Selective Bystander Proliferation of Memory CD4+ and CD8+ T Cells Upon NK T or T Cell Activation

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8+ T cells that correlated with the use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct from one another and implicate CD8+ T cells in the clinical presentation and trajectory of MIS-C.

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A Randomized Phase II Trial of Idiotype Vaccination and Adoptive Autologous T-Cell Transfer in Multiple Myeloma patients

Blood ◽

10.1182/blood.2020008493 ◽

2021 ◽

Author(s):

Muzaffar H Qazilbash ◽

Neeraj Y Saini ◽

Cha Soung-chul ◽

Zhe Wang ◽

Edward Stadtmauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase Ii ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Phase Ii Trial ◽

Ex Vivo ◽

Vaccine Strategy ◽

Randomized Phase Ii

We hypothesized that combining adoptively transferred autologous T cells with a cancer vaccine strategy would enhance therapeutic efficacy by adding anti-myeloma idiotype-keyhole limpet hemocyanin (Id-KLH) vaccine to vaccine-specific co-stimulated T cells. In this randomized, phase II trial, eligible patients received either the control (KLH only) or Id-KLH vaccine, an auto-transplant, vaccine-specific co-stimulated T-cells expanded ex-vivo, and two booster doses of the assigned vaccine. In 36 patients (20 in KLH, 16 in Id-KLH) enrolled, no dose-limiting toxicity was seen in either arm. At last evaluation, 6 (30%) and 8 (50%) had achieved complete remission in KLH-only and Id-KLH, respectively (p=0.22) and no difference in 3-year progression-free survival was observed (59% and 56%, respectively; p=0.32). In a 594 Nanostring nCounter gene panel analyzed for immune reconstitution (IR), compared with KLH-only patients, there was a greater change in IR genes in T-cells in Id-KLH patients relative to baseline. Specifically, upregulation of genes associated with activation, induction of effector function, and generation of memory CD8+ T cells after Id-KLH, but not after KLH control vaccination, was observed. Similarly, responding patients across both arms were associated with upregulation of genes associated with T-cell activation. At baseline, all patients had greater expression of CD8+ T-cell exhaustion markers. These changes were associated with functional Id-specific immune responses in a subset of Id-KLH patients analyzed. In conclusion, in this combination immunotherapy approach, we observed a significantly more robust IR in CD4+ and CD8+ T cells in the Id-KLH arm, supporting further investigation of vaccine and adoptive immunotherapy strategies.

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Activation Outcomes Induced in Naïve CD8 T-Cells by Macrophages Primed via “Phagocytic” and Nonphagocytic Pathways

Molecular Biology of the Cell ◽

10.1091/mbc.e07-07-0650 ◽

2008 ◽

Vol 19 (2) ◽

pp. 701-710 ◽

Cited By ~ 10

Author(s):

Isabel María Olazabal ◽

Noa Beatriz Martín-Cofreces ◽

María Mittelbrunn ◽

Gloria Martínez del Hoyo ◽

Balbino Alarcón ◽

...

Keyword(s):

Cell Proliferation ◽

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

T Cell Proliferation ◽

Microtubule Organizing Center ◽

Antigen Uptake ◽

Soluble Peptide

The array of phagocytic receptors expressed by macrophages make them very efficient at pathogen clearance, and the phagocytic process links innate with adaptive immunity. Primary macrophages modulate antigen cross-presentation and T-cell activation. We assessed ex vivo the putative role of different phagocytic receptors in immune synapse formation with CD8 naïve T-cells from OT-I transgenic mice and compared this with the administration of antigen as a soluble peptide. Macrophages that have phagocytosed antigen induce T-cell microtubule-organizing center and F-actin cytoskeleton relocalization to the contact site, as well as the recruitment of proximal T-cell receptor signals such as activated Vav1 and PKCθ. At the same doses of loaded antigen (1 μM), “phagocytic” macrophages were more efficient than peptide-antigen–loaded macrophages at forming productive immune synapses with T-cells, as indicated by active T-cell TCR/CD3 conformation, LAT phosphorylation, IL-2 production, and T-cell proliferation. Similar T-cell proliferation efficiency was obtained when low doses of soluble peptide (3–30 nM) were loaded on macrophages. These results suggest that the pathway used for antigen uptake may modulate the antigen density presented on MHC-I, resulting in different signals induced in naïve CD8 T-cells, leading either to CD8 T-cell activation or anergy.

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702 TJ-CD4B (ABL111), a Claudin18.2-targeted 4-1BB tumor engager induces potent tumor-dependent immune response without dose-limiting toxicity in preclinical studies

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.702 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A730-A730

Author(s):

Wenqing Jiang ◽

Zhengyi Wang ◽

Zhen Sheng ◽

Jaeho Jung ◽

Taylor Guo

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Gene Expression Analysis ◽

Cell Activation ◽

Clinical Development ◽

Cynomolgus Monkeys ◽

Anti Tumor Activity

Background4-1BB (CD137) is a co-stimulatory receptor that stimulates the function of multiple immune cells. Its ability to induce potent anti-tumor activity makes 4-1BB an attractive target for immuno-oncology. However, clinical development of a monospecific 4-1BB agonistic antibody has been hampered by dose-limiting hepatic toxicities. To minimize systemic toxicities, we have developed a novel Claudin18.2 (CLDN18.2) x 4-1BB bispecific antibody, TJ-CD4B (ABL111) that stimulates 4-1BB pathway only when it engages with Claudin 18.2, a tumor-associated antigen specifically expressed in gastrointestinal cancers. TJ-CD4B (ABL111) is now being evaluated in patients with advanced solid tumors in a first-in-human trial (NCT04900818).MethodsTJ-CD4B (ABL111) was evaluated in vivo using the human 4-1BB knock-in mice bearing CLDN18.2 expressing MC38 tumor cells. Pharmacodynamic effects upon treatment were characterized in tumor tissue and blood. Immunophenotyping of the tumor microenvironment (TME) and peripheral blood was performed by flow cytometry. Soluble biomarkers were measured using Luminex-based multiplex assay. In-depth gene expression analysis was performed on primary human CD8+ T cells that were co-cultured with CLDN18.2 expressing cells in the presence of anti-CD3 using NanoString nCounter®. Pharmacokinetic (PK) and toxicity study were performed in cynomolgus monkeys.ResultsTJ-CD4B (ABL111) elicited complete tumor regression in 13 out of 18 MC38 tumor bearing mice given at a dose above 2 mg/kg. Dose-dependent anti-tumor activity was associated with enhanced T cell activation in TME and expansion of memory T cells in the peripheral blood. Increased CD8+ T cells number and proliferation were observed in both tumor nest and surrounding stroma while the level of soluble 4-1BB in the serum was also elevated in response to the treatment. In vitro gene expression analysis by Nanostring revealed TJ-CD4B(ABL111) effectively activated immune pathways characterized by IFN?-signaling and T cell inflammation. Preclinically, TJ-CD4B was well tolerated at the repeated doses up to 100 mg/kg/wk in cynomolgus monkeys without the adverse influence on the liver function which is generally affected by 4-1BB activation. Besides, no cytokine release or immune activation was observed in the periphery.ConclusionsTJ-CD4B (ABL111) is a novel CLDN18.2 dependent 4-1BB bispecific agonist antibody that induced T cell activation and memory response in tumor with CLDN18.2 expression, leading to a strong anti-tumor activity in vivo. TJ-CD4B did not induce systemic immune response nor hepatic toxicity due to the CLDN18.2 dependent 4-1BB stimulation. These data warrant the current clinical development in phase I trial to validate the safety properties and tumor specific responses.

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368 Consistent pattern of immune activation induced by oncolytic adenovirus ONCOS-102 across diverse types of solid tumors

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.368 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A396-A396

Author(s):

Lukasz Kuryk ◽

Anne-Sophie Moller ◽

Sandeep Kumar ◽

Alexander Shoushtari ◽

Luis Paz Ares ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Solid Tumors ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Clinical Importance ◽

Oncolytic Adenovirus ◽

Link Type ◽

Tumor Types

BackgroundSolid tumors exhibit highly variable compositions of immune infiltrates. Therapeutic compounds driving uniform remodeling of tumor microenvironment (TME) across tumor types may improve the efficacy of cancer immunotherapy. ONCOS-102, a granulocyte-macrophage colony stimulating factor (GM-CSF)-expressing oncolytic adenovirus (Ad5/3-D24-GMCSF), was tested for its safety, therapeutic efficacy and capacity to remodel TME in recently completed phase I/II clinical studies in anti-PD-1 refractory melanoma (NCT03003676) and malignant pleural mesothelioma (MPM) (NCT02879669).MethodsBiopsies were obtained from tumor lesions of patients treated with intra-tumoral injections of ONCOS-102 in combination with chemotherapy or pembrolizumab for MPM and melanoma, respectively. Tumor immune infiltrates were analyzed by immunohistology using several antibody panels. On-treatment biopsies were compared to paired baseline samples as wells as to samples from control patients treated with chemotherapy alone in the case of MPM. Gene expression data obtained by next generation RNA sequencing were used to complement the immunohistology analysis and all results were correlated to clinical outcomes.ResultsComparative TME analysis of anti-PD-1 refractory melanoma and MPM tumors revealed noticeably lower baseline T-cell infiltration in mesothelioma. Thus, fractions of CD8+ T-cells were significantly below 10% in 80% of MPM biopsies while approaching or exceeding this level in 60% of melanoma baseline samples. Comparison of tumor biopsies obtained at baseline or on-treatment, demonstrated increased infiltration by both CD4+ and CD8+ T-cells in large proportions of melanoma (CD4+: 13/20 (65%); CD8+: 16/19 (84%) and MPM (CD4+: 10/15 (67%); CD8+: 9/15 (60%) tumor lesions in response to ONCOS-102. Frequencies of cytotoxic T-cells with high granzyme-B expression also increased in response to the treatment in both tumor types, in particular when assessed as percentage of total CD8+ T-cells. Other observed changes induced by ONCOS-102 in samples taken from CR, PR and SD patients with MPM or melanoma included increased CD8/Treg ratio and modulation of PD-L1 expression. Biological and clinical importance of these findings was further supported by correlation between modulation of several subsets of genes related to the process of T-cell activation, such as cytotoxic granule components and co-stimulatory molecules, and clinical response to ONCOS-102 in melanoma and both tumor response and overall survival in MPM patients.ConclusionsONCOS-102 drives pro-inflammatory modulation of immune TME across tumor types of different origins, anatomical locations and immunological baseline characteristics. Our data support potential of ONCOS-102 to serve as a potent immune sensitizing agent in combination therapies with various classes of immunomodulatory compounds and chemotherapy.

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Combination Treatment of Topical Imiquimod Plus Anti-PD-1 Antibody Exerts Significantly Potent Antitumor Effect

Cancers ◽

10.3390/cancers13163948 ◽

2021 ◽

Vol 13 (16) ◽

pp. 3948

Author(s):

Kazumasa Oya ◽

Yoshiyuki Nakamura ◽

Zhu Zhenjie ◽

Ryota Tanaka ◽

Naoko Okiyama ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Combination Therapy ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Antitumor Effect ◽

Skin Lesions ◽

Ifn Γ ◽

Deficient Mice

The exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody. Topical IMQ significantly suppressed the tumor growth of MC38 in wildtype mice. IMQ upregulated interferon γ (IFN-γ) expression in CD8+ T cells in both the lymph nodes and the tumor, and the antitumor effect was abolished in both Rag1-deficient mice and IFN-γ-deficient mice, indicating that IFN-γ produced by CD8+ T cells play a crucial role in the IMQ-induced antitumor effect. IMQ also upregulated PD-1 expression in T cells as well as PD-L1/PD-L2 expression in myeloid cells, suggesting that IMQ induces not only T-cell activation but also T-cell exhaustion by enhanced PD-1 inhibitory signaling. Combination therapy of topical IMQ plus anti-PD-1 antibody exerted a significantly potent antitumor effect when compared with each single therapy, indicating that the combination therapy is a promising therapy for the skin lesions of various cancers.

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Abstract 449: Novel Role of Bim in the Regulation of Allogeneic T-Cell Activation and Development of Transplant Vasculopathy

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a449 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Anna von Rossum ◽

Winnie Enns ◽

Yu P Shi ◽

Jonathan C Choy

Keyword(s):

T Cells ◽

Cell Death ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

T Cell Responses ◽

Intimal Thickening ◽

Cell Responses ◽

Transplant Vasculopathy

Transplant vasculopathy (TV) is an arteriosclerotic disease characterized by intimal thickening of allograft arteries and is a leading cause of heart transplant rejection. T cell responses towards allograft arteries are responsible for the development of TV and understanding the regulatory pathways controlling T cell activation in allograft arteries provides opportunities for the therapeutic attenuation of TV as well as other arteriosclerotic diseases. Bim is a pro-apoptotic Bcl-2 protein known to down-regulate immune responses after viral infections by inducing cell death of effector T cells but its role in regulating allogeneic T cell responses is not known. We compared cell death and alloantigen-driven activation of T cells from Bim +/+ (wild-type), Bim +/- and Bim -/- mice as well as the development of TV in these mice. Bim was required for cell death of both CD4 and CD8 T cells in response to cytokine deprivation in vitro . Unexpectedly, Bim was also required for alloantigen-induced proliferation of both CD4 and CD8 T cells as well as for IL-2 production. When TV was examined in aortic interposition grafts implanted into complete major histocompatibility complex-mismatched mice, intimal thickening was significantly reduced in Bim +/- but not Bim -/- recipients as compared to Bim +/+ counterparts. There was signficantly less CD4 T cell accumulation in the intima of arteries from Bim +/- as compared to Bim +/+ recipients but this effect was not observed in Bim -/- recipients. The accumulation of CD8 T cells in allograft arteries was not affected by differences in Bim expression. Taken together, our data support a novel role for Bim in driving T cell activation in response to allogeneic stimuli and indicate that the effects of this Bcl-2 protein in the pathogenesis of TV likely depends on its dual role in supporting T cell activation and death.

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Regulation of Tim-3 function by binding to phosphatidylserine

Biochemical Journal ◽

10.1042/bcj20210652 ◽

2021 ◽

Vol 478 (22) ◽

pp. 3999-4004

Author(s):

Lawrence P. Kane

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Transmembrane Protein ◽

Cytotoxic T Cells ◽

Cross Presentation ◽

First Time

Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T cell activation.

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IL4I1 Accelerates the Expansion of Effector CD8+ T Cells at the Expense of Memory Precursors by Increasing the Threshold of T-Cell Activation

Frontiers in Immunology ◽

10.3389/fimmu.2020.600012 ◽

2020 ◽

Vol 11 ◽

Cited By ~ 1

Author(s):

Marie-Line Puiffe ◽

Aurélie Dupont ◽

Nouhoum Sako ◽

Jérôme Gatineau ◽

José L. Cohen ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Cell Clone ◽

Cd8 T Cell ◽

Lymphocytic Choriomeningitis ◽

T Cell Clone

IL4I1 is an immunoregulatory enzyme that inhibits CD8 T-cell proliferation in vitro and in the tumoral context. Here, we dissected the effect of IL4I1 on CD8 T-cell priming by studying the differentiation of a transgenic CD8 T-cell clone and the endogenous repertoire in a mouse model of acute lymphocytic choriomeningitis virus (LCMV) infection. Unexpectedly, we show that IL4I1 accelerates the expansion of functional effector CD8 T cells during the first several days after infection and increases the average affinity of the elicited repertoire, supporting more efficient LCMV clearance in WT mice than IL4I1-deficient mice. Conversely, IL4I1 restrains the differentiation of CD8 T-cells into long-lived memory precursors and favors the memory response to the most immunodominant peptides. IL4I1 expression does not affect the phenotype or antigen-presenting functions of dendritic cells (DCs), but directly reduces the stability of T-DC immune synapses in vitro, thus dampening T-cell activation. Overall, our results support a model in which IL4I1 increases the threshold of T-cell activation, indirectly promoting the priming of high-affinity clones while limiting memory T-cell differentiation.

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Complete differentiation of CD8+ T cells activated locally within the transplanted liver

Journal of Experimental Medicine ◽

10.1084/jem.20051775 ◽

2006 ◽

Vol 203 (2) ◽

pp. 437-447 ◽

Cited By ~ 88

Author(s):

Ingo Klein ◽

Ian Nicholas Crispe

Keyword(s):

T Cells ◽

T Cell ◽

Antigen Presentation ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Underlying Mechanism ◽

Color Flow ◽

Antigen Presenting ◽

Transplantation Model

The transplanted liver elicits systemic tolerance, and the underlying mechanism may also account for the persistence of liver infections, such as malaria and viral hepatitis. These phenomena have led to the hypothesis that antigen presentation within the liver is abortive, leading to T cell tolerance or apoptosis. Here we test this hypothesis in an optimized orthotopic liver transplantation model. In direct contradiction to this model, the liver itself induces full CD8+ T cell activation and differentiation. The effects of microchimerism were neutralized by bone marrow transplantation in the liver donor, and the lack of liver-derived antigen-presenting cells was documented by eight-color flow cytometry and by sensitive functional assays. We conclude that local antigen presentation cannot explain liver tolerance. On the contrary, the liver may be an excellent priming site for naive CD8+ T cells.

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