scholarly journals Trib1 regulates T cell differentiation during chronic infection by restraining the effector program

2020 ◽  
Vol 217 (5) ◽  
Author(s):  
Kelly S. Rome ◽  
Sarah J. Stein ◽  
Makoto Kurachi ◽  
Jelena Petrovic ◽  
Gregory W. Schwartz ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Cell Function ◽  
T Cell Differentiation ◽  
Negative Regulator ◽  
Chronic Infections ◽  
Tcr Signaling ◽  
Viral Control ◽  
Cell Immunity

In chronic infections, the immune response fails to control virus, leading to persistent antigen stimulation and the progressive development of T cell exhaustion. T cell effector differentiation is poorly understood in the context of exhaustion, but targeting effector programs may provide new strategies for reinvigorating T cell function. We identified Tribbles pseudokinase 1 (Trib1) as a central regulator of antiviral T cell immunity, where loss of Trib1 led to a sustained enrichment of effector-like KLRG1+ T cells, enhanced function, and improved viral control. Single-cell profiling revealed that Trib1 restrains a population of KLRG1+ effector CD8 T cells that is transcriptionally distinct from exhausted cells. Mechanistically, we identified an interaction between Trib1 and the T cell receptor (TCR) signaling activator, MALT1, which disrupted MALT1 signaling complexes. These data identify Trib1 as a negative regulator of TCR signaling and downstream function, and reveal a link between Trib1 and effector versus exhausted T cell differentiation that can be targeted to improve antiviral immunity.

scholarly journals Cytomegalovirus exploits IL-10–mediated immune regulation in the salivary glands

2007 ◽  
Vol 204 (5) ◽  
pp. 1217-1225 ◽  
Author(s):  
Ian R. Humphreys ◽  
Carl de Trez ◽  
April Kinkade ◽  
Chris A. Benedict ◽  
Michael Croft ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Salivary Glands ◽  
Virus Replication ◽  
Cd4 T Cells ◽  
Interferon Γ ◽  
T Cell Differentiation ◽  
Effector T Cell ◽  
Cell Immunity

The salivary glands represent a major site of cytomegalovirus replication and transmission to other hosts. Despite control of viral infection by strong T cell responses in visceral organs cytomegalovirus replication continues in the salivary glands of mice, suggesting that the virus exploits the mucosal microenvironment. Here, we show that T cell immunity in the salivary glands is limited by the induction of CD4 T cells expressing the regulatory cytokine interleukin (IL)-10. Blockade of IL-10 receptor (IL-10R) with an antagonist antibody dramatically reduced viral load in the salivary glands, but not in the spleen. The mucosa-specific protection afforded by IL-10R blockade was associated with an increased accumulation of CD4 T cells expressing interferon γ, suggesting that IL-10R signaling limits effector T cell differentiation. Consistent with this, an agonist antibody targeting the tumor necrosis factor receptor superfamily member OX40 (TNFRSF4) enhanced effector T cell differentiation and increased the number of interferon γ–producing T cells, thus limiting virus replication in the salivary glands. Collectively, the results indicate that modulating effector T cell differentiation can counteract pathogen exploitation of the mucosa, thus limiting persistent virus replication and transmission.

scholarly journals Cellular Factors Targeting APCs to Modulate Adaptive T Cell Immunity

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Anabelle Visperas ◽  
Jeongsu Do ◽  
Booki Min
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Differentiation ◽  
T Cell Immunity ◽  
Immune Functions ◽  
Effector Cells ◽  
Cell Immunity

The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

scholarly journals Enhancing therapeutic vaccination by blocking PD-1–mediated inhibitory signals during chronic infection

2008 ◽  
Vol 205 (3) ◽  
pp. 543-555 ◽  
Author(s):  
Sang-Jun Ha ◽  
Scott N. Mueller ◽  
E. John Wherry ◽  
Daniel L. Barber ◽  
Rachael D. Aubert ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Treatment Strategies ◽  
T Cell Responses ◽  
Lymphocytic Choriomeningitis ◽  
Therapeutic Vaccination ◽  
Chronic Infections ◽  
Viral Control ◽  
Cell Responses ◽  
Cell Immunity

Therapeutic vaccination is a potentially promising strategy to enhance T cell immunity and viral control in chronically infected individuals. However, therapeutic vaccination approaches have fallen short of expectations, and effective boosting of antiviral T cell responses has not always been observed. One of the principal reasons for the limited success of therapeutic vaccination is that virus-specific T cells become functionally exhausted during chronic infections. We now provide a novel strategy for enhancing the efficacy of therapeutic vaccines. In this study, we show that blocking programmed death (PD)-1/PD-L1 inhibitory signals on exhausted CD8+ T cells, in combination with therapeutic vaccination, synergistically enhances functional CD8+ T cell responses and improves viral control in mice chronically infected with lymphocytic choriomeningitis virus. This combinatorial therapeutic vaccination was effective even in the absence of CD4+ T cell help. Thus, our study defines a potent new approach to augment the efficacy of therapeutic vaccination by blocking negative signals. Such an approach may have broad applications in developing treatment strategies for chronic infections in general, and perhaps also for tumors.

scholarly journals TET2 Regulates CD8+ T Cell Differentiation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1423-1423
Author(s):  
Shannon A. Carty ◽  
Mercy Gohil ◽  
Gary A Koretzky ◽  
Martha S Jordan
Keyword(s):  
Dna Methylation ◽  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Differentiation ◽  
Tcr Signaling ◽  
Cell Responses ◽  
And Function

Abstract Regulation of DNA methylation is critical for proper T cell differentiation and function. Antigen-specific CD8+ T cells undergo global remodeling of DNA methylation following viral infection, suggesting that DNA methylation may direct antigen-specific T cell responses. TET2 is a member of the Ten-Eleven-Translocation (TET) family, which converts 5-methylcytosine (5mC) in DNA to 5-hydroxymethylcytosine (5hmC) and subsequent intermediates ultimately leading to DNA demethylation. How TET2 regulates T cell differentiation and function is unknown. Here we demonstrate that TET2 expression is regulated by TCR signaling in primary murine T cells. Furthermore, using a novel flow cytometric assay to measure 5hmC levels on a single cell basis, we find that TCR signaling also regulates TET activity as evidenced by a rapid increase in global 5hmC levels after TCR stimulation that is blunted in TET2-deficient T cells. To determine the role of TET2 in T cell responses, we generated mice deficient in TET2 in the T cell compartment (TET2fl/flCD4Cre+) mice. These mice develop grossly normal thymic and peripheral T cell subsets. Given the regulation of TET2’s expression and activity by TCR stimulation, we used a murine model of acute viral infection, specifically LCMV-Armstrong, to test if TET2 regulates antigen-specific T cell responses in vivo. Following viral challenge, TET2fl/flCD4Cre+ mice have similar antigen-specific CD8+ T cell expansion and effector responses but exhibit significantly enhanced memory CD8+ T cell differentiation compared to control mice. These data demonstrate that TET2 plays a critical role in directing CD8+ T cell differentiation and function. Studies are ongoing to identify specific TET2 regulated genes important in the development of CD8+ T cell memory. Disclosures No relevant conflicts of interest to declare.

scholarly journals 752 Novel, orally administered HPK1 inhibitors demonstrate anti-tumor efficacy and enhanced immune response

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A786-A786
Author(s):  
Stefan Chmielewski ◽  
Maciej Kujawa ◽  
Eliza Zimolag ◽  
Michal Galezowski ◽  
Andrzej Gondela ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Small Molecule ◽  
Cell Function ◽  
Adaptor Protein ◽  
Negative Regulator ◽  
Tcr Signaling ◽  
T Cell Function ◽  
Tcr Activation

BackgroundHematopoietic progenitor kinase 1 (HPK1, MAP4K1) is emerging as a well-renowned, druggable target for T cell-based immunotherapies. HPK1 is a member of the serine/threonine MAP4K family, predominantly expressed in hematopoietic cell lineages and shown to be a negative regulator of the T cell receptor (TCR) signaling pathway. Upon TCR activation, HPK1 is recruited to the proximity of the cell membrane and phosphorylates an adaptor protein SLP-76 at the Ser376 residue which, in turn, abrogates TCR signaling. Other studies point to a potential role of HPK1 in T cell exhaustion as well as in functional re-programming of regulatory T cells. Moreover, mounting evidence suggest that HPK1 kinase activity suppresses the immune functions of a wide range of other immune cell subsets like B cells and dendritic cells. Taken together, these observations support small-molecule HPK1 inhibitors as an attractive modality in cancer immunotherapy either as single agents or in combination with immune checkpoint inhibitors.MethodsActivity of compounds against HPK1 and selected off- and anti-targets was assessed in biochemical assays. Phosphorylation of SLP-76 was measured either by flow cytometry or TR-FRET. Jurkat and primary T cells were activated and cultured in the presence of tested compounds and immunosuppressive agents. Impact on TCR selectivity and T cell function was measured by AlphaLISA and flow cytometry. Target engagement was measured in splenocytes of mice administered orally with tested compounds followed by IP injection of aCD3 antibody. Anti-tumor efficacy of HPK1 inhibitors was assessed in a syngeneic tumor model.ResultsRyvu's proprietary small molecule HPK1 inhibitors exhibit sub-nanomolar activity against human and mouse HPK1 proteins and good selectivity against other TCR pathway kinases. Tested compounds efficiently block phosphorylation of SLP-76 upon TCR engagement. TCR selectivity of Ryvu's inhibitors, measured as a ratio between CD69 and pSer376 SLP-76 inhibition, is on par or superior to reference molecules. Tested compounds are not only able to overcome PGE-2 induced resistance following TCR activation in human PBMCs, inducing elevated IL-2 release but also affect T cell function in co-culture assay. Developed molecules have favorable PK profiles, allowing for sustained target coverage in proposed dosing regimens and demonstrate efficacy in a mammary carcinoma syngeneic model.ConclusionsRyvu has developed potent and selective HPK1 inhibitors with favorable PK and PD profiles, whose activity in vitro translates to in vivo efficacy. Further preclinical work is warranted to select a lead candidate for IND-enabling studies and subsequently clinical studies across a variety of solid tumors.

Modulation of asymmetric cell division as a mechanism to boost CD8+ T cell memory

2019 ◽  
Vol 4 (34) ◽  
pp. eaav1730 ◽  
Author(s):  
Mariana Borsa ◽  
Isabel Barnstorf ◽  
Nicolas S. Baumann ◽  
Katharina Pallmer ◽  
Alexander Yermanos ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Division ◽  
Cell Differentiation ◽  
T Cell ◽  
Asymmetric Cell Division ◽  
T Cell Differentiation ◽  
Viral Control ◽  
Mtor Inhibition ◽  
Term Survival ◽  
Lcmv Infection

Asymmetric partitioning of fate determinants is a mechanism that contributes to T cell differentiation. However, it remains unclear whether the ability of T cells to divide asymmetrically is influenced by their differentiation state, as well as whether enforcing asymmetric cell division (ACD) rates would have an impact on T cell differentiation and memory formation. Using the murine LCMV infection model, we established a correlation between cell stemness and the ability of CD8+ T cells to undergo ACD. Transient mTOR inhibition was proven to increase ACD rates in naïve and memory cells and to install this ability in exhausted CD8+ T cells. Functionally, enforced ACD correlated with increased memory potential, leading to more efficient recall response and viral control upon acute or chronic LCMV infection. Moreover, transient mTOR inhibition also increased ACD rates in human CD8+ T cells. Transcriptional profiling revealed that progenies emerging from enforced ACD exhibited more pronounced early memory signatures, which functionally endowed these cells with better survival in the absence of antigen exposure and more robust homing to secondary lymphoid organs, providing critical access to survival niches. Our data provide important insights into how ACD can improve long-term survival and function of T cells and open new perspectives for vaccination and adoptive T cell transfer therapies.

scholarly journals Akt-Fas to Quell Aberrant T Cell Differentiation and Apoptosis in Covid-19

2020 ◽  
Vol 11 ◽  
Author(s):  
Anthony J. Leonardi ◽  
Rui B. Proenca
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Cell Function ◽  
T Cell Differentiation ◽  
Serine Threonine Kinase ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
T Cell Lymphopenia ◽  
Infected Cells

Aberrant T cell differentiation and lymphopenia are hallmarks of severe COVID-19 disease. Since T cells must race to cull infected cells, they are quick to differentiate and achieve cytotoxic function. With this responsiveness, comes hastened apoptosis, due to a coupled mechanism of death and differentiation in both CD4+ and CD8+ lymphocytes via CD95 (Fas) and serine-threonine kinase (Akt). T cell lymphopenia in severe cases may represent cell death or peripheral migration. These facets depict SARS-Cov-2 as a lympho-manipulative pathogen; it distorts T cell function, numbers, and death, and creates a dysfunctional immune response. Whether preservation of T cells, prevention of their aberrant differentiation, and expansion of their population may alter disease course is unknown. Its investigation requires experimental interrogation of the linked differentiation and death pathway by agents known to uncouple T cell proliferation and differentiation in both CD4+ and CD8+ T cells.

scholarly journals Akt Fas to Quell Aberrant T Cell Differentiation and Death in Covid-19

2020 ◽  
Author(s):  
Anthony Joseph Leonardi
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Cell Function ◽  
T Cell Differentiation ◽  
Serine Threonine Kinase ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Hastened Death ◽  
Infected Cells

Aberrant T cell differentiation and lymphopenia are hallmarks of severe COVID-19 disease. Since T cells must race to cull infected cells, they are quick to differentiate and achieve cytotoxic function. With this responsiveness, unfortunately, comes hastened death, due to a coupled mechanism of death and differentiation in both CD4+ and CD8+ lymphocytes via CD95 (Fas) and serine-threonine kinase (Akt). T cell lymphopenia in severe cases may represent cell death or peripheral migration. These facets depict SARS-Cov-2 as a lympho-manipulative pathogen; it distorts T cell function, numbers, and death, and creates a dysfunctional immune response. Whether preservation of T cells, prevention of their differentiation, and expansion of their population may alter disease course is unknown. Its investigation requires experimental interrogation of the linked differentiation and death pathway by agents known to uncouple T cell proliferation and differentiation in both CD4+ and CD8+ T cells.

Stem cell mobilization with G-CSF analogs: a rational approach to separate GVHD and GVL?

Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3430-3435 ◽  
Author(s):  
Edward S. Morris ◽  
Kelli P. A. MacDonald ◽  
Geoffrey R. Hill
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Cell Differentiation ◽  
T Cell ◽  
Acute Gvhd ◽  
Cell Function ◽  
T Cell Differentiation ◽  
Rational Approach ◽  
Stem Cell Source ◽  
T Cell Function

The separation of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) remains the “holy grail” of allogeneic stem cell transplantation, and improvements are urgently needed to allow more effective therapy of malignant disease. The use of G-CSF–mobilized peripheral blood as a clinical stem cell source is associated with enhanced GVL effects without amplification of significant acute GVHD. Preclinical studies have demonstrated that G-CSF modulates donor T cell function before transplantation, promoting TH2 differentiation and regulatory T cell function. In addition, the expansion of immature antigen-presenting cells (APCs) and plasmacytoid dendritic cells (DCs) favors the maintenance of this pattern of T cell differentiation after transplantation. Although these patterns of T cell differentiation attenuate acute GVHD, they do not have an impact on the cytolytic pathways of the CD8+ T cells that are critical for effective GVL. Recently, it has been demonstrated that modification of G-CSF, either by pegylation of the native cytokine or conjugation to Flt-3L, results in the expansion and activation of donor iNKT cells, which significantly augment CD8+ T cell–mediated cytotoxicity and GVL effects after transplantation. Given that these cytokines also enhance the expansion of regulatory T cells and APCs, they further separate GVHD and GVL, offering potential clinical advantages for the transplant recipient.

158 Inhibition of PI3Kδ improves tumor specific T cell immunity and metabolic fitness

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A172-A172
Author(s):  
Guillermo Rangel Rivera ◽  
Guillermo Rangel RIvera ◽  
Connor Dwyer ◽  
Dimitrios Arhontoulis ◽  
Hannah Knochelmann ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Cell Therapy ◽  
Tumor Immunity ◽  
Mitochondrial Function ◽  
T Cell Differentiation ◽  
Tumor Control ◽  
T Cell Therapy

BackgroundDurable responses have been observed with adoptive T cell therapy (ACT) in some patients. However, current protocols used to expand T cells often exhibit suboptimal tumor control. Failure in these therapies has been attributed to premature differentiation and impaired metabolism of the infused T cells. Previous work done in our lab showed that reduced PI3Kδ signaling improved ACT. Because PI3Kγ and PI3Kδ have critical regulatory roles in T cell differentiation and function, we tested whether inhibiting PI3Kγ could recapitulate or synergize PI3Kδ blockade.MethodsTo test this, we primed melanoma specific CD8+ pmel-1 T cells, which are specific to the glycoprotein 100 epitope, in the presence of PI3Kγ (IPI-459), PI3Kδ (CAL101 or TGR-1202) or PI3Kγ/δ (IPI-145) inhibitors following antigen stimulation with hgp100, and then infused them into 5Gy total body irradiated B16F10 tumor bearing mice. We characterized the phenotype of the transferred product by flow cytometry and then assessed their tumor control by measuring the tumor area every other day with clippers. For metabolic assays we utilized the 2-NBDG glucose uptake dye and the real time energy flux analysis by seahorse.ResultsSole inhibition of PI3Kδ or PI3Kγ in vitro promoted greater tumor immunity and survival compared to dual inhibition. To understand how PI3Kδ or PI3Kγ blockade improved T cell therapy, we assessed their phenotype. CAL101 treatment produced more CD62LhiCD44lo T cells compared to IPI-459, while TGR-1202 enriched mostly CD62LhiCD44hi T cells. Because decreased T cell differentiation is associated with mitochondrial metabolism, we focused on CAL101 treated T cells to study their metabolism. We found that CAL101 decreased glucose uptake and increased mitochondrial respiration in vitro, indicating augmented mitochondrial function.ConclusionsThese findings indicate that blocking PI3Kδ is sufficient to mediate lasting tumor immunity of adoptively transferred T cells by preventing premature differentiation and improving mitochondrial fitness. Our data suggest that addition of CAL101 to ACT expansion protocols could greatly improve T cell therapies for solid tumors by preventing T cell differentiation and improving mitochondrial function.

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