Faculty Opinions recommendation of CD25(+)CD4(+) regulatory T cells from the peripheral blood of asymptomatic HIV-infected individuals regulate CD4(+) and CD8(+) HIV-specific T cell immune responses in vitro and are associated with favorable clinical markers of disease status.

Human immunodeficiency virus (HIV) disease is associated with loss of CD4+ T cells, chronic immune activation, and progressive immune dysfunction. HIV-specific responses, particularly those of CD4+ T cells, become impaired early after infection, before the loss of responses directed against other antigens; the basis for this diminution has not been elucidated fully. The potential role of CD25+CD4+ regulatory T cells (T reg cells), previously shown to inhibit immune responses directed against numerous pathogens, as suppressors of HIV-specific T cell responses was investigated. In the majority of healthy HIV-infected individuals, CD25+CD4+ T cells significantly suppressed cellular proliferation and cytokine production by CD4+ and CD8+ T cells in response to HIV antigens/peptides in vitro; these effects were cell contact dependent and IL-10 and TGF-β independent. Individuals with strong HIV-specific CD25+ T reg cell function in vitro had significantly lower levels of plasma viremia and higher CD4+: CD8+ T cell ratios than did those individuals in whom this activity could not be detected. These in vitro data suggest that CD25+CD4+ T reg cells may contribute to the diminution of HIV-specific T cell immune responses in vivo in the early stages of HIV disease.

Download Full-text

Maintenance of Telomere Length in Peripheral Blood CD4+CD25+ Regulatory T-Cells of Cancer Patients Despite Active Proliferation.

Blood ◽

10.1182/blood.v106.11.3309.3309 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3309-3309

Author(s):

Dominik Wolf ◽

Holger Rumpold ◽

Christian Koppelstaetter ◽

Guenther Gastl ◽

Eberhard Gunsilius ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Telomere Length ◽

Cancer Patients ◽

Peripheral Blood ◽

Telomerase Activity ◽

Telomere Shortening ◽

Active Proliferation

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.

Download Full-text

New differentiation pathway for double-negative regulatory T cells that regulates the magnitude of immune responses

Blood ◽

10.1182/blood-2006-10-050625 ◽

2006 ◽

Vol 109 (9) ◽

pp. 4071-4079 ◽

Cited By ~ 64

Author(s):

Dong Zhang ◽

Wei Yang ◽

Nicolas Degauque ◽

Yan Tian ◽

Allison Mikita ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Cell Surface ◽

Immune Responses ◽

Lymphoid Tissues ◽

Double Negative ◽

Healthy Humans

Abstract Recent studies have demonstrated that in peripheral lymphoid tissues of normal mice and healthy humans, 1% to 5% of αβ T-cell receptor–positive (TCR+) T cells are CD4−CD8− (double-negative [DN]) T cells, capable of down-regulating immune responses. However, the origin and developmental pathway of DN T cells is still not clear. In this study, by monitoring CD4 expression during T-cell proliferation and differentiation, we identified a new differentiation pathway for the conversion of CD4+ T cells to DN regulatory T cells. We showed that the converted DN T cells retained a stable phenotype after restimulation and that furthermore, the disappearance of cell-surface CD4 molecules on converted DN T cells was a result of CD4 gene silencing. The converted DN T cells were resistant to activation-induced cell death (AICD) and expressed a unique set of cell-surface markers and gene profiles. These cells were highly potent in suppressing alloimmune responses both in vitro and in vivo in an antigen-specific manner. Perforin was highly expressed by the converted DN regulatory T cells and played a role in DN T-cell–mediated suppression. Our findings thus identify a new differentiation pathway for DN regulatory T cells and uncover a new intrinsic homeostatic mechanism that regulates the magnitude of immune responses. This pathway provides a novel, cell-based, therapeutic approach for preventing allograft rejection.

Download Full-text

Mechanisms of Immunosuppression By FVIII-Specific TCR Engineered Human Regulatory T Cells

Blood ◽

10.1182/blood.v126.23.3514.3514 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3514-3514

Author(s):

Yong Chan Kim ◽

Ai-Hong Zhang ◽

Jeong Heon Yoon ◽

David William Scott

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Immune Responses ◽

Immune Tolerance ◽

Hemophilia A ◽

Culture Media ◽

Cell Contact ◽

Suppressive Function

Abstract Expanded antigen-specific engineered regulatory T cells (Tregs) have been proposed for potential clinical application for the treatment of undesirable immune responses, such as inhibitor responses in hemophilia A patients and autoimmune diseases. By providing an antigen-specific T-cell receptor (TCR) to polyclonal natural Tregs, we suggested that antigen-specific engineered Tregs would migrate specifically to particular target tissues and induce antigen-specific immune tolerance in the local milieu. Previously, we developed FVIII C2-specific Tregs using a long-term stabilization protocol in vitro and demonstrated that these stabilized engineered Tregs successfully modulated FVIII-specific T-cell- and B-cell immune responses. Herein, we examined the mechanism of suppression by antigen-specific engineered Tregs compared to polyclonal normal natural Tregs. Initially, we tested whether these FVIII-specific engineered Tregs were able to suppress neighboring activated T-cell effectors locally. We found that FVIII C2-specific Tregs strongly suppressed myelin basic protein (MBP)-specific T effectors by presentation of both specific antigens in same APC population. However, we also observed that C2-specific Tregs could suppress MBP-specific T effectors presented on different APCs. These results imply contactless suppressive function of C2-specific engineered Tregs. Using a modified trans-well suppression assay, in which physical distance and clear separation between Tregs and a set of T effectors was created, we found that C2-specific activated Tregs showed significant contactless suppression only when T effectors were also present. In addition, and confirming previous studies with polyclonal Tregs, suppression by FVIII-specific engineered Tregs could be overcome by increasing the dose of IL-2 in co-culture media. This suggests that Tregs act, in part, by usurping IL-2 needed by T effectors to proliferate. Surprisingly, neutralization of CTLA-4 did not interfere with FVIII C2-specific suppression of engineered Tregs in contrast to the reversal seen with anti-CD3e-driven non-specific immunosuppression. Our data strongly suggest that suppressive function of FVIII-specific engineered Tregs is not restricted to cell-to-cell contact. Rather cross-talk of engineered Tregs and T effectors potentially generate a contactless suppressive mechanism to suppress other FVIII-specific multiple effector cells in the local milieu for effective immune tolerance. Understanding the mechanism of contactless suppression mechanism should provide critical clues to develop more effective engineered Tregs as a therapeutic tool in hemophilia A. (Supported by NIH grants HL061883 and HL126727) Disclosures Kim: Henry Jackson Foundation: Other: patent filed. Zhang:Henry Jackson Foundation: Other: patent filed. Scott:Henry Jackson Foundation: Other: patent filed.

Download Full-text

Endometrial mesenchymal stem/stromal cell modulation of T cell proliferation

Reproduction ◽

10.1530/rep-18-0266 ◽

2018 ◽

Cited By ~ 3

Author(s):

Xiaoqing Yang ◽

Meivita Devianti ◽

Yuan H Yang ◽

Yih Rue Ong ◽

Ker Sin Tan ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Immune Responses ◽

Stromal Cells ◽

Lymphocyte Proliferation ◽

Interleukin 10 ◽

Immunomodulatory Properties ◽

Tgf Β1

Perivascular mesenchymal stem/stromal cells can be isolated from the human endometrium using the surface marker SUSD2, and are being investigated for use in tissue repair. Mesenchymal stem/stromal cells from other tissues modulate T cell responses via mechanisms including interleukin-10, prostaglandin E2, TGF-β1 and regulatory T cells. Animal studies demonstrate that endometrial mesenchymal stem/stromal cells can also modify immune responses to implanted mesh, but the mechanism/s they employ have not been explored. We examined the immunomodulatory properties of human endometrial mesenchymal stem/stromal cells on lymphocyte proliferation using mouse splenocyte cultures. Endometrial mesenchymal stem/stromal cells inhibited mitogen-induced lymphocyte proliferation in vitro in a dose-dependent manner. Inhibition of lymphocyte proliferation was not affected by blocking the mouse interleukin-10 receptor or inhibiting prostaglandin production. Endometrial mesenchymal stem/stromal cells continued to restrain lymphocyte proliferation in the presence of an inhibitor of TGF-β receptors, despite a reduction in regulatory T cells. Thus the in vitro inhibition of mitogen-induced lymphocyte proliferation by endometrial mesenchymal stem/stromal cells occurs by a mechanism distinct from the interleukin-10, prostaglandin E2, TGF-β1, and regulatory T cell-mediated mechanisms employed by MSC from other tissues. eMSC were shown to produce interleukin-17A and Dickkopf-1 which may contribute to their immunomodulatory properties. In contrast to MSC from other sources, systemic administration of endometrial mesenchymal stem/stromal cells did not inhibit swelling in a T cell-mediated model of skin inflammation. We conclude that, while endometrial mesenchymal stem/stromal cells can modify immune responses, their immunomodulatory repertoire may not be sufficient to restrain some T cell-mediated inflammatory events.

Download Full-text

FVIII-Specific TCR Engineered Human Regulatory T Cells Suppress the Production of FVIII-Specific Responses Vitro and In Vivo

Blood ◽

10.1182/blood.v128.22.2586.2586 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2586-2586

Author(s):

Yong Chan Kim ◽

Aihong Zhang ◽

Jeong-Heon Yoon ◽

David W. Scott

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Immune Responses ◽

Hemophilia A ◽

Cell Receptor ◽

Cell Contact ◽

Therapeutic Trial

Abstract Expanded antigen-specific engineered regulatory T cells (Tregs) have been proposed for potential clinical application for the treatment of undesirable immune responses, such as inhibitor responses in hemophilia A patients and autoimmune diseases. By providing an antigen-specific T-cell receptor (TCR) to polyclonal natural Tregs, we suggested that antigen-specific engineered Tregs would migrate specifically to particular target tissues and induce antigen-specific immune tolerance in the local milieu. Previously, we developed FVIII C2-specific Tregs using a long-term stabilization protocol in vitro and demonstrated that these stabilized engineered Tregs successfully modulated FVIII-specific T-cell and B-cell immune responses in vitro. Furthermore, these engineered Tregs could suppress T-effectors specific for additional epitopes in local milieu in both a cell contact and contactless manner. From these data, we hypothesized that IL-2 and related signaling pathways are major regulatory mechanisms of the suppression. To further investigate how IL-2R signaling is engaged to control T effectors and Tregs, we followed the phospho-STAT5 status of these cells kinetically. Our results showed clearly that IL-2 from activated T effectors is a key requirement for Treg activation, inducing subsequent blockage of STAT5 signal in T effectors by activated Tregs. As further evidence of the efficacy of these specific Tregs, we then determined whether FVIII C2-specific Tregs could suppress the induction of FVIII inhibitor antibody in vivo. Thus, we transferred FVIII C2-specific human Tregs into HLA DR1 hemophilic mice and challenged them with FVIII in vivo. Our results showed that induction of FVIII-specific antibodies was inhibited for over 8 weeks. Taken together, our results suggest a potential therapeutic trial of FVIII-specific engineered Tregs in hemophilia A. Disclosures Kim: Henry Jackson Foundation: Patents & Royalties: Provisional submitted.

Download Full-text

Regulatory T cells in rheumatoid arthritis showed increased plasticity toward Th17 but retained suppressive function in peripheral blood

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2013-204228 ◽

2014 ◽

Vol 74 (6) ◽

pp. 1293-1301 ◽

Cited By ~ 53

Author(s):

Tian Wang ◽

Xiaolin Sun ◽

Jing Zhao ◽

Jing Zhang ◽

Huaqun Zhu ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Peripheral Blood ◽

Negative Regulator ◽

Suppressive Function ◽

Treg Population ◽

Treg Subset

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.

Download Full-text

Signaling through C5a receptor and C3a receptor diminishes function of murine natural regulatory T cells

Journal of Experimental Medicine ◽

10.1084/jem.20121525 ◽

2013 ◽

Vol 210 (2) ◽

pp. 257-268 ◽

Cited By ~ 132

Author(s):

Wing-hong Kwan ◽

William van der Touw ◽

Estela Paz-Artal ◽

Ming O. Li ◽

Peter S. Heeger

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Cell Function ◽

Foxp3 Expression ◽

C5a Receptor ◽

Self Tolerance ◽

T Cell Immune Responses

Thymus-derived (natural) CD4+ FoxP3+ regulatory T cells (nT reg cells) are required for immune homeostasis and self-tolerance, but must be stringently controlled to permit expansion of protective immunity. Previous findings linking signals transmitted through T cell–expressed C5a receptor (C5aR) and C3a receptor (C3aR) to activation, differentiation, and expansion of conventional CD4+CD25− T cells (T conv cells), raised the possibility that C3aR/C5aR signaling on nT reg cells could physiologically modulate nT reg cell function and thereby further impact the induced strength of T cell immune responses. In this study, we demonstrate that nT reg cells express C3aR and C5aR, and that signaling through these receptors inhibits nT reg cell function. Genetic and pharmacological blockade of C3aR/C5aR signal transduction in nT reg cells augments in vitro and in vivo suppression, abrogates autoimmune colitis, and prolongs allogeneic skin graft survival. Mechanisms involve C3a/C5a-induced phosphorylation of AKT and, as a consequence, phosphorylation of the transcription factor Foxo1, which results in lowered nT reg cell Foxp3 expression. The documentation that C3a/C3aR and C5a/C5aR modulate nT reg cell function via controlling Foxp3 expression suggests targeting this pathway could be exploited to manipulate pathogenic or protective T cell responses.

Download Full-text

Protection from graft-versus-host disease by HIV-1 envelope protein gp120-mediated activation of human CD4+CD25+ regulatory T cells

Blood ◽

10.1182/blood-2009-02-206730 ◽

2009 ◽

Vol 114 (6) ◽

pp. 1263-1269 ◽

Cited By ~ 55

Author(s):

Christian Becker ◽

Christian Taube ◽

Tobias Bopp ◽

Christoph Becker ◽

Kai Michel ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Immune Responses ◽

Graft Versus Host Disease ◽

Adenosine Monophosphate ◽

Host Disease ◽

Graft Versus Host

AbstractNaturally occurring CD4+CD25+ regulatory T cells (Tregs) represent a unique T-cell lineage that is endowed with the ability to actively suppress immune responses. Therefore, approaches to modulate Treg function in vivo could provide ways to enhance or reduce immune responses and lead to novel therapies. Here we show that the CD4 binding human immunodeficiency virus-1 envelope glycoprotein gp120 is a useful and potent tool for functional activation of human Tregs in vitro and in vivo. Gp120 activates human Tregs by binding and signaling through CD4. Upon stimulation with gp120, human Tregs accumulate cyclic adenosine monophosphate (cAMP) in their cytosol. Inhibition of endogeneous cAMP synthesis prevents gp120-mediated Treg activation. Employing a xenogeneic graft versus host disease model that has been shown to be applicable for the functional analysis of human Tregs in vivo, we further show that a single dose of gp120 is sufficient to prevent lethal graft versus host disease and that the tolerizing effect of gp120 is strictly dependent on the presence of human Tregs and their up-regulation of cAMP upon gp120-mediated activation. Our findings demonstrate that stimulation via the CD4 receptor represents a T-cell receptor–independent Treg activating pathway with potential to induce immunologic tolerance in vivo.

Download Full-text

Elevated thyroglobulin level is associated with dysfunction of regulatory T cells in patients with thyroid nodules

Endocrine Connections ◽

10.1530/ec-18-0545 ◽

2019 ◽

Vol 8 (4) ◽

pp. 309-317

Author(s):

Yun Hu ◽

Na Li ◽

Peng Jiang ◽

Liang Cheng ◽

Bo Ding ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

Peripheral Blood ◽

Thyroid Nodules ◽

Inhibitory Effect ◽

High Concentration ◽

Autoimmune Thyroid Diseases ◽

Autoimmune Thyroid

Objective Thyroid nodules are usually accompanied by elevated thyroglobulin (Tg) level and autoimmune thyroid diseases (AITDs). However, the relationship between Tg and AITDs is not fully understood. Dysfunction of regulatory T cells (Tregs) plays an important role in the development of AITDs. We aimed to evaluate the effects of Tg on the function of Tregs in patients with thyroid nodules. Methods Tg levels and the functions of Tregs in peripheral blood and thyroid tissues of patients with thyroid nodules from Nanjing First Hospital were evaluated. The effects of Tg on the function of Tregs from healthy donors were also assessed in vitro. The function of Tregs was defined as an inhibitory effect of Tregs on the effector T cell (CD4+ CD25− T cell) proliferation rate. Results The level of Tg in peripheral blood correlated negatively with the inhibitory function of Tregs (R = 0.398, P = 0.03), and Tregs function declined significantly in the high Tg group (Tg >77 μg/L) compared with the normal Tg group (11.4 ± 3.9% vs 27.5 ± 3.5%, P < 0.05). Compared with peripheral blood, the function of Tregs in thyroid declined significantly (P < 0.01), but the proportion of FOXP3+ Tregs in thyroid increased (P < 0.01). High concentration of Tg (100 μg/mL) inhibited the function of Tregs and downregulated FOXP3, TGF-β and IL-10 mRNA expression in Tregs in vitro. Conclusions Elevated Tg level could impair the function of Tregs, which might increase the risk of AITDs in patient with thyroid nodules.

Download Full-text