preclinical data, ALG.APV-527 is a promising anti-cancer therapeutic for the treatment of a variety of 5T4-expressing solid tumors and is progressing towards a phase I clinical trial in 2021.

scholarly journals 687 Enhancement of anti-tumor immunity by ICT01: a novel g9d2 T cell-activating antibody targeting butyrophilin-3A (BTN3A)

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A726-A726
Author(s):  
Aude de Gassart ◽  
Patrick Brune ◽  
LE Suong ◽  
Sophie Agaugue ◽  
Emmanuel Valentin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Cell Subset ◽  
List Type ◽  
Human Cancers ◽  
Wide Range

BackgroundgdT-cells are innate-like lymphocytes described as potent killer of cancer cells whose infiltration into tumors is associated with a positive prognosis.1 2 This supports gd T-cells use in cancer immunotherapy. BTN3A, which belongs to the B7-subfamily of Ig proteins, is required for the recognition of malignant or infected cells by human g9d2 T-cells by sensing intracellular accumulation of phosphoantigens.3 ImCheck Therapeutics is developing ICT01, a humanized anti-BTN3A (IgG1, Fc-silenced), g9d2 T-cell-activating antibody for the treatment of patients with solid or hematologic tumors.MethodsA complete IND-enabling program was conducted to characterize the preclinical activity and safety of ICT01. ICT01 effects on human and cynomolgus PBMCs were characterized in vitro using flow cytometry. ICT01-mediated killing activity of g9d2 T-cells was assessed using in vitro co-cultures with tumor and non-tumor cells. Immunocompromised mice bearing human tumors and adoptively transferred with human g9d2 T cells were used to assess ICT01 anti-tumor activity in vivo. The PK, PD and safety of intravenous ICT01 (0.1 to 100 mg/kg single- and repeated-dose) were evaluated in Cynomolgus monkeys.ResultsICT01 selectively binds to all three BTN3A isoforms with high affinity (<10nM). When assayed in human and cynomolgus PBMCs in vitro, ICT01 promoted a robust and specific activation of g9d2 T-cells as shown by concentration dependent increase in cell surface CD69 and CD25 and cytokines secretion (IFNγ, TNFα). In co-culture experiments, ~20% of target occupancy on tumor cells is sufficient for maximal g9d2 T-cell degranulation (e.g. CD107a/b expression). ICT01-activated g9d2 T-cells continuously and serially kill a wide range of tumor cells in multi-day co-culture conditions. In contrast, non-tumoral BTN3A-expressing B cells, HUVEC and fibroblasts were unaffected. In mouse AML and ovarian cancer models, repeated injections of ICT01 delayed tumor growth and significantly prolonged animal survival. In primates, ICT01 exposure and target engagement was dose-dependent, with all tested doses producing a specific g9d2 T cell activation and trafficking out of the circulation within 1 hour. ICT01 administration was well tolerated with no safety signals observed at doses up to 25 mg/kg/week based on clinical, laboratory, and anatomic pathology parameters.ConclusionsThe combined in vitro and in vivo pharmacology data provide evidence that ICT01 is an attractive and novel therapeutic approach for enhancing the innate anti-tumor potential of g9d2 T-cells by activating BTN3A. Importantly, ICT01 did not affect healthy BTN3A-expressing cells, and NHP studies confirmed ICT01 safety with a wide therapeutic index. Therefore, ICT01 is being tested in the ongoing EVICTION trial (NCT04243499).Ethics ApprovalPseudonymized samples isolated from healthy volunteers’ whole blood by ImCheck Therapeutics under the agreement n° 7173 between ImCheck Therapeutic SAS and EFS PACA (Etablissement Français du Sang Provence-Alpes-cote d’Azur)ReferencesGentles AJ, Newman AM, Liu CL, et al. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nature Medicine 2015;21(8):938–945.Tosolini M, Pont F, Poupot M, et al. Assessment of tumor-infiltrating TCRVγ9Vδ2 γδ lymphocyte abundance by deconvolution of human cancers microarrays. OncoImmunology. 2017;6(3):e1284723.Harly C, Guillaume Y, Nedellec S, et al. Key implication of CD277/butyrophilin-3 (BTN3A) in cellular stress sensing by a major human γδ T-cell subset. Blood 2012;120(11):2269–2279.

scholarly journals 795 APVO603: a dual 4-1BB and OX40 bispecific approach utilizing ADAPTIRTM technology designed to deliver a conditional T cell/NK response against solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A830-A830
Author(s):  
Michelle Nelson ◽  
Ashly Lucas ◽  
Rebecca Gottschalk ◽  
Catherine McMahan ◽  
Jane Gross ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Solid Tumors ◽  
Tumor Cells ◽  
Bispecific Antibody ◽  
Expression Profiles ◽  
T Cell Subsets ◽  
Dependent Manner ◽  
Dose Dependent

BackgroundAPVO603 is a dual targeting bispecific antibody for 4-1BB (CD137) and OX40 (CD134), engineered with Aptevo's ADAPTIRTM technology. We have previously shown that the distinct characteristics of APVO603 may enable conditional agonism of 4-1BB and OX40 only when cross-linked through engagement of the other receptor via cis and/or trans cellular interactions. Thus, APVO603 is designed with the potential to overcome both the on-target toxicity and limited efficacy observed with 4-1BB and OX40 monoclonal antibody treatment in the clinic.MethodsGenevestigator Software was used to analyze curated transcriptomic data for the expression profiles of OX40 and 4-1BB across select human heme and solid cancer patient sample data sets, as well as, non diseased tissue. Primary inducible Treg (iTreg) cells were sub-optimally stimulated with an anti-CD3/CD28 antibody and cell proliferation was assessed using CFSE-labelled. Cytokines were measured using intracellular flow-based methods. For in vitro tumor lysis studies, activated T cells were co-cultured with Nuclight-labelled tumor cells expressing a tumor-associated antigen (TAA) and activated with TAA x CD3 bispecific protein. Live tumor cells were continually assessed using the Incucyte Live-Cell Analysis System and Cell-By-Cell Software Module.ResultsOX40 and 4-1BB displayed distinct tumor expression profiles, however, several tumor indications were identified with high co-expression and may aid in identifying indications for the clinical development of APVO603. In vitro, APVO603 favored activation of effector T cell subsets and had minimal impact in augmenting iTreg cells proliferation, cytokine production or expression of effector-related molecules, despite the fact that a portion of the iTreg cells expressed OX40 and 4-1BB. The mechanistic activity of APVO603 resulted in dose-dependent control of in vitro tumor growth when paired with a T-cell activating TAA x CD3 bispecific under standard conditions or those leading to T cell exhaustion. In preclinical assays using PBMCs sub-optimally stimulated with TAA x CD3, APVO603 enhanced TAA-expressing tumor cell lysis when compared to TAA x CD3 alone.ConclusionsAPVO603 is a dual-agonistic bispecific antibody that augments the effector function of activated CD4+ and CD8+ T cells and NK cells, but not iTreg cells, in a dose-dependent manner and reduces growth of tumors in vitro and in vivo. Further, mechanistic evaluation supports the ability of APVO603 to pair with T-cell modulating IO approaches to support a more fit T cell response and favorable TME. This preclinical data supports further development of APVO603, a promising immuno-oncology therapeutic with potential for benefit in hematologic and solid tumors.

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 Regulatory T Cells Contribute to Resistance against Lyme Arthritis

2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lyme Disease ◽  
Regulatory T Cells ◽  
Regulatory T Cell ◽  
Interleukin 10 ◽  
Lyme Arthritis ◽  
Interleukin 17 ◽  
Content Type

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.

scholarly journals P01.02 TLR-mediated suppression of the CCL22-CCR4 axis as a new target for tumor immunotherapy

2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A3.2-A4
Author(s):  
J Grün ◽  
I Piseddu ◽  
C Perleberg ◽  
N Röhrle ◽  
S Endres ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
Regulatory T Cells ◽  
Type I ◽  
List Type ◽  
Gm Csf

BackgroundUnmethylated CpG-DNA is a potent ligand for the endosomal Toll-like-receptor-9, important for the immune activation to pathogen-associated molecules.1 CpG and other TLR-ligands show effective immunotherapeutic capacities in cancer treatment by inducing an antitumorigenic immunity.2 They are able to reduce tumor progression by reduction of intratumoral secretion of the immunoregulating chemokine CCL223 and subsequent recruitment of immunosuppressive regulatory T cells (Treg), which express CCR4 the only so far known receptor for CCL22.4 Our recent work has shown that CCL22 secretion by dendritic cells (DC) in the lymph node, mediates tolerance by inducing DC-Treg contacts.5 Indeed, in the absence of CCL22, immune responses to vaccination were stronger and resulted in tumor rejection.6 Therefore, we are aiming to investigate the effects of TLR-ligands on systemic CCL22 levels, elucidating all involved mechanisms to identify new targets for cancer immunotherapy.Materials and MethodsT, B and CD11c+ DCs of wildtype (wt) and RAG1-/- mice were isolated from splenocytes by magnetic-activated cell sorting for in vitro assays. Different co-cultures were incubated with CpG and GM-CSF, known as an CCL22 inducer.5 For in vivo experiments, wt mice were treated with CpG, R484 or poly(I:C) alone and in combination with GM-CSF. CCL22-levels in a number of organs were analyzed.ResultsAnalyzing the different immune cell compartments in vitro, we found that DCs in whole splenocytes secrete CCL22 during culture while DC cultured alone showed no CCL22 secretion. When treated with CpG, CCL22-levels were reduced in splenocytes, while it was induced in DC culture alone. The same results were seen when RAG splenocytes, that lack functional B and T cells, were cultured with CpG. CpG treated B cells were able to suppress CCL22 secretion by DC unlike T cells alone. Co-cultures of T and B cells treated with CpG, however, induced the strongest CCL22 suppression in DC. In vivo, we could show that all TLR ligands tested reduced CCL22 in a number of organs significantly. Furthermore, CpG showed the strongest suppression of CCL22 even in the presence of the CCL22 inducer GM-CSF.5ConclusionsWe could show that B cells with T cells mediate CCL22 suppression by TLR ligands. The fact that CpG was able to reduce CCL22 levels even in the presence of the inducer GM-CSF demonstrates the potent CCL22 suppressive capacity of TLR ligands.ReferencesO’Neill LA, et al. The history of toll-like receptors – redefining innate immunity. Nat Rev Immunol 2013;13(6):453–60.Rothenfusser S, et al. Recent advances in immunostimulatory CpG oligonucleotides. Curr Opin Mol Ther 2003;5(2):98–106.Wang S, et al. Intratumoral injection of a CpG oligonucleotide reverts resistance to PD-1 blockade by expanding multifunctional CD8+ T cells. Proc Natl Acad Sci U S A 2016;113(46): E7240–E7249.Rapp M, et al. CCL22 controls immunity by promoting regulatory T cell communication with dendritic cells in lymph nodes. J Exp Med 2019;216(5):1170–1181.Piseddu I, et al. Constitutive expression of CCL22 is mediated by T cell-derived GM-CSF. J Immunol 2020;205(8):2056–2065.Anz D, et al. Suppression of intratumoral CCL22 by type i interferon inhibits migration of regulatory T cells and blocks cancer progression. Cancer Res 2015;75(21):4483–93.Disclosure InformationJ. Grün: None. I. Piseddu: None. C. Perleberg: None. N. Röhrle: None. S. Endres: None. D. Anz: None.

scholarly journals The Activated Type 1–Polarized Cd8+ T Cell Population Isolated from an Effector Site Contains Cells with Flexible Cytokine Profiles

1999 ◽  
Vol 190 (8) ◽  
pp. 1081-1092 ◽  
Author(s):  
Anthony G. Doyle ◽  
Kathy Buttigieg ◽  
Penny Groves ◽  
Barbara J. Johnson ◽  
Anne Kelso
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
Expression Profiles ◽  
Lung Parenchyma ◽  
Activated T Cells ◽  
Cytokine Genes ◽  
Effector Site

The capacity of activated T cells to alter their cytokine expression profiles after migration into an effector site has not previously been defined. We addressed this issue by paired daughter analysis of a type 1–polarized CD8+ effector T cell population freshly isolated from lung parenchyma of influenza virus–infected mice. Single T cells were activated to divide in vitro; individual daughter cells were then micromanipulated into secondary cultures with and without added IL-4 to assess their potential to express type 2 cytokine genes. The resultant subclones were analyzed for type 1 and 2 cytokine mRNAs at day 6–7. When the most activated (CD44highCD11ahigh) CD8+ subpopulation from infected lung was compared with naive or resting (CD44lowCD11alow) CD8+ cells from infected lung and from normal lymph nodes (LNs), both clonogenicity and plasticity of the cytokine response were highest in the LN population and lowest in the activated lung population, correlating inversely with effector function. Multipotential cells were nevertheless detected among clonogenic CD44highCD11ahigh lung cells at 30–50% of the frequency in normal LNs. The data indicate that activated CD8+ T cells can retain the ability to proliferate and express new cytokine genes in response to local stimuli after recruitment to an effector site.

scholarly journals High levels of interleukin 10 production in vivo are associated with tolerance in SCID patients transplanted with HLA mismatched hematopoietic stem cells.

1994 ◽  
Vol 179 (2) ◽  
pp. 493-502 ◽  
Author(s):  
R Bacchetta ◽  
M Bigler ◽  
J L Touraine ◽  
R Parkman ◽  
P A Tovo ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Cell ◽  
Mrna Expression ◽  
Fetal Liver ◽  
Hla Antigens ◽  
Interleukin 10 ◽  
Hematopoietic Stem

Transplantation of HLA mismatched hematopoietic stem cells in patients with severe combined immunodeficiency (SCID) can result in a selective engraftment of T cells of donor origin with complete immunologic reconstitution and in vivo tolerance. The latter may occur in the absence of clonal deletion of donor T lymphocytes able to recognize the host HLA antigens. The activity of these host-reactive T cells is suppressed in vivo, since no graft-vs. -host disease is observed in these human chimeras. Here it is shown that the CD4+ host-reactive T cell clones isolated from a SCID patient transplanted with fetal liver stem cells produce unusually high quantities of interleukin 10 (IL-10) and very low amounts of IL-2 after antigen-specific stimulation in vitro. The specific proliferative responses of the host-reactive T cell clones were considerably enhanced in the presence of neutralizing concentrations of an anti-IL-10 monoclonal antibody, suggesting that high levels of endogenous IL-10 suppress the activity of these cells. These in vitro data correlate with observations made in vivo. Semi-quantitative polymerase chain reaction analysis carried out on freshly isolated peripheral blood mononuclear cells (PBMC) of the patient indicated that the levels of IL-10 messenger RNA (mRNA) expression were strongly enhanced, whereas IL-2 mRNA expression was much lower than that in PBMC of healthy donors. In vivo IL-10 mRNA expression was not only high in the T cells, but also in the non-T cell fraction, indicating that host cells also contributed to the high levels of IL-10 in vivo. Patient-derived monocytes were found to be major IL-10 producers. Although no circulating IL-10 could be detected, freshly isolated monocytes of the patient showed a reduced expression of class II HLA antigens. However, their capacity to stimulate T cells of normal donors in primary mixed lymphocyte cultures was within the normal range. Interestingly, similar high in vivo IL-10 mRNA expressions in the T and non-T cell compartment were also observed in three SCID patients transplanted with fetal liver stem cells and in four SCID patients transplanted with T cell-depleted haploidentical bone marrow stem cells. Taken together, these data indicate that high endogenous IL-10 production is a general phenomenon in SCID patients in whom allogenic stem cell transplantation results in immunologic reconstitution and induction of tolerance. Both donor T cells and host accessory cells contribute to these high levels of IL-10, which would suppress the activity of host-reactive T cell in vivo.

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