scholarly journals Epinephrine Production in Th17 Cells and Experimental Autoimmune Encephalitis

2021 ◽  
Vol 12 ◽  
Author(s):  
Pinguang Yang ◽  
Hong Tian ◽  
Yong-Rui Zou ◽  
Pierre Chambon ◽  
Hiroshi Ichinose ◽  
...  
Keyword(s):  
T Cells ◽  
Alternative Pathway ◽  
Autoimmune Encephalitis ◽  
T Cell Subsets ◽  
Experimental Autoimmune Encephalitis ◽  
Wild Type ◽  
Mouse Brain Endothelial Cells ◽  
Experimental Autoimmune

Epinephrine is a hormone secreted primarily by medullary cells of the adrenal glands which regulates permeability of blood–brain barrier (BBB). Recent studies showed signaling by epinephrine/epinephrine receptor in T cells is involved in autoimmune diseases. Nevertheless, the production of epinephrine by T cells and its pathogenic function in T cells are not well investigated. Our results show that phenylethanol N-methyltransferase (PNMT), a rate-limiting enzyme of epinephrine synthesis, is specifically expressed in vitro in differentiated TH17 cells and in tissue-resident TH17 cells. Indeed, expression levels of enzymes involved in epinephrine production are higher in TH17 cells from animals after EAE induction. The induction of PNMT was not observed in other effector T cell subsets or regulatory T cells. Epinephrine producing TH17 cells exhibit co-expression of GM-CSF, suggesting they are pathogenic TH17 cells. To delineate the function of epinephrine-production in TH17 cells, we generated a TH17-specific knockout of tyrosine hydroxylase (Th) by breeding a Th-flox and a ROR-gt-CRE mouse (Th-CKO). Th-CKO mice are developmentally normal with an equivalent T lymphocyte number in peripheral lymphoid organs. Th-CKO mice also show an equivalent number of TH17 cells in vivo and following in vitro differentiation. To test whether epinephrine-producing TH17 cells are key for breaching the BBB, migration of T cells through mouse brain endothelial cells was investigated in vitro. Both epi+ wild-type and epi- TH17 cells migrate through an endothelial cell barrier. Mice were immunized with MOG peptide to induce experimental autoimmune encephalitis (EAE) and disease progression was monitored. Although there is a reduced infiltration of CD4+ T cells in Th-CKO mice, no difference in clinical score was observed between Th-CKO and wild-type control mice. Increased neutrophils were observed in the central nervous system of Th-CKO mice, suggesting an alternative pathway to EAE progression in the absence of TH17 derived epinephrine.

Hyperactivable NFAT1 Ameliorates Autoimmune Encephalitis In Vivo.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 711-711
Author(s):  
Srimoyee Ghosh ◽  
Sergei B Koralov ◽  
Irena Stevanovic ◽  
Mark S Sundrud ◽  
Yoshiteru Sasaki ◽  
...  
Keyword(s):  
T Cells ◽  
Transgenic Mice ◽  
Cd4 T Cells ◽  
Th17 Cells ◽  
Autoimmune Encephalitis ◽  
Cell Types ◽  
Wild Type ◽  
Ifn Γ

Abstract Abstract 711 Naïve CD4 T cells differentiate into diverse effector and regulatory subsets to coordinate the adaptive immune response. TH1 and TH2 effector subsets produce IFN-γ and IL-4, respectively, whereas proinflammatory TH17 cells are key regulators of autoimmune inflammation, characteristically produce IL-17 and IL-22 and differentiate in the presence of inflammatory cytokines like IL-6 and IL-21 together with TGF-β. Naive T cells can also differentiate into tissue-protective induced T regulatory (iTreg) cells. NFAT proteins are highly phosphorylated and reside in the cytoplasm of resting cells. Upon dephosphorylation by the Ca2+/calmodulin-dependent serine phosphatase calcineurin, NFAT proteins translocate to the nucleus, where they orchestrate developmental and activation programs in diverse cell types. In this study, we investigated the role of the Ca/NFAT signaling pathway in regulating T cell differentiation and the development of autoimmune diseases. We generated transgenic mice conditionally expressing a hyperactivable version of NFAT1 (AV-NFAT1) from the ROSA26 locus. To restrict AV-NFAT1 expression to the T cell compartment, ROSA26-AV-NFAT1 transgenic mice were bred to CD4-Cre transgenic mice. Naïve CD4 T cells freshly isolated from AV mice produced significantly less IL-2 but increased amounts of the inhibitory cytokine IL-10. To investigate the role of NFAT1 in the generation of TH1, TH2, Tregand TH17 cells, the respective cell types were generated from CD4 T cells of AV mice by in vitro differentiation. T cells from AV-NFAT1 mice exhibited a dysregulation of cytokine expression, producing more IFN-γ and less IL-4. While the numbers of CD4+CD25+ “natural” Treg cells in peripheral lymphoid organs and their in vitro suppressive functions were slightly decreased in AV mice, iTreg generation from CD4+CD25- T cells of AV mice as compared to wild type cells was markedly enhanced. Moreover, TH17 cells generated in vitro from CD4 T cells of AV mice in the presence of IL-6, IL-21 and TGF-β exhibited dramatically increased expression of both IL-10 and IL-17 as compared to wild type controls. To investigate putative NFAT binding sites in the IL-10 and IL-17 gene loci, we performed chromatin immunoprecipitation experiments. We show that NFAT1 can bind at the IL-17 locus at 3 out of 9 CNS regions which are accessible specifically during TH17 but not during TH1 and TH2 differentiation. Furthermore, we provide evidence that NFAT1 binds one CNS region in the IL10-locus in TH17 cells. To verify our observations in vivo, we induced experimental autoimmune encephalitis (EAE) in AV mice and wild type controls with the immunodominant myelin antigen MOG33-55 emulsified in complete Freund‘s adjuvant. While wild type animals showed a normal course of disease with development of tail and hind limb paralysis after approximately 10 days, AV mice showed a markedly weaker disease phenotype with less severe degrees of paralysis and accelerated kinetics of remission. Moreover at the peak of the response, there were fewer CD4+CD25- but more CD4+CD25+ T cells in the CNS of AV animals compared to wild type controls. Surprisingly, these cells produced significantly more IL-2, IL-17 and IFN-γ upon restimulation, even though they displayed decreased disease. In summary, our data provide strong evidence that NFAT1 contributes to the regulation of IL-10 and IL-17 expression in TH17 cells and show that increasing NFAT1 activity can ameliorate autoimmune encephalitis. This could occur in part through upregulation of IL-10 expression as observed in vitro, but is also likely to reflect increased infiltration of regulatory T cells into the CNS as well as increased conversion of conventional T cells into Foxp3+ regulatory T cells within the CNS. Disclosures: No relevant conflicts of interest to declare.

Knockout of the PKC Substrate Pleckstrin Causes Pleomorphic Defects in Platelets, Lymphocytes and Granulocytes.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 394-394
Author(s):  
Lurong Lian ◽  
Yanfeng Wang ◽  
Xinsheng Chen ◽  
Tami Bach ◽  
Laurie Lenox ◽  
...  
Keyword(s):  
T Cells ◽  
Platelet Aggregation ◽  
Alternative Pathway ◽  
Second Messengers ◽  
Pi3k Inhibitor ◽  
Loss Of Function ◽  
Wild Type

Abstract Pleckstrin is a 40 kDa phosphoprotein containing amino- and carboxyl-terminal Pleckstrin Homology (PH) domains separated by a DEP domain. Pleckstrin’s expression is restricted to platelets and leukocytes, and represents approximately 1% of total cellular protein within these cells. Following platelet and leukocyte activation, PKC rapidly phosphorylates pleckstrin inducing it to bind membrane bound phospholipids such as phosphatidylinositol 4,5 bisphosphate (PIP2). Heterologously expressed phosphorylated pleckstrin colocalized with integrins and induces cytoskeletal reorganization. To better define the role of pleckstrin in vivo, we introduced a loss-of-function mutation into the murine pleckstrin gene. Pleckstrin-null mice were present in offspring at a frequency consistent with a Mendelian inheritance pattern. Adult pleckstrin −/− mice had 32% lower platelet counts than their littermates, but exhibited no spontaneous hemorrhage. Given the role of PKC and phospholipid second messengers on cytoskeletal dynamics, and our observations of pleckstrin overexpression in cell lines, we analyzed whether loss of pleckstrin affected cell spreading. Pleckstrin −/− platelets spread extremely poorly upon immobilized fibrinogen, and rarely exhibited broad membrane extensions. Granulocytes from pleckstrin −/− mice also have a spreading defect, as well as impaired ability to generate reactive oxygen species in the response to TNFα. Knockout B-cells, CD4-T-cells, and CD8-T-cells all migrated approximately 30% as efficiently as wild type cells in response to a gradient of SDF-1α in a transwell assay. These data suggest that loss of pleckstrin causes cytoskeletal defects in cells of multiple hematopoietic lineages. Analyzing whether this caused a functional defect, we found that pleckstrin −/− platelets exhibited a 22% dense- and 24% alpha-granule exocytosis defect, and a 35% defect in thrombin-induced calcium entry. In spite of these abnormalities, platelets changed shape and aggregated normally after stimulation with thrombin, ADP, or collagen in vitro. Pleckstrin knockout platelets did have a markedly impaired aggregation response following exposure to the PKC stimulant, PMA. This suggested that pleckstrin is a critical effector for PKC-mediated aggregation, but another pathway is able to compensate for this loss of pleckstrin following agonist stimulation. We reasoned that the alternative pathway might also utilize PIP2-dependent second messengers. Since the phosphorylation of PIP2 by PI3K generates second messengers that also contribute to platelet aggregation, we tested whether PI3K compensated for the loss of pleckstrin. We found that the PI3K inhibitor, LY294002 profoundly impaired the aggregation of pleckstrin knockout platelets in response to stimulation of the thrombin receptor. In contrast, the PI3K inhibitor minimally affected wild type platelets. This demonstrates that second messengers generated by PI3K are able to compensate for loss of pleckstrin. This also demonstrates that thrombin-induced platelet aggregation can be mediated by one of two parallel pathways, one involving PKC and pleckstrin, and the other involving PI3K. Together, our results show that pleckstrin is an essential component of PKC-mediated platelet activation and signals directed to the cytoskeleton.

scholarly journals Failure to Suppress the Expansion of the Activated Cd4 T Cell Population in Interferon γ–Deficient Mice Leads to Exacerbation of Experimental Autoimmune Encephalomyelitis

2000 ◽  
Vol 192 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Cong-Qiu Chu ◽  
Susan Wittmer ◽  
Dyana K. Dalton
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
Cd4 T Cells ◽  
Wild Type ◽  
Autoimmune Encephalomyelitis ◽  
Ifn Γ ◽  
Experimental Autoimmune

Mice deficient in interferon (IFN)-γ or IFN-γ receptor develop progressive and fatal experimental autoimmune encephalomyelitis (EAE). We demonstrate that CD4 T cells lacking IFN-γ production were required to passively transfer EAE, indicating that they were disease-mediating cells in IFN-γ knockout (KO) mice. IFN-γ KO mice accumulated 10–16-fold more activated CD4 T cells (CD4+CD44hi) than wild-type mice in the central nervous system during EAE. CD4+CD44hi T cells in the spleen and central nervous system of IFN-γ KO mice during EAE showed markedly increased in vivo proliferation and significantly decreased ex vivo apoptosis compared with those of wild-type mice. IFN-γ KO CD4+CD44hi T cells proliferated extensively to antigen restimulation in vitro and accumulated larger numbers of live CD4+ CD44hi T cells. IFN-γ completely suppressed proliferation and significantly induced apoptosis of CD4+CD44hi T cells responding to antigen and hence inhibited accumulation of live, activated CD4 T cells. We thus present novel in vivo and in vitro evidence that IFN-γ may limit the extent of EAE by suppressing expansion of activated CD4 T cells.

scholarly journals Multiple T Cell Subsets Control Francisella tularensis LVS Intracellular Growth Without Stimulation Through Macrophage Interferon γ Receptors

2003 ◽  
Vol 198 (3) ◽  
pp. 379-389 ◽  
Author(s):  
Siobhán C. Cowley ◽  
Karen L. Elkins
Keyword(s):  
T Cells ◽  
T Cell ◽  
Francisella Tularensis ◽  
T Cell Subsets ◽  
Wild Type ◽  
Intracellular Growth ◽  
Tnf Α ◽  
Ifn Γ

A variety of data suggest that in vivo production of interferon (IFN)-γ is necessary, but not sufficient, for expression of secondary protective immunity against intracellular pathogens. To discover specific IFN-γ–independent T cell mediated mechanisms, we took advantage of an in vitro culture system that models in vivo immune responses to the intracellular bacterium Francisella tularensis live vaccine strain (LVS). LVS-immune lymphocytes specifically controlled 99% of the growth of LVS in wild-type murine bone marrow–derived macrophages. Surprisingly, LVS-immune lymphocytes also inhibited LVS intracellular growth by as much as 95% in macrophages derived from IFN-γ receptor knockout (IFNγR KO) mice. CD8+ T cells, and to a lesser degree CD4+ T cells, controlled LVS intracellular growth in both wild-type and IFNγR KO macrophages. Further, a unique population of Thy1+αβ+CD4−CD8− cells that was previously suggested to operate during secondary immunity to LVS in vivo strongly controlled LVS intracellular growth in vitro. A large proportion of the inhibition of LVS intracellular growth in IFNγR KO macrophages by all three T cell subsets could be attributed to tumor necrosis factor (TNF) α. Thus, T cell mechanisms exist that control LVS intracellular growth without acting through the IFN-γ receptor; such control is due in large part to TNF-α, and is partially mediated by a unique double negative T cell subpopulation.

696 Brentuximab vedotin, a CD30-directed antibody-drug conjugate, selectively depletes activated Tregs in vitro and in vivo

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A738-A738
Author(s):  
Bryan Grogan ◽  
Reice James ◽  
Michelle Ulrich ◽  
Shyra Gardai ◽  
Ryan Heiser ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Efflux Pump ◽  
Apoptotic Cell ◽  
T Cell Subsets ◽  
Memory Cells ◽  
Antibody Drug Conjugate ◽  
Selective Depletion

BackgroundRegulatory T cells (Tregs) play an important role in maintaining immune homeostasis, preventing excessive inflammation in normal tissues. In cancer, Tregs hamper anti-tumor immunosurveillance and facilitate immune evasion. Selective targeting of intratumoral Tregs is a potentially promising treatment approach. Orthogonal evaluation of tumor-infiltrating lymphocytes (TILs) in solid tumors in mice and humans have identified CCR8, and several tumor necrosis family receptors (TNFRs), including TNFSFR8 (CD30), as receptors differentially upregulated on intratumoral Tregs compared to normal tissue Tregs and other intratumoral T cells, making these intriguing therapeutic targets.Brentuximab vedotin (BV) is approved for classical Hodgkin lymphoma (cHL) across multiple lines of therapy including frontline use in stage III/IV cHL in combination with doxorubicin, vinblastine, and dacarbazine. BV is also approved for certain CD30-expressing T-cell lymphomas. BV is comprised of a CD30-directed monoclonal antibody conjugated to the highly potent microtubule-disrupting agent monomethyl auristatin E (MMAE).The activity of BV in lymphomas is thought to primarily result from tumor directed intracellular MMAE release, leading to mitotic arrest and apoptotic cell death.The role CD30 plays in normal immune function is unclear, with both costimulatory and proapoptotic roles described. CD30 is transiently upregulated following activation of memory T cells and expression has been linked to highly activated/suppressive IRF4+ effector Tregs.MethodsHere we evaluated the activity of BV on CD30-expressing T cell subsets in vitro and in vivo.ResultsTreatment of enriched T cell subsets with clinically relevant concentrations of BV drove selective depletion of CD30-expressing Tregs > CD30-expressingCD4+ T memory cells, with minimal effects on CD30-expressing CD8+ T memory cells. In a humanized xeno-GVHD model, treatment with BV selectively depleted Tregs resulting in accelerated wasting and robust T cell expansion. The observed differential activity on Tregs is likely attributable to significant increases in CD30 expression and reduced efflux pump activity relative to other T cell subsets. Interestingly, blockade of CD25 signaling prevents CD30 expression on T cell subsets without impacting proliferation, suggesting a link between CD25, the high affinity IL-2 receptor, and CD30 expression.ConclusionsTogether, these data suggest that BV may have an immunomodulatory effect through selective depletion of highly suppressive CD30-expressing Tregs.AcknowledgementsThe authors would like to thank Michael Harrison, PharmD for their assistance in abstract preparation.Ethics ApprovalAnimals studies were approved by and conducted in accordance with Seattle Genetics Institutional Care and Use Committee protocol #SGE-024.

scholarly journals Differential Activation of CD8+Tumor-Specific Tc1 and Tc2 Cells by an IL-10-Producing Murine Plasmacytoma

1998 ◽  
Vol 6 (3-4) ◽  
pp. 331-342 ◽  
Author(s):  
Christoph Specht ◽  
Hans-Gerd Pauels ◽  
Christian Becker ◽  
Eckehart Kölsch
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Tumor Cells ◽  
T Cell Subsets ◽  
Early Stages ◽  
Specific Tolerance

The involvement of counteractiveCD8+T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model.CD8+Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cellsin vivoandin vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinducedCD8+T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γas a suppressive factor. Whereas most longterm cultivated CD8+ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primaryin vitroTc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10.CD8+Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γor IL-12. In contrast, ADJ-PC- 5-specificCD8+Tc cells from immunized mice are IFN-γproducing Tc1 cells. Since the primaryin vitroTc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γthese Tc1 cells behave similar to the suppressiveCD8+T cells that are induced during early stages of ADJ-PC-5 tumorigenesis.

scholarly journals The Decreased Replicative Capacity of Simian Immunodeficiency Virus SIVmac239Δnef Is Manifest in Cultures of Immature Dendritic Cells and T Cells

2000 ◽  
Vol 74 (5) ◽  
pp. 2406-2413 ◽  
Author(s):  
Davorka Messmer ◽  
Ralf Ignatius ◽  
Christine Santisteban ◽  
Ralph M. Steinman ◽  
Melissa Pope
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Culture System ◽  
Wild Type ◽  
Virus Dose ◽  
Immunodeficiency Virus

ABSTRACT Transmission of simian immunodeficiency virus SIVmac239Δnef (Δnef) to macaques results in attenuated replication of the virus in most animals and ultimately induces protection against challenge with some pathogenic, wild-type SIV strains. It has been difficult, however, to identify a culture system in which the replication of Δnef is severely reduced relative to that of the wild type. We have utilized a primary culture system consisting of blood-derived dendritic cells (DCs) and autologous T cells. When the DCs were fully differentiated or mature, the DC–CD4+ T-cell mixtures supported replication of both the parental SIV strain, 239 (the wild type), and its mutant withnef deleted (Δnef), irrespective of virus dose and the cell type introducing the virus to the coculture. In contrast, when immature DCs were exposed to Δnef and cocultured with T cells, virus replication was significantly lower than that of the wild type. Activation of the cultures with a superantigen allowed both Δnef and the wild type to replicate comparably in immature DC–T-cell cultures. Immature DCs, which, it has been hypothesized, capture and transmit SIV in vivo, are deficient in supporting replication of Δnef in vitro and may contribute to the reduced pathogenicity of Δnef in vivo.

scholarly journals Leptin: A Critical Regulator of CD4+ T-cell Polarization in Vitro and in Vivo

Endocrinology ◽  
2010 ◽  
Vol 151 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Arvind Batra ◽  
Besir Okur ◽  
Rainer Glauben ◽  
Ulrike Erben ◽  
Jakob Ihbe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Polarization ◽  
Th2 Cells ◽  
Regulatory Function ◽  
Wild Type ◽  
T Helper ◽  
T Cell Polarization

Abstract Besides being mandatory in the metabolic system, adipokines like leptin directly affect immunity. Leptin was found to be necessary in T helper 1 (Th1)-dependent inflammatory processes, whereas effects on Th2 cells are rarely understood. Here, we focused on leptin in T-helper cell polarization and in Th2-mediated intestinal inflammation in vivo. The induction of cytokine-producing Th1 or Th2 cells from naive CD4+ T cells under polarizing conditions in vitro was generally decreased in cells from leptin-deficient ob/ob mice compared with wild-type mice. To explore the in vivo relevance of leptin in Th2-mediated inflammation, the model of oxazolone-induced colitis was employed in wild-type, ob/ob, and leptin-reconstituted ob/ob mice. Ob/ob mice were protected, whereas wild-type and leptin-reconstituted ob/ob mice developed colitis. The disease severity went in parallel with local production of the Th2 cytokine IL-13. A possible explanation for the protection of ob/ob mice in Th1- as well as in Th2-dependent inflammation is provided by a decreased expression of the key transcription factors for Th1 and Th2 polarization, T-bet and GATA-3, in naive ob/ob T cells. In conclusion, these results support the regulatory function of the adipokine leptin within T-cell polarization and thus in the acquired immune system and support the concept that there is a close interaction with the endocrine system.

A shift in encephalitogenic T cell cytokine pattern is associated with suppression of EAE by intravenous immunoglobulins (IVIg)

1997 ◽  
Vol 3 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Anastas Pashov ◽  
Blanche Bellon ◽  
Srini V Kaveri ◽  
Michel D Kazatchkine
Keyword(s):  
T Cells ◽  
T Cell ◽  
Intravenous Immunoglobulins ◽  
Ivig Treatment ◽  
Autoimmune Encephalomyelitis ◽  
Proliferative Effect ◽  
Kinetics Of ◽  
Experimental Autoimmune

Pooled human polyspecific IgG preparations for intravenous use (IVIg) have been used in a number of antibody mediated autoimmune diseases and recently in some T cell mediated disorders including multiple sclerosis, birdshot retinopathy and rheumatoid arthritis. Furthermore, IVIg has been proven beneficial in the corresponding animal models, i.e. experimental autoimmune encephalomyelitis (EAE), experimental autoimmune uveoretinitis and adjuvant arthritis respectively. The exact mechanisms for IVIg adion in T cell mediated disorders are still poorly understood. There is evidence that IVIg treatment in vitro and in vivo decreases or changes the kinetics of the secretion by normal PBMC of a number of cytokines and anti-proliferative effect of IVIg on T cells in vitro and in vivo has also been reported. It remains unclear though to what extent the IVIg effects in T cell mediated autoimmunity are related only to non-specifc T cell suppression and whether it also reshapes the autoimmune T cell cytokine profile. In this study we demonstrate that IVIg protects against EAE and that this beneficial effed is associated with a decreased proli feration of T cells specific for the immunizing antigen. Moreover, we show that these antigen-specific cells produce low amount of Th /-type cytokines and transfer an attenuated EAE

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