Mesenchymal stem cells induce Foxp3-Tregs to suppress effector T cells and protect against retinal ischemic injury
0
Citation
0
Reference
20
Related Paper
Cite
Abstract The therapeutic potential of targeting CD4+Foxp3+ regulatory T cells (Tregs) remains controversial under the condition of neuroinflammation. This study aims to explore the neuroprotective role of Tregs in optic nerve ischemia (ONI) and evaluate the therapeutic strategy of Tregs transfer with a focus on targeting the mammalian target of rapamycin (mTOR) pathway. Intraocular pressure was transiently increased in adult C57BL/6 mice to induce ONI. Mucosal tolerance of myelin basic protein (MBP) markedly increased retinal ganglion cell (RGC) survival after ONI through enhanced Tregs suppression. mTOR inhibition significantly promoted the frequency of MBP-immunized Tregs in vitro with increased production of anti-inflammatory cytokines. Transient rapamycin treatment highly promoted the immunosuppressive capacity of Tregs and inhibited retinal inflammation in ONI animals. Intravenous infusion of MBP-immunized Tregs, instead of regular Tregs, beneficially modulated immune activities of host retinal CD11b+ cells and CD4+ effector T cells, leading to significant improvement of RGC survival. Importantly, rapamycin treatment further enhanced the neuroprotective effect of Tregs transfer. Taken together, these findings reveal a fine regulation of mTOR signaling on immunized Tregs after acute retinal injury. Adoptive transfer with targeting-mTOR strategy markedly improves neuronal recovery after ONI, supporting the therapeutic potentials of Tregs in acute and chronic neurological disorder.
Adoptive Cell Transfer
Cite
Citations (16)
A major conceptual shift in immunology has been the recent discovery of regulatory T-cells (Treg), of which CD4+Foxp3+ cells are already known to be essential to self-tolerance. Their role in transplant tolerance remains unproven due to the absence of a natural cell surface marker by which they can be manipulated in vivo. A transgenic B6.Foxp3hCD2 mouse was created to express an artificial GPI-anchored human CD2/CD52 surface fusion protein under the control of the Foxp3 promoter. Monoclonal antibodies directed against the human CD2 and human CD52 were used in B6.Foxp3hCD2 mice to isolate and ablate Foxp3+ Treg. CD4+Foxp3+ cells were found to be crucial for transplant tolerance induced by non-ablative co-receptor and co-stimulatory blockade. In tolerant animals, Foxp3+ Treg are constantly required to suppress effector T-cells still capable of causing tissue damage. Remarkably, tolerated tissue contains T-cells capable of rejecting it, but these are prevented from doing so by therapeutically induced Foxp3+ Treg. Finally, induced Foxp3+ cells sustain tolerance by converting naive T-cells into the next generation of Foxp3+ cells in the periphery, providing one potential mechanism by which infectious tolerance may operate in vivo. .
Cite
Citations (0)
Mesenchymal stem cells (MSCs) suppress T helper (Th)17 cell differentiation and are being clinically pursued for conditions associated with aberrant Th17 responses. Whether such immunomodulatory effects are enhanced by coadministration of MSCs with other agents is not well known. In the present study, individual and combined effects of MSCs and the vitamin D receptor (VDR) agonist paricalcitol on Th17 induction were investigated in vitro and in a mouse model of sterile kidney inflammation (unilateral ureteral obstruction). In vitro, MSCs and paricalcitol additively suppressed Th17 differentiation, although only MSCs suppressed expression of Th17-associated transcriptions factors. Combined administration of MSCs and paricalcitol resulted in an early (day 3) reduction of intrarenal CD4(+) and CD8(+) T cells, CD11b(+)/lymphocyte antigen 6G(+) neutrophils, and inflammatory (lymphocyte antigen 6C(hi)) monocytes as well as reduced transcript for IL-17 compared with untreated animals. Later (day 8), obstructed kidneys of MSC/paricalcitol double-treated mice, but not mice treated with either intervention alone, had reduced tubular injury and interstitial fibrosis as well as lower numbers of neutrophils and inflammatory monocytes and an increase in the ratio between M2 (CD206(+)) and M1 (CD206(-)) macrophages compared with control mice. Adjunctive therapy with VDR agonists may enhance the immunosuppressive properties of MSCs in the setting of pathogenic Th17-type immune responses and related inflammatory responses.
Paricalcitol
Cite
Citations (15)
Summary Autoimmune inner ear disease is characterized by progressive, bilateral although asymmetric, sensorineural hearing loss. Patients with autoimmune inner ear disease had higher frequencies of interferon‐γ‐producing T cells than did control subjects tested. Human adipose‐derived mesenchymal stem cells (hASCs) were recently found to suppress effector T cells and inflammatory responses and therefore have beneficial effects in various autoimmune diseases. The aim of this study was to examine the immunosuppressive activity of hASCs on autoreactive T cells from the experimental autoimmune hearing loss (EAHL) murine model. Female BALB/c mice underwent β‐tubulin immunization to develop EAHL; mice with EAHL were given hASCs or PBS intraperitoneally once a week for 6 consecutive weeks. Auditory brainstem responses were examined over time. The T helper type 1 (Th1)/Th17‐mediated autoreactive responses were examined by determining the proliferative response and cytokine profile of splenocytes stimulated with β‐tubulin. The frequency of regulatory T (Treg) cells and their suppressive capacity on autoreactive T cells were also determined. Systemic infusion of hASCs significantly improved hearing function and protected hair cells in established EAHL. The hASCs decreased the proliferation of antigen‐specific Th1/Th17 cells and induced the production of anti‐inflammatory cytokine interleukin‐10 in splenocytes. They also induced the generation of antigen‐specific CD4 + CD25 + Foxp3 + Treg cells with the capacity to suppress autoantigen‐specific T‐cell responses. The experiment demonstrated that hASCs are one of the important regulators of immune tolerance with the capacity to suppress effector T cells and to induce the generation of antigen‐specific Treg cells.
Cite
Citations (65)
Abstract Regulatory T cell (Treg) therapy is a potential curative approach for a variety of immune-mediated conditions, including autoimmunity and transplantation, in which there is pathological tissue damage. In mice, IL-33R (ST2)–expressing Tregs mediate tissue repair by producing the growth factor amphiregulin, but whether similar tissue-reparative Tregs exist in humans remains unclear. We show that human Tregs in blood and multiple tissue types produced amphiregulin, but this was neither a unique feature of Tregs nor selectively upregulated in tissues. Human Tregs in blood, tonsil, synovial fluid, colon, and lung tissues did not express ST2, so ST2+ Tregs were engineered via lentiviral-mediated overexpression, and their therapeutic potential for cell therapy was examined. Engineered ST2+ Tregs exhibited TCR-independent, IL-33–stimulated amphiregulin expression and a heightened ability to induce M2-like macrophages. The finding that amphiregulin-producing Tregs have a noneffector phenotype and are progressively lost upon TCR-induced proliferation and differentiation suggests that the tissue repair capacity of human Tregs may be an innate function that operates independently from their classical suppressive function.
Regulatory T cell
Cell therapy
Cite
Citations (41)
MPTP
Adoptive Cell Transfer
Galectin-1
Cite
Citations (54)
Mice lacking CD4 T cells develop a more pro‐inflammatory phenotype when injured. We subsequently showed that CD4+CD25+ regulatory T cells (Tregs) were required to control this injury‐induced change in innate immunity. We now demonstrate that injured Treg‐deficient mice are more susceptible to LPS‐induced shock suggesting that Tregs play an active role in controlling Toll‐like receptor 4 (TLR4) reactivity. Since macrophages are the primary cells responsible for enhanced LPS reactivity after injury, we wished to test whether Tregs might directly control macrophage responses to innate stimuli. To accomplish this, we first developed a macrophage/Treg suppression assay. Macrophages were purified from the spleens and CD4+CD25+ T cells (Tregs) were purified from the lymph nodes of C57BL/6J mice. Cells were then mixed at various Treg:macrophage ratios and stimulated with pure LPS (a TLR4 agonist) or Pam3Cys‐Ser‐(Lys)4 (a TLR2 agonist) and anti‐CD3 antibody. Supernatants were then tested for TNF□, IL‐6, and IL‐10 levels. In some experiments, anti‐IL‐10 or anti‐TGFβ antibodies were tested as blocking reagents. Tregs from burn‐injured versus sham mice were also compared for Treg‐mediated suppression of macrophages. Our results indicate that Tregs can directly suppress TLR4‐ and TLR2‐induced inflammatory cytokine production by macrophages. Moreover, we find that both IL‐10 and TGFβ act synergistically to mediate the suppression of TLR4 and TLR2 responses by macrophages. Finally, we demonstrate that Tregs prepared from injured mice are more potent than sham Tregs at suppressing macrophage TLR2 and TLR4 responses. Taken together, our findings show that Tregs can actively suppress macrophage TLR responses through IL‐10‐and TGFβ‐dependent mechanisms and provide new insight into how Tregs control innate immune responses to injury and inflammation.
Cite
Citations (0)
Abstract Ocular infection with herpes simplex virus 1 (HSV-1) can result in a chronic immuno-inflammatory lesion that is a significant cause of human blindness. IFN-γ producing CD4 + T cells are generally considered the main orchestrators, and lesions are more severe if the regulatory T cell (Treg) response is compromised. Tregs have been shown to lose FoxP3 (Treg lineage factor) and adopt alternate lineage fates in a changing cytokine environment. Moreover, little is known about the stability of Treg cells in an ongoing inflammatory reaction such as is the case of SK. In this study-using fate mapping mice, we were able to demonstrate that the population of ex-Tregs increased at the site of infection that is the cornea and also at the secondary lymphoid organs after HSV-1 infection. In vivo studies showed that these ex-Tregs acquired the Th1 and Th17 phenotype, which may play a destructive role in stromal keratitis. We also demonstrate in vivo that CD25lo subset of Tregs is less suppressive and more prone to conversion than CD25hi Tregs. Additionally, in-vitro studies suggested that Tregs in the presence of IL-12 converted into ex-Tregs, however this plasticity was prevented when Tregs were generated in the presence of DNMT inhibitor (Azacytidine). Thus, plasticity of Tregs might represent a problem during SK, which needs to be controlled with appropriate therapeutic procedures. Overall, our results indicate that Tregs lose FoxP3 expression in ocular inflammatory setting and drugs that reverse Treg plasticity could be useful to restore Treg function and to inhibit ocular immunopathology.
Ex vivo
Proinflammatory cytokine
Cite
Citations (0)
The auto antigen (Ag)-specific regulatory T cells (Tregs) from pluripotent stem cells (PSCs), i.e., PSC-Tregs, have the ability to suppress autoimmunity. PSC-Tregs can be programmed to be tissue-associated and to infiltrate into local inflamed tissues to suppress autoimmune responses after adoptive transfer. Nevertheless, the mechanisms by which the auto Ag-specific PSC-Tregs suppress the autoimmune response remain to be fully elucidated. In this study, we generated the functional auto Ag-specific Tregs from the induced PSC (iPSCs), i.e., iPSC-Tregs, and investigated the underlying mechanisms of autoimmunity suppression by these Tregs in a type 1 diabetes (T1D) murine model. A double transgenic (Tg) mouse model of T1D was established in F1 mice in which the first generation of RIP-mOVA Tg mice that were crossed with OT-I T cell receptor (TCR) Tg mice was challenged with vaccinia viruses expressing OVA (VACV-OVA). We show that adoptive transfer of OVA-specific iPSC-Tregs greatly suppressed autoimmunity in the animal model and prevented the insulin-secreting pancreatic β cells from destruction. Further, we demonstrate that the adoptive transfer significantly reduced the expression of ICAM-1 in the diabetic pancreas and inhibited the migration of pathogenic CD8+ T cells and the production of the pro-inflammatory IFN-γ in the pancreas. These results indicate that the stem cell-derived tissue-associated Tregs can robustly accumulate in the diabetic pancreas, and through down-regulating the expression of ICAM-1 in the local inflamed tissues and inhibiting the production of pro-inflammatory cytokine IFN-γ, suppress the migration and activity of the pathogenic immune cells that cause T1D. Disclosure J.J. Song: None. Funding American Diabetes Association (1-16-IBS-281); National Institutes of Health (R01AI121180, R21AI109239)
Adoptive Cell Transfer
Insulitis
Cite
Citations (0)
Abstract The liver plays a pivotal role in maintaining immunological tolerance, although the exact molecular mechanism is still largely unknown. The induction of systemic tolerance by liver resident APCs has been attributed to peripheral deletion and to the induction of Tregs. HCs, the parenchymal cells in the liver, could function as nonprofessional APCs and interact and establish cell–cell contact with T lymphocytes. We hypothesized that HCs from healthy or regenerated livers may contribute to induction of functional Tregs. Here, we show that murine HCs induced Foxp3+ Tregs within CD4+ T cells in vitro, which increased in the presence of TGF-β. Interestingly, a further Foxp3+ Treg expansion was observed if HCs were isolated from regenerated livers. Additionally, the induction of Foxp3+ Tregs was associated with the Notch signaling pathway, as the ability of HCs to enhance Foxp3 was abolished by γ-secretase inhibition. Furthermore, HC-iTregs showed ability to suppress the proliferative response of CD4+ T cells to anti-CD3 stimulation in vitro. Thus, HCs may play a pivotal role in the induction of tolerance via Notch-mediated conversion of CD4+ T cells into Foxp3+ Tregs upon TCR stimulation.
Hes3 signaling axis
Regulatory T cell
Cite
Citations (43)