scholarly journals The Role of Interleukin-10 (IL-10) in IL-15–Mediated T-Cell Responses

Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4513-4521
Author(s):  
Dieter Körholz ◽  
Ursula Banning ◽  
Halvard Bönig ◽  
Markus Grewe ◽  
Marion Schneider ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Interleukin 10 ◽  
T Cell Proliferation ◽  
Cell Production ◽  
Cd25 Expression ◽  
Tnf Α ◽  
Ifn Γ

Interleukin-15 (IL-15) is a potent T-cell stimulating factor, which has recently been used for pre-clinical in vivo immunotherapy. Here, the IL-15 effect on CD3-stimulated peripheral human T cells was investigated. IL-15 induced a significant T-cell proliferation and upregulated CD25 expression. IL-15 significantly enhanced T-cell production of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-10. Between 10- and 100-fold greater concentrations of IL-15 were necessary to reach a biological effect equivalent to that of IL-2. Blockade of IL-2 binding to the high-affinity IL-2 receptor did not affect the IL-15 effects, suggesting that IL-15 did not act by inducing endogenous IL-2. Exogenously administered IL-10 significantly reduced the IL-15 and IL-2–mediated IFN-γ and TNF-α production, whereas T-cell proliferation and CD25 expression were not affected. The inhibitory effects of exogenously administered IL-10 on T-cell cytokine production appeared indirect, and are likely secondary to decreased IL-12 production by accessory cells. Inhibition of endogenous IL-10 binding to the IL-10 receptor significantly increased IFN-γ and TNF-α release from T cells. These data suggest that endogenous IL-10 can regulate activated T-cell production of IFN-γ and TNF-α via a paracrine negative feedback loop. The observations of this study could be of relevance for the therapeutic use of IL-15 in vivo.

scholarly journals The Role of Interleukin-10 (IL-10) in IL-15–Mediated T-Cell Responses

Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4513-4521 ◽  
Author(s):  
Dieter Körholz ◽  
Ursula Banning ◽  
Halvard Bönig ◽  
Markus Grewe ◽  
Marion Schneider ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Interleukin 10 ◽  
T Cell Proliferation ◽  
Cell Production ◽  
Cd25 Expression ◽  
Tnf Α ◽  
Ifn Γ

Abstract Interleukin-15 (IL-15) is a potent T-cell stimulating factor, which has recently been used for pre-clinical in vivo immunotherapy. Here, the IL-15 effect on CD3-stimulated peripheral human T cells was investigated. IL-15 induced a significant T-cell proliferation and upregulated CD25 expression. IL-15 significantly enhanced T-cell production of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-10. Between 10- and 100-fold greater concentrations of IL-15 were necessary to reach a biological effect equivalent to that of IL-2. Blockade of IL-2 binding to the high-affinity IL-2 receptor did not affect the IL-15 effects, suggesting that IL-15 did not act by inducing endogenous IL-2. Exogenously administered IL-10 significantly reduced the IL-15 and IL-2–mediated IFN-γ and TNF-α production, whereas T-cell proliferation and CD25 expression were not affected. The inhibitory effects of exogenously administered IL-10 on T-cell cytokine production appeared indirect, and are likely secondary to decreased IL-12 production by accessory cells. Inhibition of endogenous IL-10 binding to the IL-10 receptor significantly increased IFN-γ and TNF-α release from T cells. These data suggest that endogenous IL-10 can regulate activated T-cell production of IFN-γ and TNF-α via a paracrine negative feedback loop. The observations of this study could be of relevance for the therapeutic use of IL-15 in vivo.

scholarly journals Low-Dose Decitabine Augments the Activation and Anti-Tumor Immune Response of IFN-γ+ CD4+ T Cells Through Enhancing IκBα Degradation and NF-κB Activation

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiang Li ◽  
Liang Dong ◽  
Jiejie Liu ◽  
Chunmeng Wang ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Low Dose ◽  
T Cell Proliferation ◽  
Ifn Γ ◽  
Iκbα Degradation

BackgroundCD4+ T cells play multiple roles in controlling tumor growth and increasing IFN-γ+ T-helper 1 cell population could promote cell-mediated anti-tumor immune response. We have previously showed that low-dose DNA demethylating agent decitabine therapy promotes CD3+ T-cell proliferation and cytotoxicity; however, direct regulation of purified CD4+ T cells and the underlying mechanisms remain unclear.MethodsThe effects of low-dose decitabine on sorted CD4+ T cells were detected both in vitro and in vivo. The activation, proliferation, intracellular cytokine production and cytolysis activity of CD4+ T cells were analyzed by FACS and DELFIA time-resolved fluorescence assays. In vivo ubiquitination assay was performed to assess protein degradation. Moreover, phosphor-p65 and IκBα levels were detected in sorted CD4+ T cells from solid tumor patients with decitabine-based therapy.ResultsLow-dose decitabine treatment promoted the proliferation and activation of sorted CD4+ T cells, with increased frequency of IFN-γ+ Th1 subset and enhanced cytolytic activity in vitro and in vivo. NF-κB inhibitor, BAY 11-7082, suppressed decitabine-induced CD4+ T cell proliferation and IFN-γ production. In terms of mechanism, low-dose decitabine augmented the expression of E3 ligase β-TrCP, promoted the ubiquitination and degradation of IκBα and resulted in NF-κB activation. Notably, we observed that in vitro low-dose decitabine treatment induced NF-κB activation in CD4+ T cells from patients with a response to decitabine-primed chemotherapy rather than those without a response.ConclusionThese data suggest that low-dose decitabine potentiates CD4+ T cell anti-tumor immunity through enhancing IκBα degradation and therefore NF-κB activation and IFN-γ production.

Monocytic Myeloid-Derived Suppress Cells Restore Adipogenic Bone Marrow Microenvironment in Aplastic Anemia By Inhibiting Intra-BM CD8+ T Cells Proliferation

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1211-1211
Author(s):  
Ying Qu ◽  
Zhengxu Sun ◽  
Yan Yuan ◽  
Fen Wang ◽  
Kunpeng Wu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Proliferation ◽  
Immune Balance ◽  
Ifn Γ

Aplastic anemia (AA) is a hematopoietic disorder resulted from immune-related hypocellular hematopoiesis in bone marrow (BM). It has been clearly addressed that the activated T cells contribute to the exhaustion of hematopoietic progenitors and hypo-hematopoiesis. The adipogenic BM is one of the characteristics to make AA diagnosis. However, little is known about the relationship of intra-BM immune imbalance and hematopoietic microenvironment abnormity in this disease entity. Functional hematopoiesis relies on not only abundant hematopoietic stem cells (HSCs) but also the balanced supportive hematopoietic niche. Intra-BM immune balance, at either cellular or cytokine level, is one of the key footstones to maintain hematopoietic microenvironment. Various intra-BM immune cellular components play both sides of one coin. Among them, myeloid-derived suppressive cells (MDSCs) are heterogeneous myeloid progenitor cells characterized by the negative immune response in cancers and other inflammatory diseases. In BM aspiration and biopsy samples from the patients who were diagnosed as AA in our study, massive activated lymphocytes infiltration and adipocytes accumulation were observed. Interestingly, the absolute numbers of immune modulatory MDSCs either in AA patients' PB or in BM of immune-related AA mice were reduced, indicating a potential link between polarized BM adipo-osteogenic microenvironment and immune disorder under AA circumstance. We thus adopted AA mice model to look into the embedded details both in vivo and in vitro. We clarified that BM components were more vulnerable to the attack of CD8+ T cells than that of CD4+ T cells. Taking into the fact that BM adipocytes are more abundant either in AA patients or in AA mice models, we differentiated mesenchymal stromal cells (MSCs), the major BM stroma cells, into osteoblastic or adipogenic lineages to mimic the osteo-adipogenic differentiation in BM microenvironment. Interestingly, CD8+ T cells and interferon-γ(IFN-γ) exerted dramatically adipocytic stimulation on BM-MSCs either in vitro or in vivo, by determination of increasing expression of adipogenetic genes including Ap2, Perilipin, Pparg and Cebpα, as well as staining of Oil Red O and perilipin. To dissect intra-BM cellular immune balance, MDSCs were isolated as representative immune regulating population to investigate their function on osteo-adipogenic balance. Interestingly, not CD11b+Ly6G+Ly6C-granulocytic-MDSCs (gMDSCs) but CD11b+Ly6G-Ly6C+monocytic-MDSCs (mMDSCs) inhibited both T cell proliferation and IFN-γ production. Addition of L-NMMA, the antagonist of iNOS pathway in mMDSCs-containing system restored T cell proliferative curve and cell numbers, whereas Nor-NOHA, the antagonist of Arg-1 pathway didn't abrogate mMDSCs' immune-regulation properties, indicating that mMDSCs inhibited T cell proliferation via iNOS pathway. We then performed single dose or multi-dose injection of mMDSCs in AA mice to see whether mMDSCs are able to reconstitute the impacted hematopoiesis. Single injection of mMDSCs was able to prevent from CTL infiltration in a very short term. However, multi-injection of mMDSCs showed significant benefit in overall survival rate compared to AA mice. We further detected the function of mMDSCs on polarized BM-MSCs adipo-osteogenic differentiation potential. To detect sequential BM adipogenetic progression in AA microenvironment, we performed in vivo fluorescent microscopy on AP2 (Fabp4)-Cre×mT/mG reporting mice at different transfusion time points of T cells and mMDSCs. GFP-expressing AP2+ adipocytes accumulated adjacently to perivascular niches whose boarders were labelled by Dextran-CY5 in a time-dependent manner after T cell infusion. Monocytic MDSCs transfused AA mice showed decreased GFP+ adipocytes which was coincident with our in vitro findings. In conclusion, intra-BM immune balance is one of the environmental factors seesawing by activating and suppressive ends to support functional hematopoiesis. Adoptive transfusion of mMDSCs, the immune-suppressive population might be a novel immune-regulating strategy to treat AA, relying on not only restoring the intra-BM immune balance but also improving stroma's multi-differentiating microenvironment. Figure Disclosures No relevant conflicts of interest to declare.

Chimeric Regulatory T cells Enhance HSC Engraftment in An Antigen-Specific Fashion.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2424-2424
Author(s):  
Yiming Huang ◽  
Larry D Bozulic ◽  
Thomas Miller ◽  
Hong Xu ◽  
Yujie Wen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Third Party ◽  
T Cell Proliferation ◽  
Hematopoietic Stem ◽  
Mixed Chimeras

Abstract Abstract 2424 Poster Board II-401 We previously reported that CD8+TCR- facilitating cells (FC) induce the generation of chimeric regulatory T cells (Treg) in vivo. Transplantation of a mixture of CD8+/TCR- FC and hematopoietic stem cells (HSC) into ablated recipients results in chimerism and tolerance. Treg harvested from the spleen of chimeras (chimeric Treg) potently increase long-term donor chimerism in secondary NOD recipient mice. Here, we evaluated whether chimeric Treg enhance engraftment of hematopoietic stem cells (HSC) in an antigen-specific manner. To prepare mixed chimeras (B6 → NOD), NOD recipients were conditioned with 950 cGy TBI and transplanted with 10,000 B6 HSC and 1,000 NOD HSC plus 45,000 CD8+TCR- B6 FC. At 5 weeks, CD8-CD4+CD25bright chimeric Treg were sorted from spleens of the mixed chimeras (B6 → NOD). 100,000 chimeric Treg were then mixed with 10,000 B6 HSC (donor-specific) + 10,000 B10.BR HSC (third-party) and transplanted into conditioned NOD recipients in competitive repopulation assays. NOD mice given HSC plus nonchimeric naïve B6 Treg or HSC alone served as controls. Two of the four animals that received HSC alone engrafted and exhibited an average of 6.7% donor B6 chimerism at 30 days, 11.2% at 60 days, and 10.6% at 90 days. Three of five animals given HSC plus naïve B6 Treg engrafted with 21.3% donor B6 chimerism at 30 days, 28.8% at 60 days, and 28.9% at 90 days. In contrast, eight of nine recipients of HSC + chimeric Treg engrafted. These animals exhibited a significantly higher level of donor B6 chimerism, ranging from 56.3% at 30 days, 75.4% at 60 days to 85% at 90 days (P = 0.034). None of the recipients engrafted with the MHC-disparate third-party B10.BR HSC. We then assessed the suppressive function of chimeric Tregin vitro by using MLR suppressor cell assays. CD8-/CD4+/CD25bright Treg were sorted from chimeric spleens 5 wks to 12 wks after HSC + FC transplantation. As shown in the Figure 1, Treg from naïve B6 mice resulted in 1.9 fold; 1.3 fold and 1.1 fold inhibition of proliferation at 1:1, 1:0.25, 1:0.125 responder/Treg ratios (n = 3). In contrast, chimeric Treg potently suppressed T cell proliferation by 10.5 fold; 3.2 fold; and 1.7 fold at responder/Treg ratios of 1:1, 1:0.25, 1:0.125 (n = 4). Chimeric Treg significantly suppressed T cell proliferation at responder/Treg ratios of 1:1 and 1:0.25 compared with naïve B6 Treg (P < 0.05). NOD responder splenocytes remained hypoproliferative in response to B6 stimulator and chimeric Treg compared with stimulator plus B6 Treg, suggesting that chimeric Treg are significantly more potent than naïve B6 Treg in suppressing effector T cell proliferation in vitro. These data show that chimeric Treg enhance donor B6 HSC engraftment but not third-party B10.BR HSC, demonstrating that chimeric Treg function in vivo in an antigen-specific fashion. These data also show that the mechanism of FC function in vivo is associated with the establishment of an antigen-specific regulatory feedback loop. Figure 1 Figure 1. Disclosures: Bozulic: Regenerex: Employment. Ildstad:Regenerex: Equity Ownership.

CD11b+gr-1+ myeloid Derived Suppressor Cells (MDSC) In Normal Bone Marrow Suppress T Cell Proliferation and Enhance T-Regulatory Function Via a IL10-, IL4- and IDO-Independent Mechanism

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4801-4801 ◽  
Author(s):  
Parvin Forghani ◽  
Wayne Harris ◽  
jian-Ming Li ◽  
M.R. Khorramizadeh ◽  
Edmund Waller
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Regulatory Function ◽  
T Cell Proliferation ◽  
Suppressive Activity ◽  
Ifn Γ

Abstract Abstract 4801 MDSC have been described as an important negative regulators of autologous anti-cancer immune responses. Considering the important role of MDSC in immune regulation in allogenic stem cell and organ transplantation, we undertook an investigation of the mechanism(s) by which MDSC inhibit T–cell activation and proliferation, and tested the hypothesis that local cytokine secretion or IDO activity is required for suppression of T-cell proliferation. Two separate populations CD11bhiGr-1hi and CD11bhi Gr-1int were isolated by high-speed FACS from lineage- BM antigen presenting cells (C57 & BALB/c mice). Both MDSC subsets had potent capacity for in–vitro suppression of CD4+ and CD8+ T cells proliferation in response to anti-CD3/anti-CD28 beads and Con A. A ratio of 0.5/1 MDSC: T-cells were sufficient to inhibit >66% control levels of T-cell proliferation. MDSC isolated from transgenic mice that had been “knocked-out” for IFN-γ and IDO had equivalent suppressive activity as MDSC from wild-type donors. Addition of saturating concentrations of anti IL-10 and IL-4 MAb, or in combination with anti- IFN-γ MAb did not abrogate MDSC-suppressive activity. Ex-vivo culture of MDSC with mitogen-activated T-cells generated two—fold more Fox-p3 T-reg compared with cultures of T cell plus mitogen. Data will be presented regarding the novel role of MDSC involving in the homeostasis regulation of normal T-cell activation and proliferation in non-tumor-bearing mice. Disclosures: No relevant conflicts of interest to declare.

Induction of Indoleamine 2,3-Dioxygenase Expression by Interferon-g in Human Mesenchymal Stem Cells Inhibits Graft Versus Host Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4698-4698
Author(s):  
Myoung Woo Lee ◽  
Dae Seong Kim ◽  
Hye Jin Kim ◽  
Meong Hi Son ◽  
Soo Hyun Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
T Cell Proliferation ◽  
Activated T Cells ◽  
Graft Versus Host ◽  
Ifn Γ ◽  
Immunomodulatory Properties

Abstract Abstract 4698 Background: It is important to overcome the limitations such as graft rejection and graft versus host disease (GvHD) in allogeneic hematopoietic stem cell transplantation. Mesenchymal stem cells (MSCs), which evoke only minimal immune reactivity, may have anti-inflammatory and immunomodulatory effects. Purpose: In this study, we aimed to identify the immunomodulatory properties of human MSCs and to elucidate the possible mechanism of their properties for clinical treatment of allogeneic conflicts using MSCs. Materials & Methods: We conducted a comparative analysis about the immunomodulatory properties of MSCs derived from adult human tissues, including bone marrow (BM), adipose tissues (AT), umbilical cord blood (CB), and cord Wharton's jelly (WJ), in vitro and in vivo models. Results: AT-MSCs, CB-MSCs, and WJ-MSCs effectively suppressed phytohemagglutinin (PHA)-induced T-cell proliferation as effectively as did BM-MSCs. Levels of interferon (IFN)-g secreted from activated T-cells increased over time, but these levels were significantly reduced when cocultured with each type of MSCs. In addition, expression of indoleamine 2,3-dioxygenase (IDO) increased in MSCs treated with IFN-γ via JAK/STAT1 signaling pathways. Treatment with anti-IFN-g antibodies, JAK1/2 inhibitor or STAT1 siRNA restored PHA-induced T-cell proliferation. Use of an antagonist, 1-methyl-L-tryptophan, also restored PHA-induced T-cell proliferation, suggesting that IDO contributes to IFN-g-induced immunosuppression in MSCs. Moreover, infusion of IFN-g-treated MSCs decreased symptoms for human peripheral blood-derived mononuclear cells-induced GvHD in NOD/SCID mice, which resulted in an increase of survival rate of in vivo GvHD model. Conclusion: These data indicate that IFN-γ produced by activated T-cells is correlated with induction of IDO expression in MSCs by IFN-γ receptor/JAK/STAT1 pathway, which resulted in suppression of T-cell proliferation. Our findings suggest that MSCs derived from BM, AT, CB, or WJ could be used for clinical treatment of allogeneic conflicts. Disclosures: No relevant conflicts of interest to declare.

Donor Requirements For CD4+CD25+FoxP3+ Regulatory T Cells Capable Of Suppressing CD4+ and CD8+ Conventional T Cell Proliferation and Graft Versus Host Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4484-4484 ◽  
Author(s):  
Antonio Pierini ◽  
Lucrezia Colonna ◽  
Maite Alvarez ◽  
Dominik Schneidawind ◽  
Byung-Su Kim ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Animal Models ◽  
Graft Versus Host Disease ◽  
Third Party ◽  
T Cell Proliferation ◽  
Graft Versus Host

Adoptive transfer of CD4+CD25+FoxP3+ regulatory T cells (Tregs) prevents graft versus host disease (GvHD) in several animal models and following allogeneic hematopoietic cell transplantation (HCT) in clinical trials. In these models donor derived Tregs have been mainly used as they share the same major histocompatibility complex (MHC) with conventional CD4+ and CD8+ T cells (Tcons) that are primarily responsible for GvHD onset and persistence. Third-party derived Tregs are a promising alternative tool for cellular therapy as they can be prepared in advance, screened for pathogens and activity and banked. In this study we explored MHC disparities between Tregs and Tcons in HCT to evaluate the impact of these different cell populations in GvHD prevention and survival after transplant. Methods and Results We evaluated the ability of highly purified Treg to suppress proliferation of C57BL/6 (H-2b) Tcons following exposure to irradiated splenocytes from BALB/C (H-2d) mice in vitro in a mixed lymphocyte reaction (MLR). Either donor derived C57BL/6 (H-2b) or third party FVB (H-2q) Tregs suppressed Tcon proliferation at the Treg/Tcon ratios of 1:2 and 1:4. The same Treg population effectively suppressed different MHC derived Tcons where BALB/C (H-2d) or FVB (H-2q, third-party) Tcons were incubated with irradiated splenocytes from C57BL/6 (H-2b) mice and were effectively suppressed with BALB/C (H-2d) Tregs. In the MLR, third-party Tregs present the same activation molecule expression patterns as MHC matched Tregs: CTLA4 and LAG3 expression is enhanced after stimulation with interleukin-2 (IL-2) and anti-CD3/CD28 beads, while MHC class II molecule expression is increased after 3-4 days of culture with Tcons and irradiated splenocytes. Furthermore third-party and MHC matched Tregs express the same levels of interleukin-10 (IL-10). We translated these results to in vivo studies in animal models. In these studies T cell depleted bone marrow (TCD BM) from C57BL/6 (H-2b) mice was injected into lethally irradiated (total body irradiation, 8 Gy) BALB/C (H-2d) recipient mice. 2 days later GvHD was induced by injecting luc+ donor derived Tcons (1x106/mouse). Using this model GvHD was evaluated following the adoptive transfer of freshly isolated CD4+CD25+FoxP3+ Tregs derived from BALB/C (H-2d, host type), C57BL/6 (H-2b, donor type), FVB (H-2q, third-party) or BALB/B (H-2b, minor mismatched with the donor, major mismatched with the host) mice at the different Treg/Tcon ratios of 1:1, 1:2 and 1:4. As expected, donor Tregs exerted the strongest dose dependent GvHD protection (p = 0.028), while host Tregs did not improve mouse survival (p = 0.58). Third-party and minor mismatched with the donor Tregs improved mouse survival (third-party and minor mismatched with the donor respectively, p = 0.028 and p = 0.17) but mice had worse GvHD score profiles (both p< 0.001) and could not recover their weight as well as mice treated with donor Tregs (both p< 0.001). In vivoTcon bioluminescent imaging confirmed these results showing a reduced Tcon proliferation in mice treated with donor, third-party and minor mismatched with the donor Tregs, the first exerting the strongest effect (after 6 weeks of observation, p< 0.001). Conclusions Our studies indicate that MHC disparities between Tregs and Tcons do not represent an insurmountable barrier for Treg function. In vitro and in vivo data strongly suggest that Tregs can suppress Tcon proliferation without requiring MHC matching. In vivo GvHD prevention efficiency was affected by MHC disparities with donor derived Treg being the most effective, however, third party Treg also resulted in GvHD attenuation. These studies indicate that both donor and third party Treg could be effective in clinical application raising the possibility of screening and banking Treg for use. Further, these studies highlight the need for activation of the Treg on host tissues to effectively suppress conventional T cell proliferation and GvHD induction. Disclosures: No relevant conflicts of interest to declare.

Expanded CD4+Foxp3+ Regulatory T Cells through DR3 Signaling Have a Distinct Immunophenotype and Abrogate the Lethal Acute-Graft and Host Disease after Allogeneic Transplantation

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1876-1876
Author(s):  
Hidekazu Nishikii ◽  
Byung-Su Kim ◽  
Yasuhisa Yokoyama ◽  
Jeanette Baker ◽  
Antonio Pierini ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Proliferation ◽  
Agonistic Antibody ◽  
Host Disease ◽  
Acute Graft

Abstract Background : CD4+Foxp3+ regulatory T cells (Treg) are a subpopulation of T cells which regulate the immune system, maintain self-tolerance and enhance immune tolerance after transplantation. Several groups have demonstrated that donor-derived Treg prevent the development of lethal acute graft and host disease (GVHD) in murine allogeneic transplant models. However, the low frequency of Treg limits clinical translation. To overcome the paucity of Treg, several strategies have been developed for Treg expansion. However, the activation of other immune cells and the instability of Foxp3 expression in ex vivo culture are problematic for widescale clinical usage. Recently, we showed that a single dose of agonistic antibody to DR3 (Death receptor 3, also called tumor necrosis factor super family 25; TNFSF25) into donor mice resulted in the expansion of donor derived Treg and prevented acute GVHD (Blood. 2015). Although the treatment with DR3 antibodies can preferentially expand Treg in vivo, the precise role of DR3 signaling in Treg has not been fully elucidated. In this study, we investigated the immune phenotype, gene expression profiles, and function of Treg after activation with DR3 signaling. Methods: To analyze the heterogeneous immunophenotype of Treg after DR3 signal activation, we comprehensively analyzed multicolor cytometry data using viSNE (visualization of stochastic neighbor embedding algorithm). For gene expression analysis using microarray (Affymetrix GeneChip 2.0 ST Array), CD4+Foxp3+ cells from Foxp3-GFP mice with or without DR3 activation were sorted by FACS. Normalized expression data was analyzed using TIGR Multi Experiment Viewer (MeV, version 4.9). To investigate the function of Treg after DR3 activation, CD4+CD25+Treg from wild type (WT) C57BL/6 mice (H2kb) with or without treatment of agonistic antibody to DR3 were isolated by FACS and then injected into lethally irradiated (8Gy in total) BALB/c mice (H2kd) together with 5x106 T cell depleted bone marrow (from WT C57BL/6 mice) and 1x106 T cells (C57BL/6-luciferase mice). The transplanted mice were monitored by clinical GVHD score, weight, bioluminescence imaging (BLI) for donor T cell trafficking and survival. Results: The results of viSNE showed the heterogenic elevated expression level of Nrp1, Helios (natural occurring Treg marker/transcription factor), CD103, KLRG1, CD44, ICOS, PD-1, Lag3, TIGIT (effector or inhibitory molecules), and Ki67 (proliferation marker) in Treg after DR3 activation. On the other hand, the expression of CD25, the receptor for IL-2 was down regulated. In the microarray data, a significant elevated level (>2 fold relative expression levels in DR3 activated Treg) of chemokine/cytokine (ccr3, cxcl10) and effector molecules (CD74, Gzmb) were observed. These data suggest that the effect of DR3 signaling in Treg results in not only the expansion of Treg but also their activation. In transplantation experiments, the mice that received DR3 activated Treg (5X105/mouse) showed significantly lower donor T cell proliferation compared with the mice that received non-activated Tregs (n=5 in each group, P<0.01 on day 7 and 10 after transplant). Interestingly, even a smaller number (1x105/mouse) of DR3 treated Treg suppressed donor T cell proliferation in host mice (n=5 in each group, P<0.05 on day7 and day10), and the survival of the mice in the DR3 activated Treg group was also improved compared with control GVHD group (n=10 in each group, P<0.01 in Log-rank test). These data suggested that Treg isolated after DR3 activation were more functional for the prevention in GVHD. Conclusion: In conclusion, our data demonstrate that the activation of DR3 signaling can induce Treg populations with enhanced function in vivo. These observations support for future clinical testing using human DR3 signal modulation. Disclosures No relevant conflicts of interest to declare.

Opposing Effects of PD-1/PD-L1/L2 Engagement and IFN-γ/TNF-α in the Treatment of AML w/ Anti-CD33 Chimeric Antigen Receptor-Modified T Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5891-5891
Author(s):  
Jacob Halum Basham ◽  
Terrence L. Geiger
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
Chimeric Antigen Receptor ◽  
Short Term ◽  
Car T Cells ◽  
Tnf Α ◽  
Car T ◽  
Ifn Γ

Abstract Chimeric antigen receptor-modified T lymphocytes (CART cells) have shown benefit as an adjuvant immunotherapy in the treatment of B cell malignancies. This success of re-targeted T cells has not been extended to other hematologic malignancies. We have developed an immunotherapeutic approach to treat acute myeloid leukemia (AML) using CAR T cells re-directed against the myeloid-specific antigen CD33 (CART-33). CART-33 cells are potent and specific in eliminating AML cells in vitro and in vivo. Despite this, CART-33 cells have shown poor in vivo expansion and persistence in NOD-SCID IL2rγ (-/-) (NSG) AML xenograft models. To address the reason for this, we assessed the impact of AML-expressed programmed death ligands 1 & 2 (PD-L1/2) on CART-33 cell activity. PD-L1 inhibits T cell functions upon binding PD-1, which is upregulated with T cell activation. Less is known about PD-L2's effect. Interferon-gamma (IFN-γ), a primary effector cytokine secreted by CD4+ and CD8+ effector T cells, is a known potent inducer of PD-L1 on AML blasts. Using AML cell lines U937, Oci-AML3, CMK, and MV4-11 we show that IFN-γ, TNF-α, and activated CART-33 supernatant can induce up-regulation of PD-L1 and PD-L2 on AML. IFN-γ and TNF-α synergize strongly in up-regulating PD-1 ligands on AML. The kinetics and induction of PD-L2 are distinct from that of PD-L1. Although PD-L1 is well documented to suppress T cell function via ligation of T cell expressed PD-1, induction of PD-L1/L2 had no effect on the cytolytic activity of CART-33 cells against AML in short term (<48 h) cultures. Paradoxically, 24 hr pre-treatment of AML with either IFN-γ or CART-33 supernatant increased AML susceptibility to killing by CART-33 cells despite elevated expression of PD-L1/L2 by AML. Our results highlight the regulatory complexity of AML cytolysis by re-targeted T lymphocytes, and argue that tumor-expressed PD-L1 and PD-L2 impacts the sustainability, but not short-term killing activity, of adoptively transferred CAR T cells in the treatment of AML. Disclosures No relevant conflicts of interest to declare.

scholarly journals Targeting Antigen Presenting   Cells to Treat Autoimmune  Inflammation

2021 ◽  
Author(s):  
◽  
Aras Toker
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Mhc Class Ii ◽  
T Cell Proliferation ◽  
Target Cells ◽  
Antigen Presenting

<p>Glatiramer acetate (GA) is approved for the treatment of relapsing-remitting multiple sclerosis (MS), and can suppress experimental autoimmune encephalomyelitis (EAE), a murine model of human MS. GA treatment is associated with the induction of anti-inflammatory TH2 responses and with the antigen specific expansion of regulatory T cells that counteract or inhibit pathogenic events in MS and EAE. These T cell mediated mechanisms of protection are considered to be a result of modulation of antigen presenting cells (APCs) by GA, rather than direct effects on T cells. However, it is unknown if GA preferentially targets a specific APC subset or can act through multiple APCs in vivo. In addition, GA-modulated innate cells may also exhibit direct antigen non-specific suppression of autoreactive cells. One objective of this study was to identify the in vivo target cell population of GA and to assess the potential of the target cells to antigen non-specifically suppress immune responses. Fluorophor-labelled GA bound to monocytes after intravenous injections, suggesting that monocytes may be the primary target of GA in vivo. In addition, intravenous GA treatment enhanced the intrinsic ability of monocytes to suppress T cell proliferation, both in vitro and in vivo. The findings of this study therefore suggest that GA-induced monocytes may contribute to GA therapy through direct mechanisms of antigen non-specific T cell immunosuppression. A further objective of this work was to investigate the potential of an in vivo drug targeting approach. This approach was hypothesised to increase the uptake of GA by the target cells and substantially improve GA treatment through antigen specific mechanisms such as induction of TH2 or regulatory T cells. Targeting antigens to professional APCs with an anti-MHC class II antibody resulted in significantly enhanced T cell proliferation in vitro. However, no EAE suppression occurred when GA was targeted to MHC class II in vivo. In addition, targeting GA specifically to monocytes also failed to suppress EAE. These findings suggest that GA treatment may selectively modulate monocytes to enhance their ability to inhibit autoreactive T cells, which could be part of the mechanism by which GA ameliorates MS. Targeting GA to a specific cell type may not be a powerful approach to improve treatment, because increased proliferation of GA specific T cells is not sufficient for disease suppression, and conjugation to antibodies may functionally reduce GA to a mere antigen devoid of immunomodulatory capacity.</p>

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