Levels Of Treg Cells Research Articles

Level of Granzyme B-positive T-regulatory cells is a strong predictor biomarker of acute Graft-versus-host disease after day +30 after allo-HSCT

Acute Graft-versus-host-disease (aGVHD), the major complication and one of the main causes of poor outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Nowadays there are no widely accepted cell, plasma or another biomarker that can be used for aGVHD prediction. We hypothesized that a level of Granzyme B-positive T regulatory (GZMB-positive Treg) cells on day+30 after allo-HSCT could be the measure of immune response suppression and could predict aGVHD development after day +30. We applied a widespread and easy-to-perform method of multicolor flow cytometry to measure level of GZMB-positive Treg cells. Levels of GZMB-positive Tregs on day +30 after allo-HSCT were significantly higher in those patients who never developed aGVHD in comparison with the other group of patient with aGVHD after day +30 (p=0.0229). We conclude that the level of GZMB-positive Treg cells is a strong predictor of acute Graft-versus-host disease after day +30 after allo-HSCT.

Cancer-FOXP3 directly activated CCL5 to recruit FOXP3+Treg cells in pancreatic ductal adenocarcinoma

Forkheadbox protein 3 (FOXP3), initially identified as a key transcription factor for regulatory T cells (Treg cells), was also expressed in many tumors including pancreatic ductal adenocarcinoma (PDAC). However, its role in PDAC progression remains elusive. In this study, we utilized 120 PDAC tissues after radical resection to detect cancer-FOXP3 and Treg cells by immunohistochemistry and evaluated clinical and pathological features of these patients. Cancer-FOXP3 was positively correlated with Treg cells accumulation in tumor tissues derived from PDAC patients. In addition, high cancer-FOXP3 expression was associated with increased tumor volumes and poor prognosis in PDAC especially combined with high levels of Treg cells. Overexpression of cancer-FOXP3 promoted the tumor growth in immunocompetent syngeneic mice but not in immunocompromised or Treg cell-depleted mice. Furthermore, CCL5 was directly trans-activated by cancer-FOXP3 and promoted the recruitment of Treg cells from peripheral blood to the tumor site in vitro and in vivo. This finding has been further reinforced by the evidence that Treg cells recruitment by cancer-FOXP3 was impaired by neutralization of CCL5, thereby inhibiting the growth of PDAC. In conclusion, cancer-FOXP3 serves as a prognostic biomarker and a crucial determinant of immunosuppressive microenvironment via recruiting Treg cells by directly trans-activating CCL5. Therefore, cancer-FOXP3 could be used to select patients with better response to CCL5/CCR5 blockade immunotherapy.

Critical influence of the thymus on peripheral T cell homeostasis.

IntroductionA tight balance between regulatory CD4+Foxp3+ (Treg) and conventional CD4+Foxp3− (Tconv) T cell subsets in the peripheral compartment, maintained stable throughout most of lifetime, is essential for preserving self‐tolerance along with efficient immune responses. An excess of Treg cells, described for aged individuals, may critically contribute to their reported immunodeficiency. In this work, we investigated if quantitative changes in thymus emigration may alter the Treg/Tconv homeostasis regardless of the aging status of the peripheral compartment.MethodsWe used two different protocols to modify the rate of thymus emigration: thymectomy of adult young (4–6 weeks old) mice and grafting of young thymus onto aged (18 months old) hosts. Additionally, lymphoid cells from young and aged B6 mice were intravenously transferred to B6.RAG2−/− mice. Alterations in Treg and Tconv peripheral frequencies following these protocols were investigated after 30 days by flow cytometry.ResultsThymectomized young mice presented a progressive increase in the Treg cell frequency, while the grafting of a functional thymus in aged mice restored the young‐like physiological Treg/Tconv proportion. Strikingly, T cells derived from young or aged splenocytes colonized the lymphopenic periphery of RAG−/− hosts to the same extent, giving rise to similarly elevated Treg cell levels irrespective of the age of the donor population. In the absence of thymus output, the Treg subset seems to survive longer, as confirmed by their lower proportion of Annexin‐V+ cells.ConclusionsOur data suggest that the thymus‐emigrating population, harboring an adequate proportion of Treg/Tconv lymphocytes, may be essential to keep the Treg cell balance, independently of age‐related shifts intrinsic to the peripheral environment or to the T cell biology.

Effects of the Sympathetic Nervous System on Regulatory T Cell and T Helper 1 Chemokine Expression in Patients with Acute Coronary Syndrome

Objective: To observe the effects of sympathetic overactivity on the immune system involved in the imbalance of T helper (Th) lymphocytes, we investigated the correlation between autonomic dysregulation and the generation of regulatory T (Treg) and Th1 chemokines in patients with acute coronary syndrome (ACS). Methods: Blood samples obtained from patients with coronary artery disease and controls were analyzed for levels of Th1 and Treg cells and their associated cytokines by flow cytometry. In addition, the activity of the cyclic adenosine monophosphate (cAMP), the levels of norepinephrine (NE), epinephrine (EPI) and serum cytokines, and the activity of protein kinase A (PKA) were analyzed by Western blot, radioimmunoassay, high-performance liquid chromatography and enzyme-linked immunoassay, respectively. All subjects were evaluated for heart rate variability (HRV). Results: Levels of Th1 cells and T-bet (a T-box transcription factor), NE, EPI, cAMP and PKA significantly increased (all p < 0.01) whereas HRV and levels of Treg cells and STAT5 decreased (all p < 0.01) in ACS patients compared to patients with stable angina and controls. The disorder of Th1 and Treg cells is closely related to the activation of cAMP-PKA induced by hyperactivity of the sympathetic system. Conclusions: This study showed that the abnormalities in specific subsets of CD4+ T cells are associated with sympathetic hyperactivity in ACS patients. It may provide surprising insights into the pathogenesis of arteriosclerosis, involving the regulation of the sympathetic nervous system on immune inflammation.

Regulatory T Cells and Vitamin D Status in Children with Chronic Autoimmune Thyroiditis.

Objective:It is suggested that vitamin D is one of the factors that can regulate the function of Treg cells. In this study, the relationships between Treg cells and vitamin D levels was investigated in pediatric chronic autoimmune thyroiditis (CAT) patients.Methods:Thirty-two children with CAT and 24 healthy subjects were studied. FOXP3 expressing CD4+CD25+high Foxp3+T cells were identified as Treg cells. At diagnosis, 25-hydroxycholecalciferol (25OHD3) levels were determined in all patients. FOXP3 expression was measured before and after vitamin D replacement therapy in patients having low levels of 25OHD3.Results:In the CAT patients, Treg cell levels did not differ from the control group, while the frequency of vitamin D deficiency was higher and FOXP3 molecule expression was lower. FOXP3 molecule expression significantly increased in CAT patients having vitamin D deficiency who were given vitamin D replacement.Conclusion:FOXP3 expression is decreased in pediatric CAT patients. This reduction seems to be associated with vitamin D levels. Vitamin D can play a role in enhancing natural Treg cell functions.

Butyrate inhibits interleukin-17 and generates Tregs to ameliorate colorectal colitis in rats.

BackgroundButyrate is an energy source for colonocytes that is formed by bacterial fermentation of dietary fiber in the colon and that exerts broad anti-inflammatory activities. Although the administration of butyrate improves homeostasis in patients and ameliorates IBD (Inflammatory Bowel Disease)-related lesions and symptoms, the anti-inflammatory mechanisms of butyrate still remain unclear. To explore the impact of butyrate on Treg (Regulatory T cell)/Th17 (T helper 17 cell) differentiation and colitis in rats.MethodsThe effect of butyrate on the expression of markers related to both Tregs and Th17 cells were determined in human monocytes as well as a rat model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid. Rats were treated with butyrate in vivo, whereas the rat splenocytes and human monocytes were treated in vitro.ResultsWe found that butyrate administration increased peripheral blood Treg cell levels as well as plasma levels of anti-Th17 cytokines (IL-10 and IL-12). Butyrate administration further suppressed IL-17 levels in both plasma and colonic mucosa, and ameliorated colonic colitis lesions in rats. This promotion of Treg activity and inhibition of IL-17 release was also observed in human venous monocytes and rat splenocytes in vitro.ConclusionsOur results suggest that butyrate plays a key role in regulating the Treg/Th17 balance and ultimately protects the colon mucosa against the development of IBD.

Association of preoperative EpCAM Circulating Tumor Cells and peripheral Treg cell levels with early recurrence of hepatocellular carcinoma following radical hepatic resection.

BackgroundThis study was carried out to determine the prognostic significance of preoperative peripheral epithelial cell adhesion molecule- positive (EpCAM+) circulating tumor cell (CTC) and T regulatory (Treg) cell levels in hepatocellular carcinoma (HCC) patients for the prediction of postoperative recurrence following curative resection.MethodsA total of 49 patients about to undergo curative resection for HCC were recruited into the study. PCR and FACS were used to detect the preoperative levels of EpCAMmRNA+ CTCs and CD4+CD25+Foxp3+ Treg cells. The prognostic value of EpCAMmRNA+ CTCs, CD4+CD25+Foxp3+ Treg cells, and other clinicopathological factors were analyzed by applying the Kaplan–Meier method and the multivariate Cox proportional hazards model.ResultsThe number of EpCAMmRNA+ CTCs and Treg/CD4+ cells showed significant correlation as prognostic factors of postoperative HCC recurrence: EpCAMmRNA+ CTC ≥ 2.22 (P = 0.001) and Treg/CD4+ ≥ 5.07 (P = 0.045), with EpCAMmRNA+ CTC ≥ 2.22 (P = 0.003, HR = 6.668) being the most important indicator. Patients with high CTC/Treg levels showed a significantly higher risk of developing postoperative HCC recurrence than those with low CTC/Treg levels (66.7 % vs. 10.3 %, P < 0.001). The high CTC/low Treg group also presented higher 1-year recurrence rates compared with the low CTC/low Treg level group (50.0 % vs. 10.3 %, P = 0.004).ConclusionsElevated EpCAMmRNA+ CTC and Treg/CD4+ levels were associated with early recurrence of HCC, indicative of poor clinical outcome. The combined detection of EpCAMmRNA+ CTC and Treg/CD4+ may therefore provide a novel prognostic predictor for HCC patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2526-4) contains supplementary material, which is available to authorized users.

Association of Increased Treg Cell Levels With Elevated Indoleamine 2,3-Dioxygenase Activity and an Imbalanced Kynurenine Pathway in Interferon-Positive Primary Sjögren's Syndrome.

Indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme that converts tryptophan to kynurenine, is driven in part by type I and type II interferons (IFNs). Naive T cells are polarized into FoxP3+ Treg cells upon exposure to either IDO+ cells or kynurenine. Recent studies have suggested that the kynurenine pathway reflects a crucial interface between the immune and nervous system. The aims of the present study were to evaluate whether Treg cell levels are elevated, in conjunction with increased IDO activity, in patients with primary Sjögren's syndrome (SS) who are positive for the IFN gene expression signature, and to investigate the downstream kynurenine pathway in these patients. Serum from 71 healthy controls, 58 IFN-negative patients with primary SS, and 66 IFN-positive patients with primary SS was analyzed using high-performance liquid chromatography to measure the levels of tryptophan and kynurenine. Expression levels of messenger RNA (mRNA) for IDO and downstream enzymes in the kynurenine pathway were assessed in CD14+ monocytes using real-time quantitative polymerase chain reaction. CD4+CD45RO+ T helper memory cell populations were analyzed by flow cytometry. Significantly increased levels of IDO activity (assessed as the kynurenine:tryptophan ratio) (P = 0.0054) and percentages of CD25(high) FoxP3+ Treg cells (P = 0.039) were observed in the serum from IFN-positive patients with primary SS, and these parameters were significantly correlated with one another (r = 0.511, P = 0.002). In circulating monocytes from IFN-positive patients with primary SS, the expression of IDO1 mRNA was up-regulated (P < 0.0001), and this was correlated with the IFN gene expression score (r = 0.816, P < 0.0001). Interestingly, the proapoptotic and neurotoxic downstream enzyme kynurenine 3-monooxygenase was up-regulated (P = 0.0057), whereas kynurenine aminotransferase I (KATI) (P = 0.0003), KATIII (P = 0.016), and KATIV (P = 0.04) were down-regulated in IFN-positive patients with primary SS compared to healthy controls. These findings demonstrate enhanced IDO activity in conjunction with increased percentages of CD25(high) FoxP3+ Treg cells in primary SS patients who carry the IFN signature. In addition, IFN-positive patients with primary SS exhibit an imbalanced kynurenine pathway, with evidence of a shift toward potentially more proapoptotic and neurotoxic metabolites. Intervening in these IFN- and IDO-induced immune system imbalances may offer a new array of possibilities for therapeutic interventions in patients with primary SS.

Immune dysregulation in patients with PTEN hamartoma tumor syndrome: Analysis of FOXP3 regulatory T cells

BackgroundPatients with heterozygous germline mutations in phosphatase and tensin homolog deleted on chromosome 10 (PTEN) experience autoimmunity and lymphoid hyperplasia.ObjectivesBecause regulation of the phosphoinositide 3-kinase (PI3K) pathway is critical for maintaining regulatory T (Treg) cell functions, we investigate Treg cells in patients with heterozygous germline PTEN mutations (PTEN hamartoma tumor syndrome [PHTS]).MethodsPatients with PHTS were assessed for immunologic conditions, lymphocyte subsets, forkhead box P3 (FOXP3)+ Treg cell levels, and phenotype. To determine the functional importance of phosphatases that control the PI3K pathway, we assessed Treg cell induction in vitro, mitochondrial depolarization, and recruitment of PTEN to the immunologic synapse.ResultsAutoimmunity and peripheral lymphoid hyperplasia were found in 43% of 79 patients with PHTS. Immune dysregulation in patients with PHTS included lymphopenia, CD4+ T-cell reduction, and changes in T- and B-cell subsets. Although total CD4+FOXP3+ Treg cell numbers are reduced, frequencies are maintained in the blood and intestine. Despite pathogenic PTEN mutations, the FOXP3+ T cells are phenotypically normal. We show that the phosphatase PH domain leucine-rich repeat protein phosphatase (PHLPP) downstream of PTEN is highly expressed in normal human Treg cells and provides complementary phosphatase activity. PHLPP is indispensable for the differentiation of induced Treg cells in vitro and Treg cell mitochondrial fitness. PTEN and PHLPP form a phosphatase network that is polarized at the immunologic synapse.ConclusionHeterozygous loss of function of PTEN in human subjects has a significant effect on T- and B-cell immunity. Assembly of the PTEN-PHLPP phosphatase network allows coordinated phosphatase activities at the site of T-cell receptor activation, which is important for limiting PI3K hyperactivation in Treg cells despite PTEN haploinsufficiency.

Anti-inflammatory effect of cholera toxin B subunit in experimental stroke.

BackgroundCholera toxin B subunit (CTB) has multifaceted immunoregulatory functions. Immunity plays an important role in the mechanism of stroke. However, little is known about whether CTB is beneficial for stroke.MethodsCTB was administered intraperitoneally after ischemia to rats subjected to transient focal ischemia. Infarct volumes, body weight loss, and neurologic deficits were measured. Cytokines, microglia/macrophage activation, and transcriptional factors in the ischemic brain were tested. The mRNA expressions of IL-1β and TNF-α were tested in the microglia/macrophage isolated from the ischemic hemisphere. γδT cells, IL-17-producing γδT cells, Th17 cells, and regulatory T (Treg) cells in the ischemic brain were tested. γδT cells and Treg cells in the peripheral blood were also evaluated.ResultsCTB reduced infarct volumes, neurologic deficits, and body weight loss after ischemia. At 24 h after ischemia, CTB downregulated the levels of IL-1β, TNF-α, NF-kB p65, phosphorylated-ERK1/2, and microglia/macrophage activation and suppressed NF-kB binding activity, but did not affect the level of ERK1/2. The mRNA expressions of IL-1β and TNF-α in the microglia/macrophage isolated from the ischemic hemisphere were suppressed after CTB therapy. In the ischemic hemisphere, CTB treatment reduced the levels of γδT cells, IL-17-producing γδT cells, and IL-17 at both 24 and 72 h after ischemia, while Th17 cells were not affected. After CTB treatment, the levels of Treg cells, TGF-β, and IL-10 remained unchanged at 24 h and upregulated at 72 h after ischemia. Inactivation of Treg cells using anti-CD25 attenuated the increase of TGF-β and IL-10 induced by CTB at 72 h after ischemia. In the peripheral blood, CTB increased Treg cells and suppressed γδT cells at 24 h after ischemia. And then at 72 h after ischemia, it increased Treg cells but did not impact γδT cells. CTB had no effect on cytokines, transcription factors, infiltrating γδT cells, and Treg cells in the brain of shams. In the peripheral blood of shams, CTB increased Treg cells at both 24 and 72 h, while it did not affect γδT cells.ConclusionsCTB decreased neurologic impairment and tissue injury after cerebral ischemia via its immunomodulatory functions, including inhibiting microglia/macrophage activation, suppressing γδT cells, and inducing production of Treg cells, thus regulating the secretion of related cytokines. Suppression of NF-kB and ERK1/2 pathways is involved in the neuroprotective mechanism of CTB.

Role of Interleukin - 1 alpha (IL-1α) and Regulatory T (Treg) Cells In The Pathogenesis of Inflammatory Bowel Disease

Background: Continuous effort has been paid to deeply understanding the pathophysiology of Inflammatory bowel diseases (IBD).It has been postulated that multiple factors such as genetic susceptibility, immunological and environmental factors are involved and generate a dysregulated response of the mucosal immune system toward intraluminal antigens. Accumulating evidence indicates that discrepancy between the number of T regulatory cells (Treg) in peripheral blood and in inflamed colonic mucosa has a central role and Interleukin (IL)-1 is a key mediator in the pathogenesis of IBD. Objective: The aim of this study was to determine the role of Interleukin1 alpha (IL-1α) and T regulatory (Treg) cells in the pathogenesis of IBD. Study Design: This study was conducted in internal medicine Department of ElHussein university hospital, AL-Azhar University. In this study, 50 subjects were selected and divided into two groups; Group A (n=30) were patients with IBD and Group B (n=20) were healthy control group. The two groups were subjected to the following; full history taking, clinical evaluation, Abdominal ultrasonography, CBC with differential count, Liver function tests, renal function tests, C-reactive protein , ESR and serum level of both Treg cells and IL-1α . IL-1α was detected in serum by ELISA and (Treg) (FoxP3) cells by flow cytometry techniques. Colonoscopy with multiple biopsies and histopathological assessment was performed to group A only. Results: Our results showed that the serum level of Treg cells was significantly decreased in Group A (3.16±2.26) in comparison to control group B (9.14±0.639) (P<0.001). moreover ,the serum level of Treg cells was significantly decreased in moderate to severe disease activity (1.755± 0.556) as compared with patients with mild disease activity (5.980±1.616) (P<0.001) . The present study also revealed that, the serum level of IL-1α was significantly increased in patients Group A (11.74±3.24) in comparison to control Group B (2.84±0.877) (P<0.001). Additionally, the level IL-1α was significantly higher in moderate to sever disease activity (13.750 ± 1.602) than patients with mild disease activity (7.720±1.289) (P<0.001). Conclusion: The level of Treg cells and Interleukin1 alpha have an important role in the pathogenesis and propagation of the inflammatory response in IBD and had a dynamic changes in both remission and active disease stages. These results suggested that Treg cells and Interleukin1 alpha can be used as a diagnostic markers and a potential therapeutic targets for IBD.

Immunomodulatory Properties of Induced Pluripotent Stem Cell-Derived Mesenchymal Cells.

MSC-like populations derived from induced pluripotent stem cells (iPSC-MSC) serve as an alternative stem cell source due to their high proliferative capacity. In this study, we assessed the immunomodulatory potential of iPSC-MSC generated from periodontal ligament (PDL) and gingival (GF) tissue. The iPSC-MSC lines exhibited a similar level of suppression of mitogen-stimulated peripheral blood mononuclear cells (PBMNC) proliferation compared to their respective parental fibroblast populations in vitro. Moreover, iPSC-MSC demonstrated the ability to suppress T-cells effector cells, Th1/Th2/Th17 populations, and increase levels of Treg cells. In order to investigate the mechanisms involved, expression of common MSC-derived soluble factors known to supress lymphocyte proliferation were assessed in iPSC-MSC cultured with PBMNC with direct cell-cell contact or separated in transwells. Real-time PCR analysis of factors known to be involved in MSC mediated immune regulation, found a general trend of elevated IDO1 and IL6 transcript levels in iPSC-MSC lines and their respective primary cells co-cultured with activated PBMNC, with a wide range of gene expression levels between the different mesenchymal cell types. The results suggest that different iPSC-MSC may be useful as a potential alternative source of cells for future clinical use in therapeutic applications because of their potent immunosuppressive properties. J. Cell. Biochem. 117: 2844-2853, 2016. © 2016 Wiley Periodicals, Inc.

Shen-Qi-Jie-Yu-Fang exerts effects on a rat model of postpartum depression by regulating inflammatory cytokines and CD4(+)CD25(+) regulatory T cells.

BackgroundShen-Qi-Jie-Yu-Fang (SJF) is composed of eight Chinese medicinal herbs. It is widely used in traditional Chinese medicine for treating postpartum depression (PPD). Previous studies have shown that SJF treats PPD through the neuroendocrine mechanism.AimTo further investigate the effect of SJF on the immune system, including the inflammatory response system and CD4+CD25+ regulatory T (Treg) cells.Materials and methodsSprague Dawley rats were used to create an animal model of PPD by inducing hormone-simulated pregnancy followed by hormone withdrawal. After hormone withdrawal, the PPD rats were treated with SJF or fluoxetine for 1, 2, and 4 weeks. Levels of Treg cells in peripheral blood were measured by flow cytometry analysis. Serum interleukin (IL)-1β and IL-6 were evaluated by enzyme-linked immunosorbent assay, and gene and protein expressions of IL-1RI, IL-6Rα, and gp130 in the hippocampus were observed by reverse-transcription polymerase chain reaction and Western blot.ResultsSerum IL-1β in PPD rats increased at 2 weeks and declined from then on, while serum IL-6 increased at 1, 2, and 4 weeks. Both IL-1β and IL-6 were downregulated by SJF and fluoxetine. Changes in gene and protein expressions of IL-1RI and gp130 in PPD rats were consistent with changes in serum IL-1β, and were able to be regulated by SJF and fluoxetine. The levels of Treg cells were negatively correlated with serum IL-1β and IL-6, and were decreased in PPD rats. The levels of Treg cells were increased by SJF and fluoxetine.ConclusionDysfunction of proinflammatory cytokines and Tregs in different stages of PPD was attenuated by SJF and fluoxetine through the modulation of serum concentrations of IL-1β and IL-6, expressions of IL-1RI, and gp130 in the hippocampus, and CD4+CD25+ Treg cells in peripheral blood.

Lactobacillus acidophilus regulates STAT3 and STAT5 signaling in bovine β-lg-sensitized mice model

Our previous study has shown that oral supplementation with Lactobacillus acidophilus KLDS 1.0738 could inhibit β-lactoglobulin (β-lg) allergy. In this study, we investigated the effect of L. acidophilus on the balance between T helper type 17 (Th17) cells and regulatory T cells (Treg) in allergic mouse model and explored the participation of related signal transducers and activator of transcription (STAT) in this process. Bovine β-lg-sensitized mice received strains KLDS 1.0738 for 3 weeks. After the allergen challenge, the percentages of Treg and Th17 cells, cytokine and STAT mRNA expression, and pSTAT protein levels were detected by flow cytometry, quantitative RT-PCR, and western blot, respectively. The results showed that stimulation with β-lg increased the levels of IL-6, pSTAT3, and Th17 cells, but decreased the levels of IL-2, pSTAT5, and Treg cells compared to the controls (P < 0.05). However, oral administration of L. acidophilus KLDS 1.0738 suppressed β-lg-induced inflammatory and improved the Treg/Th17 imbalance. In addition, L. acidophilus-treated group presented decrease in pSTAT3 activation, SOCS3, and IL-6 level, but increase in STAT5a/b, CD25, and IL-2 mRNA expression. These findings suggest that L. acidophilus could regulate IL-6/STAT3 and IL-2/STAT5 pathway, which may be responsible for the Treg/Th17 imbalance in β-lg-sensitized mice.

A Recombinant G Protein Plus Cyclosporine A-Based Respiratory Syncytial Virus Vaccine Elicits Humoral and Regulatory T Cell Responses against Infection without Vaccine-Enhanced Disease.

Respiratory syncytial virus (RSV) infection can cause severe disease in the lower respiratory tract of infants and older people. Vaccination with a formalin-inactivated RSV vaccine (FI-RSV) and subsequent RSV infection has led to mild to severe pneumonia with two deaths among vaccinees. The vaccine-enhanced disease (VED) was recently demonstrated to be due to an elevated level of Th2 cell responses following loss of regulatory T (Treg) cells from the lungs. To induce high levels of neutralizing Abs and minimize pathogenic T cell responses, we developed a novel strategy of immunizing animals with a recombinant RSV G protein together with cyclosporine A. This novel vaccine induced not only a higher level of neutralizing Abs against RSV infection, but, most importantly, also significantly higher levels of Treg cells that suppressed VED in the lung after RSV infection. The induced responses provided protection against RSV challenge with no sign of pneumonia or bronchitis. Treg cell production of IL-10 was one of the key factors to suppress VED. These finding indicate that G protein plus cyclosporine A could be a promising vaccine against RSV infection in children and older people.

Efficacy of immunomodulatory therapy with all-trans retinoid acid in adult patients with chronic immune thrombocytopenia

IntroductionImmune thrombocytopenia (ITP) is a common hematologic disorder characterized by isolated thrombocytopenia. In adults, ITP is more likely to be chronic, requiring individualised treatment and management. Corticosteroids and splenectomy are the most common therapy for ITP. However, these routine approaches failed in these patients with chronic ITP. The aim of this study was to evaluate the efficacy of immunomodulatory therapy with all-trans retinoid acid (ATRA) in adult patients with chronic ITP. Materials and methodsATRA therapy was applied in a total of 35 patients with chronic ITP who failed with standard dose corticosteroids and/or splenectomy. The response ratio and the change of the T cell subsets including Th1, Th2, Th17 and Treg, were evaluated. ResultsComplete response and overall response were observed in 10 (28.6%) and 19 patients (54.3%), respectively. Compared with the control group, a significant decreased level of Treg cells, IL-10 and Foxp3 expression were found in ITP patients. ATRA therapy could significantly increase the percentage of Treg cell, IL-10 level and Foxp3 expression. ConclusionsOur findings indicate that ATRA therapy could induce significant changes of Treg cells to induce response in patients with chronic ITP.

Mesenchymal stem cells and their secreted molecules predominantly ameliorate fulminant hepatic failure and chronic liver fibrosis in mice respectively.

BackgroundOrthotopic liver transplantation is the only effective treatment for liver failure but limited with shortage of available donor organs. Recent studies show promising results of mesenchymal stem cells (MSCs)-based therapies.MethodsWe systematically investigate the therapeutic effects of MSCs or MSC-conditioned medium (MSC-CM) in ameliorating fulminant hepatic failure (FHF) and chronic liver fibrosis in mice. In addition, extensive flow cytometry analysis of spleens from vehicle and MSC- and MSC-CM-treated mice was applied to reveal the alteration of inflammatory state.ResultsIn FHF model, MSCs treatment reduced remarkably the death incidents; the analysis of gross histopathology showed that control livers were soft and shrunken with extensive extravasated blood, which was gradually reduced at later time points, while MSC–treated livers showed gross pathological changes, even 24 h after MSC infusion, and hematoxylin and eosin staining revealed dramatical hepatocellular death with cytoplasmic vacuolization suppressed by MSCs treatment; flow cytometry analysis of total lymphocytes showed that macrophages (F4/80) infiltrated into control livers more than MSC-treated livers; by contrast, MSC-CM partially ameliorates FHF. In chronic liver injury model, MSC and MSC-CM both suppressed fibrogenesis and necroinflammatory, and the later was better; activation of hepatic stellate cells (α-SMA) was inhibited; glycogen synthesis and storage (indicated by periodic acid-Schiff -staining) was improved; liver regeneration (Ki67) was promoted while liver apoptosis (TUNEL) was reduced. In the in vitro, MSCs promote macrophage line RAW264.7 apoptosis and MSC-CM promotes apoptosis and inhibits proliferation of HSC line LX-2. We also found that MSCs and MSC-CM could improve spleen; MSC-CM increased levels of Th2 and Treg cells, and reduced levels of Th17 cells, whereas levels of Th1 cells were unchanged; comparatively, MSC treatment did not affect Th17 and Treg cells and only slightly alters inflammatory state; MSC and MSC-CM treatment both substantially down-regulated macrophages in the spleens.ConclusionBoth MSCs and MSC-CM exert therapeutic effects by acting on various key cells during the pathogenesis of FHF and chronic fibrosis, stimulating hepatocyte proliferation and suppressing apoptosis, down-regulating infiltrating macrophages, converting CD4+ T lymphocyte system into an anti-inflammatory state, and facilitating hepatic stellate cell death.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0792-1) contains supplementary material, which is available to authorized users.

Circulating level of regulatory T cells in rheumatic heart disease: An observational study

BackgroundThe regulatory T cell (Treg) is essential for prevention of autoimmunity. In a preliminary study, we showed significant deficiency of Tregs (CD4CD25 T cells) in rheumatic heart disease (RHD) patients (an autoimmune disease), but the markers used could not reliably differentiate Treg from nonregulatory conventional T cells (Tcon). The study aim was to reassess the level of circulatory Tregs by using more specific markers. Methods70 adults of RHD and 35 controls were studied. Patients were subdivided according to the extent of left-sided valvular involvement. 35 patients with significant mitral-valve disease only were enrolled in the univalvular group while 35 patents with significant involvement of both mitral and aortic-valves in the multivalvular group. Circulating Treg cell level was determined by flow-cytometry. ResultsLevel of Tregs (CD4+CD25med–highCD127low Foxp3high) in CD4+ T lymphocyte was significantly lower in RHD patients compared to controls (median 0.6% versus 3.2%; p=0.001) with no significant difference in Tcon cells (p=0.94). Within the study group Treg count was significantly lower in patients with multivalvular-disease only (median 0.1% versus 3.2%; p=0.001) with no significant difference in Treg cell count between the univalvular group and control (median 1.9% versus 3.2%, p=0.10). ConclusionThere is significant deficiency of circulating Tregs in patients of chronic RHD and the deficiency is greater in patients with multivalvular than univalvular involvement.

Pancreatic cancer microenvironment, to target or not to target?

We have collectively been spoiled by the astounding clinical benefit of antimicrobials. Much like the discovery and use of penicillin to eradicate once deadly infections, we continue to desperately search for the next “magic bullet” to kill cancer while sparing the non‐transformed cells. Greater appreciation for the molecular intricacies of malignancy has resulted in dedicated pursuit of cancer genomics and large‐scale informatics to identify “drugable” targets within the cancer cell itself. However, studies at the bench elucidating a dynamic relationship between tumor and microenvironment have become more common and demonstrate promise for novel therapeutic intervention.

Suppressor of cytokine signaling 2 modulates the immune response profile and development of experimental cerebral malaria

Plasmodium falciparum infection results in severe malaria in humans, affecting various organs, including the liver, spleen and brain, and resulting in high morbidity and mortality. The Plasmodium berghei ANKA (PbA) infection in mice closely recapitulates many aspects of human cerebral malaria (CM); thus, this model has been used to investigate the pathogenesis of CM. Suppressor of cytokine signaling 2 (SOCS2), an intracellular protein induced by cytokines and hormones, modulates the immune response, neural development, neurogenesis and neurotrophic pathways. However, the role of SOCS2 during CM remains unknown. SOCS2 knockout (SOCS2−/−) mice infected with PbA show an initial resistance to infection with reduced parasitemia and production of TNF, TGF-β, IL-12 and IL-17 in the brain. Interestingly, in the late phase of infection, SOCS2−/− mice display increased parasitemia and reduced Treg cell infiltration, associated with enhanced levels of Th1 and Th17 cells and related cytokines IL-17, IL-6, and TGF-β in the brain. A significant reduction in protective neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF), was also observed. Moreover, the molecular alterations in the brain of infected SOCS2−/− mice were associated with anxiety-related behaviors and cognition impairment. Mechanistically, these results revealed enhanced nitric oxide (NO) production in PbA-infected SOCS2−/− mice, and the inhibition of NO synthesis through l-NAME led to a marked decrease in survival, the disruption of parasitemia control and more pronounced anxiety-like behavior. Treatment with l-NAME also shifted the levels of Th1, Th7 and Treg cells in the brains of infected SOCS2−/− mice to the background levels observed in infected WT, with remarkable exception of increased CD8+IFN+ T cells and inflammatory monocytes. These results indicate that SOCS2 plays a dual role during PbA infection, being detrimental in the control of the parasite replication but crucial in the regulation of the immune response and production of neurotrophic factors. Here, we provided strong evidence of a critical relationship between SOCS2 and NO in the orchestration of the immune response and development of CM during PbA infection.