scholarly journals O82 A phase 1 dose escalation study of PRS-343, a HER2/4–1BB bispecific molecule, in patients with HER2-positive malignancies

2020 ◽  
Vol 8 (Suppl 1) ◽  
pp. A1.2-A2 ◽  
Author(s):  
Sarina Piha-Paul ◽  
Johanna Bendell ◽  
Anthony Tolcher ◽  
Sara Hurvitz ◽  
Amita Patnaik ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Dose Escalation ◽  
Phase 1 ◽  
Cd8 T Cell ◽  
Post Treatment ◽  
Primary Study ◽  
Biomarker Response ◽  
Active Dose

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

T Cell Responses during Long-Term Continuous Infusion of MT103 (MEDI-538; Anti-CD19 BiTE) in Patients with Relapsed B-NHL: Data from Dose-Escalation Study MT103-104.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2725-2725 ◽  
Author(s):  
Matthias Klinger ◽  
Peter Kufer ◽  
Petra Kirchinger ◽  
Ralf Lutterbüse ◽  
Eugen Leo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Dose Escalation ◽  
Cell Expansion ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Cell Counts ◽  
T Cell Expansion

Abstract MT103 (MEDI-538) is a bispecific single-chain antibody construct directed at CD3 on human T cells and CD19 on human B lymphoma and normal B cells. Transient linkage of B and T cells by MT103 provides T cells with a T cell receptor (TCR)-like signal leading to redirected lysis of B cell targets without apparent need of costimulation and inducing T cells to proliferate, secrete cytokines and upregulate surface activation markers. TCR-like signalling by MT103 is strictly dependent on the presence of target cells. Redirected lysis of CD19-positive cells by MT103 is seen at low picomolar concentrations and at low effector-to-target ratios. The in-vivo half-life of MT103 is approximately two hours. In the ongoing dose escalation study MT103-104, patients with relapsed B-NHL have so far received continuous infusion of MT103 at maintenance flow-rates of 0.5, 1.5, 5 and 15 μg/m2/24h for 4 or 8 weeks following a 3+3 dose escalation design. Serum concentrations of MT103 remained constant over the entire treatment period at a level depending on the respective maintenance flow-rate. Depletion of circulating B (lymphoma) cells could be observed more frequently with increasing dose levels (DL) from DL1 to DL3, and in all evaluable patients at DL4. Three of six evaluable patients at DL4 showed clinical responses (2 PR, 1 CR) according to standardized Cheson criteria, but no patient of DL1-3. The time courses of absolute CD4 and CD8 T cell counts in peripheral blood were determined by flow cytometry. CD8 T lymphocytes were further subdivided for analysis into naïve T cells, TCM (central memory T cells), TEM (effector memory T cells) and TEMRA (non-proliferating terminally differentiated CTL), and CD4 T lymphocytes into naïve T cells, TCM and TEM. Activation of CD4 and CD8 T cell subsets was determined by measuring upregulation of CD69, CD25 and HLA-DR. Serum levels of cytokines were determined as additional biomarkers for T cell activation. In 50% of patients at DL1 to DL3, CD4 and CD8 T cell counts increased during the course of treatment - over pre-treatment levels. The TEM subset from both CD4 and CD8 T cells accounted for most of the observed increases, while the naïve T cell subsets showed no increase but also no signs of apoptosis. The non-proliferative TEMRA subset of CD8 T cells also remained unchanged in most patients. This indicated that the selective increase of proliferation-competent TEM subsets was attributed to MT103-induced T cell proliferation. At DL4, all evaluable patients showed signs of T cell expansion after 2 weeks of MT103 infusion, which was most pronounced in those who developed a partial or complete remission. The increase of CD8 T cell counts was more pronounced than that of CD4 T cells. T cell expansion was accompanied by upregulation of T cell activation markers as well as by increases in serum concentrations of cytokines like IFN-γ. T cell expansion and activation reverted in all cases when the infusion of MT103 was stopped. In summary, MT103 induced a reversible secondary T cell response involving T cell activation and proliferation as well as T cell cytotoxicity against circulating B cells and lymphoma tissue. The dose-dependent T cell expansion observed during long-term infusion of MT103, particularly within the cytotoxic TEM subset of CD8 T cells, appears to play a key role for clinical activity.

PEGylated human IL-10 (AM0010) monotherapy in refractory metastatic colorectal cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3571-3571
Author(s):  
Jeffrey R. Infante ◽  
Kyriakos P. Papadopoulos ◽  
Aung Naing ◽  
Karen A. Autio ◽  
Patrick Alexander Ott ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Dose Escalation ◽  
Stable Disease ◽  
De Novo ◽  
Phase 1 ◽  
Second Line ◽  
Line Of Therapy

3571 Background: Colorectal Cancer (CRC) has been refractory to immune therapies. The clinical benefit of immunotherapy is thought to depend on the expansion of activated, intratumoral, tumor specific cytotoxic CD8+ T cells which are low in most CRCs. AM0010 stimulates the survival, expansion and cytotoxicity of intratumoral CD8+ T cells. Patients with CRC who have progressed on SOC first and second line of therapy have a reported 7.1 months OS with TAS-102 (Meyer et al. NEJM372;20, 2015). In this Phase 1 study the efficacy of AM0010 was studied in refractory metastatic CRC patients. Methods: CRC pts progressing on a median of 4 prior therapies (range 2-7) were treated daily with AM0010 in doses of 1 ug/kg SQ daily to 40 ug/kg in a dose escalation design. Tumor responses were assessed using irRC. Serum cytokines, activation of blood derived T cells and peripheral T cell clonality were analyzed. Pretreatment archival tissue samples were evaluated by IHC for tumor infiltration by CD8+T cells. Results: AM0010 was tolerated with reversible TrAEs. 10 pts (of 27) had a G3/4 TrAE. There were no objective responses. 11 patients were treated in dose escalation cohorts (1-10 ug/kg) and 16 pts were treated at or above RP2D (20 ug/kg or 40 ug/kg). Seven of 25 pts with at least one radiographic response evaluation had stable disease at 8 weeks. One patient had SD for 19.4 months. The mPFS (ITT n = 27 pts) was 1.6 months, mOS was 11.7 (range 2.4 – 32+) months. The median follow-up is 25.2 months (range 13-35). AM0010 increased Th1 cytokines IL-18 and IFNg in the serum of patients, while decreasing mediators of chronic, tumor promoting inflammation (Th17 cytokines) and TGFb. Tumor infiltrating granzyme B+ CD8+ T cells increased during the treatment. AM0010 induced de-novo oligoclonal expansion of T cell clones in patients. Conclusions: AM0010 is well tolerated in patients with refractory CRC. Although objective tumor responses were not seen in this very advanced CRC population, the observed immune activation including clonal T cell expansion, prolonged stable disease, and the mOS of 11.7 months is encouraging in this advanced CRC population. Future study of AM0010 in combination with FOLFOX in a second – line of therapy colorectal cancer patients is being planned. Clinical trial information: NCT02009449.

801 PRIME™ IL-15 (RPTR-147): Preliminary clinical results and biomarker analysis from a first-in-human Phase 1 study of IL-15 loaded peripherally-derived autologous T cell therapy in solid tumor patients

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A850-A850
Author(s):  
Erika Hamilton ◽  
Sarah Nikiforow ◽  
Philip Bardwell ◽  
Christine McInnis ◽  
Jeffrey Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Metastatic Disease ◽  
Cd8 T Cells ◽  
Dose Escalation ◽  
Phase 1 ◽  
T Cell Clones ◽  
Cell Product ◽  
Cell Clones ◽  
Biomarker Analysis

BackgroundRPTR-147 is a novel autologous non-genetically modified multi-clonal T cell product loaded with an IL15-Fc nanogel. The product was derived from rare peripherally-derived anti-tumor T cell clones that were primed against a multi-antigen cassette containing tumor associated antigens (TAA), known to be over-expressed in specific tumor types. We describe preliminary results from the ongoing first-in-human Phase 1 trial.MethodsAutologous anti-TAA T cells are generated with a proprietary dendritic cell priming process and then loaded with an IL15-Fc nanogel. TAAs used in cassette: PRAME, NY-ESO-1, SSX2, Survivin and WT1. Thawed RPTR-147 is delivered by infusion. Pre- and post-treatment biopsies were collected for biomarker analysis by immunohistochemistry (IHC) and transcriptome sequencing. Serial blood collections were obtained for measuring IL-15 pharmacokinetics and pharmacodynamic parameters including plasma cytokine levels and immunophenotyping by flow cytometry. T cell receptor sequencing (TCRSeq) was used to characterize the T cell repertoire from manufactured T cell product and the patient‘s blood.ResultsInterim clinical and biomarker data from 17 patients with advanced metastatic disease refractory to SOC who received monthly infusions of 20-360 million cells/m², were reviewed (table 1). There were no dose-limiting toxicities and no evidence of cytokine-release syndrome. The 360M/m² dose contained 3X more IL15-Fc than the MTD of systemically administered IL15-Fc,1 but produced less than a tenth of the systemic exposure to free IL15-Fc. Currently, 360M cells/m² is considered safe and well-tolerated. Further dose escalation is planned.Matched evaluable biopsies were obtained in 7 patients. Tumor-infiltrating T cell lymphocytes was observed in 5 cases for CD8 T cells and 4 cases for CD4 T cells. A dose dependent increase in both inflammatory cytokines and NK & CD8+ T cells was observed, consistent with expected MOA and PK. TCRSeq analysis demonstrated that product specific T cell clones could be tracked in both patient‘s blood and tumor over time. Further analysis to decode the specificity of those cells and demonstrate that tumor antigen specific T cells can be found in patient‘s blood and tumor biopsies is ongoing.Of the 17 patients who received RPTR-147 infusions 10 were noted to have stable disease (SD) and in 4 patients SD lasted > 6 months.Abstract 801 Table 1Summary of PatientsTumor types for the 17 patients with advanced metastatic disease included in this clinical trial (NCT0381568)ConclusionsInterim results with RPTR-147 have shown it to be well-tolerated and have a favorable safety profile. Dose-escalation is proceeding. Ongoing biomarker analysis will inform future clinical strategies in matching patients to an optimized PRIME IL-15 T cell product.Trial RegistrationNCT03815682Ethics ApprovalThe study was approved by local institutional IRBs after acceptance of the IND by the FDA.ConsentWritten informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.ReferenceRomee R, Cooley S, Berrien-Elliott MM, et al. First-in-human phase 1 clinical study of the IL-15 superagonist complex ALT-803 to treat relapse after transplantation. Blood 2018;131(23):2515-2527.

scholarly journals Phase 1/2 Study of Nexi-002 Autologous Multi-Antigen-Specific CD8+ T Cells for the Treatment of Relapsed or Refractory Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2824-2824
Author(s):  
Robert D Knight ◽  
Myo Htut ◽  
Juan C. Varela ◽  
Andrew Kin ◽  
Vineetha Edavana ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Phase 1 ◽  
Cd8 T Cell ◽  
Clinical Activity ◽  
Cell Product ◽  
Over Time

Abstract The NEXI-002 study is a prospective, multicenter, open-label phase 1/2 trial designed to characterize the safety, immunologic, and preliminary anti-myeloma activity of the NEXI-002 antigen specific CD8+ T cell product. Multiple myeloma (MM) is an incurable malignancy that occurs predominantly in older patients and is characterized by the growth of malignant plasma cells in the bone marrow. Despite substantial advances in therapy, virtually all patients relapse after treatment, emphasizing the unmet medical need for additional effective treatments. The NEXI-002 product is an autologous non-genetically engineered therapy of CD8+ T cells that recognize HLA 02.01-restricted peptides from the WT1, CD138, CS1, and NY-ESO-1 antigens. This T-cell product includes key memory phenotypes such as stem-like memory, central memory, and effector memory cells. Eligible patients have relapsed or refractory multiple myeloma (RRMM) who have received at least three prior lines of treatment that included at least an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 agent. Three patients were enrolled into the Safety Evaluation phase and received a single infusion of 80 million (M) to 100M cells of NEXI-002 product. In this phase of the study the primary endpoint is safety and secondary endpoints include expansion, persistence, and trafficking of the NEXI-002 cells. Bridging anti-MM treatment was permitted during the manufacture of the cellular product with a wash-out period of at least 14 days prior to lymphodepletion (LD) chemotherapy (intravenous fludarabine 30 mg/m 2 and cyclophosphamide 300 mg/m 2), which was administered on Days -5, -4, and -3 prior to the infusion of the NEXI-002 product up to 72 hours later (Day1). Treatment-related adverse events, including infusion reactions, events that prolong hospitalization post infusion, CRS, and neurotoxicity (ICANS) have not developed in these patients who received the NEXI-002 product. Lymphocyte recovery to baseline levels occurred within a few days after the infusion of the NEXI-002 product, demonstrating robust CD4 and CD8 T cell reconstitution following LD chemotherapy. NEXI-002 antigen specific T cells were detected in peripheral blood (PB) by multimer staining and proliferated over time and trafficked to the bone marrow (BM). The phenotype composition of detectable antigen specific T cells at both sites maintained that of the infused product. These NEXI-002 T cells persisted in PB and BM during follow-up. T-cell receptor (TCR) sequencing assays revealed T cell clones in the NEXI-002 product that were not detected in PB of patients tested at baseline. These clones subsequently expanded and persisted over time in the PB and BM. In conclusion, these results show that infusion of the NEXI-002 product is safe, well tolerated, and capable of generating a cell-mediated immune response that may lead to clinical activity. RNA Seq transcriptional profiling of the CD8+ T cells is planned. Additional patients have recently received NEXI-002 infusions and the trial will continue to be expanded to gain additional safety, immunologic, and clinical activity experience. Disclosures Knight: Neximmune, Inc: Current Employment. Varela: Nexlmmune: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite: Speakers Bureau. Edavana: Neximmune, Inc: Current Employment. Lu: Neximmune, Inc: Current Employment. Kim: Neximmune, Inc: Current Employment. Suarez: Neximmune, Inc: Current Employment. Oelke: Neximmune, Inc: Current Employment. Bednarik: Neximmune, Inc: Current Employment.

Predictive biomarkers for response to nivolumab in head and neck squamous cell carcinoma (HNSCC) (NCT#03652142).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 6060-6060
Author(s):  
Amanda Psyrri ◽  
Niki Gavrielatou ◽  
Aris Spathis ◽  
Maria Anastasiou ◽  
Ekaterina Fortis ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Checkpoint Inhibitors ◽  
Predictive Biomarkers ◽  
Cd8 T Cell ◽  
Post Treatment ◽  
Tertiary Lymphoid Structures ◽  
Pre Treatment ◽  
Lymphoid Structures

6060 Background: Tumor immune cell compositions determine response to immunotherapy. For a better understanding of the mechanisms of resistance to nivolumab in HNSCC, we sought to investigate a prospective cohort of longitudinal HNSCC samples from recurrent/metastatic HNSCC pts treated with nivolumab and identify biomarkers of response and resistance. We will specifically focus on modulation of immune markers following two cycles of nivolumab. Methods: Patients with platinum-refractory HNSCC with no contraindication to nivolumab therapy are included in this study. Tumor biopsies are performed at baseline, 24-72 hours after the second cycle and at progression with appropriate written informed consent. Samples were assessed for the presence of Tertiary Lymphoid Structures (TLS), PD-L1 expression (TPS and CPS) and CD8 T cell infiltrates combined with Ki67 (CD8/Ki67 double IHC stain). The primary outcome measure of the study is change in the percentage of immune cells in post treatment compared to baseline biopsies. Secondary endpoints include safety of performing a second biopsy, best overall response rate, biomarker expression in association with response and survival. Evaluation of other biomarkers including tumor mutational burden, HLA class I and II expression and adaptive immunity cell populations using multiplex IF is ongoing. Results: Of 20 patients evaluable for response, 14 had PD (8 of whom showed hyper-progression) and 6 attained disease control (1 with PR). PD-L1 status (CPS or TPS) was not altered by treatment (p = 0.905) and CPS > 20 pre-treatment showed a favorable trend towards response (p = 0.117). Absence of tertiary lymphoid structures was associated with disease progression (p = 0.0374). Infiltrating plasma cell count remained unchanged pre- and post-treatment and was unrelated to response (p = 0.458). The percentage of proliferating CD8+ T cells (CD8+/Ki67+) increased in post-treatment biopsies in the entire population (p = 0.022) and especially in progressors (p = 0.039). Pre-treatment CD8+ T cell density was higher in patients with hyper-progression compared to progressors (p = 0.029). Conclusions: Increased percentage of proliferating CD8+ T cells in progressors might represent dysfunctional T cells as has been recently shown in melanoma pts (Li H et al Cell 2019) and clinical efforts to reactivate intratumoral T cells may augment the efficacy of PD1 checkpoint inhibitors. Clinical trial information: NCT03652142.

Interrogation of neoantigen-specific CD8 T cells in peripheral blood following PD-L1 blockade in patients with metastatic urothelial carcinoma (mUC).

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3075-3075
Author(s):  
Jeppe Sejerø Holm ◽  
Samuel Aaron Funt ◽  
Anne-Mette Bjerregaard ◽  
James L. Reading ◽  
Colleen Anne Maher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Treatment Initiation ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Post Treatment ◽  
Cell Responses ◽  
Pre Treatment

3075 Background: Proliferation of CD8 T cells can be detected in the blood of cancer patients (pts) following a single dose of immune checkpoint blockade (ICB) and tends to be more robust in responding pts. Furthermore, tumor mutational burden (TMB) is seen to predict outcome to ICB across cancers. Mutation-derived neoepitopes presented on the tumor cell surface is believed to be recognized by T cells and are thus critical for tumor clearance. However, the capacity to mount a neoantigen T cell response and the kinetics in relation to ICB remain poorly understood. Methods: 24 pts with mUC were treated with atezolizumab (anti-PD-L1) 1200mg q3w on IMVigor 210 at MSKCC and included in here. Pt-specific neoepitopes were predicted based on whole-exome and RNA sequencing of pre-treatment archival tumors using the MuPeXI platform. Using DNA-barcode labelled pMHC multimers, we investigated CD8 T cell recognition of mutation-derived neoepitopes by screening pt PBMC samples pre- and post-treatment with atezolizumab (n = 85 PBMC samples). The kinetics of neoepitope-specific CD8 T cells were assessed for association with durable clinical benefit (DCB; defined as progression free survival > 6 mo). Results: Neoepitope peptide libraries of between 200-587 peptides were generated per pt (mean = 260 peptides per pt). 31 out of a combined 56 possible pt HLA types across the cohort were utilized for T cell analyses (mean four HLAs per pt). MHC multimer-based screening of pt PBMCs revealed detection of neoepitope-specific CD8 T cells in 22 of 24 pts pre-treatment (range one to 14 neoepitope responses) and 21 of 22 pts post-treatment (up to 273 weeks after trial start; one to 19 neoepitope responses). There were large inter- and intra-patient variations of neoepitope-specific CD8 T cell responses during treatment with the largest increases occurring at the 3-wk, post-treatment initiation timepoint. We observed that pts with DCB tend to raise a broader neoantigen T cell response than patients without DCB. 38% of pts without DCB and 67% of pts with DCB exhibited an increase in neoepitope-specific CD8 T cell responses within 3 wks of treatment initiation. Conclusions: Using high-throughput screening, pt-specific neoepitope reactive CD8 T cells could be detected pre- and post-treatment in pts with mUC treated with atezolizumab. Phenotypic characterization of neoepitope reactive CD8 T cells is ongoing. These data may help elucidate the dynamics and characteristics of the T cells of highest relevance to the ICB-induced, anti-tumor immune response.

451 Combining Bempegaldesleukin (CD122-preferential IL-2 pathway agonist) and NKTR-262 (TLR7/8 agonist) pairs local innate activation with systemic CD8+ T cell expansion to enhance anti-tumor immunity

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A478-A478
Author(s):  
Annah Rolig ◽  
Daniel Rose ◽  
Saul Kivimae ◽  
Werner Rubas ◽  
William Redmond
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Cell Expansion ◽  
Nk Cell ◽  
Tumor Regression ◽  
Cell Activity ◽  
Cd8 T Cell ◽  
Post Treatment

BackgroundPreviously, we demonstrated that radiation therapy (RT) combined with Bempegaldesleukin (BEMPEG;NKTR-214), a first-in-class CD122-preferential IL-2 pathway agonist, led to enhanced anti-tumor efficacy through a T cell-dependent mechanism. However, we observed only modest systemic responses to BEMPEG/RT across several murine tumor models. Therefore, we explored alternative approaches to improve systemic tumor-specific immunity. We evaluated whether intratumoral NKTR-262, a polymer-modified toll-like receptor (TLR) 7/8 agonist, combined with systemic BEMPEG treatment resulted in improved tumor-specific immunity and survival compared to BEMPEG combined with RT. We hypothesized that BEMPEG/NKTR-262 immunotherapy would promote synergistic activation of local immunostimulatory innate immune responses followed by systemic adaptive immunity to significantly improve tumor regression and overall survival.MethodsTumor-bearing mice (CT26; EMT6) received BEMPEG (0.8 mg/kg; iv), RT (12 Gy x 1), and/or intratumoral NKTR-262 (0.5 mg/kg). Flow cytometry was used to evaluate CD4+ and CD8+ T cell activation status in the blood and/or tumor (7 days post-treatment) and NK cell activity in the tumor (1, 3 days post-treatment). The contribution of specific immune subsets was determined by depletion of CD4+, CD8+, or NK cells. CD8+ T cell activity was determined in vitro by tracking apoptosis in an Incucyte assay. Data are representative of 1–2 independent experiments (n=5–14/group) and statistical significance was determined by 1-way ANOVA (p-value cut-off of 0.05).ResultsBEMPEG/NKTR-262 resulted in significantly improved survival compared to BEMPEG/RT. BEMPEG/NKTR-262 efficacy was NK and CD8+ T cell-dependent, while BEMPEG/RT primarily relied on CD8+ T cells. Response to BEMPEG/NKTR-262 was characterized by a significant expansion of activated CD8+ T cells (GzmA+; Ki-67+; ICOS+; PD-1+) in the blood, which correlated with reduced tumor size (p<0.05). In the tumor, NKTR-262/BEMPEG induced higher frequencies of GzmA+ CD8+ T cells exhibiting reduced expression of suppressive molecules (PD-1+, TIM-3+), compared to BEMPEG/RT. Indeed, CD8+ T cells isolated from BEMPEG/NKTR-262-treated tumors had greater cytolytic capacity than those from BEMPEG/RT-treated mice. CD8+ T cell expansion (blood) and activity (tumor) depended upon the initial NK response, as neither occurred in the absence of NK cells. BEMPEG/NKTR-262 uniquely induced the expansion of early and high effector NK cells.ConclusionsCombining BEMPEG with NKTR-262 lead to an early and robust NK cell expansion not observed in the BEMPEG/RT combination. The improved tumor regression and survival was dependent on the NKTR-262 driven expansion of NK cells. A clinical trial of BEMPEG/NKTR-262 for patients with metastatic solid tumors is in progress (NCT03435640).

scholarly journals Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

2019 ◽  
Vol 5 (3) ◽  
pp. 63
Author(s):  
Alice Bayiyana ◽  
Samuel Okurut ◽  
Rose Nabatanzi ◽  
Godfrey Zziwa ◽  
David R. Boulware ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Cell Surface ◽  
Cd8 T Cells ◽  
Cryptococcal Meningitis ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Effector Memory ◽  
Memory Subset

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4+ and CD8+ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4+ and CD8+ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4+ and CD8+ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27+CD45R0+), effector memory (CD45R0+CD27–), immune activation (CD38+ and Human Leucocyte Antigen DR (HLA-DR+), and exhaustion (Programmed cell death protein one (PD-1) in the CD4+ T cell subset. In comparison to the CD4+ T cell population, the CD8+ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4+ and CD8+ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4+ T cells during ART treatment during CM co-infection.

Class I–unrestricted noncytotoxic anti–HTLV-I activity of CD8+ T cells

Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1994-1995 ◽  
Author(s):  
Masako Moriuchi ◽  
Hiroyuki Moriuchi
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Membrane Filter ◽  
Cd8 T Cell ◽  
Class I ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Permeable Membrane

Abstract Although it is widely believed that viral clearance is mediated principally by the destruction of infected cells by cytotoxic T cells, noncytolytic antiviral activity of CD8+ T cells may play a role in preventing the progression to disease in infections with immunodeficiency viruses and hepatitis B virus. We demonstrate here that (1) replication of human T-lymphotropic virus type I (HTLV-I) is more readily detected from CD8+ T-cell–depleted (CD8−) peripheral blood mononuclear cells (PBMCs) of healthy HTLV-I carriers than from unfractionated PBMCs, (2) cocultures of CD8− PBMCs with autologous or allogeneic CD8+ T cells suppressed HTLV-I replication, and (3) CD8+ T-cell anti-HTLV-I activity is not abrogated intrans-well cultures in which CD8+ cells are separated from CD8− PBMCs by a permeable membrane filter. These results suggest that class I-unrestricted noncytolytic anti–HTLV-I activity is mediated, at least in part by a soluble factor(s), and may play a role in the pathogenesis of HTLV-I infection.

scholarly journals Immunodominant Cytomegalovirus Epitopes Suppress Subdominant Epitopes in the Generation of High-Avidity CD8 T Cells

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 956
Author(s):  
Kirsten Freitag ◽  
Sara Hamdan ◽  
Matthias J. Reddehase ◽  
Rafaela Holtappels
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Escape ◽  
Cd8 T Cell ◽  
Antigenic Drift ◽  
Murine Cytomegalovirus ◽  
High Avidity ◽  
Infected Cells ◽  
Cd8 T Cell Memory

CD8+ T-cell responses to pathogens are directed against infected cells that present pathogen-encoded peptides on MHC class-I molecules. Although natural responses are polyclonal, the spectrum of peptides that qualify for epitopes is remarkably small even for pathogens with high coding capacity. Among those few that are successful at all, a hierarchy exists in the magnitude of the response that they elicit in terms of numbers of CD8+ T cells generated. This led to a classification into immunodominant and non-immunodominant or subordinate epitopes, IDEs and non-IDEs, respectively. IDEs are favored in the design of vaccines and are chosen for CD8+ T-cell immunotherapy. Using murine cytomegalovirus as a model, we provide evidence to conclude that epitope hierarchy reflects competition on the level of antigen recognition. Notably, high-avidity cells specific for non-IDEs were found to expand only when IDEs were deleted. This may be a host’s back-up strategy to avoid viral immune escape through antigenic drift caused by IDE mutations. Importantly, our results are relevant for the design of vaccines based on cytomegaloviruses as vectors to generate high-avidity CD8+ T-cell memory specific for unrelated pathogens or tumors. We propose the deletion of vector-encoded IDEs to avoid the suppression of epitopes of the vaccine target.

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