scholarly journals Negative feedback control of the autoimmune response through antigen-induced differentiation of IL-10–secreting Th1 cells

2009 ◽  
Vol 206 (8) ◽  
pp. 1755-1767 ◽  
Author(s):  
Leona Gabryšová ◽  
Kirsty S. Nicolson ◽  
Heather B. Streeter ◽  
Johan Verhagen ◽  
Catherine A. Sabatos-Peyton ◽  
...  
Keyword(s):  
T Cells ◽  
Negative Feedback ◽  
Cd4 T Cells ◽  
Peripheral Tolerance ◽  
Autoimmune Response ◽  
Regulatory Function ◽  
Th1 Cell ◽  
Peptide Epitopes ◽  
Ifn Γ ◽  
Immune Pathology

Regulation of the immune response to self- and foreign antigens is vitally important for limiting immune pathology associated with both infections and hypersensitivity conditions. Control of autoimmune conditions can be reinforced by tolerance induction with peptide epitopes, but the mechanism is not currently understood. Repetitive intranasal administration of soluble peptide induces peripheral tolerance in myelin basic protein (MBP)–specific TCR transgenic mice. This is characterized by the presence of anergic, interleukin (IL)-10–secreting CD4+ T cells with regulatory function (IL-10 T reg cells). The differentiation pathway of peptide-induced IL-10 T reg cells was investigated. CD4+ T cells became anergic after their second encounter with a high-affinity MBP peptide analogue. Loss of proliferative capacity correlated with a switch from the Th1-associated cytokines IL-2 and interferon (IFN)-γ to the regulatory cytokine IL-10. Nevertheless, IL-10 T reg cells retained the capacity to produce IFN-γ and concomitantly expressed T-bet, demonstrating their Th1 origin. IL-10 T reg cells suppressed dendritic cell maturation, prevented Th1 cell differentiation, and thereby created a negative feedback loop for Th1-driven immune pathology. These findings demonstrate that Th1 responses can be self-limiting in the context of peripheral tolerance to a self-antigen.

scholarly journals Hydrophilic Astragalin Galactoside Induces T Helper Type 1-Mediated Immune Responses via Dendritic Cells

2018 ◽  
Vol 19 (10) ◽  
pp. 3120
Author(s):  
Jae Jeon ◽  
Byung-Cheol Lee ◽  
Doman Kim ◽  
Daeho Cho ◽  
Tae Kim
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Biological Activities ◽  
Water Soluble ◽  
Th1 Cells ◽  
Dependent Manner ◽  
T Helper ◽  
Th1 Cell ◽  
Ifn Γ

A flavonoid Astragalin (kaempferol-3-O-β-d-glucopyranoside, Ast) has several biological activities including anti-oxidant, anti-HIV, and anti-allergic effects. Nonetheless, its insolubility in hydrophilic solvents imposes restrictions on its therapeutic applications. In this study, we investigated the effects of water-soluble astragalin-galactoside (kaempferol-3-O-β-d-isomaltotrioside, Ast-Gal) on murine bone marrow-derived dendritic cell (DC) maturation and T helper (Th) cell-mediated immune responses. Ast-Gal significantly increased maturation and activation of DCs through the upregulation of surface markers, such as cluster of differentiation (CD)80, CD86, and Major histocompatibility complex (MHC) II in a dose-dependent manner, while Ast had little effects. Additionally, Ast-Gal-treated DCs markedly secreted immune-stimulating cytokines such as interleukin (IL)-1β, IL-6, and IL-12. Importantly, Ast-Gal strongly increased expression of IL-12, a polarizing cytokine of Th1 cells. In a co-culture system of DCs and CD4+ T cells, Ast-Gal-treated DCs preferentially differentiates naïve CD4+ T cells into Th1 cells. The addition of neutralizing IL-12 monoclonal antibody (mAb) to cultures of Ast-Gal-treated DCs and CD4+ T cells significantly decreased interferon (IFN)-γ production, thereby indicating that Ast-Gal-stimulated DCs enhance the Th1 response through IL-12 production by DCs. Injection with Ast-Gal-treated DCs in mice increased IFN-γ-secreting Th1 cell population. Collectively, these findings indicate that hydrophilically modified astragalin can enhance Th1-mediated immune responses via DCs and point to a possible application of water-soluble astragalin-galactoside as an immune adjuvant.

scholarly journals IFN-γ production by alloantigen-reactive regulatory T cells is important for their regulatory function in vivo

2005 ◽  
Vol 201 (12) ◽  
pp. 1925-1935 ◽  
Author(s):  
Birgit Sawitzki ◽  
Cherry I. Kingsley ◽  
Vanessa Oliveira ◽  
Mahzuz Karim ◽  
Manuela Herber ◽  
...  
Keyword(s):  
T Cells ◽  
Skin Graft ◽  
Cd4 T Cells ◽  
Regulatory Function ◽  
Unique Role ◽  
Expression Kinetic ◽  
Exposure In Vivo ◽  
Ifn Γ ◽  
And Function

The significance of cytokine production by CD4+ regulatory T (T reg) cells after antigen exposure in vivo and its impact on their regulatory activity remains unclear. Pretreatment with donor alloantigen under the cover of anti-CD4 therapy generates alloantigen reactive T reg cells that can prevent rejection of donor-specific skin grafts that are mediated by naive CD45RBhighCD4+ T cells. To examine the kinetics and importance of cytokine gene transcription by such alloantigen-reactive T reg cells, pretreated mice were rechallenged with donor alloantigen in vivo. CD25+CD4+ T cells, but not CD25−CD4+ T cells, showed a fivefold increase in IFN-γ mRNA expression within 24 h of reencountering alloantigen in vivo. This expression kinetic was highly antigen-specific and was of functional significance. Neutralizing IFN-γ at the time of cotransfer of alloantigen reactive T reg cells, together with CD45RBhighCD4+ effector T cells into Rag−/− skin graft recipients, resulted in skin graft necrosis in all recipients; the generation and function of alloantigen-reactive T reg cells was impaired dramatically in IFN-γ–deficient mice. These data support a unique role for IFN-γ in the functional activity of alloantigen-reactive T reg cells during the development of operational tolerance to donor alloantigens in vivo.

scholarly journals Dexmedetomidine Directs T Helper Cells toward Th1 Cell Differentiation via the STAT1-T-Bet Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Daoyun Lei ◽  
Li Liu ◽  
Songhui Xie ◽  
Haiyan Ji ◽  
Yanxing Guo ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
Cd4 T Cells ◽  
Quantitative Polymerase Chain Reaction ◽  
Cell Subset ◽  
Enzyme Linked Immunosorbent Assay ◽  
T Helper ◽  
Th1 Cell ◽  
Adrenergic Antagonist ◽  
Ifn Γ

Dexmedetomidine is an α2 adrenergic receptor agonist that has been reported to modulate the polarization of CD4+ T cells. However, the underlying mechanisms by which dexmedetomidine induces T-helper 1 (Th1) cell differentiation remain poorly understood. The aim of this study was to explore the potential mechanisms through which dexmedetomidine can induce Th1 cell differentiation. Purified CD4+ T cells were stimulated with anti-CD3/anti-CD28 and then treated with dexmedetomidine. Flow cytometry analysis was adopted to measure the concentration of Th1 cells. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qPCR) were performed to detect protein levels and mRNA expression, respectively, of IFN-γ and IL-4. Western blotting was used to determine the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and T-bet expression. The Th1 cell subset and IFN-γ levels were elevated in the dexmedetomidine-induced CD4+ T cells. Dexmedetomidine enhanced the phosphorylation of STAT1 and the expression of T-bet in the CD4+ T cells. Atipamezole (an α2 adrenergic antagonist) and fludarabine (a STAT1 inhibitor) reversed the dexmedetomidine-induced Th1 cell differentiation. These results suggested that dexmedetomidine induced Th1 cell differentiation via the STAT1-T-bet signaling pathway.

PD-1/PD-L Pathway Potentially Involved in ITP Immunopathogenesis

2019 ◽  
Vol 119 (05) ◽  
pp. 758-765 ◽  
Author(s):  
Mu Nie ◽  
Yang Liu ◽  
Xiu-xiu Li ◽  
Ya-nan Min ◽  
Dan-dan Yang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Apoptosis ◽  
Cd4 T Cells ◽  
Peripheral Tolerance ◽  
Healthy Controls ◽  
T Cell Apoptosis ◽  
Ifn Γ

AbstractThe binding of programmed death 1 (PD-1) to its ligands PD-L1 and PD-L2 on antigen-presenting cells turns off autoreactive T cells and induces peripheral tolerance. Aberrant PD-1/PD-L signalling could result in a breakdown of peripheral tolerance and lead to autoimmune diseases. In this study, we detected PD-1 and PD-L expression on T cells and dendritic cells (DCs) in immune thrombocytopenia (ITP) patients with active disease by flow cytometry. The effects of PD-L1-Fc fusion protein (PD-L1-Fc) on T cells and on secretion of interferon-γ (IFN-γ) and interleukin-2 (IL-2) were detected by flow cytometry and enzyme-linked immunosorbent assay, respectively. Compared with healthy controls, PD-1 expression was significantly increased in CD4+ T cells and CD8+ T cells from patients with active ITP. However, PD-L1 expression on monocyte-derived DCs was lower in patients with active ITP than in healthy controls. In vitro assays revealed that PD-L1-Fc increased T cell apoptosis, inhibited activation and proliferation of CD4+ T cells and CD8+ T cells and decreased IFN-γ and IL-2 secretion in patients with active ITP. These results suggest that the aberrant PD-1/PD-L negative co-stimulatory pathway may play a role in ITP. Enhancing PD-1/PD-L signalling might be a promising therapeutic approach for ITP patients by enhancing T cell apoptosis, inhibiting T cell activation and proliferation and reducing secretion of inflammatory factors.

scholarly journals Acquisition of direct antiviral effector functions by CMV-specific CD4+ T lymphocytes with cellular maturation

2006 ◽  
Vol 203 (13) ◽  
pp. 2865-2877 ◽  
Author(s):  
Joseph P. Casazza ◽  
Michael R. Betts ◽  
David A. Price ◽  
Melissa L. Precopio ◽  
Laura E. Ruff ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cd4 T Cells ◽  
Viral Infections ◽  
Surface Expression ◽  
Cytolytic Activity ◽  
Peptide Epitopes ◽  
Tnf Α ◽  
Intracellular Expression ◽  
Ifn Γ

The role of CD4+ T cells in the control of persistent viral infections beyond the provision of cognate help remains unclear. We used polychromatic flow cytometry to evaluate the production of the cytokines interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-2, the chemokine macrophage inflammatory protein (MIP)-1β, and surface mobilization of the degranulation marker CD107a by CD4+ T cells in response to stimulation with cytomegalovirus (CMV)-specific major histocompatibility complex class II peptide epitopes. Surface expression of CD45RO, CD27, and CD57 on responding cells was used to classify CD4+ T cell maturation. The functional profile of virus-specific CD4+ T cells in chronic CMV infection was unique compared with that observed in other viral infections. Salient features of this profile were: (a) the simultaneous production of MIP-1β, TNF-α, and IFN-γ in the absence of IL-2; and (b) direct cytolytic activity associated with surface mobilization of CD107a and intracellular expression of perforin and granzymes. This polyfunctional profile was associated with a terminally differentiated phenotype that was not characterized by a distinct clonotypic composition. Thus, mature CMV-specific CD4+ T cells exhibit distinct functional properties reminiscent of antiviral CD8+ T lymphocytes.

scholarly journals Hydrophilic Astragalin Galactoside Induces T Helper Type 1-Mediated Immune Responses via Dendritic Cells

2018 ◽  
Author(s):  
Jae Hyoung Jeon ◽  
Byung-Cheol Lee ◽  
Doman Kim ◽  
Daeho Cho ◽  
Tae Sung Kim
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Cd4 T Cells ◽  
Biological Activities ◽  
Water Soluble ◽  
Th1 Cells ◽  
Dependent Manner ◽  
T Helper ◽  
Th1 Cell ◽  
Ifn Γ

A flavonoid Astragalin (kaempferol-3-O-β-D-glucopyranoside, Ast) has several biological activities including anti-oxidant, anti-HIV, and anti-allergic effects. Nonetheless, its insolubility in hydrophilic solvents imposes restrictions on its therapeutic applications. In this study, we investigated the effects of water-soluble astragalin-galactoside (kaempferol-3-O- β-D-isomaltotrioside, Ast-Gal) on dendritic cell (DC) maturation and T helper (Th) cell-mediated immune responses. Ast-Gal significantly increased maturation and activation of DCs through up-regulation of surface markers, such as CD80, CD86, and MHC II in a dose-dependent manner, while Ast had little effects. Also, Ast-Gal-treated DCs markedly secreted immune-stimulating cytokines such as IL-1β, IL-6, and IL-12. Importantly, Ast-Gal strongly increased expression of IL-12, a polarizing cytokine of Th1 cells. In a co-culture system of DCs and CD4+ T cells, Ast-Gal-treated DCs preferentially differentiates naïve CD4+ T cells into Th1 cells. The addition of neutralizing IL-12 mAb to cultures of Ast-Gal-treated DCs and CD4+ T cells significantly increased IFN- γ production, thereby indicating that Ast-Gal-stimulated DCs enhance the Th1 response through IL-12 production by DCs. Injection with Ast-Gal-treated DCs in mice increased IFN-γ-secreting Th1 cell population. Collectively, these findings indicate that hydrophilically modified astragalin can enhance Th1-mediated immune responses via DCs, and point to a possible application of water-soluble astragalin-galactoside as an immune adjuvant.

HCA587 protein vaccine induces specific antitumor immunity mediated by CD4+ T-cells expressing granzyme B in a mouse model of melanoma

2020 ◽  
Vol 20 ◽  
Author(s):  
Weiming Yang ◽  
Weiheng Zhang ◽  
Xiaozhong Wang ◽  
Liming Tan ◽  
Hua Li ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Antitumor Effect ◽  
Granzyme B ◽  
Cell Subset ◽  
Cell Mediated Immunity ◽  
Protein Vaccine ◽  
Tumor Tissues ◽  
Wide Range ◽  
Ifn Γ

Background: The antigen HCA587 (also known as MAGE-C2), which is considered a cancer-testis antigen, exhibits upregulated expression in a wide range of malignant tumors with unique immunological properties, and may thus serve as a promising target for tumor immunotherapy. Objective: To explore the antitumor effect of the HCA587 protein vaccine and the response of humoral and cell-mediated immunity. Methods: The HCA587 protein vaccine was formulated with adjuvants CpG and and ISCOM. B16 melanoma cells were subcutaneously inoculated to C57BL/6 mice, followed by treatment with HCA587 protein vaccine subcutaneously. Mouse survival was monitored daily, and tumor volume was measured every 2 to 3 days. The tumor sizes, survival time and immune cells in tumor tissues were detected. And the vital immune cell subset and effector molecules were explored. Results: After treatment with HCA587 protein vaccine, the vaccination generated elicited significant immune responses, which delayed tumor growth and improved animal survival. The vaccination increased the proportion of CD4+ T cells expressing IFN-γ and granzyme B in tumor tissues. Depletion of CD4+T cells resulted in an almost complete abrogation of the antitumor effect of the vaccination, suggesting that the antitumor efficacy was mediated by CD4+ T cells. In addition, knockout of IFN-γ resulted in a decrease in granzyme B levels which were secreted by CD4+ T cells, and the antitumor effect was also significantly attenuated. Conclusion: The HCA587 protein vaccine may increase the levels of granzyme B expressed by CD4+ T cells, and this increase is dependent on IFN-γ, and the vaccine resulted in a specific tumor immune response and subsequent eradication of the tumor.

scholarly journals Circulating CD4 T cells elicited by endemic coronaviruses display vast disparities in abundance and functional potential linked to both antigen specificity and age

2021 ◽  
Author(s):  
Katherine A Richards ◽  
Maryah Glover ◽  
Jeremy C Crawford ◽  
Paul Thomas ◽  
Chantelle White ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Protective Immunity ◽  
Granzyme B ◽  
Antigen Specificity ◽  
Functional Potential ◽  
Membrane Envelope ◽  
Ifn Γ ◽  
Human Coronaviruses ◽  
Repeated Infections

Abstract Repeated infections with endemic human coronaviruses are thought to reflect lack of long-lasting protective immunity. Here, we evaluate circulating human CD4 T cells collected prior to 2020 for reactivity towards hCoV spike proteins, probing for the ability to produce IFN-γ, IL-2 or granzyme B. We find robust reactivity to spike-derived epitopes, comparable to influenza, but highly variable abundance and functional potential across subjects, depending on age and viral antigen specificity. To explore the potential of these memory cells to be recruited in SARS-CoV-2 infection, we examined the same subjects for cross-reactive recognition of epitopes from SARS-CoV-2 nucleocapsid, membrane/envelope, and spike. The functional potential of these cross-reactive CD4 T cells was highly variable, with nucleocapsid-specific CD4 T cells, but not spike-reactive cells showing exceptionally high levels of granzyme production upon stimulation. These results are considered in light of recruitment of hCoV-reactive cells into responses of humans to SARS-CoV infections or vaccinations.

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