Advances in Foxp3+ regulatory T cells (Foxp3+ Treg) and key factors in digestive malignancies.

Foxp3+ regulatory T cells (Foxp3+ Treg) play a role in regulating various types of tumors, but uncertainty still exists regarding the exact mechanism underlying Foxp3+ Treg activation in gastrointestinal malignancies. As of now, research has shown that Foxp3+ Treg expression, altered glucose metabolism, or a hypoxic tumor microenvironment all affect Foxp3+ Treg function in the bodies of tumor patients. Furthermore, it has been demonstrated that post-translational modifications are essential for mature Foxp3 to function properly. Additionally, a considerable number of non-coding RNAs (ncRNAs) have been implicated in the activation of the Foxp3 signaling pathway. These mechanisms regulating Foxp3 may one day serve as potential therapeutic targets for gastrointestinal malignancies. This review primarily focuses on the properties and capabilities of Foxp3 and Foxp3+Treg. It emphasizes the advancement of research on the regulatory mechanisms of Foxp3 in different malignant tumors of the digestive system, providing new insights for the exploration of anticancer treatments.

The impact of Foxp3+ regulatory T-cells on CD8+ T-cell dysfunction in tumour microenvironments and responses to immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICIs) have been a breakthrough in cancer therapy, inducing durable remissions in responding patients. However, they are associated with variable outcomes, spanning from disease hyperprogression to complete responses with the onset of immune-related adverse events. The consequences of checkpoint inhibition on Foxp3+ regulatory T (Treg ) cells remain unclear but could provide key insights into these variable outcomes. In this review, we first cover the mechanisms that underlie the development of hot and cold tumour microenvironments, which determine the efficacy of immunotherapy. We then outline how differences in tumour-intrinsic immunogenicity, T-cell trafficking, local metabolic environments and inhibitory checkpoint signalling differentially impair CD8+ T-cell function in tumour microenvironments, all the while promoting Treg -cell suppressive activity. Finally, we focus on the mechanisms that enable the induction of polyfunctional CD8+ T-cells upon checkpoint blockade and discuss the role of ICI-induced Treg -cell reactivation in acquired resistance to treatment.

Short-term administration of Qipian®, a mixed bacterial lysate, inhibits airway inflammation in ovalbumin-induced mouse asthma by modulating cellular, humoral and neurogenic immune responses.

AIMS: Qipian® is a commercialized agent composed of extracts of three genera of commensal bacteria, and its mechanism of action on asthma is unclear. This study aimed to examine the impact of Qipian® on airway inflammation and investigate the underlying mechanisms. MATERIALS AND METHODS: Qipian® or dexamethasone (DEX) was administered before OVA challenge in an ovalbumin-induced asthma mouse model, and then asthmatic symptoms were observed and scored. Samples of lung tissues, blood, and bronchoalveolar lavage fluid (BALF) were collected, and eosinophils (Eos), immunoglobins (Igs), and type 1 T helper (Th1)/Th2 cell cytokines were measured. Mucus production in the lung was assessed by periodic acid-Schiff (PAS) staining. The effects of Qipian® on dendritic and T regulatory (Treg) cells were investigated using flow cytometry. KEY FINDINGS: The short-term administration of Qipian® significantly inhibited the cardinal features of allergic asthma, including an elevated asthmatic behaviour score, airway inflammation and immune response. Histological analysis of the lungs showed that Qipian® attenuated airway inflammatory cell infiltration and mucus hyperproduction. Qipian® restored Th1/Th2 imbalance by decreasing interleukin (IL)-4, IL-5, and IL-13 while increasing interferon (IFN)-γ and IL-10. Further investigation revealed that Qipian® treatment induced the upregulation of CD4+CD25+Foxp3+ Treg cells and CD103+ DCs and downregulation of tachykinins neurokinin A (NKA) and NKB in the lung. SIGNIFICANCE: Our findings suggested that short-term treatment with Qipian® could alleviate inflammation in allergic asthma through restoring the Th1/Th2 balance by recruiting Treg cells to airways and inducing the proliferation of CD103+ DCs, which actually provides a new treatment option for asthma.

Foxp3+ regulatory T cells in the central nervous system and other nonlymphoid tissues.

Foxp3+ regulatory T (Treg) cells are indispensable for the maintenance of immunologic self-tolerance as well as for the confinement of autoimmune inflammation after the breach of self-tolerance. In order to fulfill these tasks, Treg cells operate in secondary lymphoid tissues and nonlymphoid tissues. The conditions for Treg cell stability and for their modes of action are different according to their compartment of residence. In addition, Treg cells initiate residency programs to inhabit niches in nonlympoid tissues (NLT) in steady state and after re-establishment of previously deflected homeostasis for extended periods of time. These NLT Treg cells are different from lymphoid tissue residing Treg cells and are functionally specialized to subserve not only immune functions but support intrinsic functions of their tissue of residence. This review will highlight current ideas about the functional specialization of NLT Treg cells in particular in the central nervous system (CNS) and discuss challenges that we are facing in an effort to exploit the power of NLT Treg cells for maintenance of tissue homeostasis and perhaps also tissue regeneration.

MUC1 induces the accumulation of Foxp3+ Treg cells in the tumor microenvironment to promote the growth and metastasis of cholangiocarcinoma through the EGFR/PI3K/Akt signaling pathway.

Tumor microenvironment (TME) plays an important role in the progression of cholangiocarcinoma. This study aims to explore whether Mucin 1 (MUC1) regulates Foxp3+ Treg cells in the TME of cholangiocarcinoma through the epidermal growth factor receptor (EGFR)/phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway. High-throughput sequencing dataset in the GEO database combined with GeneCards and Phenolyzer databases was used to obtain key genes in cholangiocarcinoma, followed by downstream pathway prediction. The relationship among MUC1, EGFR, and PI3K/Akt signaling pathway was explored. CD4+ T cells extracted from peripheral blood were induced to differentiate into Treg cells, followed by co-culture with cholangiocarcinoma cells. A mouse model was constructed to detect the role of MUC1 in the accumulation of Foxp3+ Treg cells, malignant phenotypes of cholangiocarcinoma, and tumorigenesis in vivo. MUC1, highly expressed in cholangiocarcinoma, might be involved in cholangiocarcinoma development. MUC1 interacted with the EGFR to activate the EGFR/PI3K/Akt signaling pathway. MUC1 overexpression could activate the EGFR/PI3K/Akt signaling pathway, which promoted the accumulation of Foxp3+ Treg cells in the TME and the malignant phenotypes of cholangiocarcinoma cells both in vitro and in vivo and enhanced tumorigenesis in vivo. MUC1 may interact with EGFR to activate the EGFR/PI3K/Akt signaling pathway, which induces the accumulation of Foxp3+ Treg cells, enhancing the malignant phenotypes of cholangiocarcinoma cells and tumorigenesis in vivo and ultimately augmenting cholangiocarcinoma growth and metastasis.

5-Aminolevulinic acid combined with ferrous iron ameliorates scrotal heat stress-induced spermatogenic damage by enhancing HO-1 expression.

OBJECTIVE: To explore whether 5-Aminolevulinic acid combined with ferrous iron (5-ALA/Fe2+) could protect testicular tissues damage of mice subjected to heat stress (HS) and provide its underlying mechanisms. METHODS: 5-ALA/Fe2+ was administered intragastrically to mice for 10 days, then exposed to a scrotal heat stress at 43°C for 20 min on third day. Testes were harvested for morphologic and histopathological examination, oxidative stress, apoptosis, heme oxygenase-1 (HO-1) and inflammation detection. The mitogen-activated protein kinases (MAPK) signaling pathway in testis and CD4+FoxP3+regulatory T (Treg) cells in spleen were also investigated. RESULTS: Compared to control group, the testis weight decreased and histological damage severed in HS group. Besides, HS also increased the oxidative stress, apoptosis and inflammation in testis. However, these indicators were ameliorated after 5-ALA/Fe2+ treatment but deteriorated after receiving ZnPPIX. The expression of HO-1 was increased both in HS group and 5-ALA/Fe2+ group. The protein expression levels of MAPK proteins were activated by HS and inhibited by 5-ALA/Fe2+. The CD4+FoxP3+ Treg generation was reduced by HS and increased by 5-ALA/Fe2+. CONCLUSION: In this study, we have demonstrated that 5-ALA/Fe2+ ameliorated the spermatogenic damage induced by scrotal heat stress via up-regulating the expression of HO-1 and inhibiting MAPK mediated oxidative stress and apoptosis and inducing CD4+Foxp3+ Tregs to inhibit the inflammation induced by HS in mice.

Caveolin-1 Promotes the Imbalance of Th17/Treg in Chronic Obstructive Pulmonary Disease by Regulating Hsp70 Expression.

Objective: To investigate whether the expression of Hsp70 is associated with Cav-1 in promoting the imbalance of Th17/Treg cells in COPD. Methods: The plasma Cav-1, Hsp70 expression were quantified by enzyme-linked immunosorbent assay (ELISA). The frequencies of circulating Th17, Treg cells and Th17/Treg ratio were determined by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from subjects were transfected with Cav-1 or control plasmids and Hsp70 plasmid. Results: We found that Cav-1 expression was lower but the levels of Hsp70 and Th17 cells were higher in COPD than in healthy control (HC). Hsp70 expressions were positively correlated with Cav-1 levels, Th17 cells, and Th17/Treg ratio in COPD but not in HC. Cav-1 over-expression resulted in an increase in Hsp70 and Th17 levels. Suppressing Hsp70 expressing by small interfering RNA (siRNA), the decline of Th17 frequency was observed in Cav-1-overexpressed PBMCs. Conclusion: Collectively, our results illuminate that Cav-1 contributes to the imbalance of Th17/Treg through potentially regulating Hsp70 expression.

Dysregulation of T Cell Differentiation and the IL17A(+)Foxp3(+)Treg Subset in Chronic Hepatitis B Patients with Hepatitis Flare.

The regulatory T (Treg) and T helper 17 (Th17) cells modulate the immune response in chronic hepatitis B virus (HBV) infection by promoting immune tolerance and restricting liver damage or stimulating inflammatory response and rendering hepatocyte injury. These cells act through signaling transcription factors and secreting cytokines. We aimed to observe the percentages of Treg, Th17 cells, and their messenger RNA (mRNA) level of forkhead box protein 3 (Foxp3) and retinoid orphan receptor γt (RORγt) in the chronic hepatitis B (CHB)-infected group and CHB patients with hepatitis flare (HF). We recruited 103 participants, including 88 CHB-infected cases and 15 healthy controls (HCs) in Ho Chi Minh City. CHB cases were enrolled into two groups: HBeAg+ CHB infection (e+CHBI; n = 42) and HF (including 20 mild HF and 26 severe HF [sHF]). The Foxp3(+)Treg and Th17 cells were measured by flow cytometry. The mRNA levels of Foxp3 and RORγt were analyzed by real-time polymerase chain reaction. The percentages of Foxp3(+)Treg, of Th17, and the Foxp3(+)Treg/Th17 ratio were significantly higher in the sHF compared to the e+CHBI group. The sHF and e+CHBI groups had significantly higher mRNA levels of Foxp3 and RORγt compared to the HC group. Furthermore, a special subset, interleukin 17A(+)Foxp3(+)Treg cells, were observed with a significantly higher percentage in the sHF compared to the e+CHBI group. This finding revealed the contributions of this new subset on the severe flare cases. Our results explained the diversity of T cells and their subsets in the immune response in CHB. This subset should be further investigated as a specific tool in HBV immune response.

TCF-1 negatively regulates the suppressive ability of canonical and noncanonical Tregs.

Regulatory T cells are suppressive immune cells used in various clinical and therapeutic applications. Canonical regulatory T cells express CD4, FOXP3, and CD25, which are considered definitive markers of their regulatory T-cell status when expressed together. However, a subset of noncanonical regulatory T cells expressing only CD4 and FOXP3 have recently been described in some infection contexts. Using a unique mouse model for the first time demonstrated that the TCF-1 regulation of regulatory T-cell suppressive function is not limited to the thymus during development. Our data showed that TCF-1 also regulated regulatory T cells' suppressive ability in secondary organs and graft-vs-host disease target organs as well as upregulating noncanonical regulatory T cells. Our data demonstrated that TCF-1 regulates the suppressive function of regulatory T cells through critical molecules like GITR and PD-1, specifically by means of noncanonical regulatory T cells. Our in vitro approaches show that TCF-1 regulates the regulatory T-cell effector-phenotype and the molecules critical for regulatory T-cell migration to the site of inflammation. Using in vivo models, we show that both canonical and noncanonical regulatory T cells from TCF-1 cKO mice have a superior suppressive function, as shown by their ability to control conventional T-cell proliferation, avert acute graft-vs-host disease, and limit tissue damage. Thus, for the first time, we provide evidence that TCF-1 negatively regulates the suppressive ability of canonical and noncanonical regulatory T cells. These findings provide evidence that TCF-1 is a novel target for developing strategies to treat alloimmune disorders.

The prognostic values of FOXP3+ tumor-infiltrating T cells in breast cancer: a systematic review and meta-analysis.

BACKGROUND: Tumor microenvironment is infiltrated by many immune cells, of which Regulatory T (Treg) cells are usually considered as negative regulators of the immune responses. However, the effect of FOXP3+ (forkhead box transcription factor 3) Treg cells infiltrated into the tumor areas on the prognosis of breast cancer is controversial. This meta-analysis aimed to dissect the potential values of FOXP3+ tumor-infiltrating lymphocytes (TILs) as a prognosis predictor of breast cancer. METHODS: After systematic retrieval of all relevant studies, 28 eligible articles were identified for meta-analysis. Odd ratio (OR), hazard ratio (HR), and 95% confidence interval (CI) were obtained for pooled analyses of pathological complete response (pCR), overall survival (OS), and corresponding forest plots and funnel plots were plotted, respectively. RESULTS: Pooled results revealed that patients with higher levels of FOXP3+ TILs experienced better pCR (OR: 1.24, 95% CI 1.09-1.41) and OS (HR: 0.79, 95% CI 0.64-0.97). Subgroup analysis revealed that elevated FOXP3+ TILs were significantly associated with improved pCR (OR: 1.20, 95% CI 1.02-1.40) and OS (HR: 0.22, 95% CI 0.06-0.88) in human epidermal growth factor receptor 2 positive (HER2+) breast cancer patients. Furthermore, FOXP3+ TILs in the stromal area were statistically correlated with the favorable pCR (OR: 1.22, 95% CI 1.08-1.38) and OS (HR: 0.68, 95% CI 0.49-0.96). CONCLUSIONS: The predictive role of FOXP3+ TILs in the prognosis of breast cancer is influenced by various factors such as molecular subtype of breast cancer and the location of Treg. In HER2+ breast cancer and triple-negative breast cancer, FOXP3+ TILs are associated with better pCR and OS. Additionally, FOXP3+ TILs in stromal represent a favourable prognosis.

CD49b Targeting Inhibits Tumor Growth and Boosts Anti-tumor Immunity.

The suppressive function of T-regulatory cells (Tregs) can have a detrimental effect on immune responses against tumor cells. Within the Treg cells subset, a new non-classical population has been reported, which expresses high levels of CD49b molecule and, depending on their activation status, can also express the canonical Tregs transcription factor Foxp3. In this report, we sought to characterize Tregs subsets in a murine melanoma model and disrupt the CD49b/CD29 axis by administering an anti-CD29 antibody in tumor-bearing mice. Our data shows that whereas in the draining lymph nodes, the Tr1 cells subset composes <5% of CD4+ T cells, in the tumor, they reach ∼30% of CD4+ T cells. Furthermore, Tr1 cells share the expression of suppressive molecules, such as Nrp-1, PD-1, and CD73, which are highly expressed on Tr1 cells found in tumor-infiltrating leukocytes (TILs). Regardless of the phenotypic similarities with cTreg cells, Tr1 cells display a low proliferative activity, as shown in the kinetics and the incorporation of 5-bromodeoxyuridine (BrdU) experiments. With the intent to impact on Tr1 cells, we administered anti-CD29 antibody into tumor mice, observing that the treatment effectively inhibits tumor growth. This effect is at least mediated by the enrichment of pro-inflammatory T cells, including IFN-γ+ cTreg and IFN-γ+ Tr1 cells (with reduced expression of IL-10), plus Th1 and Tc cells. In this study, we present Tr1 cell characterization in tumor-bearing animals and introduce CD29 as a target for tumor therapy, supported by a meta-analysis indicating that CD29 is present in human biopsies.

Progesterone modulates CD4+ CD25+ FoxP3+ regulatory T Cells and TGF-ß1 in the maternal-fetal interface of the late pregnant mouse.

OBJECTIVE: Progesterone supplementation is recommended to prevent spontaneous preterm birth (sPTB) in clinical practice. However, the exact mechanism is still unclear. This study aims to better understand the mechanisms that progesterone can prevent PTB. METHODS: Late pregnant mice were given various doses of progesterone receptor antagonist mifepristone, and pregnancy outcomes were observed. Then, non-pregnant and pregnant mice were given a subcutaneous injection of 40 mg/kg progesterone and 5 mg/kg mifepristone, respectively. CD4+ CD25+ FoxP3+ Treg cells in peripheral blood and decidua basalis were detected by FACS. Expressions of FoxP3 and TGF-ß1 in the decidua basalis were detected. RESULTS: Mifepristone induced preterm birth, and an obvious dose-response was found. Proportions of CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of non-pregnant mice increased significantly after progesterone injection. CD4+ CD25+ FoxP3+ Treg cells in the peripheral blood of pregnant mice increased significantly compared with those of non-pregnant mice. In pregnant mice, mifepristone significantly decreased the proportions of CD4+ CD25+ FoxP3+ Treg cells in peripheral blood, and reduced proportions of Treg cells at the maternal-fetal interface and expressions of FoxP3 and TGF-ß1 in the maternal-fetal interface. Total 40 mg/kg of progesterone did not increase CD4+ CD25+ FoxP3+ Treg in the peripheral blood of pregnant mice, but increased proportions of Treg cells at the maternal-fetal interface and up-regulated FoxP3 and TGF-ß1 expressions in the maternal-fetal interface. CONCLUSION: Progesterone promotes pregnancy immune homeostasis by up-regulating Treg cells and TGF-ß1 expression in the maternal-fetal interface. It may be one of the mechanisms of progesterone in preventing sPTB.

The prognostic value of intratumoral and peritumoral tumor-infiltrating FoxP3+Treg cells in of pancreatic adenocarcinoma: a meta-analysis.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) are major participants in the tumor microenvironment. The prognostic value of TILs in patients with pancreatic cancer is still controversial. METHODS: The aim of our meta-analysis was to determine the impact of FoxP3+Treg cells on the survival of pancreatic cancer patients. We searched for related studies in PubMed, EMBASE, Ovid, and Cochrane Library from the time the databases were established to Mar 30, 2017. We identified studies reporting the prognostic value of FoxP3+Treg cells in patients with pancreatic cancer. Overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS)/relapse-free survival (RFS) were investigated by pooling the data. The pooled hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the association between FoxP3+Treg cells and survival outcomes of pancreatic cancer patients. A total of 972 pancreatic cancer patients from 8 studies were included in our meta-analysis. RESULTS: High levels of infiltration with FoxP3+Treg cells were significantly associated with poor OS (HR=2.13; 95% CI 1.64-2.77; P<0.05) and poor DFS/PFS/RFS (HR=1.70; 95% CI 1.04 ~ 2.78; P< 0.05). Similar results were also observed in the peritumoral tissue; high levels of FoxP3+Treg cells were associated with poor OS (HR =2.1795% CI, CI 1.50-3.13). CONCLUSION: This meta-analysis indicated that high levels of intratumoral or peritumoral FoxP3+Treg cell infiltration could be recognized as a negative factor in the prognosis of pancreatic cancer.

PD-L1+NEUT, Foxp3+Treg, and NLR as New Prognostic Marker with Low Survival Benefits Value in Hepatocellular Carcinoma.

Background: This presented study was aimed to evaluate the diagnostic and prognostic value of PD-L1+Neutrophils (PD-L1+NEUT) and neutrophil to lymphocyte ratio (NLR) based on our previous experience of Foxp3+Treg in transplantation. Methods: the NLR cutoff value of 1.79 was used to include 136 cases from the 204 patients with hepatocellular carcinoma (HCC) confirmed by clinical pathology, which were divided into highly-moderately and poorly differentiated HCC groups. The expressions of PD-L1+NEUT and Foxp3+Treg in peripheral blood and cancer tissue were detected with flow cytometry, meanwhile, PD-L1 and Foxp3 expressed in carcinoma and para-carcinoma tissues were marked by immunohistochemistry. Survival rates, including overall survival and disease-free survival, were calculated by the Kaplan-Meier curve and evaluated with the log-rank test. Finally, Cox risk regression model was used to analyze the independent risk factors for prognostic survival. Results: The level of PD-L1+NEUT, Foxp3+Treg, and NLR in peripheral blood of patients with poorly differentiated HCC were significantly increased (all P < .001). Both PD-L1+NEUT and NLR were positively correlated with Foxp3+Treg (r = 0.479, P = .0017; r = 0.58, P < .0001). The level of PD-L1+NEUT and Foxp3+Treg as well as PD-L1 and Foxp3 in cancer tissue and patients with poorly differentiated HCC were obviously increased (all P < .01), respectively. Cox regression analysis indicated that PD-L1+NEUT, NLR, and Foxp3+Treg were independent risk factors for the prognosis (P = .000, .000, .006) with a RR and 95%CI of 2.704-(2.155-3.393), 3.139-(2.361-4.173), 1.409-(1.105-1.798), respectively. Conclusion: PD-L1+NEUT, NLR, and Foxp3+Treg are independent risk factors for prognosis which maybe new marker of lower survival benefits.

A Central Role for Atg5 in Microbiota-Dependent Foxp3+ RORγt+ Treg Cell Preservation to Maintain Intestinal Immune Homeostasis.

Autophagy is an evolutionary conserved catabolic pathway that ensures the degradation of intracellular components. The autophagic pathway is regulated by autophagy-related (Atg) proteins that govern formation of double-membraned vesicles called autophagosomes. Autophagy deficiency in regulatory T (Treg) cells leads to increased apoptosis of these cells and to the development of autoimmune disorders, predominantly characterized by intestinal inflammation. Recently, RORγt-expressing Treg cells have been identified as key regulators of gut homeostasis, preventing intestinal immunopathology. To study the role of autophagy in RORγt+ Foxp3+ Treg cells, we generated mice lacking the essential component of the core autophagy machinery Atg5 in Foxp3+ cells. Atg5 deficiency in Treg cells led to a predominant intestinal inflammation. While Atg5-deficient Treg cells were reduced in peripheral lymphoid organs, the intestinal RORγt+ Foxp3+ subpopulation of Treg cells was most severely affected. Our data indicated that autophagy is essential to maintain the intestinal RORγt+ Foxp3+ Treg population, thereby protecting the mice from gut inflammatory disorders.

High levels of Tim-3+Foxp3+Treg cells in the tumor microenvironment is a prognostic indicator of poor survival of diffuse large B cell lymphoma patients.

Foxp3+Treg cells display phenotypic and functional heterogeneity, which express high levels of T cell immunoglobulin and mucin-domain containing-3 (Tim-3) in the tumor microenvironment (TME) of colorectal and lung cancer. High abundance of Tim-3+Foxp3+Treg (TFT) cells are associated with poor prognosis in these patients. However, the expression patterns and roles of TFT cells in TME of diffuse large B cell lymphoma (DLBCL) remain to be established. Double immunofluorescence and flow cytometry analyses were employed to investigate TFT cell enrichment in paraffin-embedded fresh tumor tissues from patients with DLBCL. Spearman's or Pearson's correlation and Kaplan-Meier survival analyses were further applied to decide the prognostic value of TFT cell levels in DLBCL. The IL-10-secreting function of TFT cells in vitro was examined via flow cytometry and ELISA. Our results showed for the first time that TFT cells are highly enriched in TME of DLBCL patients and associated with predictions of poor prognoses. TFT cell-induced secretion of IL-10 in the TME was suppressed by an anti-Tim-3 antibody in vitro. In conclusion, high abundance of TFT cells in the TME is predictive of poor outcomes of DLBCL. TFT cells promote DLBCL development partly by secreting IL-10 in the TME. Anti-Tim-3 antibodies (that block IL-10 secretion) may present an effective therapeutic agent for DLBCL.

Cryptotanshinone possesses therapeutic effects on ischaemic stroke through regulating STAT5 in a rat model.

CONTEXT: Cryptotanshinone (CT), a lipophilic compound extracted from roots of Salvia miltiorrhiza Bunge (Lamiaceae) (Danshen), has multiple properties in diseases, such as pulmonary fibrosis, lung cancer, and osteoarthritis. Our previous findings suggest that CT plays a protective role in cerebral stroke. However, the molecular mechanisms underlying CT protection in ischaemic stroke remain unclear. OBJECTIVE: This study examines the effect of CT on ischaemic stroke. MATERIALS AND METHODS: We used the middle cerebral artery occlusion (MCAO) rat (Sprague-Dawley rats, 200 ± 20 g, n = 5) model with a sham operation group was treated as negative control. MCAO rats were treated with 15 mg/kg CT using intragastric administration. Moreover, TGF-ß (5 ng/mL) was used to treat MCAO rats as a positive control group. RESULTS: The 50% inhibitory concentration (IC50) of CT on CD4+ cell damage was 485.1 µg/mL, and median effective concentration (EC50) was 485.1 µg/mL. CT attenuates the infarct region in the MCAO model. The percentage of CD4+CD25+FOXP3+ Treg cells in the peripheral blood of the MCAO group was increased with CT treatment. The protein level of FOXP3 and the phosphorylation of STAT5 were recovered in the CD4+CD25+ Treg cells of model group after treated with CT. Importantly, the effects of CT treatment were blocked by treatment with the inhibitor STAT5-IN-1 in CD4+ T cells of the MCAO model. DISCUSSION AND CONCLUSION: Our findings not only enhance the understanding of the mechanisms underlying CT treatment, but also indicate its potential value as a promising agent in the treatment of ischaemic stroke. Further study will be valuable to examine the effects of CT on patients with ischaemic stroke.

Influenza A virus-induced thymus atrophy differentially affects dynamics of conventional and regulatory T-cell development in mice.

Foxp3+ Treg cells, which are crucial for maintenance of self-tolerance, mainly develop within the thymus, where they arise from CD25+ Foxp3- or CD25- Foxp3+ Treg cell precursors. Although it is known that infections can cause transient thymic involution, the impact of infection-induced thymus atrophy on thymic Treg (tTreg) cell development is unknown. Here, we infected mice with influenza A virus (IAV) and studied thymocyte population dynamics post infection. IAV infection caused a massive, but transient thymic involution, dominated by a loss of CD4+ CD8+ double-positive (DP) thymocytes, which was accompanied by a significant increase in the frequency of CD25+ Foxp3+ tTreg cells. Differential apoptosis susceptibility could be experimentally excluded as a reason for the relative tTreg cell increase, and mathematical modeling suggested that enhanced tTreg cell generation cannot explain the increased frequency of tTreg cells. Yet, an increased death of DP thymocytes and augmented exit of single-positive (SP) thymocytes was suggested to be causative. Interestingly, IAV-induced thymus atrophy resulted in a significantly reduced T-cell receptor (TCR) repertoire diversity of newly produced tTreg cells. Taken together, IAV-induced thymus atrophy is substantially altering the dynamics of major thymocyte populations, finally resulting in a relative increase of tTreg cells with an altered TCR repertoire.

MSCs-released TGFß1 generate CD4+CD25+Foxp3+ in T-reg cells of human SLE PBMC.

BACKGROUND/PURPOSE: Regulatory T-cell (Treg) defects may cause autoreactivity of both T and B cells, leading to autoimmune disease including systemic lupus erythematosus (SLE). The immune response defects in SLE are characterized by the decreased expression of CD4, CD25, and Foxp3, known as inducible Treg (iTreg). Therefore, restoring iTreg expression can reverse autoimmunity states into immune tolerances leading to normal immune responses. Mesenchymal stem cells (MSCs) have immunomodulatory properties to control inflammatory milieu, including in SLE inflammation by releasing TGFß1, IL10, and PGE2, thus MSCs can potentially generate iTreg cells. However, the mechanisms of MSC-released TGFß1 to promote iTreg generation in human SLE remains unclear. This study aims to analyze the role of MSC-released TGFß1 in generating CD4+, CD25+, and Foxp3+ expression in iTreg cells from human SLE peripheral blood mononuclear cells (PBMCs). METHODS: This study used a post-test control group design. MSCs were obtained from human umbilical cord blood and characterized according to their surface antigen expression and multilineage differentiation capacities. PBMCs isolated from SLE patients were divided into five groups, including sham, control, and three treatment groups. The treatment groups were treated by co-culturing MSCs to PBMCs with ratio of 1:1 (T1), 1:25 (T2), and 1:50 (T3) for 72 h incubation. The expression of CD4, CD25, and Foxp3 in Treg was analyzed by flow cytometry assay while TGFß1 level was determined by Cytometric Bead Array (CBA). RESULTS: This study showed that the percentage of CD4+CD25+Foxp3+ iTreg cells was significantly increased in T1 and T2. This finding was aligned with the significant increase of TGFß1 level. CONCLUSION: MSCs promote iTreg cells generation from human SLE PBMCs by releasing TGFß1 to control SLE disease.

Increase in CD4+FOXP3+ regulatory T cell number and upregulation of the HGF/c-Met signaling pathway during the liver metastasis of colorectal cancer.

Colorectal cancer (CRC) is the third and second most common type of cancer diagnosed in males and females, respectively, and is the fourth leading cause of cancer-associated mortality worldwide. Liver metastasis is the primary cause of mortality in patients with CRC, and therefore requires therapeutic focus. Regulatory T cells (Tregs) and hepatic stellate cells (HSCs) are potentially involved in regulating the immune response during liver metastasis. The aim of the present study was to evaluate the influence of CD4+ forkhead box p3 (Foxp3)+ Tregs and the HGF/c-Met signaling pathway in the liver metastasis of CRC. A model of the latter was established using Balb/c mice via splenic injection of human CRC cells (CT-26 line). The mice were monitored for 3 weeks after being injected, and the spleens and livers were removed on day 22 for further analysis. Moreover, the single-cell suspensions were labeled with CD4 and Foxp3 antibodies, and were analyzed using flow cytometry. Expression levels of α-smooth muscle actin (SMA), hepatocyte growth factor (HGF) and hepatocyte growth factor receptor (c-Met) were analyzed using immunohistochemistry. Mice injected with CT-26 cells exhibited signs of illness and significant weight loss, compared with the control mice (P=0.013), and they also developed liver metastases, at an average of 20.5 tumors per mouse. Pathological evaluation using hematoxylin and eosin staining confirmed the tumors as liver metastases of CRC. The numbers of CD4+ T cells were significantly decreased in the spleen (P<0.001) and liver (P=0.003) of tumor-bearing mice, while the proportions of CD4+FOXP3+ Tregs increased significantly in the spleen (P<0.001) and liver (P=0.026) compared with that in the controls. Additionally, α-SMA, HGF and c-Met levels increased significantly during metastatic growth in the liver. In conclusion, CD4+FOXP3+ Treg levels increased and the HGF/c-Met pathway was upregulated during the liver metastasis of CRC in mice, indicating the presence of potential therapeutic targets.