scholarly journals Epigenetic mechanisms, T-cell activation, andCCR5genetics interact to regulate T-cell expression of CCR5, the major HIV-1 coreceptor

2015 ◽  
Vol 112 (34) ◽  
pp. E4762-E4771 ◽  
Author(s):  
German G. Gornalusse ◽  
Srinivas Mummidi ◽  
Alvaro A. Gaitan ◽  
Fabio Jimenez ◽  
Veron Ramsuran ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Methylation Status ◽  
T Cell Subsets ◽  
Critical Determinant ◽  
Expression Levels ◽  
Cell Expression ◽  
Hiv Aids

T-cell expression levels of CC chemokine receptor 5 (CCR5) are a critical determinant of HIV/AIDS susceptibility, and manifest wide variations (i) between T-cell subsets and among individuals and (ii) in T-cell activation-induced increases in expression levels. We demonstrate that a unifying mechanism for this variation is differences in constitutive and T-cell activation-induced DNA methylation status ofCCR5 cis-regulatory regions (cis-regions). Commencing at an evolutionarily conserved CpG (CpG −41),CCR5 cis-regions manifest lower vs. higher methylation in T cells with higher vs. lower CCR5 levels (memory vs. naïve T cells) and in memory T cells with higher vs. lower CCR5 levels. HIV-related and in vitro induced T-cell activation is associated with demethylation of thesecis-regions.CCR5haplotypes associated with increased vs. decreased gene/surface expression levels and HIV/AIDS susceptibility magnify vs. dampen T-cell activation-associated demethylation. Methylation status ofCCR5intron 2 explains a larger proportion of the variation in CCR5 levels than genotype or T-cell activation. The ancestral, protectiveCCR5-HHA haplotype bears a polymorphism at CpG −41 that is (i) specific to southern Africa, (ii) abrogates binding of the transcription factor CREB1 to thiscis-region, and (iii) exhibits a trend for overrepresentation in persons with reduced susceptibility to HIV and disease progression. Genotypes lacking theCCR5-Δ32 mutation but with hypermethylatedcis-regions have CCR5 levels similar to genotypes heterozygous forCCR5-Δ32. In HIV-infected individuals,CCR5 cis-regions remain demethylated, despite restoration of CD4+ counts (≥800 cells per mm3) with antiretroviral therapy. Thus, methylation content ofCCR5 cis-regions is a central epigenetic determinant of T-cell CCR5 levels, and possibly HIV-related outcomes.

EP.WE.805From bench to bedside; A rationale for Immunotherapy in the adjuvant setting for Oesophageal cancer

2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Noel Donlon ◽  
Maria Davern ◽  
Andrew Sheppard ◽  
John Reynolds ◽  
Joanne Lysaght
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Immune Checkpoint ◽  
Cell Activation ◽  
Single Agent ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Post Surgery ◽  
Post Operative Period

Abstract Background Immunotherapy is being intensively investigated for its utilisation in the curative setting as a single agent and in the multimodal setting, however, the most appropriate time to incorporate ICIs remains unknown. Our study profiles systemic anti-tumour immunity perioperatively to provide a rationale for adjuvant immunotherapy. Methods Systemic immunity was immunophenotyped pre and post-oesophagectomy on days 0, 1, 3, 7 and week 6 by flow cytometry (n = 14). The frequency of circulating lymphocytes, T cells, cytotoxic and helper T lymphocytes was profiled longitudinally including the proportion of T cell subsets in circulation. This study also profiled immune checkpoint expression on circulating T cells including: PD-1, CTLA-4, TIGIT, TIM-3, LAG-3, PD-L1 and PD-L2. Markers of immunogenicity (calreticulin, HMGB1 and MIC-A/B) were also assessed. Results The frequency of circulating CD27 + T cells increases sequentially in the immediate post-operative period peaking on day 7 in OAC patients. (p < 0.01) There is a sequential decrease in the percentage of effector memory and central memory T cells in circulation and an increase in the percentage of naïve T cells in peripheral circulation of OAC patients in the immediate post-operative period. The expression of CTLA-4 on the surface of circulating CD4 + T cells decreases 6 weeks post-operatively in OAC patients. Conclusions We observed increased T cell activation and immune checkpoints immediately post-surgery with returns to baseline by week 6. These results suggest that immune checkpoint inhibitors such as anti-PD-1 may be beneficial immediately post-surgery to maintain T cell activation and prevent exhaustion of this increased population of activated T cells observed immediately post-surgery.

scholarly journals Rapid Flow Cytometry Method for Quantitation of LFA-1-Adhesive T Cells

2006 ◽  
Vol 13 (3) ◽  
pp. 403-408 ◽  
Author(s):  
Brian Crucian ◽  
Mayra Nelman-Gonzalez ◽  
Clarence Sams
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Subsets ◽  
Activated T Cells ◽  
Peripheral Blood Mononuclear ◽  
Simple Method ◽  
Rapid Flow

ABSTRACT Adhesion molecules are important for leukocyte endothelial attachment and migration to sites of inflammation. The LFA-1 (CD11a and CD18) integrin molecule is constitutively expressed on the T-cell surface. Following T-cell activation, a rapid conformational change of LFA-1 to an “adhesive” state occurs, allowing LFA-1 binding to intracellular cell adhesion molecule type 1 (ICAM-1)-expressing targets, such as antigen-presenting cells. For this study, a rapid flow cytometry method for the quantitation of LFA-1-adhesive T cells following activation was developed. Purified ICAM-1 was bound to 4.5-μm-diameter beads. Following peripheral blood mononuclear cell activation culture (phorbol myristate acetate and ionomycin), the cells were incubated with the ICAM-1 beads, which allowed attachment to occur. The T cell-bead complexes were then resolved from unbound T cells by flow cytometry. Multicolor analysis allowed a complete phenotypic analysis of the adhesive T-cell subsets. Experimental controls indicated that the T cell-bead attachment was LFA-1 and ICAM-1 specific. Very little binding between unactivated T cells and ICAM beads or between activated T cells and plain beads was observed. The kinetics of the response was extremely rapid, with nearly maximal numbers of adhesive T cells observed following 5 min of activation. Scanning electron microscopy analysis was used to characterize legitimate bead-cell binding. By using multicolor cytometry, the responding adhesive T-cell population was usually identified as a distinct subset of T cells with the following phenotype: CD3+ CD4+ or CD8+ CD19− CD16− CD45RO+ CD62L+ CD27+ CD57−. A rapid and simple method for the scoring of LFA-1-adhesive T cells was developed and may have significant utility for immune function studies.

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 Time-Dependent Serial Changes of Antigen-Presenting Cell Subsets in the Ocular Surface Are Distinct between Corneal Sterile Inflammation and Allosensitization in a Murine Model

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2210
Author(s):  
Kyoung-Woo Kim ◽  
Hyun-Ju Lee ◽  
Hyeon-Ji Kim ◽  
Mee-Kum Kim
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Ocular Surface ◽  
Cell Activation ◽  
Corneal Transplantation ◽  
Cell Subset ◽  
Sterile Inflammation ◽  
T Cell Subsets ◽  
Antigen Presenting

The kinetics of antigen-presenting cells (APCs) vary depending on their resident tissues and the manner of immunization. We investigated the long-term changes in mature APC and T-cell subsets over 4 weeks in the ocular surface in murine models of corneal quiescent or potent sterile inflammation, and allosensitization using partial (PT), syngeneic (Syn), and allogeneic (Allo) corneal transplantation. In PT, CD11bintCD11chiMHCIIhiCD86hi cells increased until 4 weeks with an increase in IFNγhi T cells. In Syn, both CD11bintCD11chiMHCIIhiCD86hi and CD11bhiCD11chiMHCIIhiCD86hi APC subsets increased until 4 weeks with a brief increase in CD69hi T cells at 2 weeks. In Allo, CD11bintCD11chiMHCIIhiCD86hi and CD11bhiCD11chiMHCIIhiCD86hi APC subsets increased until 4 weeks, and an early increase in CD69hi T cells was observed at 2 weeks followed by a late increase in IFNγhi T cells at 4 weeks. The frequency of the IFNγhi T cell subset was positively correlated with the frequency of the CD11bintCD11chiMHCIIhiCD86hi subset, indicating the existence of APC–T cell interaction in the ocular surface. Together, the results indicate that allosensitization in mature APCs leads to T-cell activation in the ocular surface, whereas sterile inflammation merely induces a brief and non-specific T-cell activation in the ocular surface.

scholarly journals Acute infectious mononucleosis stimulates the selective expression/expansion of V beta 6.1-3 and V beta 7 T cells

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1521-1526 ◽  
Author(s):  
TJ Smith ◽  
N Terada ◽  
CC Robinson ◽  
EW Gelfand
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Infectious Mononucleosis ◽  
Gel Electrophoresis ◽  
Cell Activation ◽  
T Cell Subsets ◽  
Pcr Analysis ◽  
Selective Expression ◽  
Acute Infectious Mononucleosis

Acute infectious mononucleosis (AIM) is caused by the Epstein-Barr virus (EBV) and is characterized by a proliferation of atypical lymphocytes, predominantly CD8+ T cells. Various diseases associated with T-cell activation have been shown to stimulate the selective expansion of certain V beta (variable region of the T-cell receptor beta chain) expressing T-cell populations. The purpose of this investigation was to determine if the proliferation of T cells accompanying AIM is associated with selective expression/expansion of distinct populations of V beta T cells. We determined V beta expression in eight patients with clinical and laboratory evidence of AIM, including an atypical lymphocytosis. Gel electrophoresis and quantitative analysis were performed on cDNA amplified by the polymerase chain reaction (PCR) using different V beta region primers. Gel electrophoresis analysis showed prominent V beta 6.1–3 and V beta 7 bands in all eight patients with AIM but not in the controls. Quantitative PCR analysis showed that the V beta 6.1–3 and V beta 7 mean PCR ratios increased, respectively, from 163.0 +/- 22.5 and 142.3 +/- 5.5 in controls to 339.9 +/- 38.8 (P < .03) and 396.1 +/- 45.6 (P < .01) in the eight patients with AIM. Two of the eight patients who had increased V beta 6.1–3 and V beta 7 expression were retested after clinical resolution of AIM and no longer had evidence of increased V beta 6.1–3 and V beta 7 T-cell expression. AIM is associated with a selective increased expression of V beta 6.1–3 and V beta 7 T cells present at the time of initial clinical symptoms and atypical lymphocytosis. This increased expression resolves following recovery from AIM. This V beta-specific selective expression resembles the super- antigen response seen after staphylococcal toxin stimulation and may be caused by EBV triggering of selective expansion of V beta 6.1–3 and V beta 7 T-cell subsets.

scholarly journals Tuberculosis Antigen-Specific T-Cell Responses During the First 6 Months of Antiretroviral Treatment

2019 ◽  
Vol 221 (1) ◽  
pp. 162-167 ◽  
Author(s):  
Catherine Riou ◽  
Nishtha Jhilmeet ◽  
Molebogeng X Rangaka ◽  
Robert J Wilkinson ◽  
Katalin A Wilkinson
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Antiretroviral Treatment ◽  
Cell Activation ◽  
T Cell Subsets ◽  
Cd4 T Cell ◽  
Immune Memory ◽  
Tuberculosis Antigen

Abstract The reconstitution of Mycobacterium tuberculosis antigen-specific CD4 T cells in a cohort of HIV-infected persons starting antiretroviral treatment (ART) in a high tuberculosis endemic area is described. Restoration of the antigen-specific CD4 T-cell subsets mirrored the overall CD4 T-cell compartment. Activation (assessed by HLA-DR expression) decreased during ART but remained elevated compared to HIV-uninfected persons. Despite known M. tuberculosis sensitization determined by interferon-γ release assay, 12/23 participants had no M. tuberculosis-specific CD4 T cells detectable by flow cytometry, combined with overall elevated T-cell activation and memory differentiation, suggesting heightened turnover. Our data suggest early ART initiation to maintain polyfunctional immune memory responses.

scholarly journals Limited Model Antigen Expression by Transgenic Fungi Induces Disparate Fates during Differentiation of Adoptively Transferred T Cell Receptor Transgenic CD4+T Cells: Robust Activation and Proliferation with Weak Effector Function during Recall

2011 ◽  
Vol 80 (2) ◽  
pp. 787-797 ◽  
Author(s):  
Marcel Wüthrich ◽  
Karen Ersland ◽  
John C. Pick-Jacobs ◽  
Benjamin H. Gern ◽  
Christopher A. Frye ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Fluorescent Protein ◽  
Antigen Expression ◽  
Cell Receptor ◽  
T Cell Subsets ◽  
T Cell Memory ◽  
Cell Memory

ABSTRACTCD4+T cells are the key players of vaccine resistance to fungi. The generation of effective T cell-based vaccines requires an understanding of how to induce and maintain CD4+T cells and memory. The kinetics of fungal antigen (Ag)-specific CD4+T cell memory development has not been studied due to the lack of any known protective epitopes and clonally restricted T cell subsets with complementary T cell receptors (TCRs). Here, we investigated the expansion and function of CD4+T cell memory after vaccination with transgenic (Tg)Blastomyces dermatitidisyeasts that display a model Ag, Eα-mCherry (Eα-mCh). We report that Tg yeast led to Eα display on Ag-presenting cells and induced robust activation, proliferation, and expansion of adoptively transferred TEa cells in an Ag-specific manner. Despite robust priming by Eα-mCh yeast, antifungal TEa cells recruited and produced cytokines weakly during a recall response to the lung. The addition of exogenous Eα-red fluorescent protein (RFP) to the Eα-mCh yeast boosted the number of cytokine-producing TEa cells that migrated to the lung. Thus, model epitope expression on yeast enables the interrogation of Ag presentation to CD4+T cells and primes Ag-specific T cell activation, proliferation, and expansion. However, the limited availability of model Ag expressed by Tg fungi during T cell priming blunts the downstream generation of effector and memory T cells.

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.

Complementary Costimulation of Human T Cell Subpopulations by CD28 and CD81

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1124-1124
Author(s):  
Shoshana Levy ◽  
Yael Sagi
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Conflicts Of Interest ◽  
Cell Subset ◽  
T Cell Subsets ◽  
T Cell Subset ◽  
Human T Cell

Abstract Abstract 1124 CD81 is a widely expressed tetraspanin molecule that physically associates with CD4 and CD8 on the surface of human T cells. Coengagement of CD81 and CD3 results in the activation and proliferation of T cells. CD81 also costimulated mouse T cells that lack CD28, suggesting either a redundant or a different mechanism of action. Here we show that CD81 and CD28 have a preference for different subsets of T cells - primary human naïve T cells are better costimulated by CD81, while the memory T cell subsets and Tregs are better costimulated by CD28. The more efficient activation of naïve T cells by CD81 was due to prolonged signal transduction compared to that by CD28. We found that IL-6 played a role in the activation of the naïve T cell subset by CD81. Combined costimulation through both CD28 and CD81 resulted in an additive effect on T cell activation. Thus, these two costimulatory molecules complement each other both in the strength of signal transduction and in T cell subset inclusions. Costimulation via CD81 might be useful for expansion of T cells for adoptive immunotherapy to allow the inclusion of naïve T cells with their broad repertoire. Disclosures: No relevant conflicts of interest to declare.

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