Human Immunodeficiency Virus-Specific Circulating CD8 T Lymphocytes Have Down-Modulated CD3ζ and CD28, Key Signaling Molecules for T-Cell Activation

ABSTRACT Although human immunodeficiency virus (HIV)-infected subjects without AIDS have a high frequency of HIV-specific CD8 T lymphocytes, cellular immunity is unable to control infection. Freshly isolated lymphocytes often do not lyse HIV-infected targets in 4-h cytotoxicity assays. A large fraction of circulating CD8 T cells from HIV-infected donors down-modulate CD3ζ, the signaling component of the T-cell receptor complex, which is reexpressed in vitro coincident with the return of cytotoxic function. To investigate further the link between CD3ζ down-modulation and possible CD8 T-cell functional defects, we used flow cytometry to characterize further the properties of the CD3ζ-down-modulated subset. HIV-specific CD8 T cells, identified by tetramer staining, are CD3ζ−. CD8 T cells with down-modulated CD3ζ also do not express the key costimulatory receptor CD28 and have the cell surface phenotype of activated or memory T cells (HLA-DR+ CD62L−). After T-cell activation, CD3ζ-down-modulated cells express the activation marker CD69 but not the high-affinity interleukin 2 (IL-2) receptor α-chain CD25 and produce gamma interferon but not IL-2. Therefore HIV-specific CD8 T cells have down-modulated key signaling molecules for T-cell activation and costimulation and require exogenous cytokine stimulation. The typical impairment of HIV-specific CD4 T helper cells, which would normally provide specific CD8 T-cell stimulation, means that in vivo CTL function in vivo is compromised in most HIV-infected individuals. In AIDS patients, the functional defect is more severe, since CD3ζ is not reexpressed even after IL-2 exposure.

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CD8+ T Cell Metabolic Rewiring Defined by Single-Cell RNA-Sequencing Identifies a Critical Role of ASNS Expression Dynamics in T Cell Differentiation

10.1101/2021.07.27.453976 ◽

2021 ◽

Author(s):

Juan Fernandez-Garcia ◽

Fabien Franco ◽

Sweta Parik ◽

Antonino A Pane ◽

Dorien Broekaert ◽

...

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Cd8 T Cell ◽

T Cell Differentiation

Cytotoxic T cells dynamically rewire their metabolism during the course of an immune response. While T cell metabolism has been extensively studied at phenotypic endpoints of activation and differentiation, the underlying dynamics remain largely elusive. Here, we leverage on single-cell RNA-sequencing (scRNA-seq) measurements of in vitro activated and differentiated CD8+ T cells cultured in physiological media to resolve these metabolic dynamics. We find that our scRNA-seq analysis identifies most metabolic changes previously defined in in vivo experiments, such as a rewiring from an oxidative to an anabolism-promoting metabolic program during activation to an effector state, which is later reverted upon memory polarization. Importantly, our scRNA-seq data further provide a dynamic description of these changes. In this sense, our data predict a differential time-dependent reliance of CD8+ T cells on the synthesis versus uptake of various non-essential amino acids during T cell activation, which we corroborate with additional functional in vitro experiments. We further exploit our scRNA-seq data to identify metabolic genes that could potentially dictate the outcome of T cell differentiation, by ranking them based on their expression dynamics. Among the highest-ranked hits, we find asparagine synthetase (Asns), whose expression sharply peaks for effector CD8+ T cells and further decays towards memory polarization. We then confirm that these in vitro Asns expression dynamics are representative of an in vivo situation in a mouse model of viral infection. Moreover, we find that disrupting these expression dynamics in vitro, by depleting asparagine from the culture media, delays central-memory polarization. Accordingly, we find that preventing the decay of ASNS by stable overexpression at the protein level in vivo leads to a significant increase in effector CD8+ T cell expansion, and a concomitant decrease in central-memory formation, in a mouse model of viral infection. This shows that ASNS expression dynamics dictate the fate of CD8+ T cell differentiation. In conclusion, we provide a resource of dynamic expression changes during CD8+ T cell activation and differentiation that is expected to increase our understanding of the dynamic metabolic requirements of T cells progressing along the immune response cascade.

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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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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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Tumor masses support naive T cell infiltration, activation, and differentiation into effectors

Journal of Experimental Medicine ◽

10.1084/jem.20092454 ◽

2010 ◽

Vol 207 (8) ◽

pp. 1791-1804 ◽

Cited By ~ 134

Author(s):

Elizabeth D. Thompson ◽

Hilda L. Enriquez ◽

Yang-Xin Fu ◽

Victor H. Engelhard

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Adoptive Transfer ◽

Cell Activation ◽

Ex Vivo ◽

Tumor Infiltrating Lymphocytes ◽

T Cell Infiltration

Studies of T cell responses to tumors have focused on the draining lymph node (LN) as the site of activation. We examined the tumor mass as a potential site of activation after adoptive transfer of naive tumor-specific CD8 T cells. Activated CD8 T cells were present in tumors within 24 h of adoptive transfer and proliferation of these cells was also evident 4–5 d later in mice treated with FTY720 to prevent infiltration of cells activated in LNs. To confirm that activation of these T cells occurred in the tumor and not the tumor-draining LNs, we used mice lacking LNs. Activated and proliferating tumor-infiltrating lymphocytes were evident in these mice 24 h and 4 d after naive cell transfer. T cells activated within tumors acquired effector function that was evident both ex vivo and in vivo. Both cross-presenting antigen presenting cells within the tumor and tumor cells directly presenting antigen activated these functional CD8 effectors. We conclude that tumors support the infiltration, activation, and effector differentiation of naive CD8 T cells, despite the presence of immunosuppressive mechanisms. Thus, targeting of T cell activation to tumors may present a tool in the development of cancer immunotherapy.

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A Critical Role for Cd40–Cd40 Ligand Interactions in Amplification of the Mucosal Cd8 T Cell Response

Journal of Experimental Medicine ◽

10.1084/jem.190.9.1275 ◽

1999 ◽

Vol 190 (9) ◽

pp. 1275-1284 ◽

Cited By ~ 62

Author(s):

Leo Lefrançois ◽

Sara Olson ◽

David Masopust

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Adoptive Transfer ◽

Cell Activation ◽

Cd8 T Cell ◽

Cd40 Ligand ◽

Interleukin 12 ◽

Cd8 Cells

The role of CD40 ligand (CD40L) in CD8 T cell activation was assessed by tracking antigen-specific T cells in vivo using both adoptive transfer of T cell receptor transgenic T cells and major histocompatibility complex (MHC) class I tetramers. Soluble antigen immunization induced entry of CD8 cells into the intestinal mucosa and cytotoxic T lymphocyte (CTL) differentiation, whereas CD8 cells in secondary lymphoid tissue proliferated but were not cytolytic. Immunization concurrent with CD40L blockade or in the absence of CD40 demonstrated that accumulation of CD8 T cells in the mucosa was CD40L dependent. Furthermore, activation was mediated through CD40L expressed by the CD8 cells, since inhibition by anti-CD40L monoclonal antibodies occurred after adoptive transfer to CD40L-deficient mice. However, mucosal CD8 T cells in normal and CD40−/− mice were equivalent killers, indicating that CD40L was not required for CTL differentiation. Appearance of virus-specific mucosal, but not splenic, CD8 cells also relied heavily on CD40–CD40L interactions. The mucosal CTL response of transferred CD8 T cells was MHC class II and interleukin 12 independent. The results established a novel pathway of direct CD40L-mediated CD8 T cell activation.

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Immunologic ignorance of vascular endothelial cells expressing minor histocompatibility antigen

Blood ◽

10.1182/blood-2007-09-114769 ◽

2008 ◽

Vol 111 (9) ◽

pp. 4588-4595 ◽

Cited By ~ 11

Author(s):

Beatrice Bolinger ◽

Philippe Krebs ◽

Yinghua Tian ◽

Daniel Engeler ◽

Elke Scandella ◽

...

Keyword(s):

T Cells ◽

Endothelial Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Histocompatibility Antigen ◽

Target Cells ◽

Minor Histocompatibility Antigen

Abstract Endothelial cells (ECs) presenting minor histocompatibility antigen (mhAg) are major target cells for alloreactive effector CD8+ T cells during chronic transplant rejection and graft-versus-host disease (GVHD). The contribution of ECs to T-cell activation, however, is still a controversial issue. In this study, we have assessed the antigen-presenting capacity of ECs in vivo using a transgenic mouse model with beta-galactosidase (β-gal) expression confined to the vascular endothelium (Tie2-LacZ mice). In a GVHD-like setting with adoptive transfer of β-gal–specific T-cell receptor–transgenic T cells, β-gal expression by ECs was not sufficient to either activate or tolerize CD8+ T cells. Likewise, transplantation of fully vascularized heart or liver grafts from Tie2-LacZ mice into nontransgenic recipients did not suffice to activate β-gal–specific CD8+ T cells, indicating that CD8+ T-cell responses against mhAg cannot be initiated by ECs. Moreover, we could show that spontaneous activation of β-gal–specific CD8+ T cells in Tie2-LacZ mice was exclusively dependent on CD11c+ dendritic cells (DCs), demonstrating that mhAgs presented by ECs remain immunologically ignored unless presentation by DCs is granted.

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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 ◽

10.1182/blood.v108.11.2725.2725 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2725-2725 ◽

Cited By ~ 2

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.

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Efficacy, safety, and immune activation with pegylated human IL-10 (AM0010) in combination with an anti-PD1 in advanced NSCLC.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.9091 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. 9091-9091

Author(s):

Deborah Jean Lee Wong ◽

Jeffrey Gary Schneider ◽

Raid Aljumaily ◽

Wolfgang Michael Korn ◽

Jeffrey R. Infante ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Advanced Nsclc ◽

De Novo ◽

Cd8 T Cell ◽

Outcome Data ◽

Low Grade

9091 Background: Although IL-10 has anti-inflammatory properties, it stimulates cytotoxicity and proliferation of intratumoral antigen activated CD8+ T cell at higher concentrations. AM0010 is anticipated to activate antigen stimulated, intratumoral CD8 T cells while PD-1 inhibits them, providing the rationale for combining AM0010 and anti-PD-1 antibody. Methods: We treated a cohort of 34 NSCLC pts with AM0010 (10-20mg/kg QD, SC) and a PD-1 inhibitor [pembrolizumab (2mg/kg, q3wk IV; n=5) or nivolumab (3mg/kg, q2wk IV; n=29)]. Tumor responses were assessed by irRC every 8 weeks. Immune responses were measured by analysis of serum cytokines (Luminex), activation of blood derived T cells (FACS) and peripheral T cell clonality (TCR sequencing). Tumor PD-L1 expression was confirmed by IHC (22C3). Results: Pts had a median of 2 prior therapies. Median follow-up is 9.6 mo (range 0.5-77.3) in this fully enrolled cohort. AM0010 plus anti-PD-1 was well-tolerated. TrAEs were reversible and transient, with most being low grade, most commonly fatigue and pyrexia. G3/4 TrAEs were thrombocytopenia (7), anemia (6), fatigue (4), rash (3), pyrexia (2), hypertriglyceridemia (1) and pneumonitis (1). As of Jan. 31 2017, 22 pts had at least 1 tumor assessment. Partial responses (PRs) were observed in 8 pts (36.4%). 17 of these 22 pts had tissue for analysis of percent of tumor cells with PD-L1 expression (22C3): 58.8% had <1%, 17.7% had 1-49% and 23.5% had >50%. Best response data stratified for PD-L1 are shown in the table. Median PFS and OS for the entire cohort have not been reached. Updated outcome data that includes all enrolled pts will be available at the meeting. AM0010 plus anti-PD1 increased serum Th1 cytokines (IL-18, IFNγ), the number and proliferation of PD1+ Lag3+ activated CD8+ T cells and a de-novo oligoclonal expansion of T cell clones in the blood while decreasing TGFβ. Conclusions: AM0010 in combination with anti-PD1 is well-tolerated in advanced NSCLC pts. The efficacy and the observed CD8+ T cell activation is promising. Clinical trial information: NCT02009449. [Table: see text]

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Effects of in Vivo Cd8+ T Cell Depletion on Virus Replication in Rhesus Macaques Immunized with a Live, Attenuated Simian Immunodeficiency Virus Vaccine

Journal of Experimental Medicine ◽

10.1084/jem.191.11.1921 ◽

1999 ◽

Vol 191 (11) ◽

pp. 1921-1932 ◽

Cited By ~ 112

Author(s):

Karin J. Metzner ◽

Xia Jin ◽

Fred V. Lee ◽

Agegnehu Gettie ◽

Daniel E. Bauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Simian Immunodeficiency Virus ◽

Cd8 T Cells ◽

Rhesus Macaques ◽

Cd8 T Cell ◽

T Cell Depletion ◽

Challenge Virus ◽

Immunodeficiency Virus

The role of CD8+ T lymphocytes in controlling replication of live, attenuated simian immunodeficiency virus (SIV) was investigated as part of a vaccine study to examine the correlates of protection in the SIV/rhesus macaque model. Rhesus macaques immunized for >2 yr with nef-deleted SIV (SIVmac239Δnef) and protected from challenge with pathogenic SIVmac251 were treated with anti-CD8 antibody (OKT8F) to deplete CD8+ T cells in vivo. The effects of CD8 depletion on viral load were measured using a novel quantitative assay based on real-time polymerase chain reaction using molecular beacons. This assay allows simultaneous detection of both the vaccine strain and the challenge virus in the same sample, enabling direct quantification of changes in each viral population. Our results show that CD8+ T cells were depleted within 1 h after administration of OKT8F, and were reduced by as much as 99% in the peripheral blood. CD8+ T cell depletion was associated with a 1–2 log increase in SIVmac239Δnef plasma viremia. Control of SIVmac239Δnef replication was temporally associated with the recovery of CD8+ T cells between days 8 and 10. The challenge virus, SIVmac251, was not detectable in either the plasma or lymph nodes after depletion of CD8+ T cells. Overall, our results indicate that CD8+ T cells play an important role in controlling replication of live, attenuated SIV in vivo.

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