Dendritic Cell-Induced T Cell Non-Responsiveness Is Mediated by FOXP3+ and TGF-beta+IL-10+ CD4+ T Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3891-3891
Author(s):  
Zwi N. Berneman ◽  
Nathalie Cools ◽  
Viggo F.I. Van Tendeloo ◽  
Marc Lenjou ◽  
Griet Nijs ◽  
...  

Abstract Dendritic cells (DC), the professional antigen presenting cells of the immune system, exert important functions both in induction of T cell immunity as well as of tolerance. Previously, it was accepted that the main function of immature DC (iDC) in their in vivo steady state condition is to maintain peripheral tolerance to self-antigens and that these iDC mature upon encounter of so-called danger signals and subsequently promote T cell immunity. However, a growing body of experimental evidence now indicates that traditional DC maturation can no longer be used to distinguish between tolerogenic and immunogenic properties of DC. In this study, we compared the in vitro stimulatory capacity of immature DC (iDC), cytokine cocktail-matured DC (CC-mDC) and poly I:C-matured DC (pIC-mDC) in the absence and presence of antigen. All investigated DC types could induce at least 2 subsets of regulatory T cells. We observed a significant increase in both the number of functionally suppressive transforming growth factor (TGF)-beta+ interleukin (IL)-10+ T cells as well as of CD4+CD25+FOXP3+ T cells within DC/T cell co-cultures as compared to T cell cultures without DC. The induction of these regulatory T cells correlates with in vitro T cell non-responsiveness after co-culture with iDC and CC-mDC, while stimulation with pIC-mDC resulted in reproducible cytomegalovirus pp65 or influenza M1 matrix peptide-specific T cell activation as compared to control cultures in the absence of DC. In addition, the T cell non-responsiveness after stimulation with iDC was shown to be mediated by TGF-beta and IL-10. Moreover, the suppressive capacity of CD4+ T cells activated by iDC and CC-mDC was shown to be transferable when these CD4+ T cells were added to an established T cell response. In contrast, addition of CD4+ T cells stimulated by pIC-mDC made responder T cells refractory to their suppressive activity. In conclusion, we hypothesize that DC have a complementary role in inducing both regulatory T cells and effector T cells, where the final result of antigen-specific T cell activation will depend on the activation state of the DC. This emphasizes the need for proper DC activation when T cell immunity is the desired effect, especially when used in clinical trials.

Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.


2019 ◽  
Vol 11 (2) ◽  
pp. 108-123
Author(s):  
Dan Tong ◽  
Li Zhang ◽  
Fei Ning ◽  
Ying Xu ◽  
Xiaoyu Hu ◽  
...  

Abstract Common γ chain cytokines are important for immune memory formation. Among them, the role of IL-2 remains to be fully explored. It has been suggested that this cytokine is critically needed in the late phase of primary CD4 T cell activation. Lack of IL-2 at this stage sets for a diminished recall response in subsequent challenges. However, as IL-2 peak production is over at this point, the source and the exact mechanism that promotes its production remain elusive. We report here that resting, previously antigen-stimulated CD4 T cells maintain a minimalist response to dendritic cells after their peak activation in vitro. This subtle activation event may be induced by DCs without overt presence of antigen and appears to be stronger if IL-2 comes from the same dendritic cells. This encounter reactivates a miniature IL-2 production and leads a gene expression profile change in these previously activated CD4 T cells. The CD4 T cells so experienced show enhanced reactivation intensity upon secondary challenges later on. Although mostly relying on in vitro evidence, our work may implicate a subtle programing for CD4 T cell survival after primary activation in vivo.


1995 ◽  
Vol 182 (1) ◽  
pp. 5-13 ◽  
Author(s):  
P Stumbles ◽  
D Mason

In vitro experiments using purified rat CD4+ T cells in primary and secondary mixed leukocyte cultures (MLC) have been carried out to explore the mechanism of inhibition of cell-mediated autoimmune disease in the rat by a nondepleting monoclonal antibody (mAb) to CD4. Previous work has shown that W3/25, a mouse anti-rat CD4 mAb of immunoglobulin G1 isotype, completely prevents the development of the paralysis associated with experimental allergic encephalomyelitis (EAE) in Lewis rats, but does so without eliminating the encephalitogenic T cells. The in vitro experiments described in this study have shown that when CD4+ T cells were activated in the presence of the anti-CD4 mAb in a primary MLC, the synthesis of interferon (IFN) gamma, but not interleukin (IL) 2, was completely inhibited. After secondary stimulation, now in the absence of the mAb, the synthesis of IL-4 and IL-13 mRNA was greatly enhanced compared with that observed from CD4+ T cells derived from primary cultures in which the mAb was omitted. As IL-4 and IL-13 are known to antagonize cell-mediated immune reactions, and as EAE is cell-mediated disease, the data suggest that the W3/25 mAb controls EAE by modifying the cytokine repertoire of T cells that respond to the encephalitogen. The capacity for the mAb to suppress IFN-gamma synthesis provides, in part, an explanation for this change in cytokine production. These findings are discussed in terms of what is known of the factors that determine which cytokine genes are expressed on T cell activation. Possible implications for the evolution of T cell responses in human immunodeficiency virus infection are also discussed.


2015 ◽  
Vol 36 (4) ◽  
pp. 1259-1273 ◽  
Author(s):  
Virginia Seiffart ◽  
Julia Zoeller ◽  
Robert Klopfleisch ◽  
Munisch Wadwa ◽  
Wiebke Hansen ◽  
...  

Background/Aims: IL10 is a key inhibitor of effector T cell activation and a mediator of intestinal homeostasis. In addition, IL10 has emerged as a key immunoregulator during infection with various pathogens, ameliorating the excessive T-cell responses that are responsible for much of the immunopathology associated with the infection. Because IL10 plays an important role in both intestinal homeostasis and infection, we studied the function of IL10 in infection-associated intestinal inflammation. Methods: Wildtype mice and mice deficient in CD4+ T cell-derived or regulatory T cells-derived IL10 were infected with the enteric pathogen Citrobacter (C.) rodentium and analyzed for the specific immune response and pathogloy in the colon. Results: We found that IL10 expression is upregulated in colonic tissue after infection with C. rodentium, especially in CD4+ T cells, macrophages and dendritic cells. Whereas the deletion of IL10 in regulatory T cells had no effect on C. rodentium induced colitis, infection of mice deficient in CD4+ T cell-derived IL10 exhibited faster clearance of the bacterial burden but worse colitis, crypt hyperplasia, and pathology than did WT mice. In addition, the depletion of CD4+ T cell-derived IL10 in infected animals was accompanied by an accelerated IFNγ and IL17 response in the colon. Conclusion: Thus, we conclude that CD4+ T cell-derived IL10 is strongly involved in the control of C. rodentium-induced colitis. Interference with this network could have implications for the treatment of infection-associated intestinal inflammation.


Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 300 ◽  
Author(s):  
Konstantina Antoniou ◽  
Fanny Ender ◽  
Tillman Vollbrandt ◽  
Yves Laumonnier ◽  
Franziska Rathmann ◽  
...  

Activation of the C5/C5a/C5a receptor 1 (C5aR1) axis during allergen sensitization protects from maladaptive T cell activation. To explore the underlying regulatory mechanisms, we analyzed the impact of C5aR1 activation on pulmonary CD11b+ conventional dendritic cells (cDCs) in the context of house-dust-mite (HDM) exposure. BALB/c mice were intratracheally immunized with an HDM/ovalbumin (OVA) mixture. After 24 h, we detected two CD11b+ cDC populations that could be distinguished on the basis of C5aR1 expression. C5aR1− but not C5aR1+ cDCs strongly induced T cell proliferation of OVA-reactive transgenic CD4+ T cells after re-exposure to antigen in vitro. C5aR1− cDCs expressed higher levels of MHC-II and CD40 than their C5aR1+ counterparts, which correlated directly with a higher frequency of interactions with cognate CD4+ T cells. Priming of OVA-specific T cells by C5aR1+ cDCs could be markedly increased by in vitro blockade of C5aR1 and this was associated with increased CD40 expression. Simultaneous blockade of C5aR1 and CD40L on C5aR1+ cDCs decreased T cell proliferation. Finally, pulsing with OVA-induced C5 production and its cleavage into C5a by both populations of CD11b+ cDCs. Thus, we propose a model in which allergen-induced autocrine C5a generation and subsequent C5aR1 activation in pulmonary CD11b+ cDCs promotes tolerance towards aeroallergens through downregulation of CD40.


1997 ◽  
Vol 185 (12) ◽  
pp. 2133-2141 ◽  
Author(s):  
Elizabeth Ingulli ◽  
Anna Mondino ◽  
Alexander Khoruts ◽  
Marc K. Jenkins

Although lymphoid dendritic cells (DC) are thought to play an essential role in T cell activation, the initial physical interaction between antigen-bearing DC and antigen-specific T cells has never been directly observed in vivo under conditions where the specificity of the responding T cells for the relevant antigen could be unambiguously assessed. We used confocal microscopy to track the in vivo location of fluorescent dye-labeled DC and naive TCR transgenic CD4+ T cells specific for an OVA peptide–I-Ad complex after adoptive transfer into syngeneic recipients. DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells. In contrast, the OVA peptide-specific T cells formed large clusters around paracortical DC that were pulsed in vitro with the OVA peptide before injection. Interactions were also observed between paracortical DC of the recipient and OVA peptide-specific T cells after administration of intact OVA. Injection of OVA peptide-pulsed DC caused the specific T cells to produce IL-2 in vivo, proliferate, and differentiate into effector cells capable of causing a delayed-type hypersensitivity reaction. Surprisingly, by 48 h after injection, OVA peptide-pulsed, but not unpulsed DC disappeared from the lymph nodes of mice that contained the transferred TCR transgenic population. These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell–rich regions of lymph nodes. This interaction results in T cell activation and disappearance of the DC.


Blood ◽  
2018 ◽  
Vol 131 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Sarah L. Buchan ◽  
Anne Rogel ◽  
Aymen Al-Shamkhani

In recent years, monoclonal antibodies (mAbs) able to reinvigorate antitumor T-cell immunity have heralded a paradigm shift in cancer treatment. The most high profile of these mAbs block the inhibitory checkpoint receptors PD-1 and CTLA-4 and have improved life expectancy for patients across a range of tumor types. However, it is becoming increasingly clear that failure of some patients to respond to checkpoint inhibition is attributable to inadequate T-cell priming. For full T-cell activation, 2 signals must be received, and ligands providing the second of these signals, termed costimulation, are often lacking in tumors. Members of the TNF receptor superfamily (TNFRSF) are key costimulators of T cells during infection, and there has been an increasing interest in harnessing these receptors to augment tumor immunity. We here review the immunobiology of 2 particularly promising TNFRSF target receptors, CD27 and OX40, and their respective ligands, CD70 and OX40L, focusing on their role within a tumor setting. We describe the influence of CD27 and OX40 on human T cells based on in vitro studies and on the phenotypes of several recently described individuals exhibiting natural deficiencies in CD27/CD70 and OX40. Finally, we review key literature describing progress in elucidating the efficacy and mode of action of OX40- and CD27-targeting mAbs in preclinical models and provide an overview of current clinical trials targeting these promising receptor/ligand pairings in cancer.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Anabelle Visperas ◽  
Jeongsu Do ◽  
Booki Min

The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuki Fujiwara ◽  
Robert J. Torphy ◽  
Yi Sun ◽  
Emily N. Miller ◽  
Felix Ho ◽  
...  

AbstractThe recently identified G-protein-coupled receptor GPR171 and its ligand BigLEN are thought to regulate food uptake and anxiety. Though GPR171 is commonly used as a T cell signature gene in transcriptomic studies, its potential role in T cell immunity has not been explored. Here we show that GPR171 is transcribed in T cells and its protein expression is induced upon antigen stimulation. The neuropeptide ligand BigLEN interacts with GPR171 to suppress T cell receptor-mediated signalling pathways and to inhibit T cell proliferation. Loss of GPR171 in T cells leads to hyperactivity to antigen stimulation and GPR171 knockout mice exhibit enhanced antitumor immunity. Blockade of GPR171 signalling by an antagonist promotes antitumor T cell immunity and improves immune checkpoint blockade therapies. Together, our study identifies the GPR171/BigLEN axis as a T cell checkpoint pathway that can be modulated for cancer immunotherapy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Alana MacDonald ◽  
Brandon Lam ◽  
John Lin ◽  
Louise Ferrall ◽  
Yu Jui Kung ◽  
...  

The phospholipid phosphatidylserine (PS) is naturally maintained on the cytoplasmic side of the plasma membrane. Independent of apoptosis, PS is redistributed to the surface of CD8 T cells in response to TCR-mediated activation. Annexin V (AnnV) is a protein known to bind PS with high affinity and has been effectively utilized to anchor antigen to the surface of CD8 T cells. To expand these studies, we aimed to exploit TCR activation driven PS exposure as a target to deliver cytokine, namely interleukin-2 (IL-2), to the surface of CD8 T cells. This was accomplished using a novel chimeric fusion protein of annexin V and interleukin 2 (AnnV-IL2). In vitro analysis revealed that AnnV-IL2 is able to specifically bind PS on the T cell surface following TCR stimulation. Consequently, AnnV-IL2 proved to be significantly more effective at enhancing T cell activation compared to recombinant IL-2. In vivo, AnnV-IL2 promotes robust expansion of antigen-specific cells capable of interferon gamma (IFNγ) production when administered following peptide vaccination. Importantly, upon antigen rechallenge, AnnV-IL2 treatment mice demonstrated a stronger secondary expansion, indicating durability of AnnV-IL2 mediated responses. Our data supports the use of AnnV-IL2 to modulate antigen-specific T cell immunity and demonstrates that the PS-AnnV axis is a feasible mechanism to target diverse cargo to CD8 T cells.


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