KY1044 to target the ICOS pathways inducing intratumoral Treg depletion and agonism of effector T cells: Preliminary pharmacodynamic markers from a phase 1/2 multicenter trial.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2626-2626
Author(s):  
Chia-Chi Lin ◽  
Aung Naing ◽  
Manish R. Patel ◽  
Howard A. Burris III ◽  
Giuseppe Curigliano ◽  
...  

2626 Background: Inducible T-cell co-stimulator (ICOS) is an important co-stimulatory receptor on effector T cells (Teffs) that also promotes tumor growth due to its high expression on regulatory T cells (Tregs). KY1044 is a fully human IgG1 that targets ICOS, acting via a dual mode of action (MoA) by depleting ICOShigh Tregs and stimulating ICOSLow Teffs. A Phase 1/2 clinical trial (NCT03829501) is currently assessing the safety and preliminary efficacy of KY1044, as a single agent and in combination with atezolizumab, in subjects with advanced relapsed/refractory malignancies. Using longitudinal blood samples and tumor biopsies, we aim to correlate KY1044 target engagement levels with pharmacodynamic (PD) properties (e.g. dual MoA) in the tumor microenvironment (TME) and the circulation. Methods: Phase 1 subjects were enrolled in dose escalation and enrichment cohorts to evaluate the effect of KY1044 as monotherapy (0.8 – 240 mg) Q3W and in combination (0.8 – 80 mg) with atezolizumab (1200 mg) Q3W. PBMCs, plasma and tumor biopsies were collected over the first 3 cycles to confirm target engagement and KY1044 MoA. The sample analysis included: immunohistochemistry (IHC) of tumor samples (ICOS, FOXP3 and CD8); circulating T cell immunoprofiling and receptor occupancy by chip-cytometry; PBMC and tumor sample pre- and post-treatment transcriptomic analysis; and the assessment of circulating cytokines (e.g. GM-CSF). Results: As assessed in PBMCs, full/prolonged ICOS target engagement on T cells was confirmed in subjects receiving a flat dose of 8 to 240 mg, while partial/transient saturation was observed at lower doses (0.8-2.4 mg). The target engagement was not affected by atezolizumab. The immune cell profiling showed changes in some populations, but there was no significant depletion of peripheral ICOS+ cells. In contrast, pre- and post-treatment IHC analysis of ICOS+/FOXP3+ cells in tumor biopsies confirmed a KY1044-dose dependent reduction of ICOS+ Tregs and maintenance of CD8+ T cells in the TME. Together, this resulted in an increased intratumoral CD8+/ICOS+ Treg ratio at all doses, plateauing from subjects receiving a flat KY1044 dose of 8 mg. KY1044-dependent agonism was indirectly assessed by measuring circulating cytokine levels. A post-dosing transient induction of GM-CSF was evident in subjects dosed with KY1044 at the 0.8 and 2.4 mg dose, whereas minimal induction was observed at dose of 8 mg and higher. Conclusions: LongitudinalPDdata confirmed the expected KY1044 MoA, namely ICOS Treg depletion and increased CD8/ICOS Treg ratio in the TME as well as T cell co-stimulation. The observed PD responses are currently being further explored in a more homogenous patient population.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10507-10507 ◽  
Author(s):  
Mala Kiran Talekar ◽  
Shannon L. Maude ◽  
George E Hucks ◽  
Laura S Motley ◽  
Colleen Callahan ◽  
...  

10507 Background: Anti-CD19 CAR-T cell therapies have shown high efficacy in inducing durable marrow responses in patients with relapsed/refractory CD19+ ALL. We now report on outcome of 10 patients with extramedullary (EM) involvement of ALL treated with CAR-T, including 5 patients who had EM disease at time of infusion. Methods: We identified patients treated on pediatric phase 1/2a trials of murine (CTL019) or humanized (CTL119) anti-CD19 CAR-T cells for isolated EM or BM/EM relapse of ALL. EM relapse was defined as involvement of non-CNS site by imaging +/- pathology within 12 months (mos) of infusion. Post infusion, patients had diagnostic imaging done at 1, 3, 6, 9, and 12 mos. Results: Among 97 patients receiving CAR-T, ten (CTL019, n=6; CTL119, n=4) were identified who had EM involvement on average 2.3 mos (range 0-9 mos) prior to infusion; including 5/10 at time of infusion. Sites of EM relapses included testes, sinus, parotid, bone, uterus, kidney and skin, and 5 patients had multiple sites of EM involvement. Patients ranged from 2-4 relapses of their ALL pre-CAR-T. Two had isolated EM relapse (sites were parotid and multifocal bony lesions in one; testis and sinus in second). All 10 patients had undergone hematopoietic stem cell transplantation prior to EM relapse, 2 had received radiation directed to the EM site prior to CAR-T. Five patients evaluated by serial imaging had objective responses: 2 had resolution of EM disease by day 28; 2 had resolution by 3 mos; 1 had continued decrease in size of uterine mass at 3 and 6 mos and underwent hysterectomy at 8 mos with no evidence of disease on pathology. In the 4 patients with prior history of skin or testicular involvement, there was no evidence by exam at day 28. One patient had progressive EM disease within 2 weeks of CAR-T cell infusion and died at 6 weeks. Three relapsed with CD19+ disease [1 skin/medullary- died at 38 mos post CAR-T; 2 medullary (1 died at 17 mos, 1 alive at 28 mos)]. The remaining 6 are alive and well at median follow-up of 10 mos (range 3-16 mos) without recurrence of disease. Conclusions: Single agent CAR-T immunotherapy can induce potent and durable responses in patients with EM relapse of their ALL. Clinical trial information: NCT01626495, NCT02374333.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10508-10508 ◽  
Author(s):  
Meenakshi Hegde ◽  
Christopher C. DeRenzo ◽  
Huimin Zhang ◽  
Melinda Mata ◽  
Claudia Gerken ◽  
...  

10508 Background: Outcome for patients with advanced sarcoma is extremely poor and treatment options are limited. Encouragingly, in our phase 1 dose-escalation trial (Ahmed et al, JCO 2015), systemic administration of up to 1x108/m2 autologous HER2-CAR T cells in patient with HER2+ sarcoma was safe. While T cells did not expand, 4/19 evaluable patients are alive 37-61 months post infusion without evidence of disease. The goal of this study was to evaluate if lympohodepleting chemotherapy can safely induce the expansion of HER2-CAR T cells. Methods: In a phase 1 clinical study, NCT00902044, we administered 1x108/m2 autologous HER2-CAR (with a CD28.zeta signaling domain) T cells to patients with refractory/metastatic HER2+ sarcoma after lymphodepletion. Results: Six patients with refractory/metastatic HER2+ sarcoma (4 osteosarcoma, 1 rhabdomyosarcoma, 1 synovial sarcoma) with a median age of 16 (range: 4 to 55) received up to 3 infusions of 1x108 cells/m2 CAR T cells after lymphodepletion with either fludarabine (Flu; n = 3) or Flu and cyclophosphamide (Flu/Cy; n = 3). Flu and Flu/Cy induced lymphopenia with an absolute lymphocyte count (ALC) of < 100/ml at the day of the T-cell infusion. Only Flu/Cy induced neutropenia (absolute neutrophil count [ANC] < 500/ml) for up to 14 days. 4/6 patients developed grade 1-2 cytokine release syndrome (CRS) within 24 hours of CAR T-cell infusion that resolved completely with supportive care within 3 days of onset. T cells expanded in 5/6 patients (median 89-fold (range: 41 to 2,893) with a median peak expansion on day 7 (range: 5 to 28). CAR T cells could be detected by qPCR in 6/6 patients at 6 weeks post infusion. One patient with rhabdomyosarcoma metastatic to the bone marrow had a complete responses (CR), 2 had stable disease (SD), and 3 had progressive disease (PD). Two patients are alive with a median overall survival of 14.2 months. Conclusions: Infusion of autologous HER2-CAR T cells after lymphodepletion is safe, and can be associated with objective clinical benefit in patients with advanced HER2+ sarcoma. These findings warrant further evaluation in a phase 2b study as a single agent or in combination with other approaches. Clinical trial information: NCT00902044.


2020 ◽  
Vol 8 (Suppl 1) ◽  
pp. A1.2-A2 ◽  
Author(s):  
Sarina Piha-Paul ◽  
Johanna Bendell ◽  
Anthony Tolcher ◽  
Sara Hurvitz ◽  
Amita Patnaik ◽  
...  

BackgroundAnticalin® proteins are recombinantly engineered human proteins based on lipocalins. PRS-343 is a first-in-class bispecific antibody-Anticalin fusion protein targeting the oncogenic tumor antigen HER2 and the costimulatory immune receptor 4-1BB on T and other immune cells. Here, we report the results of a phase 1 single-agent dose escalation trial in patients with HER2+ solid tumors.MethodsPRS-343 has been evaluated in sequential dose cohorts from 0.0005 to 8 mg/kg i.v. Doses were administered Q3W and the 8 mg/kg dose was also given Q2W. An accelerated titration design was utilized for the initial dose escalation followed by a modified 3+3 design and the option to back-fill cohorts. Dose-limiting toxicities (DLTs) were reported during the first cycle of each schedule. The primary study objectives include the safety profile and RP2D of PRS-343. Secondary objectives include ORR and DCR, PD biomarker response and PK profile. PD response was assessed in tumor biopsies (CD8+ T cell IHC) pre- and post- PRS-343 treatment.Results51 patients (median age 61.2 years, 61% female, 82% caucasian, 57% with more than three lines of prior therapy) with a variety of solid tumor indications [gastric/GEJ (n=19); BC (n=12); gynecological cancer (n=6); CRC (n=5); BTC (n=4); UC (n=2); melanoma, pancreatic and salivary duct (n=1 each)] have been treated with PRS-343. Based on pharmacokinetic analyses and observed kinetics of the CD8+ T cell expansion post-treatment, the low end of the active dose range is considered 2.5 mg/kg. 19 patients treated at active dose levels before the data cut-off on 09-06-2019 were evaluable for response [DCR 58% (11% confirmed PR) as per RECIST 1.1]. At the active doses, we observed significant and pronounced post-treatment expansion of CD8+ T cells particularly in the tumor nests, consistent with the MoA of PRS-343, while there was no increase in the doses below 2.5 mg/kg. The post-treatment expansion of CD8+ T cells was more pronounced in patients with a confirmed PR or prolonged SD. PRS-343 was very well tolerated, with no SAEs reported. The most frequent TRAEs were fatigue (9%), chills (6%) and diarrhea (5%) of mild to moderate severity. None qualified as a DLT.ConclusionsPRS-343 is the first molecule of its kind to demonstrate encouraging evidence of safety and clinical benefit with a correlative PD effect in a heavily pre-treated population. These initial data suggest that PRS-343, the first 4-1BB bispecific to enter clinical development, merits further investigation in clinical trials.Trial RegistrationNCT03330561


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A898-A898
Author(s):  
Jemila Houacine ◽  
Anne Marie-Cardine ◽  
Aude Le Roy ◽  
Jérôme Giustiniani ◽  
Riad Abes ◽  
...  

BackgroundRegulatory T cells (Tregs) inhibit immune responses in solid cancers using cell-cell contacts and anti-inflammatory cytokine release. Also, due to high and constitutive levels of IL2Ralpha chain (CD25) expression, Tumor infiltrating (TIL)-Tregs cells preferably consume local Interleukin-2 (IL2), thus depriving conventional T cells from IL2-induced activation and proliferation. Therefore, the selective depletion of TIL-Tregs using therapeutic antibodies targeting CD25 represents a promising strategy to unleash tumor-specific immune responses in solid cancers.MethodsCD25 expression was evaluated by flow and mass cytometry on T -cell subsets from tumor biopsies collected in patients with various solid cancers (Breast, Endometrial and Cervix). ALD2510 potency was demonstrated in vitro and in vivo in human CD25 Knock-In huGEMM (huCD25-KI) MC38-bearing mice and in CD34+ humanized NSG mice grafted with human cancer cell lines (MDA-MB-231 and HT29).ResultsIn tumor biopsies, CD25 is highly and homogeneously expressed by TIL-Tregs, while being much less expressed by only a fraction of conventional CD4+ T cells and barely expressed by TIL-CD8+ cells. This confirms CD25 as the most selective marker to target TIL-Tregs in cancer patients.In vitro, ALD2510 shows potent ADCC and ADCP as well as strong Treg depletion capacity. Importantly, CD8+ and CD4+ conventional T cells are not impacted by ALD2510 even after activation confirming ALD2510 ability to selectively deplete Tregs. Accordingly, ALD2510 neither blocks IL-2 binding to CD25 nor inhibits IL-2 induced proliferation of activated T cells. In CD34+-humanized mice, ALD2510 efficiently depletes human Tregs but spares conventional T cells. Also, in the MC38 model in huCD25-KI mice, ALD2510 shows a strong anti-tumor activity as a single agent with 60% overall tumor growth inhibition together with massive Treg depletion 7 days after a single administration. In addition, combination of ALD2510 with anti-PD1 leads to complete tumor regression and strong activation of conventional T cells. Importantly, Basiliximab, a CD25-specific IL-2 blocking antibody, although efficient at depleting Treg cells, did not impact tumor growth, thus demonstrating that the IL-2 sparing feature of ALD2510 is critical to elicit anti-tumour response in vivo.ConclusionsThis preclinical data package supports CD25 as a potent and selective Treg marker allowing Tregs depletion while sparing conventional T cells. In this context, ALD2510, a novel humanized CD25-specific and IL-2 sparing antibody presents all the required attributes for selective and efficient TIL-Tregs depletion, making it a promising drug candidate to treat a broad range of solid tumor patients.Ethics ApprovalThe studies involving human material were approved by the ethical committee “Comité de Protection des Personnes Sud Méditerranée » under approval numbers 1362 and 1048. All participants gave informed consent before taking part.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A426-A426
Author(s):  
Samuel Klempner ◽  
John Strickler ◽  
Lindsey Gourley ◽  
Celine Jacquemont ◽  
Vinona Bhatia ◽  
...  

BackgroundSBT6050 is a novel therapeutic comprising a selective small molecule toll-like receptor 8 (TLR8) agonist linked to the HER2-directed monoclonal antibody pertuzumab, allowing for combination with trastuzumab-based agents and regimens. SBT6050 is designed to activate myeloid cells in tumors expressing moderate to high levels of HER2. TLR8 agonism directly activates myeloid cells, including macrophages and dendritic cells (DCs), and secondarily activates NK and T cells, inducing a broad spectrum of anti-tumor immune mechanisms. SBT6050 is currently being tested as a single agent and in combination with checkpoint inhibitors (NCT04460456). Initial results show early evidence of anti-tumor effects, activation of myeloid and NK/T cells, and a safety profile consistent with an immune activator that is generally non-overlapping with that of T-DXd or tucatinib-based regimens.A strong scientific rationale supports the combination of SBT6050 with T-DXd and SBT6050 with trastuzumab and tucatinib ± capecitabine. Both treatment regimens drive tumor cell death and release of tumor neoantigens. SBT6050 can enhance tumor neoantigen presentation and subsequent activation of T cell responses through its direct activation of DCs. SBT6050 combined with T-DXd or trastuzumab and tucatinib ± capecitabine is postulated to drive increased anti-tumor T cell responses. In addition, T-DXd and trastuzumab support antibody-dependent cell mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) and SBT6050 can enhance both functions. SBT6050 activates myeloid cells to secrete cytokines that amplify ADCC by NK cells. Additionally, SBT6050 activation downmodulates SIRPα on the surface of myeloid cells which can increase ADCP through attenuation of the CD47-SIRPα interaction. Consistent with this mechanism of action, in preclinical studies in mice, the combination of trastuzumab and a mouse surrogate of SBT6050 led to enhanced activity in the HER2-positive NCI-N87 human tumor xenograft model compared to either agent alone.MethodsProtocol SBT6050-201 is a phase 1/2, open-label, dose-escalation and expansion study evaluating SBT6050 in combination with either T-DXd (Part 1) or tucatinib and trastuzumab +/- capecitabine (Part 2). Eligible patients are at least 18 years old, have HER2-positive metastatic breast cancer, gastric/GEJ cancer, colorectal cancer, or HER2-expressing or amplified NSCLC, and have received at least one prior therapy for metastatic disease. Patients will receive SBT6050 subcutaneously q3wk starting at a dose with demonstrated pharmacodynamic activity in phase 1. Pharmacodynamic markers of myeloid and NK/T cell activation will be assessed in peripheral blood and on-treatment tumor biopsies. Circulating tumor DNA will be evaluated as an exploratory assessment.Ethics ApprovalThis clinical study has not yet obtained ethics approval or started enrollment. All participants will be required to give informed consent before taking part.


Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 101
Author(s):  
Ivet A. Yordanova ◽  
Friederike Ebner ◽  
Axel Ronald Schulz ◽  
Svenja Steinfelder ◽  
Berit Rosche ◽  
...  

Considering their potent immunomodulatory properties, therapeutic applications of Trichuris suis ova (TSO) are studied as potential alternative treatment of autoimmune disorders like multiple sclerosis (MS), rheumatoid arthritis (RA), or inflammatory bowel disease (IBD). Clinical phase 1 and 2 studies have demonstrated TSO treatment to be safe and well tolerated in MS patients, however, they reported only modest clinical efficacy. We therefore addressed the cellular and humoral immune responses directed against parasite antigens in individual MS patients receiving controlled TSO treatment (2500 TSO p.o. every 2 weeks for 12 month). Peripheral blood mononuclear cells (PBMC) of MS patients treated with TSO (n = 5) or placebo (n = 6) were analyzed. A continuous increase of serum IgG and IgE antibodies specific for T. suis excretory/secretory antigens was observed up to 12 months post-treatment. This was consistent with mass cytometry analysis identifying an increase of activated HLA-DRhigh plasmablast frequencies in TSO-treated patients. While stable and comparable frequencies of total CD4+ and CD8+ T cells were detected in placebo and TSO-treated patients over time, we observed an increase of activated HLA-DR+CD4+ T cells in TSO-treated patients only. Frequencies of Gata3+ Th2 cells and Th1/Th2 ratios remained stable during TSO treatment, while Foxp3+ Treg frequencies varied greatly between individuals. Using a T. suis antigen-specific T cell expansion assay, we also detected patient-to-patient variation of antigen-specific T cell recall responses and cytokine production. In summary, MS patients receiving TSO treatment established a T. suis-specific T- and B-cell response, however, with varying degrees of T cell responses and cellular functionality across individuals, which might account for the overall miscellaneous clinical efficacy in the studied patients.


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.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii360-iii360
Author(s):  
Nicholas Vitanza ◽  
Juliane Gust ◽  
Ashley Wilson ◽  
Wenjun Huang ◽  
Francisco Perez ◽  
...  

Abstract We report preliminary results of three Phase 1 trials of repetitively dosed locoregional CAR T cells for children with recurrent/refractory CNS tumors, targeting HER2 (BrainChild-01), EGFR (BrainChild-02), and B7-H3 (BrainChild-03). Cells are delivered into the tumor cavity (Arm A) or ventricular system (Arm B and BrainChild-03’s DIPG-specific Arm C). Primary endpoints are feasibility and safety. Successful CAR T cell manufacture occurred in 2/2 subjects (BrainChild-01) and 2/3 (BrainChild-02). All subjects tolerated intra-patient dose escalation from 1x107 to 2.5x107 cells/dose without DLTs. Two subjects were evaluable on BrainChild-01 (S-001: glioblastoma, Arm A, survival 173 days post-first infusion, received 6 infusions; S-002: ependymoma, Arm B, survival 111 days, 9 infusions). One subject was evaluable on BrainChild-02 (glioblastoma, Arm A, withdrew from trial at 49 days, 5 infusions). One enrolled patient on BrainChild-03 has not begun treatment. None of the subjects developed new neurologic toxicities, although transient worsening of baseline tumor-related signs and symptoms were seen. Secondary endpoints are efficacy and disease response. No objective radiographic responses have been observed. Both BrainChild-01 subjects had transient systemic CRP elevations following infusions (S-001: peak of 3.9 post Course 1 Week 1; S-002: peak of 2.3 post Course 2 Week 1), possibly indicating an inflammatory response. Both subjects had post-infusion CSF cytokine elevations (CXCL10, GCSF, GM-CSF, IFNa2, IFNg, IL-10, IL12-p40, IL12-p70, IL-15, IL-1a, IL-3, IL-6, IL-7, TNFa, VEGF) without concurrent systemic changes. In summary, we provide preliminary evidence of safety and feasibility of intracranial delivery of CAR T cells for pediatric CNS tumors.


Blood ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 2200-2210 ◽  
Author(s):  
Rikke Bæk Sørensen ◽  
Sine Reker Hadrup ◽  
Inge Marie Svane ◽  
Mads Christian Hjortsø ◽  
Per thor Straten ◽  
...  

Abstract Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathologic settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in patients with cancer but also in healthy persons. We show that the presence of such IDO-specific CD8+ T cells boosted T-cell immunity against viral or tumor-associated antigens by eliminating IDO+ suppressive cells. This had profound effects on the balance between interleukin-17 (IL-17)–producing CD4+ T cells and regulatory T cells. Furthermore, this caused an increase in the production of the proinflammatory cytokines IL-6 and tumor necrosis factor-α while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (ie, the TLR9 ligand cytosine-phosphate-guanosine, soluble cytotoxic T lymphocyte–associated antigen 4, or interferon γ) induced IDO-specific T cells among peripheral blood mononuclear cells from patients with cancer as well as healthy donors. In the clinical setting, IDO may serve as an important and widely applicable target for immunotherapeutic strategies in which IDO plays a significant regulatory role. We describe for the first time effector T cells with a general regulatory function that may play a vital role for the mounting or maintaining of an effective adaptive immune response. We suggest terming such effector T cells “supporter T cells.”


1976 ◽  
Vol 144 (3) ◽  
pp. 776-787 ◽  
Author(s):  
R M Zinkernagel

In mice, primary footpad swelling after local infection with lymphocytic choriomeningitis virus (LCMV) and delayed-type hypersensitivity (DTH) adoptively transferred by LCMV immune lymphocytes are T-cell dependent. Nude mice do not develop primary footpad swelling, and T-cell depletion abrogates the capacity to transfer LCMV-specific DTH. Effector T cells involved in eliciting dose-dependent DTH are virus specific in that vaccinia virus-immune lymphocytes could not elicit DTH in LCMV-infected mice. The adoptive transfer of DTH is restricted to H-2K or H-2D compatible donor-recipient combinations. Distinct from the fowl-gamma-globulin DTH model, I-region compatibility is neither necessary nor alone sufficient. Whatever the mechanisms involved in this K- or D-region associated restriction in vivo, it most likely operates at the level of T-cell recognition of "altered self" coded in K or D. T cells associated with the I region (helper T cells and DTH-T cells to fowl-gamma-globulin) are specific for soluble, defined, and inert antigens. T cells associated with the K and D region (T cells cytotoxic in vitro and in vivo for acute LCMV-infected cells, DTH effector T cells, and anti-viral T cells) are specific for infectious, multiplying virus. The fact that T-cell specificity is differentially linked with the I region or with the K and D regions of H-2 may reflect the fundamental biological differences of these antigens. Although it cannot be excluded that separate functional subclasses of T-effector cells could have self-recognizers for different cell surface structures coded in I or K and D, it is more likely that the antigen parameters determine whether T cells are specific for "altered" I or "altered" K- or D-coded structures.


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