scholarly journals Regulatory T Cells Fail to Suppress Fast Homeostatic Proliferation In Vitro

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 245
Author(s):  
Daniil Shevyrev ◽  
Valeriy Tereshchenko ◽  
Elena Blinova ◽  
Nadezda Knauer ◽  
Ekaterina Pashkina ◽  
...  

Homeostatic proliferation (HP) is a physiological process that reconstitutes the T cell pool after lymphopenia involving Interleukin-7 and 15 (IL-7 and IL-15), which are the key cytokines regulating the process. However, there is no evidence that these cytokines influence the function of regulatory T cells (Tregs). Since lymphopenia often accompanies autoimmune diseases, we decided to study the functional activity of Tregs stimulated by HP cytokines from patients with rheumatoid arthritis as compared with that of those from healthy donors. Since T cell receptor (TCR) signal strength determines the intensity of HP, we imitated slow HP using IL-7 or IL-15 and fast HP using a combination of IL-7 or IL-15 with anti-CD3 antibodies, cultivating Treg cells with peripheral blood mononuclear cells (PBMCs) at a 1:1 ratio. We used peripheral blood from 14 patients with rheumatoid arthritis and 18 healthy volunteers. We also used anti-CD3 and anti-CD3 + IL-2 stimulation as controls. The suppressive activity of Treg cells was evaluated in each case by the inhibition of the proliferation of CD4+ and CD8+ cells. The phenotype and proliferation of purified CD3+CD4+CD25+CD127lo cells were assessed by flow cytometry. The suppressive activity of the total pool of Tregs did not differ between the rheumatoid arthritis and healthy donors; however, it significantly decreased in conditions close to fast HP when the influence of HP cytokines was accompanied by anti-CD3 stimulation. The Treg proliferation caused by HP cytokines was lower in the rheumatoid arthritis (RA) patients than in the healthy individuals. The revealed decrease in Treg suppressive activity could impact the TCR landscape during lymphopenia and lead to the proliferation of potentially self-reactive T cell clones that are able to receive relatively strong TCR signals. This may be another explanation as to why lymphopenia is associated with the development of autoimmune diseases. The revealed decrease in Treg proliferation under IL-7 and IL-15 exposure can lead to a delay in Treg pool reconstitution in patients with rheumatoid arthritis in the case of lymphopenia.

Author(s):  
Daniil Shevyrev ◽  
Valeriy Tereshchenko ◽  
Alexey Sizikov ◽  
Vladimir Kozlov

Homeostatic proliferation (HP) is a physiological process to reconstitute the T-cell pool after lymphopenia with IL-7 and IL-15 being the key cytokines regulating the process. However, there is no evidence whether these cytokines influence the function of regulatory T cells (Tregs). Since lymphopenia often accompanies autoimmune diseases, we decided to study the proliferation rate and function of Tregs stimulated by IL-7 and IL-15 in patients with rheumatoid arthritis (RA) compared to healthy donors (HD). The study used peripheral blood from 14 RA patients and 18 HD. Proliferation of purified CD3CD4CD25CD127 cells was assessed by flow cytometry using CFSE. Tregs were stimulated by anti-CD3, IL-7, IL-15, IL-7, or IL-15 combined with anti-CD3, and by IL-2+anti-CD3, and their functional activity was evaluated in each case by CD4 and CD8 cells proliferation inhibition. The suppressive activity of peripheral Tregs did not differ between RA and HD; however, it significantly decreased when IL-7 or IL-15 were applied together with strong TCR stimulation with anti-CD3 antibodies. Herewith Treg proliferation caused by IL-7 and IL-15 was lower in RA than in HD. The revealed decrease in Treg suppressive activity can lead to the proliferation of potentially self-reactive T-cell clones, which can receive relatively strong TCR signals. This may be another explanation of why lymphopenia is associated with the development of autoimmune diseases. The revealed decrease of Treg proliferation under IL-7 and IL-15 may lead to a delay in Treg pool reconstitution in patients with rheumatoid arthritis.


2014 ◽  
Vol 74 (6) ◽  
pp. 1293-1301 ◽  
Author(s):  
Tian Wang ◽  
Xiaolin Sun ◽  
Jing Zhao ◽  
Jing Zhang ◽  
Huaqun Zhu ◽  
...  

ObjectiveRegulatory T cells (Tregs) with the plasticity of producing proinflammatory cytokine IL-17 have been demonstrated under normal and pathogenic conditions. However, it remains unclear whether IL-17-producing Tregs lose their suppressive functions because of their plasticity toward Th17 in autoimmunity. The aim of this study was to investigate IL-17-producing Tregs from patients with rheumatoid arthritis (RA), and characterise their regulatory capacity and clinical significance.MethodsFoxp3 and IL-17 coexpression were evaluated in CD4 T lymphocytes from RA patients. An in vitro T cell polarisation assay was performed to investigate the role of proinflammatory cytokines in IL-17-producing Treg polarisation. The suppressive function of IL-17-producing Tregs in RA was assessed by an in vitro suppression assay. The relationship between this Treg subset and clinical features in RA patients was analysed using Spearman's rank correlation test.ResultsA higher frequency of IL-17-producing Tregs was present in the peripheral blood of RA patients compared with healthy subjects. These cells from peripheral blood showed phenotypic characteristics of Th17 and Treg cells, and suppressed T cell proliferation in vitro. Tregs in RA synovial fluid lost suppressive function. The Th17 plasticity of Tregs could be induced by IL-6 and IL-23. An increased ratio of this Treg subset was associated with decreased levels of inflammatory markers, including the erythrocyte sedimentation rate and C-reactive protein level, in patients with RA.ConclusionsIncreased levels of IL-17-producing Tregs were identified in RA patients. This Treg subset with Th17 plasticity in peripheral blood retained suppressive functions and was associated with milder inflammatory conditions, suggesting that this Treg population works as a negative regulator in RA, but in RA synovial site it may be pathogenic.


2016 ◽  
Vol 71 (2) ◽  
pp. 148-153 ◽  
Author(s):  
P. N. Kravchenko ◽  
G. A. Zhulai ◽  
A. V. Churov ◽  
E. K. Oleinik ◽  
V. M. Oleinik ◽  
...  

Background: Rheumatoid arthritis (RA) is an inflammatory rheumatic disease, associated with a dysfunction of the T cell-mediated tolerance and leading to the disability of working population.  The regulatory CD4+ T cells are play important role in the regulation of autoimmunity and can suppress immune responses. With that, there is no consensus on the content of  these lymphocytes  and their role in the pathogenesis of RA. Objective: The aim of the study was to assess the content of peripheral blood regulatory T cells (Treg) according to the expression of membrane markers CD4, CD25, CD127 and intracellular FOXP3 marker, as well as the expression of two functional molecules (CTLA-4 and CCR4) in Treg cells of patients with RA. Methods: Peripheral blood samples of RA patients (mean age 61,1±10,5) and healthy controls (mean age 52,2±14,0) were analyzed. Cell count and the expression level of molecules were assessed by flow cytometry. Results: Peripheral blood samples of 36 RA patients and 20 healthy donors were analyzed. The number of the cells with Treg-associated phenotypes CD4+CD25hi and CD4+CD25hiCD127low/– was higher in RA patients in comparison with healthy donors. Increased levels of RA CD4+ T cells expressing FOXP3 were also observed. This may be due to increasing in the number of CD4+FOXP3+CD25- lymphocytes, whereas the content of RA CD4+FOXP3+CD25+ Treg cells was at the level of the control. The expression of the functional molecule CTLA-4 in Treg cells of patients with RA was not different from the control, while the expression level of the chemokine receptor CCR4, which provides migration of lymphocytes at sites of inflammation and barrier tissues, was significantly increased in RA patients. Conclusion: Increase in the levels of certain Treg-associated lymphocyte populations were detected in peripheral blood of RA patients. During the natural course of RA, alterations in the level of the chemokine receptor CCR4 might indicate the enhanced lymphocyte migration.


2004 ◽  
Vol 199 (9) ◽  
pp. 1285-1291 ◽  
Author(s):  
Martin A. Kriegel ◽  
Tobias Lohmann ◽  
Christoph Gabler ◽  
Norbert Blank ◽  
Joachim R. Kalden ◽  
...  

In autoimmune polyglandular syndromes (APS), several organ-specific autoimmune diseases are clustered. Although APS type I is caused by loss of central tolerance, the etiology of APS type II (APS-II) is currently unknown. However, in several murine models, depletion of CD4+ CD25+ regulatory T cells (Tregs) causes a syndrome resembling human APS-II with multiple endocrinopathies. Therefore, we hypothesized that loss of active suppression in the periphery could be a hallmark of this syndrome. Tregs from peripheral blood of APS-II, control patients with single autoimmune endocrinopathies, and normal healthy donors showed no differences in quantity (except for patients with isolated autoimmune diseases), in functionally important surface markers, or in apoptosis induced by growth factor withdrawal. Strikingly, APS-II Tregs were defective in their suppressive capacity. The defect was persistent and not due to responder cell resistance. These data provide novel insights into the pathogenesis of APS-II and possibly human autoimmunity in general.


2019 ◽  
Vol 20 (18) ◽  
pp. 4323 ◽  
Author(s):  
Salvo Danilo Lombardo ◽  
Emanuela Mazzon ◽  
Maria Sofia Basile ◽  
Giorgia Campo ◽  
Federica Corsico ◽  
...  

Tetraspanins are a conserved family of proteins involved in a number of biological processes including, cell–cell interactions, fertility, cancer metastasis and immune responses. It has previously been shown that TSPAN32 knockout mice have normal hemopoiesis and B-cell responses, but hyperproliferative T cells. Here, we show that TSPAN32 is expressed at higher levels in the lymphoid lineage as compared to myeloid cells. In vitro activation of T helper cells via anti-CD3/CD28 is associated with a significant downregulation of TSPAN32. Interestingly, engagement of CD3 is sufficient to modulate TSPAN32 expression, and its effect is potentiated by costimulation with anti-CD28, but not anti-CTLA4, -ICOS nor -PD1. Accordingly, we measured the transcriptomic levels of TSPAN32 in polarized T cells under Th1 and Th2 conditions and TSPAN32 resulted significantly reduced as compared with unstimulated cells. On the other hand, in Treg cells, TSPAN32 underwent minor changes upon activation. The in vitro data were finally translated into the context of multiple sclerosis (MS). Encephalitogenic T cells from Myelin Oligodendrocyte Glycoprotein (MOG)-Induced Experimental Autoimmune Encephalomyelitis (EAE) mice showed significantly lower levels of TSPAN32 and increased levels of CD9, CD53, CD82 and CD151. Similarly, in vitro-activated circulating CD4 T cells from MS patients showed lower levels of TSPAN32 as compared with cells from healthy donors. Overall, these data suggest an immunoregulatory role for TSPAN32 in T helper immune response and may represent a target of future immunoregulatory therapies for T cell-mediated autoimmune diseases.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Samantha S. Beauford ◽  
Anita Kumari ◽  
Charlie Garnett-Benson

Abstract Background The use of immunotherapy strategies for the treatment of advanced cancer is rapidly increasing. Most immunotherapies rely on induction of CD8+ tumor-specific cytotoxic T cells that are capable of directly killing cancer cells. Tumors, however, utilize a variety of mechanisms that can suppress anti-tumor immunity. CD4+ regulatory T cells can directly inhibit cytotoxic T cell activity and these cells can be recruited, or induced, by cancer cells allowing escape from immune attack. The use of ionizing radiation as a treatment for cancer has been shown to enhance anti-tumor immunity by several mechanisms including immunogenic tumor cell death and phenotypic modulation of tumor cells. Less is known about the impact of radiation directly on suppressive regulatory T cells. In this study we investigate the direct effect of radiation on human TREG viability, phenotype, and suppressive activity. Results Both natural and TGF-β1-induced CD4+ TREG cells exhibited increased resistance to radiation (10 Gy) as compared to CD4+ conventional T cells. Treatment, however, decreased Foxp3 expression in natural and induced TREG cells and the reduction was more robust in induced TREGS. Radiation also modulated the expression of signature iTREG molecules, inducing increased expression of LAG-3 and decreased expression of CD25 and CTLA-4. Despite the disconcordant modulation of suppressive molecules, irradiated iTREGS exhibited a reduced capacity to suppress the proliferation of CD8+ T cells. Conclusions Our findings demonstrate that while human TREG cells are more resistant to radiation-induced death, treatment causes downregulation of Foxp3 expression, as well as modulation in the expression of TREG signature molecules associated with suppressive activity. Functionally, irradiated TGF-β1-induced TREGS were less effective at inhibiting CD8+ T cell proliferation. These data suggest that doses of radiotherapy in the hypofractionated range could be utilized to effectively target and reduce TREG activity, particularly when used in combination with cancer immunotherapies.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3309-3309
Author(s):  
Dominik Wolf ◽  
Holger Rumpold ◽  
Christian Koppelstaetter ◽  
Guenther Gastl ◽  
Eberhard Gunsilius ◽  
...  

Abstract CD4+CD25+ regulatory T-cells (Treg) are increased in the peripheral blood of cancer patients. It remains unclear whether this is due to redistribution or active proliferation. The latter would require the up-regulation of telomerase activity, whose regulation also remains unknown for Treg. We therefore isolated Treg and the respective CD4+CD25− control T-cell population from peripheral blood of cancer patients (n=23) and healthy age-matched controls (n=17). Analysis of their content of T-cell receptor excision circles (TREC) revealed that the observed increase of Treg frequencies in peripheral blood is due to active cycling rather than to redistribution from other compartments (i.e. secondary lymphoid organs or bone-marrow), as Treg from cancer patients are characterized by a significant decrease of TREC content when compared to TREC content of Treg isolated from healthy age-matched controls. Surprisingly, despite their proven in vivo proliferation, telomere length is not further shortened in Treg from peripheral blood of cancer patients as shown by Flow-Fish, Real-Time PCR and Southern Blotting. Accodingly, telomerase activity of Treg was readily inducible in vitro by OKT3 together with IL-2. Notably, sorting of in vitro proliferating Treg using dilution of CFSE revealed a significant telomere shortening in Treg with high proliferative capacity (i.e. CFSElow fraction) under conditions of strong in vitro stimulatory growth conditions despite a high telomerase activity. Thus, under conditions of strong in vitro stimulation induction of telomerase seems to be insufficient to avoid progressive telomere shortening. In contrast, in actively proliferating peripheral blood Treg from patients with epithelial malignancies induction of telomerase activity is likely to compensate for further telomere erosion.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4642-4642
Author(s):  
Xin Wang ◽  
Wenbo Zhao ◽  
Yanxia Liu ◽  
Ying Li

Abstract Polycythaemia vera (PV) is a clonal disorder arising from a pluripotent hematopoietic progenitor cell. The etiology of PV remains unknown and there is no consensus as to the optimal therapy for this disorder. T regulatory (Treg) cells play a vital role in the maintenance of self-tolerance, control of auto-immunity and regulation of T-cell homeostasis, and they modulate overall immune responses against a variety of pathogens. Recent studies revealed that Treg cells play a crucial role in the process of hematopoietic activity. However, the effect of Treg cells in PV has not been reported. The Treg cells might participate in the dysfunction of T-cell immunity in PV. The profile and function of Treg cells in PV patients were explored in this study. Peripheral blood was withdrawn from 21 PV patients (Female 8 ; Male 13), as well as 25 age-matched healthy donors (F 9 ; M 16) as controls. All samples were taken after informed consent and collected from PV patients prior to treatment. Diagnoses of PV were made according to clinical and laboratory criteria. The peripheral blood mononuclear cells (PBMCs) were subjected to flow cytometry analyses after labeling with anti-CD4, anti-CD25, and anti-Foxp3 antibodies. Real-time PCR and Western blotting were also performed to identify quantitative FOXP3 mRNA expression and protein level in the PBMCs from PV in comparison to controls. The relationships between the percentage of Treg cells, the expressions for quantitative mRNA and protein, with the clinical data were assessed. The percentage of CD4+ T-cells was significant decreased in the group of PV than in normal control (28.7±7.07% vs 38.6±8.38%, p<0.05). But the percentage of CD4+CD25+FOXP3+ T-cells (Treg cells) in PV patients was significantly increased when compared to the control (10.93±4.02% vs 5.86±1.99%, p<0.05). Moreover, the quantitative mRNA expression of FOXP3 (64.23±18.52 vs 16.06±4.78, p<0.05) and protein expression of FOXP3 (0.74±0.16 vs 0.62±0.10, p<0.05)) were significantly enhanced in PV patients (shown in Figure 1). In conclusion, we showed that patients with PV have enhanced percentage of Treg cells in their peripheral blood. This was substantiated further with the finding that overexpressions of FOXP3 in PV both in mRNA and protein level. These results highlight important Treg-cell abnormalities in patients with PV because natural Treg cells are significantly increased in number and function. The underlying mechanism is still undefined, but the increased frequency and function of Treg cells might account for the abnormal T cell immunity in PV patients. It was suggested that there may be differently suppressive machanisms for Treg in these patients. The elevated Treg cells in PV might be activated and then affect the hematopoietic activity. We believe that Treg cells might involved in the dysfunction of T/NK cells in their disability to downregulate the hematopoietic proliferation in PV. And the expansion of Treg cells may be a feature of PV and associated with the pathogenesis of PV. Further investigation in this abnormality might provide novel therapy clue for this disease. Figure Figure


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4670-4670
Author(s):  
Chang-Qing Xia ◽  
Anna Chernatynskaya ◽  
Clive Wasserfall ◽  
Benjamin Looney ◽  
Suigui Wan ◽  
...  

Abstract Abstract 4670 Anti-thymocyte globulin (ATG) has been used in clinic for the treatment of allograft rejection and autoimmune diseases. However, its mechanism of action is not fully understood. To our knowledge, how ATG therapy affects naïve and memory T cells has not been well investigated. In this study, we have employed nonobese diabetic mouse model to investigate how administration of anti-thymocyte globulin (ATG) affects memory and naïve T cells as well as CD4+CD25+Foxp3+ regulatory T cells in peripheral blood and lymphoid organs; We also investigate how ATG therapy affects antigen-experienced T cells. Kinetic studies of peripheral blood CD4+ and CD8+ T cells post-ATG therapy shows that both populations decline to their lowest levels at day 3, while CD4+ T cells return to normal levels more rapidly than CD8+ T cells. We find that ATG therapy fails to eliminate antigen-primed T cells, which is consistent with the results that ATG therapy preferentially depletes naïve T cells relative to memory T cells. CD4+ T cell responses post-ATG therapy skew to T helper type 2 (Th2) and IL-10-producing T regulatory type 1 (Tr1) cells. Intriguingly, Foxp3+ regulatory T cells (Tregs) are less sensitive to ATG depletion and remain at higher levels following in vivo recovery compared to controls. Of note, the frequency of Foxp3+ Tregs with memory-like immunophenotype is significantly increased in ATG-treated animals, which might play an important role in controlling effector T cells post ATG therapy. In summary, ATG therapy may modulate antigen-specific immune responses through modulation of naïve and memory T cell pools and more importantly through driving T cell subsets with regulatory activities. This study provides important data for guiding ATG therapy in allogenieic hematopoietic stem cell transplantation and other immune-mediated disorders. Disclosures: No relevant conflicts of interest to declare.


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