scholarly journals Adenosine tips the pathogenic Th1 and Th17 responses in experimental autoimmune uveitis (EAU)

2020 ◽  
Author(s):  
Deming Sun ◽  
Minhee Ko ◽  
Hui Shao ◽  
Henry J. Kaplan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Atp Release ◽  
Γδ T Cells ◽  
Dendritic Cell Differentiation ◽  
Cell Responses ◽  
Extracellular Compartment

AbstractVarious pathological conditions are accompanied by ATP release from the intracellular to the extracellular compartment, where it degrades into adenosine and modulates immune responses. Previous studies concluded that both ATP and its degradation product adenosine are important immune-regulatory molecules; ATP acted as a danger signal that promotes immune responses, but adenosine’s effect was inhibitory. In this study, we show that adenosine plays an important role in balancing Th1 and Th17 pathogenic T cell responses in autoimmune disease. While its effect on Th1 responses is inhibitory, its effect on Th17 responses is enhancing, thereby impacting the balance between Th1 and Th17 responses. Mechanistic studies showed that this effect is mediated via several immune cells, among which γδ T cell activation and dendritic cell differentiation are prominent; adenosine and γδ-mediated immunoregulation synergistically impact each other’s effect. Adenosine augments the activation of γδ T cells, which is an important promoter for Th17 responses and has a strong effect on DC differentiation tipping the balance from generation of DCs that stimulate Th1 responses to those that stimulate Th17 responses. The knowledge acquired in this study should improve our understanding of the immune-regulatory effect of extracellular ATP-adenosine metabolism and improve treatment for autoimmune diseases caused by both Th1 and Th17-type pathogenic T cells.

scholarly journals Vector Order Determines Protection against Pathogenic Simian Immunodeficiency Virus Infection in a Triple-Component Vaccine by Balancing CD4+ and CD8+ T-Cell Responses

2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Ulrike Sauermann ◽  
Antonia Radaelli ◽  
Nicole Stolte-Leeb ◽  
Katharina Raue ◽  
Massimiliano Bissa ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Target Cells ◽  
Aids Vaccine ◽  
Cell Responses ◽  
Antibody Titers

ABSTRACT An effective AIDS vaccine should elicit strong humoral and cellular immune responses while maintaining low levels of CD4+ T-cell activation to avoid the generation of target cells for viral infection. The present study investigated two prime-boost regimens, both starting vaccination with single-cycle immunodeficiency virus, followed by two mucosal boosts with either recombinant adenovirus (rAd) or fowlpox virus (rFWPV) expressing SIVmac239 or SIVmac251 gag/pol and env genes, respectively. Finally, vectors were switched and systemically administered to the reciprocal group of animals. Only mucosal rFWPV immunizations followed by systemic rAd boost significantly protected animals against a repeated low-dose intrarectal challenge with pathogenic SIVmac251, resulting in a vaccine efficacy (i.e., risk reduction per exposure) of 68%. Delayed viral acquisition was associated with higher levels of activated CD8+ T cells and Gag-specific gamma interferon (IFN-γ)-secreting CD8+ cells, low virus-specific CD4+ T-cell responses, and low Env antibody titers. In contrast, the systemic rFWPV boost induced strong virus-specific CD4+ T-cell activity. rAd and rFWPV also induced differential patterns of the innate immune responses, thereby possibly shaping the specific immunity. Plasma CXCL10 levels after final immunization correlated directly with virus-specific CD4+ T-cell responses and inversely with the number of exposures to infection. Also, the percentage of activated CD69+ CD8+ T cells correlated with the number of exposures to infection. Differential stimulation of the immune response likely provided the basis for the diverging levels of protection afforded by the vaccine regimen. IMPORTANCE A failed phase II AIDS vaccine trial led to the hypothesis that CD4+ T-cell activation can abrogate any potentially protective effects delivered by vaccination or promote acquisition of the virus because CD4+ T helper cells, required for an effective immune response, also represent the target cells for viral infection. We compared two vaccination protocols that elicited similar levels of Gag-specific immune responses in rhesus macaques. Only the animal group that had a low level of virus-specific CD4+ T cells in combination with high levels of activated CD8+ T cells was significantly protected from infection. Notably, protection was achieved despite the lack of appreciable Env antibody titers. Moreover, we show that both the vector and the route of immunization affected the level of CD4+ T-cell responses. Thus, mucosal immunization with FWPV-based vaccines should be considered a potent prime in prime-boost vaccination protocols.

scholarly journals Induction of Antigen-Specific T-Cell Responses through Dendritic Cell Vaccination in AML: Results of a Phase I/II Trial and Ex Vivo Enhancement By Checkpoint Blockade

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 764-764 ◽  
Author(s):  
Felix S. Lichtenegger ◽  
Katrin Deiser ◽  
Maurine Rothe ◽  
Frauke M. Schnorfeil ◽  
Christina Krupka ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Phase I ◽  
T Cell Activation ◽  
Cell Activation ◽  
Next Generation ◽  
Cell Responses ◽  
Ifn Γ

Abstract Postremission therapy is critical for successful elimination of minimal residual disease (MRD) in acute myeloid leukemia (AML). Innovative treatment options are needed for patients that are not eligible for allogeneic stem cell transplantation. As the intrinsic immune response against leukemia-associated antigens (LAAs) is generally low, the clinical application of checkpoint inhibitors as monotherapy is less promising in AML compared to other hemato-oncological diseases. Therapeutic vaccination with autologous dendritic cells (DCs) loaded with LAAs is a promising treatment strategy to induce anti-leukemic immune responses. We have conducted a phase I/II proof-of-concept study using monocyte-derived next-generation DCs as postremission therapy of AML patients with a non-favorable risk profile in CR/CRi after intensive induction therapy (NCT01734304). These DCs are generated using a GMP-compliant 3-day protocol including a TLR7/8 agonist, loaded with RNA encoding the LAAs WT1 and PRAME as well as CMVpp65 as adjuvant/surrogate antigen, and are applied intradermally up to 10 times within 26 weeks. The primary endpoint of the trial is feasibility and safety of the vaccination. Secondary endpoints are immunological responses and disease control. After the safety and toxicity profile was evaluated within phase I (n=6), the patient cohort was expanded to a total of 13 patients. DCs of sufficient number and quality could be generated from leukapheresis in 11/12 cases. DCs exhibited an immune-stimulatory profile based on high costimulatory molecule expression, IL-12p70 secretion, migration towards a chemokine gradient and processing and presentation of antigen. In 9/9 patients that are currently evaluable, we observed delayed-type hypersensitivity (DTH) responses at the vaccination site, but no grade III/IV toxicities. TCR repertoire analysis by next-generation sequencing revealed an enrichment of particular clonotypes at DTH sites. In the peripheral blood, we detected vaccination-specific T cell responses by multimer staining and by ELISPOT analysis: 7/7 patients showed responses to CMVpp65, including both boosting of pre-existing T cells in CMV+ patients and induction of a primary T cell response in CMV- patients. 2/7 patients exhibited responses to PRAME and WT each. 7/10 vaccinated patients are still alive, and 5/10 are in CR, with an observation period of up to 840 days. In vitro, DC-activated T cells showed an upregulation of PD-1 and LAG-3, while the DCs expressed the respective ligands PD-L1 and HLA-DR. Therefore, we studied the capacity of checkpoint blocking antibodies to further enhance T-cell activation by DCs. We found that blockade of PD-1 and particularly of LAG-3 was highly effective in enhancing both IFN-γ secretion and proliferation of T cells. Both pathways seem to target different T-cell subsets, as PD-1 blockade resulted in increased IFN-γ secretion by TN- and TEM-subsets, while blockade of LAG-3 significantly affected TN- and TCM-subsets. We conclude that vaccination with next-generation LAA-expressing DCs in AML is feasible, safe, and induces anti-leukemic immune responses in vivo. Our in vitro data supports the hypothesis that T-cell activation by means of the vaccine could be further enhanced by blocking PD-1 and/or LAG-3. Disclosures Subklewe: AMGEN Research Munich: Research Funding.

scholarly journals γδ T Cells Support Pancreatic Oncogenesis by Restraining αβ T Cell Activation

Cell ◽  
2020 ◽  
Vol 183 (4) ◽  
pp. 1134-1136
Author(s):  
Donnele Daley ◽  
Constantinos Pantelis Zambirinis ◽  
Lena Seifert ◽  
Neha Akkad ◽  
Navyatha Mohan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Γδ T Cells

scholarly journals γδ T Cells Support Pancreatic Oncogenesis by Restraining αβ T Cell Activation

Cell ◽  
2016 ◽  
Vol 166 (6) ◽  
pp. 1485-1499.e15 ◽  
Author(s):  
Donnele Daley ◽  
Constantinos Pantelis Zambirinis ◽  
Lena Seifert ◽  
Neha Akkad ◽  
Navyatha Mohan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Γδ T Cells

scholarly journals A role for CD9 molecules in T cell activation.

1996 ◽  
Vol 184 (2) ◽  
pp. 753-758 ◽  
Author(s):  
X G Tai ◽  
Y Yashiro ◽  
R Abe ◽  
K Toyooka ◽  
C R Wood ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Expression Cloning ◽  
Wild Type ◽  
Almost All ◽  
Antigen Presenting ◽  
Deficient Mice

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

107 Effects of IL-2 and IL-15 on the proliferative and antitumor capacities of allogeneic CD20 CAR-engineered γδ T cells in a 3D B cell lymphoma spheroid assay

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A119-A119
Author(s):  
Lu Bai ◽  
Kevin Nishimoto ◽  
Mustafa Turkoz ◽  
Marissa Herrman ◽  
Jason Romero ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytokine Production ◽  
Γδ T Cells ◽  
Γδ T Cell ◽  
Car T

BackgroundAutologous chimeric antigen receptor (CAR) T cells have been shown to be efficacious for the treatment of B cell malignancies; however, widespread adoption and application of CAR T cell products still face a number of challenges. To overcome these challenges, Adicet Bio is developing an allogeneic γδ T cell-based CAR T cell platform, which capitalizes on the intrinsic abilities of Vδ1 γδ T cells to recognize and kill transformed cells in an MHC-unrestricted manner, to migrate to epithelial tissues, and to function in hypoxic conditions. To gain a better understanding of the requirements for optimal intratumoral CAR Vδ1 γδ T cell activation, proliferation, and differentiation, we developed a three-dimensional (3D) tumor spheroid assay, in which tumor cells acquire the structural organization of a solid tumor and establish a microenvironment that has oxygen and nutrient gradients. Moreover, through the addition of cytokines and/or tumor stromal cell types, the spheroid microenvironment can be modified to reflect hot or cold tumors. Here, we report on the use of a 3D CD20+ Raji lymphoma spheroid assay to evaluate the effects of IL-2 and IL-15, positive regulators of T cell homeostasis and differentiation, on the proliferative and antitumor capacities of CD20 CAR Vδ1 γδ T cells.MethodsMolecular, phenotypic, and functional profiling were performed to characterize the in vitro dynamics of the intraspheroid CD20 CAR Vδ1 γδ T cell response to target antigen in the presence of IL-2, IL-15, or no added cytokine.ResultsWhen compared to no added cytokine, the addition of IL-2 or IL-15 enhanced CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and cytokine production in a dose-dependent manner but were only able to alter the kinetics of Raji cell killing at low effector to target ratios. Notably, differential gene expression analysis using NanoString nCounter® Technology confirmed the positive effects of IL-2 or IL-15 on CAR-activated Vδ1 γδ T cells as evidenced by the upregulation of genes involved in activation, cell cycle, mitochondrial biogenesis, cytotoxicity, and cytokine production.ConclusionsTogether, these results not only show that the addition of IL-2 or IL-15 can potentiate CD20 CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation into antitumor effectors but also highlight the utility of the 3D spheroid assay as a high throughput in vitro method for assessing and predicting CAR Vδ1 γδ T cell activation, proliferation, survival, and differentiation in hot and cold tumors.

scholarly journals High Frequencies of Functional Virus-Specific CD4+ T Cells in SARS-CoV-2 Subjects With Olfactory and Taste Disorders

2021 ◽  
Vol 12 ◽  
Author(s):  
Dalila Mele ◽  
Anna Calastri ◽  
Eugenia Maiorano ◽  
Antonella Cerino ◽  
Michele Sachs ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Control Group ◽  
Presenting Symptoms ◽  
Cell Responses ◽  
Taste Disorders ◽  
Specific Igg

Olfactory and taste disorders (OTD) are commonly found as presenting symptoms of SARS-CoV-2 infection in patients with clinically mild COVID-19. Virus-specific T cells are thought to play an important role in the clearance of SARS-CoV-2; therefore the study of T cell specific immune responses in patients with mild symptoms may help to understand their possible role in protection from severe disease. We evaluated SARS-CoV-2-specific T cell responses to four different peptide megapools covering all SARS-CoV-2 proteins during the acute phase of the disease in 33 individuals with mild or no other symptom beside OTD and in 22 age-matched patients with severe infection. A control group of 15 outpatients with OTD and consistently negative nasopharyngeal SARS-CoV-2 RNA swabs and virus-specific IgG serology was included in the study. Increased frequencies of virus-specific CD4+ and CD8+ T cells were found in SARS-CoV-2 positive patients with OTD compared with those with severe COVID-19 and with SARS-CoV-2 negative OTD individuals. Moreover, enhanced CD4+ and CD8+ T-cell activation induced by SARS-CoV-2 peptides was associated with higher interferon (IFN)γ production. Increased frequencies of Spike (S1/S2)-specific CD4+ T cells showing enhanced IFNγ secretion and granzyme B content were associated with serum spike-specific IgG in the OTD group. In conclusion, patients with SARS-CoV-2 induced OTD develop highly functional virus-specific CD4+ and CD8+ T cells during the symptomatic phase of the disease, suggesting that robust and coordinated T-cell responses provide protection against extension of COVID-19 to the lower respiratory tract.

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

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.

Abstract P347: γδ T Cells Drive CD4 + And CD8 + T Cell Activation In Hypertension

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Antoine Caillon ◽  
Pierre Paradis ◽  
Ernesto L Schiffrin
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Vascular Injury ◽  
T Cell Activation ◽  
Cell Activation ◽  
Γδ T Cells ◽  
Ang Ii ◽  
Adaptive Immune Cells ◽  
Induced Hypertension

Objective: Both innate (monocyte/macrophages) and adaptive immune cells (T lymphocytes) have been shown to play a role in the development of vascular injury in hypertension. Recently, we demonstrated that a small subset of “innate-like” T lymphocytes, expressing the γ/δ T cell receptor (TCR) rather than the αβ TCR, plays a key role in hypertension and vascular injury. We demonstrated an increased number and activation (CD69 + ) of γδ T cells during the development of hypertension caused by angiotensin (Ang) II infusion, and that deficiency in γδ T cells prevented Ang II-induced hypertension, resistance artery endothelial dysfunction and spleen T-cell activation in mice. We hypothesized that γδ T cells mediate activation of other T cells in hypertension. Method and Results: Fourteen to 15-week old male C57BL/6 wild-type (WT) mice were infused with Ang II (490 ng/kg/min, SC) for 3, 7 and 14 days (n=5-7) and spleen T cell profile was determined by flow cytometry. A correlation was demonstrated between the frequency (FREQ) and the number (#) of activated CD69 + γδ T cells and CD4 + CD69 + T cells (FREQ: r=0.41, P <0.05 and #: r=0.58, P <0.001) and CD8 + CD69 + T cells (FREQ: r=0.36, P <0.05 and #: r=0.50, P <0.01). We also demonstrated a high correlation between the # of CD69 + γδ T cells expressing CD27, a marker of interferon-γ expressing cells and a member of the T-T interaction molecules, with CD4 + CD69 + (r=0.88, P <0.001) and CD8 + CD69 + (r=0.81, P <0.01) T cells after 7 days of Ang II infusion. Conclusion: This study demonstrated an association between CD27 + CD69 + γδ T cells and activated T cells. These results suggest that γδ T cells drive activation of other T cells in Ang II-induced hypertension. Targeting γδ T cells may contribute to reduce inflammation in hypertension.

scholarly journals HIV-specific T-cell Responses and Generalized Activation in HIV-1 Infected Long-term Non-progressors and Progressors from South India

2019 ◽  
Vol 16 (4) ◽  
pp. 302-314
Author(s):  
Chinnambedu Ravichandran Swathirajan ◽  
Ramachandran Vignesh ◽  
Greer Waldrop ◽  
Uma Shanmugasundaram ◽  
Pannerselvam Nandagopal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Activation Rates ◽  
Hiv 1

Background:Anti-viral cytokine expressions by cytotoxic T-cells and lower activation rates have been reported to correlate with suppressed HIV replication in long-term non-progressors (LTNP). Immune mechanisms underlying disease non-progression in LTNP might vary with HIV-1 subtype and geographical locations.Objective:This study evaluates cytokine expression and T-cells activation in relation to disease non-progression in LTNP.Methods:HIV-1 Subtype C infected LTNP (n=20) and progressors (n=15) were enrolled and flowcytometry assays were performed to study HIV-specific CD8 T-cells expressing IL-2, IFN-&#947;, TNF-&#945; and MIP-1&#946; against gag and env peptides. CD4+ T-cell activation was evaluated by surface expression of HLADR and CD38.Results:Proportions of cytokines studied did not differ significantly between LTNP and progressors, while contrasting correlations with disease progression markers were observed in LTNP. CD4+ T-cell activation rates were significantly lower in LTNP compared to progressors which indicate the potential role of T-cell activation rates in disease non-progression in LTNP.Conclusion:LTNP and progressors showed similar CD8+ T-cell responses, but final conclusions can be drawn only by comparing multiple immune factors in larger LTNP cohort with HIV-1 infected individuals at various levels of disease progression. A possible role of HIV-1 subtype variation and ethnic differences in addition to host-genetic and viral factors cannot be ruled out.

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