Treg-related Genes Research Articles

Upregulation of Treg-Related Genes in Addition with IL6 Showed the Significant Role for the Distant Metastasis in Colorectal Cancer.

T helper 17 (Th17) and T regulatory (Treg) cytokines appear to be contributing greatly to colorectal cancer (CRC) development and progression. The aim of the current study was to investigate the expression of Foxp3; IL10; TGFB1; IL17A; IL6 and NOS2 genes in tumor tissue, regional positive lymph nodes and distant metastasis obtained from 26 patients with advanced CRC. Quantitative real-time polymerase chain reaction (qPCR) was performed for mRNA detection by TaqMan gene expression assay. In distant metastasis, IL6 was strongly expressed, over 7.5 fold, followed by Treg-related genes Foxp3; IL10 and TGFB1 in contrast to IL17A and NOS2. The similar pattern of expression was observed in positive regional lymph node in addition to significant down-regulation of NOS2 (RQ=0.287; p=0.011) and a trend for the elevation of IL17A. In tumor tissue, Fopx3 was significantly upregulated and Foxp3 mRNA positively correlated with TGFB1 in all investigated tissue types. In tumor tissue, expression of IL17A was correlated with NOS2 (r=0.68; p=0.005), while in distant metastasis IL10 was in strong relation with TGFB1 and IL6. In addition, a reverse correlation between IL6 and NOS2 (r=-0.66; p=0.009), was observed in distant metastasis. The simultaneous expression of given Treg and Th17-related genes found both in the primary tumor and in the regional lymph nodes appears to provide suitable microenvironment sufficient for promoting metastatic growth. The upregulation of Foxp3; IL10, TGFB1 and IL6 might be a transcriptional profile hallmark for colorectal metastases.

Abstract 17: Apolipoprotein C-III Promotes Anti-Inflammatory Regulatory T Cell Phenotype Through Modulation of Intestinal Dendritic Cell Activation

Apolipoprotein C-III (apoC-III) is a cardio-metabolic modulator in multiple tissues. Circulating apoC-III in humans is an independent risk factor for cardiovascular disease (CVD) because apoC-III increases circulating triglyceride (TG) through inhibition of the LDLR in the liver and lipoprotein lipase on the capillary endothelium. In the liver, apoC-III overexpression results in increased synthesis and secretion of more TG-rich VLDL. These actions increase the resident time and amount of atherogenic remnants in circulation. Paradoxically, apoC-III acts in the intestine to inhibit dietary fat absorption, a potentially beneficial action. Using human-apoC-III transgenic mice (hu-apoCIII tg mice), which have increased circulating TG compared to C57Bl6/J littermate controls (WT), we have identified an increase in circulating IL-10 at basal conditions. Regulatory T cells (Tregs), a T cell subset that is known to delay atheroprogression, secrete the anti-inflammatory cytokine IL-10. Knowing that the immune system plays a dynamic role in atherogenesis, we asked whether apoC-III is a potential modulator of Tregs during a western diet (WD) challenge. We subjected hu-apoCIII tg and WT mice to 12 weeks of a WD and through flow cytometry, found significantly increased circulating and intestinal Tregs in hu-apoCIII tg mice compared to WT. Hu-apoCIII tg intestinal gene expression showed increases in TGF-β and maintenance of IL-10 and FOXP3, key Treg-related genes, after the WD compared to WT. We hypothesized that apoC-III may act in the intestine to induce tolerance to dietary antigens through dendritic cell (DC) activation and subsequent differentiation of naïve T cells to the Treg phenotype. Using flow cytometry of the lamina propria, we saw increased activation of intestinal DCs, in hu-apoCIII tg mice at basal and WD-challenged conditions suggesting that intestinal DCs are influenced by apoC-III overexpression. These results suggest that apoC-III may influence Treg differentiation or proliferation through alteration of intestinal DC activation. The phenotype we have uncovered in hu-apoC-III tg mice suggests a link between apoC-III overexpression, dietary fat absorption, and the immune system, and that this may be protective against inflammation.

Regulatory T cell transfer ameliorates lymphedema and promotes lymphatic vessel function.

Secondary lymphedema is a common postcancer treatment complication, but the underlying pathological processes are poorly understood and no curative treatment exists. To investigate lymphedema pathomechanisms, a top-down approach was applied, using genomic data and validating the role of a single target. RNA sequencing of lymphedematous mouse skin indicated upregulation of many T cell-related networks, and indeed depletion of CD4+ cells attenuated lymphedema. The significant upregulation of Foxp3, a transcription factor specifically expressed by regulatory T cells (Tregs), along with other Treg-related genes, implied a potential role of Tregs in lymphedema. Indeed, increased infiltration of Tregs was identified in mouse lymphedematous skin and in human lymphedema specimens. To investigate the role of Tregs during disease progression, loss-of-function and gain-of-function studies were performed. Depletion of Tregs in transgenic mice with Tregs expressing the primate diphtheria toxin receptor and green fluorescent protein (Foxp3-DTR-GFP) mice led to exacerbated edema, concomitant with increased infiltration of immune cells and a mixed TH1/TH2 cytokine profile. Conversely, expansion of Tregs using IL-2/anti-IL-2 mAb complexes significantly reduced lymphedema development. Therapeutic application of adoptively transferred Tregs upon lymphedema establishment reversed all of the major hallmarks of lymphedema, including edema, inflammation, and fibrosis, and also promoted lymphatic drainage function. Collectively, our results reveal that Treg application constitutes a potential new curative treatment modality for lymphedema.

Atherosclerosis-Driven Treg Plasticity Results in Formation of a Dysfunctional Subset of Plastic IFNγ+ Th1/Tregs.

Forkhead box P3+ T regulatory cells (Tregs) are key players in maintaining immune homeostasis. Evidence suggests that Tregs respond to environmental cues to permit or suppress inflammation. In atherosclerosis, Th1-driven inflammation affects Treg homeostasis, but the mechanisms governing this phenomenon are unclear. Here, we address whether atherosclerosis impacts Treg plasticity and functionality in Apoe-/- mice, and what effect Treg plasticity might have on the pathology of atherosclerosis. We demonstrate that atherosclerosis promotes Treg plasticity, resulting in the reduction of CXCR3+ Tregs and the accumulation of an intermediate Th1-like interferon (IFN)-γ+CCR5+ Treg subset (Th1/Tregs) within the aorta. Importantly, Th1/Tregs arise in atherosclerosis from bona fide Tregs, rather than from T-effector cells. We show that Th1/Tregs recovered from atherosclerotic mice are dysfunctional in suppression assays. Using an adoptive transfer system and plasticity-prone Mir146a-/- Tregs, we demonstrate that elevated IFNγ+ Mir146a-/- Th1/Tregs are unable to adequately reduce atherosclerosis, arterial Th1, or macrophage content within Apoe-/- mice, in comparison to Mir146a+/+ Tregs. Finally, via single-cell RNA-sequencing and real-time -polymerase chain reaction, we show that Th1/Tregs possess a unique transcriptional phenotype characterized by coexpression of Treg and Th1 lineage genes and a downregulation of Treg-related genes, including Ikzf2, Ikzf4, Tigit, Lilrb4, and Il10. In addition, an ingenuity pathway analysis further implicates IFNγ, IFNα, interleukin-2, interleukin-7, CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), T-cell receptor, and Csnk2b-related pathways in regulating Treg plasticity. Atherosclerosis drives Treg plasticity, resulting in the accumulation of dysfunctional IFNγ+ Th1/Tregs that may permit further arterial inflammation and atherogenesis.

Water soluble extracts from Actinidia arguta, PG102, attenuates house dust mite-induced murine atopic dermatitis by inhibiting the mTOR pathway with Treg generation

Ethnopharmacological relevanceActinidia arguta is widespread in northeastern Asia, being found in Siberia, Korea, Japan, and northern China. These fruits have been documented to regulate the uncontrolled heat of body resulting in various allergic diseases in the Korean traditional medicine. PG102, a water-soluble extract from an edible fruit, A. arguta, has been previously shown to control various factors involved in allergic pathogenesis. Aim of the studyIn this study, we investigated whether PG102 prevents chronic allergic reactions via the generation of Tregs, which play a preventive role in the pathogenesis of allergic disease. Methods and resultsIn dust mite extract-induced chronic atopic dermatitis, orally administered PG102 inhibited symptoms of dermatitis, including ear swelling and erythema, and decreased lymphocyte infiltration into the inflamed region. Moreover, PG102 reduced inflammatory T cell responses and increased the expression levels of Foxp3 and other Treg-related genes. PG102 treatment enhanced the induction of CD4+Foxp3+ Tregs from naive CD4+CD62L+ T cells, probably via the inhibition of mTOR activation and the phosphorylation of STAT5 rather than using the TGF-β signaling pathway. ConclusionPG102 may have potential as an orally active immunosuppressor for preventing chronic inflammatory diseases.

Abstract 447: Atherosclerosis-driven Treg Plasticity Results in the Formation of a Dysfunctional Subset of Plastic IFNg + Th1/Tregs

Foxp3 + T regulatory cells (Tregs) are key players in maintaining immune homeostasis. Emerging evidence suggests that Tregs respond to environmental cues to permit or suppress inflammation. In atherosclerosis, Th1-driven inflammation affects Treg homeostasis, but the mechanisms governing this phenomenon are unclear. Here, we addressed whether atherosclerosis impacts Treg plasticity or functionality in Apoe -/- mice and what effect Treg plasticity might have on the pathology of atherosclerosis. We demonstrate that atherosclerosis promotes Treg plasticity, resulting in the reduction of CXCR3 + Tregs, and the accumulation of an intermediate Th1-like IFNγ + CCR5 + Treg subset (Th1/Tregs) within the arterial wall. Using Foxp3 Gfp/Gfp and Foxp3 Yfp-cre/Yfp-cre Rosa tdTomato/tdTomato lineage tracing mice, we demonstrate that Th1/Tregs arise in atherosclerosis from bona fide Tregs, rather than T effector cells. Th1/Tregs recovered from atherosclerotic mice are dysfunctional in suppression assays. Importantly, using Mir146a -/- mice, we demonstrate that plasticity-prone Mir146 -/- Tregs fail to reduce atherosclerosis, arterial Th1, or macrophage content in Apoe -/- recipients. Lastly, we utilized single cell RNA-sequencing to gain whole transcriptome information on Th1/Tregs, Treg, and Th1 cells. Th1/Tregs yielded a unique transcriptional phenotype characterized by co-expression of Treg and Th1 lineage genes, and down-regulation of Treg-related genes, including Ikzf2 , Ikzf4, Tigit, and Lilrb4 . Additionally, an ingenuity pathway analysis further implicates IFNγ, IFNα, IL-2, IL-7, CTLA4, T cell receptor, and Csnk2b-related pathways in regulating Treg plasticity. In conclusion, atherosclerosis drives Treg plasticity, resulting in the accumulation of dysfunctional IFNγ + Th1/Tregs that permit further arterial inflammation and atherogenesis.

Identification of TIGIT as an HBZ-induced gene by genome-wide analyses: its association with evasion of host defense

Human T-cell leukemia virus type 1 (HTLV-1) is a causative virus of adult T-cell leukemia (ATL), and inflammatory diseases. HTLV-1 bZIP factor (HBZ) is encoded on the minus strand of HTLV-1, and expressed in all ATL cases. We performed RNA-seq and ChIP-seq using HBZ transduced T cells, and found that expressions of several Treg-related genes, including Foxp3, CD25, CCR4, CCR5, PD-1, NRP1, IKZF family genes, and T-cell immunoglobulin and ITIM domain receptor (Tigit), were upregulated by HBZ. We focused on TIGIT in this study. TIGIT expression was also upregulated in HTLV-1 infected cells in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients and CD4+ T cells of ATL patients. HBZ induced the histone modification of the promoter of TIGIT and enhanced its expression. HBZ also enhanced acetylation of H3K18, which is the specific target of p3. HBZ augments transcription of Tigit gene in the presence of PMA/Ionomycin stimulation. Although the detailed mechanism of HBZ mediated activation of Tigit transcription is still unclear, p3 and activated pathway by PMA/Ionomycin is likely involved in its regulation. Furthermore, we analyzed the function of Tigit in HBZ-expressing T cells and CD4+ T cells from HBZ-transgenic mice (HBZ-Tg), and found that stimulation of Tigit with its ligand, PVR, enhanced expression of inhibitory cytokines, such as IL-10, in HBZ-Tg. These results suggest that the enhanced Tigit expression by HBZ may play a key role to modulate the microenvironment where anti-tumor immune response is attenuated by increased expression of IL-10. This environment seems to be associated with the evasion of HTLV-1 infected cells from anti-tumor host immune response and the pathogenesis of HTLV-1 associated inflammatory diseases and ATL.

Remission of systemic lupus erythematosus disease activity with regulatory cytokine interleukin (IL)-35 in Murphy Roths Large (MRL)/lpr mice.

The immunological mechanisms mediated by regulatory cytokine interleukin (IL)-35 are unclear in systemic lupus erythematosus (SLE). We investigated the frequency of CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) regulatory T (Treg ) and IL-10(+) regulatory B (Breg ) cells and related immunoregulatory mechanisms in a female Murphy Roths Large (MRL)/lpr mouse model of spontaneous lupus-like disease, with or without IL-35 treatment. A remission of histopathology characteristics of lupus flare and nephritis was observed in the MRL/lpr mice upon IL-35 treatment. Accordingly, IL-35 and IL-35 receptor subunits (gp130 and IL-12Rβ2) and cytokines of MRL/lpr and BALB/c mice (normal controls) were measured. The increased anti-inflammatory cytokines and decreased proinflammatory cytokines were possibly associated with the restoration of Treg and Breg frequency in MRL/lpr mice with IL-35 treatment, compared to phosphate-buffered saline (PBS) treatment. mRNA expressions of Treg -related FoxP3, IL-35 subunit (p35 and EBI3) and soluble IL-35 receptor subunit (gp130 and IL12Rβ2) in splenic cells were up-regulated significantly in IL-35-treated mice. Compared with the PBS treatment group, IL-35-treated MRL/lpr mice showed an up-regulation of Treg -related genes and the activation of IL-35-related intracellular Janus kinase/signal transducer and activator of transcription signal pathways, thereby indicating the immunoregulatory role of IL-35 in SLE. These in vivo findings may provide a biochemical basis for further investigation of the regulatory mechanisms of IL-35 for the treatment of autoimmune-mediated inflammation.

Hydroxychloroquine decreases the upregulated frequencies of Tregs in patients with oral lichen planus

Regulatory T cells (Tregs) have emerged as important mediators in inflammatory and autoimmune diseases. We investigated the possible involvement of Tregs in oral lichen planus (OLP) and the influence of clinical therapy (hydroxychloroquine and prednisone) on the frequencies of Tregs in OLP patients. One hundred fifty patients diagnosed with OLP were the study cohort. Levels of Tregs in blood and tissues were detected using flow cytometry and immunostaining, respectively. Cytokine production was assessed using a proteome profiler array and determined by enzyme-linked immunosorbent assay. mRNA expression of transcription factors was detected by real-time quantitative PCR. Hydroxychloroquine or prednisone was used to treat patients randomly. The frequency of Tregs was detected before treatment and 2 weeks after treatment. Compared with healthy volunteers, OLP patients had a higher proportion of Tregs in serum and tissues before treatment (P < 0.001). Serum concentrations of interleukin (IL)-8, transforming growth factor (TGF)-β1, and IL-10 were significantly higher in patients than those in healthy controls. mRNA expression of Treg-related genes, including TGF-β, IL-10, signal transducer and activator of transcription 6, and GATA binding protein 3, were upregulated significantly in OLP patients. The frequency of Tregs was downregulated after hydroxychloroquine treatment. These results suggest that Tregs may contribute to the immunopathogenesis of OLP and may provide a new therapeutic target for OLP treatment. T cell-mediated immune dysfunction may have a crucial role in OLP development. However, T helper 1 (Th1)/Th2 imbalance does not appear to be sufficient to understand the pathogenesis of OLP. This is the first study to show that Tregs are involved in the immunopathogenesis of OLP.

Analysis of the prognostic impact of Treg-related genes in tumor and stroma in resectable NSCLC.

11073 Background: Immunosuppressive regulatory T lymphocytes (Tregs) have been proved to play a critical role in immune tolerance to tumor. In this study we have analyzed the expression of 11 genes related to Tregs in both tumor and stroma samples of resectable NSCLC patients. Methods: Primary tumor tissues of FFPE samples from 125 early-stage NSCLC patients were used in this retrospective study. The most representative areas of tumor cells and tumor stroma of each sample were carefully micro-dissected. RTqPCR using hydrolysis probes (TaqMan, Applied Biosystems) was performed to assess the expression of Treg markers such as: CD127, CD25, FOXP3, CTLA-4, IL-10, TGFB-1, LAG-3, GITR and TNF-a as well as CD4 and CD8. Relative gene expression was assessed using GAPDH and CDKN1B as endogenous controls and results were normalized against a human cDNA (Clontech) as a reference. All statistical analyses were considered significant at p&lt; 0.05. Results: In both tumor and stroma, we found over-expression of CD25 (5.40X and 7.95X, respectively) and down-expression of CD127 (0.28X and 0.37X, respectively). There was a tendency toward higher expression of FOXP3 (1.67X and 2.01X, respectively) and CTLA-4 (1.92X and 1.76X, respectively) as well. Paired Wilcoxon test showed significant gene expression differences between tumor and stroma in FOXP3 (p=0.006), CD25 (p&lt;0.0001), CD4 (p&lt;0.0001), CD8 (p=0.028), IL-10 (p&lt;0.0001) and TGFB-1 (p&lt;0.0001). Kruskal-Wallis test showed that FOXP3 expression was higher in adenocarcinoma than in SCC samples (2.56X vs 1.79X, p=0.002). Survival analyses revealed that patients with a “Treg profile” (↑CD25 and ↓CD127) had a reduced overall survival (OS) (median 29.90 vs 74.33 months, p=0.003). We also found that those patients with higher levels of the ratio FOXP3 stroma/tumor had worse time to progression (TTP) (median 32.50 vs NR, p=0.04). Conclusions: Treg markers in the tumor microenvironment seem to play an important prognostic role in early-stage NSCLC patients. Supported by grants PS09-01149 and RD06/0020/1024 from ISCIII.

Altered AKT1 and MAPK1 Gene Expression on Peripheral Blood Mononuclear Cells and Correlation with T-Helper-Transcription Factors in Systemic Lupus Erythematosus Patients

Kinases have been implicated in the immunopathological mechanisms of Systemic Lupus Erythematosus (SLE). v-akt murine-thymoma viral-oncogene-homolog 1 (AKT1) and mitogen-activated-protein-kinase 1 (MAPK1) gene expressions in peripheral mononuclear cells from thirteen SLE patients with inactive or mild disease were evaluated using quantitative real-time reverse-transcription polymerase-chain-reaction and analyzed whether there was any correlation with T-helper (Th) transcription factors (TF) gene expression, cytokines, and S100A8/S100A9-(Calprotectin). Age- and gender-matched thirteen healthy controls were examined. AKT1 and MAPK1 expressions were upregulated in SLE patients and correlated with Th17-(Retinoic acid-related orphan receptor (ROR)-C), T-regulatory-(Treg)-(Transforming Growth Factor Beta (TGFB)-2), and Th2-(interleukin (IL)-5)-related genes. MAPK1 expression correlated with Th1-(IL-12A, T-box TF-(T-bet)), Th2-(GATA binding protein-(GATA)-3), and IL-10 expressions. IL-10 expression was increased and correlated with plasma Tumor Necrosis Factor (TNF)-α and Th0-(IL-2), Th1-(IL-12A, T-bet), GATA3, Treg-(Forkhead/winged-helix transcription factor- (FOXP)-3), and IL-6 expressions. FOXP3 expression, FOXP3/RORC, and FOXP3/GATA3 expression ratios were increased. Plasma IL-1β, IL-12(p70), Interferon-(IFN)-γ, and IL-6 cytokines were augmented. Plasma IL-1β, IL-6, IL-2, IFN-γ, TNF-α, IL-10, and IL-13 correlated with C-reactive protein, respectively. Increased Calprotectin correlated with neutrophils. Conclusion, SLE patients presented a systemic immunoinflammatory activity, augmented AKT1 and MAPK1 expressions, proinflammatory cytokines, and Calprotectin, together with increased expression of Treg-related genes, suggesting a regulatory feedback opposing the inflammatory activity.

A differential interplay between the expression of Th1/Th2/Treg related cytokine genes in Teladorsagia circumcincta infected DRB1*1101 carrier lambs

Substantial debate exists on whether the immune response between sheep resistant and susceptible to gastrointestinal nematodes can be differentiated into a Th1 and Th2 phenotype. The present study addresses the hypothesis that variation in resistance to Teladorsagia circumcincta between DRB1*1101 (associated with reduced faecal egg count and worm burden) carriers and non-carriers is due to a differential interplay in the expression of Th1/Th2 and regulatory T (Treg) related cytokine genes. Lambs from each genotype were either slaughtered at day 0 (un-infected control) or infected with 3 × 104 Teladorsagia circumcincta L3 and slaughtered at 3, 7, 21, and 35 days later. Lambs carrying the DRB1*1101 allele had a significantly lower worm burden (P < 0.05) compared to the non-carriers. Abomasal mucosal cytokine gene expression was evaluated by quantitative real-time PCR and comparison made for time and genotype effects. The response generated varied through the course of infection and was affected by genotype. DRB1*1101 carriers had an up-regulated expression of the Th1-related cytokine genes (IL-1β, TNFα, and IFN-γ) at day 3, but this was replaced by an up-regulated expression of Th2-related cytokine genes (IL-10 and IL-13) and Treg-related cytokine genes (IL-2RA-CD25, TGFα, TGFβ, Arg2, MIF and FOXP3) by day 7. Conversely, in the non-carriers these changes in gene expression were delayed until days 7 and 21 post infection (pi), respectively. It is concluded that resistance to Teladorsagia circumcincta in animals carrying the DRB1*1101 allele is influenced by an earlier interplay between Th1, Th2 and T regulatory immune response genes.

Blocking of IL-6 suppresses experimental autoimmune myasthenia gravis

Suppressive regulatory T cells (Treg) and pathogenic T helper 17 (Th17) cells are two lymphocyte subsets with opposing activities in autoimmune diseases. The proinflammatory cytokine IL-6 is a potent factor in switching immune responses in vivo from the induction of Treg to pathogenic Th17 cells. We studied the Treg and Th17 cell compartments in experimental autoimmune myasthenia gravis (EAMG) and healthy control rats in order to assess whether the equilibrium between Treg and Th17 cells is perturbed in the disease. We found that Th17 cell-related genes are upregulated and Treg-related genes are downregulated in EAMG. The shift in favor of Th17 cells in EAMG could be reversed by antibodies to IL-6. Administration of anti-IL-6 antibodies to myasthenic rats suppressed EAMG when treatment started at the acute or at the chronic phase of disease. Suppression of EAMG by anti-IL-6 antibodies was accompanied by a decrease in the overall rat anti-AChR antibody titer and by a reduced number of B cells as compared with control treatment. Administration of anti-IL-6 antibodies led to down-regulation of several Th17 related genes including IL-17, IL-17R, IL-23R and IL-21 but did not affect the number of Treg cells in the lymph nodes. These data identify IL-6 as an important target for modulation of autoimmune responses.

M1747 Cationic Amino Acid Transporter 2 Has an Important Role in Regulation of Proinflammatory Mediators in DSS Colitis

molecular insights to IBD, we find 17-AAG use profoundly suppresses development of DSSinduced colitis. In another model of colitis, adoptive transfer of CD4+CD45Rbhi cells to Rag deficient mice leads to colitis at ~50 days, and compared with DMSO-treated controls, mice treated with 17-AAG did not develop colitis, gained weight(p<0.05), and had negligible diarrhea and near normal histology. In addition, flow cytometry showed increased absolute numbers of CD4+Foxp3+ cells in the lymph nodes and increased expression of Treg related genes, CTLA-4, and IL-10. Lastly, We noted an anti-inflammatory effect on effector T cells themselves including a decrease in IL-17 expression as well as decreases in Th1 cytokines. In summary, HSP90i(17-AAG) use can regulate Foxp3-dependent functions and enhance Treg suppression with biologically important consequences. In addition, HSP90i can inhibit Th1 and Th17 cell cytokine secretion. Dissecting the complex interactions of the heat shock response including HSF1, HSP90 , HSP70 and others, presents but one of several potential ways to pharmacologically manipulate Treg cells In Vitro and In Vivo, with likely future beneficial consequences for the therapy of IBD.

Evaluation of T-cell activation in the duodenum of dogs with cutaneous food hypersensitivity

To determine whether skin-related clinical signs in cutaneous food hypersensitivity (CFH) coincide with immune reactivity in the intestine in dogs. 11 dogs with CFH without intestinal clinical signs and 8 healthy control dogs. After a provocation and elimination diet, the duodenal gene expression levels of Th1-, Th2- and Treg-related cytokines and transcription factors were investigated by means of quantitative PCR assay. The presence of CD3(+), CD8(+), CD4(+), CD1c(+), gammadelta T-cell receptor(+), and major histocompatibility complex II(+) cells in duodenal epithelium and lamina propria were determined. The expression of Th1-, Th2-, and Treg-related genes in dogs with CFH and healthy control dogs was similar. Although clinical signs disappeared, there was no effect of the elimination diet on cytokines, transcription factors, or cellular phenotypes. No change in T-cell phenotypes or a distinct Th1, Th2, or Treg profile was detected in the duodenum of dogs with only cutaneous clinical signs of food hypersensitivity. This suggested that the intestinal mucosa is not the primary site of T-cell activation that eventually leads to cutaneous food hypersensitivity.

Rapamycin promotes tolerance through increased expression of CD4+CD25+Foxp3+ regulatory T cells and impaired development of CD8+CD44+CD62L+ memory T cells. (145.25)

Abstract Long-term success of transplantation is limited by the need for immunosuppression; thus, tolerance induction is an important therapeutic goal. A 16 day treatment with Rapamycin led to indefinite graft survival (&amp;gt;100 days) of fully mismatched cardiac allografts (BALB/cJ → C3H/HeJ) whereas untreated hearts were rejected at day 9 + 2 days. Specific tolerance was confirmed by the observation that skin grafts from donor mice were accepted, whereas grafts from a 3rd party were rejected. T-lymphocytes from tolerant mice exhibited lower proliferation and cytotoxicity towards donor but not to 3rd party antigens. CD8+CD44+ memory T cells were reduced in tolerant mice but had increased expression of L-selectin (CD62L). CD4+CD25+Foxp3+ regulatory T cells (Tregs) were increased in tolerant mice. We next examined 23 Treg-related genes by multiplex PCR, and found an increase in expression of Foxp3, Tgfb1, Lag3 and Fgl2 and decreased expression of IFNγ and granzyme B in tolerant hearts, but not in rejecting hearts. Plasma levels of FGL2 determined by ELISA remained elevated in tolerant mice. Here we demonstrate that Rapamycin-induced specific tolerance to fully mismatched cardiac allografts is associated with increased numbers of Tregs and impaired development of memory T cells. Expression of Treg effector molecules may serve as putative biomarkers of tolerance in patients undergoing transplantation.

Functional and genomic analyses of FOXP3-transduced Jurkat-T cells as regulatory T (Treg)-like cells

FOXP3, a forkhead transcription factor is essential for the development and function of CD4+CD25+ regulatory T cells (Tregs). In contrast to conversion of murine naive T cells to Tregs by transduction of Foxp3, it is controversial whether ectopic expression of FOXP3 in human CD4+ T cells is sufficient for acquisition of suppressive activity. Here, we show that retroviral transduction of FOXP3 induces a Treg phenotype in human leukemic CD4+ Jurkat-T cells, evidenced by increased expression of Treg-associated cell surface markers as well as inhibition of cytokine production. Furthermore, FOXP3-transduced Jurkat-T cells suppress the proliferation of human CD4+CD25− T cells. Additionally, DNA microarray analysis identifies Treg-related genes regulated by FOXP3. Our study demonstrates that enforced expression of FOXP3 confers Treg-like properties on Jurkat-T cells, which can be a convenient and efficient Treg-like cell model for further study to identify Treg cell surface markers and target genes regulated by FOXP3.