scholarly journals Increased state of activation of CD4 positive T cells and elevated interferon γ production in pouchitis

Gut ◽  
1998 ◽  
Vol 43 (4) ◽  
pp. 499-505 ◽  
Author(s):  
A Stallmach ◽  
F Schäfer ◽  
S Hoffmann ◽  
S Weber ◽  
I Müller-Molaian ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Interferon Γ ◽  
Ileoanal Pouch ◽  
T Cell Subsets ◽  
Activation Markers ◽  
Ifn Γ

Background—Immunoregulatory abnormalities of T cells might be of importance in the pathogenesis of pouchitis after ileoanal pouch anastomosis (IAP).Aims—To characterise T cell subsets, their state of activation, and production of cytokines in inflamed and non-inflamed pouches in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). The influence of T cell activation on mucosal transformation was also studied.Patients—Mucosal biopsy specimens were taken from 42 patients with IAP (33 with UC and nine with FAP).Methods—Mononuclear cells were isolated by standard techniques and characterised by three colour flow cytometry. Interferon γ (IFN-γ) production was studied using the ELISPOT technique.Results—In patients with UC with pouchitis there was a significant increase in the CD4:CD8 ratio, expression of activation markers on CD3+ cells, and number of IFNγ producing mononuclear cells compared with patients with UC without pouchitis (CD4:CD8 ratio 1.3 (range 0.7–2.7) versus 0.6 (0.1–1.0), p=0.012). In addition, a positive correlation between increased crypt depth and the number of CD4+ cells (r=0.57) was shown.Conclusion—The observed increase in activated mucosal CD4+ T cells and IFN-γ production might lead to mucosal destruction and crypt hyperplasia as seen in pouchitis.

scholarly journals Early Immune Markers Associated withMycobacterium aviumsubsp.paratuberculosisInfection in a Neonatal Calf Model

2011 ◽  
Vol 18 (3) ◽  
pp. 393-405 ◽  
Author(s):  
J. R. Stabel ◽  
S. Robbe-Austerman
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Lymphocyte Proliferation ◽  
Cell Activation ◽  
The Other ◽  
T Cell Subsets ◽  
Cell Mediated Immunity ◽  
Activation Markers ◽  
Oral Inoculation ◽  
Ifn Γ

ABSTRACTThe objective of this study was to observe early markers of cell-mediated immunity in naïve calves infected withMycobacterium aviumsubsp.paratuberculosisand how expression of these markers evolved over the 12-month period of infection. Groups for experimental infection included control (noninfected), oral (infected orally withM. aviumsubsp.paratuberculosisstrain K-10), oral/DXM (pretreatment with dexamethasone before oral inoculation), intraperitoneal (i.p.) inoculation, and oral/M (oral inoculation with mucosal scrapings from a cow with clinical disease) groups. One of the earliest markers to emerge was antigen-specific gamma interferon (IFN-γ). Only i.p. inoculated calves had detectable antigen-specific IFN-γ responses at 7 days, with responses of the other infection groups becoming detectable at 90 and 120 days. All infection groups maintained robust IFN-γ responses for the remainder of the study. At 1 month, calves in the oral and oral/M groups had higher antigen-stimulated interleukin-10 (IL-10) levels than calves in the other treatment groups, but IL-10 secretion declined by 12 months for all calves. T-cell activation markers such as CD25, CD26, CD45RO, and CD5 were significantly upregulated in infected calves compared to noninfected controls. Oral inoculation of calves resulted in significantly increased antigen-specific lymphocyte proliferation at 9 and 12 months, as well as inducible nitric oxide synthase (iNOS) secretion at 6 and 12 months. These results demonstrate that infection of naïve calves withM. aviumsubsp.paratuberculosisinvoked early immunologic responses characterized by robust antigen-specific IFN-γ responses and induction of CD25 and CD45RO expression on T-cell subsets. These were followed by antigen-specific lymphocyte proliferation, iNOS secretion, and expression of CD26 and CD5brightmarkers in the latter part of the 12-month study.

Humulus scandens Exhibits Immunosuppressive Effects in Vitro and in Vivo by Suppressing CD4+ T Cell Activation

2014 ◽  
Vol 42 (04) ◽  
pp. 921-934 ◽  
Author(s):  
Jinjin Feng ◽  
Yingchun Wu ◽  
Yang Yang ◽  
Weiqi Jiang ◽  
Shaoping Hu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interferon Γ ◽  
Delayed Type Hypersensitivity ◽  
Ifn Γ ◽  
Humulus Scandens

Humulus scandens, rich in flavonoids, is a traditional Chinese medicine. It is widely used in China to treat tuberculosis, dysentery and chronic colitis. In this study, the major active faction of Humulus scandens (H.S) was prepared. Then, its immunosuppressive effects and underlying mechanisms on T cell activation were investigated in vitro and in vivo. Results showed that H.S significantly inhibited the proliferation of splenocytes induced by concanavalin A, lipopolysaccharides, and mixed-lymphocyte reaction in vitro. Additionally, H.S could dramatically suppress the proliferation and interferon-γ (IFN-γ) production from T cells stimulated by anti-CD3 and anti-CD28. Flow cytometric results confirmed that H.S could suppress the differentiation of IFN-γ-producing type 1 helper T cells (Th1). Furthermore, using ovalbumin immunization-induced T cell reaction and CD4+ T-cell-mediated delayed type hypersensitivity reaction, H.S the immunosuppressive effects of H.S was also demonstrated in vivo. Western blot results showed that H.S could impede the activation of both Erk1/2 and P38 in primary T cells triggered by anti-CD3/28. Collectively, the active fraction of H.S showed promising immunosuppressive activities both in vitro and in vivo.

scholarly journals CD4+ T-Cell Subsets That Mediate Immunological Memory to Mycobacterium tuberculosis Infection in Mice

2000 ◽  
Vol 68 (2) ◽  
pp. 621-629 ◽  
Author(s):  
Peter Andersen ◽  
Birgitte Smedegaard
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immunological Memory ◽  
T Cell Subsets ◽  
Small Subset ◽  
Memory Cells ◽  
Activation Markers

ABSTRACT We have studied CD4+ T cells that mediate immunological memory to an intravenous infection with Mycobacterium tuberculosis. The studies were conducted with a mouse model of memory immunity in which mice are rendered immune by a primary infection followed by antibiotic treatment and rest. Shortly after reinfection, tuberculosis-specific memory cells were recruited from the recirculating pool, leading to rapidly increasing precursor frequencies in the liver and a simultaneous decrease in the blood. A small subset of the infiltrating T cells was rapidly activated (<20 h) and expressed high levels of intracellular gamma interferon and the T-cell activation markers CD69 and CD25. These memory effector T cells expressed intermediate levels of CD45RB and were heterogeneous with regard to the L-selectin and CD44 markers. By adoptive transfer into nude mice, the highest level of resistance to a challenge with M. tuberculosis was mediated by CD45RBhigh,l-selectinhigh, CD44low cells. Taken together, these two lines of evidence support an important role for memory cells which have reverted to a naive phenotype in the long-term protection against M. tuberculosis.

scholarly journals Upregulation of Phosphodiesterase 2A Augments T Cell Activation by Changing cGMP/cAMP Cross-Talk

2021 ◽  
Vol 12 ◽  
Author(s):  
Roberta Kurelic ◽  
Paula F. Krieg ◽  
Jana K. Sonner ◽  
Gloria Bhaiyan ◽  
Gustavo C. Ramos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cross Talk ◽  
Cell Activation ◽  
Inflammatory Responses ◽  
T Cell Subsets ◽  
Activation Markers ◽  
Tcr Activation ◽  
Camp Levels

3′,5′-cyclic adenosine monophosphate (cAMP) is well-known for its diverse immunomodulatory properties, primarily inhibitory effects during T cell activation, proliferation, and production of pro-inflammatory cytokines. A decrease in cAMP levels, due to the hydrolyzing activity of phosphodiesterases (PDE), is favoring inflammatory responses. This can be prevented by selective PDE inhibitors, which makes PDEs important therapeutic targets for autoimmune disorders. In this study, we investigated the specific roles of PDE2A and PDE3B in the regulation of intracellular cAMP levels in different mouse T cell subsets. Unexpectedly, T cell receptor (TCR) activation led to a selective upregulation of PDE2A at the protein level in conventional T cells (Tcon), whereas no changes were detected in regulatory T cells (Treg). In contrast, protein expression of PDE3B was significantly higher in both non-activated and activated Tcon subsets as compared to Treg, with no changes upon TCR engagement. Live-cell imaging of T cells expressing a highly sensitive Förster resonance energy transfer (FRET)-based biosensor, Epac1-camps, has enabled cAMP measurements in real time and revealed stronger responses to the PDE2A inhibitors in activated vs non-activated Tcon. Importantly, stimulation of intracellular cGMP levels with natriuretic peptides led to an increase of cAMP in non-activated and a decrease of cAMP in activated Tcon, suggesting that TCR activation changes the PDE3B-dependent positive to PDE2A-dependent negative cGMP/cAMP cross-talk. Functionally, this switch induced higher expression of early activation markers CD25 and CD69. This constitutes a potentially interesting feed-forward mechanism during autoimmune and inflammatory responses that may be exploited therapeutically.

Bone marrow mesenchymal stem cells induce division arrest anergy of activated T cells

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2821-2827 ◽  
Author(s):  
Sarah Glennie ◽  
Inês Soeiro ◽  
Peter J. Dyson ◽  
Eric W.-F. Lam ◽  
Francesco Dazzi
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Cell Subset ◽  
Activation Markers ◽  
Ifn Γ

AbstractIt has been shown that mesenchymal stem cells (MSCs) induce T cells to become unresponsive. We characterized the phenotype of these T cells by dissecting the effect of MSCs on T-cell activation, proliferation, and effector function. For this purpose, an in vitro murine model was used in which T-cell responses were generated against the male HY minor histocompatibility antigen. In the presence of MSCs, the expression of early activation markers CD25 and CD69 was unaffected but interferon-γ (IFN-γ) production was reduced. The inhibitory effect of MSCs was directed mainly at the level of cell proliferation. Analysis of the cell cycle showed that T cells, stimulated in the presence of MSCs, were arrested at the G1 phase. At the molecular level, cyclin D2 expression was profoundly inhibited, whereas p27kip1 was up-regulated. When MSCs were removed from the cultures and restimulated with the cognate peptide, T cells produced IFN-γ but failed to proliferate. The addition of exogenous interleukin-2 (IL-2) did not restore proliferation. MSCs did not preferentially target any T-cell subset, and the inhibition was also extended to B cells. MSC-mediated inhibition induces an unresponsive T-cell profile that is fully consistent with that observed in division arrest anergy.

scholarly journals Deoxynivalenol Affects Proliferation and Expression of Activation-Related Molecules in Major Porcine T-Cell Subsets

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 644 ◽  
Author(s):  
Vatzia ◽  
Pierron ◽  
Saalmüller ◽  
Mayer ◽  
Gerner
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Animal Feed ◽  
Γδ T Cells ◽  
T Cell Subsets ◽  
Peripheral Blood Mononuclear

The Fusarium mycotoxin deoxynivalenol (DON) contaminates animal feed worldwide. In vivo, DON modifies the cellular protein synthesis, thereby also affecting the immune system. However, the functional consequences of this are still ill-defined. In this study, peripheral blood mononuclear cells from healthy pigs were incubated with different DON concentrations in the presence of Concanavalin A (ConA), a plant-derived polyclonal T-cell stimulant. T-cell subsets were investigated for proliferation and expression of CD8α, CD27, and CD28, which are involved in activation and costimulation of porcine T cells. A clear decrease in proliferation of all ConA-stimulated major T-cell subsets (CD4+, CD8+, and γδ T cells) was observed in DON concentrations higher than 0.4 µM. This applied in particular to naïve CD4+ and CD8+ T cells. From 0.8 μM onwards, DON induced a reduction of CD8α (CD4+) and CD27 expression (CD4+ and CD8+ T cells). CD28 expression was diminished in CD4+ and CD8+ T cells at a concentration of 1.6 µM DON. None of these effects were observed with the DON-derivative deepoxy-deoxynivalenol (DOM-1) at 16 µM. These results indicate that DON reduces T-cell proliferation and the expression of molecules involved in T-cell activation, providing a molecular basis for some of the described immunosuppressive effects of DON.

CVID patients with autoimmunity have elevated T cell expression of granzyme B and HLA-DR and reduced levels of Treg cells

2012 ◽  
Vol 66 (2) ◽  
pp. 146-150 ◽  
Author(s):  
Clive R D Carter ◽  
Ganesha Aravind ◽  
Natuley L Smalle ◽  
June Y Cole ◽  
Sinisa Savic ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Granzyme B ◽  
Treg Cells ◽  
T Cell Subsets ◽  
Activated T Cells ◽  
Activation Markers ◽  
Hla Dr

AimsCommon variable immunodeficiency (CVID) is a primary antibody immunodeficiency with approximately 20% of patients reporting additional autoimmune symptoms. The primary aim of this study was to compare the levels of activated and regulatory T cells (Treg cells) in CVID patients in an attempt to clarify their possible interactions leading to the generation of autoimmunity.MethodsImmunophenotyping of T cells was performed by flow cytometry using a whole blood approach. Surface expression of human leukocyte antigen HLA class II DR and intracellular levels of granzyme B in T cell subsets were assessed; Treg levels were measured using CD4 CD25, FOXp3 and CTLA-4.ResultsCVID patients had higher levels of granzyme B and HLA-DR on CD8+ T cells compared with control values (mean of 59% vs 30% and 45% vs 21%, respectively). Patients also had reduced levels of Treg cells compared with control values (con mean=3.24% vs pat=2.54%). Patients with autoimmunity (5/23) had a similar level of T cell activation markers to the rest of the patients but with lower Treg cells (mean of 1.1%) and reduced CD25 and CTLA-4 expression. Patients with autoimmunity had a higher ratio of activated to Treg cells compared with patients with no autoimmune symptoms.ConclusionsThese results highlight that reduced levels of Treg cells were associated with elevated levels of activated T cells, suggesting that reduced Treg cells in these patients may have functional consequences in allowing exaggerated T cell responses.

scholarly journals Gamma Interferon Responses of CD4 and CD8 T-Cell Subsets Are Quantitatively Different and Independent of Each Other during Pulmonary Mycobacterium bovis BCG Infection

2007 ◽  
Vol 75 (5) ◽  
pp. 2244-2252 ◽  
Author(s):  
Patricia Ngai ◽  
Sarah McCormick ◽  
Cherrie Small ◽  
Xizhong Zhang ◽  
Anna Zganiacz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Mycobacterial Infection ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Ifn Γ

ABSTRACT Gamma interferon (IFN-γ) is a key cytokine in host defense against intracellular mycobacterial infection. It has been believed that both CD4 and CD8 T cells are the primary sources of IFN-γ. However, the relative contributions of CD4 and CD8 T-cell subsets to IFN-γ production and the relationship between CD4 and CD8 T-cell activation have not been examined. By using a model of pulmonary mycobacterial infection and various immunodetection assays, we found that CD4 T cells mounted a much stronger IFN-γ response than CD8 T cells at various times after mycobacterial infection, and this pronounced IFN-γ production by CD4 T cells was attributed to both greater numbers of antigen-specific CD4 T cells and a greater IFN-γ secretion capacity of these cells. By using major histocompatibility complex class II-deficient or CD4-deficient mice, we found that the lack of CD4 T cells did not negatively affect primary or secondary CD8 T-cell IFN-γ responses. The CD8 T cells activated in the absence of CD4 T cells were capable of immune protection against secondary mycobacterial challenge. Our results suggest that, whereas both CD4 and CD8 T cells are capable of IFN-γ production, the former represent a much greater cellular source of IFN-γ. Moreover, during mycobacterial infection, CD8 T-cell IFN-γ responses and activation are independent of CD4 T-cell activation.

Paradoxical Effects of Interferon-γ in Allogeneic Bone Marrow Transplant: Donor Dendritic Cells Regulate Graft-Versus-Leukemia and Graft- Versus-Host Disease Activities.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2343-2343
Author(s):  
Ying Lu ◽  
Jian-Ming Li ◽  
Wayne Harris ◽  
Edmund Waller
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interferon Γ ◽  
Wild Type ◽  
Graft Versus Host ◽  
Donor T Cells ◽  
Ifn Γ

Abstract Both host and donor dendritic cells (DCs) have been shown to play a critical role in regulating graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after MHC-mismatched bone marrow transplantation (BMT) (Shlomchik et al. Science 1999, Reddy et al. Nat Med 2005). In contrast to host DCs, much less is known about the precise mechanisms donor DCs may use to modulate donor T-cell activation and GVL activity. A clinical report has suggested an association between the number of donor plasmacytoid DC in the graft and leukemia relapses after allogeneic BMT (Waller et al. Blood 2001). Using allogeneic MHC-mismatched hematopoietic stem cell transplant (HSCT) (C57BL/6→B10.BR) in mice bearing the T lymphoblastic leukemia LBRM, we have previously reported that recipients transplanted with purified CD11b− DC in combination with purified HSC and T-cells had 45% increased long-term leukemia-free-survival, higher numbers of interferon-γ (IFN-γ) producing donor T-cells as well as higher levels of serum IFN-γ (Li et al. Blood 2007). The aim of the present work is to further define whether production of IFN-γ by donor T-cells is necessary for the augmentation of GVL effect seen with CD11b− donor DC and define the mechanism that donor CD11b− DC can augment GVL of donor T-cells without causing fatal GVHD. To evaluate the role for IFN-γ produced by donor T-cells, we used IFN-γ knockout (KO) mice as donors in the C57BL/6→B10.BR transplant model. Recipients of IFN-γ KO donor T-cells in combination with wild-type FACS-purified HSC and CD11b− DC died rapidly with 0% survival at day 80 compared with 65% survival among tumor-bearing recipients of donor CD11b− with wild-type HSC and T-cells and 75% survival in mice transplanted with wild-type cells in the absence of LBRM. Moreover, the addition of donor CD11b− DC to IFN-γ KO donor T-cells did not lead to further augmentation of GVHD. These data supported a role for donor T-cell-derived IFN-γ in the enhanced GVL activity seen among recipients of donor CD11b− DC,but did not explain the lack of increased GVHD. As a potent pro-inflammatory cytokine initiating immune response in GVHD, IFN-γ has also been demonstrated to show a suppressive effect during GVHD as a result of IFN-γ-inducible indoleamine-2,3-dioxygenase(IDO) gene expression. CD11b− DCs were freshly isolated from bone marrow of donor C57BL/6 mice, exposed to 100ng/ml IFN-γ for 18 hours, and the IDO expression was measured by intracellular staining. The results showed that following IFN-γ treatment, IDO levels of CD11b− DCs were up-regulated. Furthermore, in vitro co-culture of FACS-purified CD11b− DC with syngeneic T-cells in the presence of allogeneic antigen also demonstrated increased IDO levels on the co-cultured DCs. Taken together, our data support a model in which donor CD11b− DCs initially induce Th1 polarization of activated donor T-cells that secret high levels of IFN-γ in the lymph node microenvironment. High local levels of IFN-γ subsequently induce IDO expression in DC, resulting in down-modulation of T-cell allo-reactivity and GVHD. Thus, IFN-γ-induced IDO expression on CD11b− donor DCs appears to be a critical downstream event that inhibits continued T-cell activation and leads to less severe GVHD.

scholarly journals Correlates of tuberculosis risk: predictive biomarkers for progression to active tuberculosis

2016 ◽  
Vol 48 (6) ◽  
pp. 1751-1763 ◽  
Author(s):  
Elisa Petruccioli ◽  
Thomas J. Scriba ◽  
Linda Petrone ◽  
Mark Hatherill ◽  
Daniela M. Cirillo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
High Throughput Screening ◽  
Cell Activation ◽  
Predictive Biomarkers ◽  
Heparin Binding ◽  
Activation Markers ◽  
Ifn Γ ◽  
Latent Tb Infection

New approaches to control the spread of tuberculosis (TB) are needed, including tools to predict development of active TB from latent TB infection (LTBI). Recent studies have described potential correlates of risk, in order to inform the development of prognostic tests for TB disease progression. These efforts have included unbiased approaches employing “omics” technologies, as well as more directed, hypothesis-driven approaches assessing a small set or even individual selected markers as candidate correlates of TB risk. Unbiased high-throughput screening of blood RNAseq profiles identified signatures of active TB risk in individuals with LTBI, ≥1 year before diagnosis. A recent infant vaccination study identified enhanced expression of T-cell activation markers as a correlate of risk prior to developing TB; conversely, high levels of Ag85A antibodies and high frequencies of interferon (IFN)-γ specific T-cells were associated with reduced risk of disease. Others have described CD27−IFN-γ+CD4+ T-cells as possibly predictive markers of TB disease. T-cell responses to TB latency antigens, including heparin-binding haemagglutinin and DosR-regulon-encoded antigens have also been correlated with protection.Further studies are needed to determine whether correlates of risk can be used to prevent active TB through targeted prophylactic treatment, or to allow targeted enrolment into efficacy trials of new TB vaccines and therapeutic drugs.

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