scholarly journals Restoring regulatory T-cell dysfunction in Alzheimer’s disease through ex vivo expansion

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Alireza Faridar ◽  
Aaron D Thome ◽  
Weihua Zhao ◽  
Jason R Thonhoff ◽  
David R Beers ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Regulatory T Cell ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
T Cell Proliferation ◽  
Inflammatory Macrophages

Abstract Inflammation is a significant component of Alzheimer’s disease pathology. While neuroprotective microglia are important for containment/clearance of Amyloid plaques and maintaining neuronal survival, Alzheimer inflammatory microglia may play a detrimental role by eliciting tau pathogenesis and accelerating neurotoxicity. Regulatory T cells have been shown to suppress microglia-mediated inflammation. However, the role of regulatory T cells in ameliorating the proinflammatory immune response in Alzheimer’s disease requires further investigation. Forty-six patients with Alzheimer disease, 42 with mild cognitive impairment and 41 healthy controls were studied. The phenotypes of peripheral regulatory T cells were assessed with multicolour flow cytometry. Regulatory T cells were co-cultured with responder T cells and proliferation was determined by 3H-thymidine incorporation. In separate experiments, regulatory T cells were added to induced pluripotent stem cell-derived pro-inflammatory macrophages and changes in interleukin-6/tumour necrosis-alpha transcripts and protein levels were measured. Freshly isolated regulatory T cells were expanded ex vivo in the presence of CD3/CD28 expander beads, interleukin-2 and rapamycin to promote their suppressive function. We found that the suppressive function of regulatory T cells on responder T-cell proliferation was compromised at the Alzheimer disease stage, compared with mild cognitive impairment and healthy controls. CD25 mean fluorescence intensity in regulatory T-cell population was also reduced in Alzheimer dementia patients. Regulatory T cells did not suppress pro-inflammatory macrophages at baseline. Following ex vivo expansion, regulatory T-cell suppression of responder T-cell proliferation and pro-inflammatory macrophage activation increased in both patients and controls. Expanded regulatory T cells exerted their immunoregulatory function on pro-inflammatory macrophages through a contact-mediated mechanism. In conclusion, regulatory T-cell immunophenotype and function are compromised in Alzheimer’s disease. Following ex vivo expansion, the immunomodulatory function of regulatory T cells is enhanced even at advanced stages of Alzheimer’s disease. Restoration of regulatory T-cell function could be explored as a means to modulate the inflammatory status of Alzheimer’s disease.

Sirolimus Inhibits Proliferation but Enhances Suppressive Activity of Rhesus Macaque Natural CD4 Regulatory T Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1008-1008
Author(s):  
Karnail Singh ◽  
Natalia Kozyr ◽  
Linda Stempora ◽  
Allan D Kirk ◽  
Christian P Larsen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Ex Vivo ◽  
Cd8 T Cell ◽  
T Cell Proliferation ◽  
Suppressive Activity ◽  
Suppressive Capacity

Abstract Abstract 1008 Regulatory T cells (Tregs) have been shown to be potent inhibitors of autoimmunity, and to be capable of suppressing alloimmune responses that occur during both allograft rejection and graft-versus host disease. However, they have yet to gain widespread use clinically, due in part to the fact that it remains extremely costly and difficult to produce them in sufficient numbers and with sufficient suppressive capacity to significantly impact the alloimmune response. Here we have used our established non-human primate model to demonstrate that significant Treg expansion (up to 600-fold in 21 days) can be maintained, and suppressive capacity enhanced by exposing Treg cultures to a short burst of sirolimus at the end of the culture period. Using a highly sensitive and specific in vitro CFSE-MLR assay we show that Tregs significantly inhibit allo-proliferation of multiple T cell subpopulations including both CD4+ and CD8+ T cells (3.2 and 2.7-fold inhibition of proliferation, respectively), as well as their CD28+CD95+ and CD28-CD95+ subpopulations (2.2 and 2.1 and 1.9 and 2.7-fold inhibition of CD4+ and CD8+ subpopulation proliferation, respectively). Tregs were able to combine in vitro with the newly FDA-approved CTLA4-Ig analog belatacept to enhance the inhibition of alloproliferation that occurred with either agent alone (4.8-fold inhibition of CD8 T cell proliferation with Tregs + belatacept, compared to 3.0-fold or 1.9-fold inhibition of CD8 T cell proliferation with Tregs or belatacept alone, respectively). Importantly, we have found that the suppressive activity of ex-vivo expanded Tregs could be further enhanced by pulsing with sirolimus. Thus, while long-term culture of Tregs in the presence of sirolimus (1–1000 nM) profoundly inhibited Treg expansion (50–800 fold inhibition of expansion when cultured in the presence of 1–1000 nM sirolimus), a 48 hour pulse of sirolimus (100 nM) on days 20–21 of culture completely preserved Treg yields while doubling their suppressive function against CD8 proliferation when compared to unpulsed Tregs, p<0.01) A mechanistic evaluation of the increase potency observed with sirolimus pulsed Tregs (SPTs) has revealed several key differences that distinguish these cells from the less-potent unpulsed Tregs: SPTs were found to undergo fewer rounds of proliferation in an MLR when compared with unpulsed Tregs (14% proliferation in SPTs versus 37% proliferation in un-pulsed Tregs, p= 0.015), suggesting that the suppressive capability of Tregs may be inversely related to their proliferative capacity. SPTs were also shown to have significantly increased expression of CD25 (p=0.04) and total CTLA4 (p= 0.009) compared to unpulsed Tregs, implicating signaling through both of these molecules in their enhanced function. Our results suggest that the creation of SPTs may provide a novel avenue by which to achieve enhanced Treg-based suppression of alloimmunity, in a manner that is amenable to large-scale ex-vivo expansion and to combinatorial therapy with novel, costimulation-blockade-based immunosuppression strategies. Disclosures: No relevant conflicts of interest to declare.

Anti-CD20 therapy corrects a CD8 regulatory T cell deficit in multiple sclerosis

2021 ◽  
pp. 135245852110033
Author(s):  
Quentin Howlett-Prieto ◽  
Xuan Feng ◽  
John F Kramer ◽  
Kevin J Kramer ◽  
Timothy W Houston ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
B Cell ◽  
Regulatory T Cell ◽  
Healthy Controls ◽  
Regulatory Cells ◽  
Long Term Treatment ◽  
Anti Cd20

Objective: To determine the effect of long-term anti-CD20 B-cell-depleting treatment on regulatory T cell immune subsets that are subnormal in untreated MS patients. Methods: 30 clinically stable MS patients, before and over 38 months of ocrelizumab treatment, were compared to 13 healthy controls, 29 therapy-naïve MS, 9 interferon-β-treated MS, 3 rituximab-treated MS, and 3 rituximab-treated patients with other autoimmune inflammatory diseases. CD8, CD28, CD4, and FOXP3 expression in peripheral blood mononuclear cells was quantitated with flow cytometry. Results: CD8+ CD28− regulatory cells rose from one-third of healthy control levels before ocrelizumab treatment (2.68% vs 7.98%), normalized by 12 months (13.5%), and rose to 2.4-fold above healthy controls after 18 months of ocrelizumab therapy (19.0%). CD4+ FOXP3+ regulatory cells were lower in MS than in healthy controls (7.98%) and showed slight long-term decreases with ocrelizumab. CD8+ CD28− and CD4+ FOXP3+ regulatory T cell percentages in IFN-β-treated MS patients were between those of untreated MS and healthy controls. Interpretation: Long-term treatment with ocrelizumab markedly enriches CD8+ CD28− regulatory T cells and corrects the low levels seen in MS before treatment, while slightly decreasing CD4+ FOXP3+ regulatory T cells. Homeostatic enrichment of regulatory CD8 T cells provides a mechanism, in addition to B cell depletion, for the benefits of anti-CD20 treatment in MS.

Relative impact of CD4+CD25+ regulatory T cells and tacrolimus on inhibition of T-cell proliferation in patients with atopic dermatitis

2005 ◽  
Vol 153 (4) ◽  
pp. 750-757 ◽  
Author(s):  
M. Vukmanovic-Stejic ◽  
A. McQuaid ◽  
K.E. Birch ◽  
J.R. Reed ◽  
C. Macgregor ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Atopic Dermatitis ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Proliferation ◽  
Relative Impact

scholarly journals Regulatory T Cells Contribute to Resistance against Lyme Arthritis

2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lyme Disease ◽  
Regulatory T Cells ◽  
Regulatory T Cell ◽  
Interleukin 10 ◽  
Lyme Arthritis ◽  
Interleukin 17 ◽  
Content Type

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.

scholarly journals Thymic Regulatory T Cell Development: Role of Signalling Pathways and Transcription Factors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mark Engel ◽  
Tom Sidwell ◽  
Ajithkumar Vasanthakumar ◽  
George Grigoriadis ◽  
Ashish Banerjee
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
T Cell ◽  
Regulatory T Cells ◽  
Immune Tolerance ◽  
Regulatory T Cell ◽  
T Cell Development ◽  
Signalling Pathways ◽  
Treg Development

Regulatory T cells (Tregs) are a subset of CD4 T cells that are key mediators of immune tolerance. Most Tregs develop in the thymus. In this review we summarise recent findings on the role of diverse signalling pathways and downstream transcription factors in thymic Treg development.

FRI0010 GM-CSFR PATHWAY IS IMPLICATED IN PATHOGENIC INFLAMMATORY MECHANISMS IN GIANT CELL ARTERITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 576.1-576
Author(s):  
M. C. Cid ◽  
S. Muralidharan ◽  
M. Corbera-Bellalta ◽  
G. Espigol-Frigole ◽  
J. Marco Hernandez ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mrna Expression ◽  
Giant Cell Arteritis ◽  
Giant Cell ◽  
Signaling Pathway ◽  
Ex Vivo ◽  
Cell Marker ◽  
Gm Csf ◽  
Inflammatory Macrophages

Background:Giant Cell Arteritis (GCA) is characterized by inflammation of large and medium arteries. Classic symptoms include headaches, malaise and, in severe cases, blindness and aortic aneurysms. Corticosteroids (CS) are the first line of treatment. Relapsing disease patients undergo multiple courses of CS therapy increasing their CS exposure and toxicity. A significant unmet need for disease-modifying CS-sparing therapy remains in GCA as the efficacy of current treatment options, including tocilizumab have limitations.We have previously reported elevated expression of granulocyte-macrophage colony stimulating factor (GM-CSF) pathway transcriptomic signature in GCA vessels. GM-CSF may contribute to underlying disease mechanisms by regulating inflammatory macrophages, dendritic cells (DCs) and T helper (TH1/TH17) cells which are involved in GCA pathogenesis. GM-CSF produced by T cells1can promote polarization of inflammatory macrophages2and recruitment and differentiation of monocytes into inflammatory DCs2that can in turn recruit T cells and stimulate TH1/TH17 differentiation creating a feedback loop. GM-CSF may also exert direct effects on angiogenesis3and vessel wall remodeling4.Objectives:To demonstrate the contributing role of GM-CSF pathway to inflammation in GCA arteries.Methods:Immunostaining was used to examine expression of GM-CSF and GM-CSF-Rα proteins in temporal artery biopsies (TABs) from GCA and controls (patients with suspected but not confirmed GCA and a negative TAB). Costaining with cell markers such as CD31, CD3, and CD68 allowed visualization of cells expressing GM-CSF and GM-CSF-Rα. Expression of GM-CSF pathway molecules such as phospho-JAK2 and PU.1 proteins was detected by immunohistochemical staining of GCA and control TABs.Ex vivocultured GCA arteries treated (10 each) with mavrilimumab (anti-GM-CSF-Rα) or placebo for 5 days were assayed for gene expression by qPCR, and culture supernatants were analyzed by ELISA.Results:Endothelial cells and macrophages were the main cell types expressing GM-CSF and GM-CSF-Rα. Increased expression of phospho-JAK2 (activated signaling molecule) and nuclear-localized PU.1 (transcription factor) in GCA TABs compared to controls indicated the presence of active GM-CSF signaling pathway in GCA.Inhibition of PU.1 mRNA expression inex vivocultures of GCA arteries treated with mavrilimumab indicated blockade of GM-CSFR signaling pathway. Mavrilimumab induced decrease in mRNA expression of key cell type markers including DC and macrophage activation markers CD83 and HLA-DRA, monocyte markers CD14 and CD16, T cell marker CD3ε, and B cell marker CD20 in these GCA artery cultures. Expression of inflammatory TH1/TH17 factors IFNγ (mRNA), TNFα, CXCL10 (IFNγ-stimulated chemokine) and IL-6 (mRNA and protein) was also inhibited by mavrilimumab in GCA artery cultures.Conclusion:Increased GM-CSF, GM-CSF-Rα, and downstream pathway-associated protein levels in GCA biopsies were consistent with previously-observed increased transcriptome signature. Expression of genes associated with inflammatory cells was suppressed by mavrilimumab in cultured GCA arteries. These data implicate the GM-CSF pathway in GCA pathophysiology and increase confidence in rationale for targeting the GM-CSF pathway in GCA.References:[1]GM-CSF and T-cell responses: what we do and don’t know. Shiet al., Cell Res 2006[2]GM-CSF-Dependent Inflammatory Pathways. Hamilton, Front Immunol 2019[3]GM-CSF increases tumor growth and angiogenesis. Zhenget al., Tumour Biol 2017[4]GM-CSF deficiency affects vascular elastin production and integrity of elastic lamellae. Weissen-Plenzet al., J Vasc Res 2008Disclosure of Interests:Maria C. Cid Grant/research support from: Kiniksa Pharmaceuticals, Consultant of: Janssen, Abbvie, Roche, GSK, Speakers bureau: Vifor, Sujatha Muralidharan Shareholder of: Kiniksa, Employee of: Kiniksa, Marc Corbera-Bellalta: None declared, Georgina Espigol-Frigole Consultant of: Roche and Janssen, Javier Marco Hernandez: None declared, Amanda Denuc: None declared, Roberto Rios-Garces: None declared, Nekane Terrades-Garcia: None declared, John F. Paolini Shareholder of: Kiniksa, Employee of: Kiniksa, Annalisa D’Andrea Shareholder of: Kiniksa, Employee of: Kiniksa

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