FOXP3 modifies the phenotypic and functional properties of regulatory T cells

Modulation of the tumor microenvironment in non-muscle-invasive bladder cancer by OncoTherad® (MRB-CFI-1) nanoimmunotherapy: effects on tumor-associated macrophages, tumor-infiltrating lymphocytes, and monoamine oxidases

Non-muscle-invasive bladder cancer (NMIBC) presents management challenges due to its high recurrence rate and a complex tumor microenvironment (TME). This study investigated the effects of OncoTherad® (MRB-CFI1) nanoimmunotherapy on the TME of BCG-unresponsive NMIBC, focusing on alterations in monoamine oxidases (MAO-A and MAO-B) and immune markers: CD163, FOXP3, CD8, and CX3CR1. A comparative analysis of immunoreactivities was made before and after OncoTherad® treatment and an immune score (IS) was established to evaluate the correlation between immunological changes and clinical outcomes. Forty bladder biopsies of twenty patients were divided into 2 groups (n = 20/group): 1 (pre-treatment biopsies); and 2 (post-treatment biopsies). Our results showed stable MAO-A levels but a significant (p < 0.05) decrease in MAO-B immunoreactivity after treatment, suggesting OncoTherad®'s efficacy in targeting the tumor-promoting and immunosuppressive functions of MAO-B. Significant (p < 0.05) reductions in CD163 and FOXP3 immunoreactivities were seen in post-treatment biopsies, indicating a decreased presence of M2 macrophages and Tregs. Corroborating with these results, we observed reductions in tumor histological grading, focality and size, factors that collectively enhanced recurrence-free survival (RFS) and pathological complete response (PCR). Moreover, elevated IFN-γ immunoreactivities in treated biopsies correlated with increased counts of CD8+ T cells and higher CX3CR1 expression, underscoring OncoTherad®'s enhancement of cytotoxic T cell functionality and overall antitumor immunity. The IS revealed improvements in immune responses post-treatment, with higher scores associated with better RFS and PCR outcomes. These findings validate OncoTherad®'s capability to modify the bladder cancer microenvironment favorably, promoting effective immune surveillance and response.

Correlations between components of the immune system

Background

No evidence of the possibility of altering a constituent of the immune system without directly affecting one of its associated components has yet been shown.

Methods

A schematic model was developed in which two triggers, fasting and splenectomy, were studied for their ability to affect the expression of cell membrane epitopes and the cytokine secretion of out-of-body autogeneic and syngeneic lymphocytes.

Results

The effect of fasting and/or splenectomy on promoting correlations between immune systems was studied by determining the alterations in expressions of cell membrane epitopes and in cytokine secretion by out-of-body autogeneic and syngeneic lymphocytes. The effect of fasting as a trigger decreased expression of CD8 and CD25 and increased TNFα levels. The effect of splenectomy as a trigger was investigated in non-fasting mice by comparing splenectomized and non-splenectomized mice. An increase in the CD8 expression and in TNFα, IFNg, and IL10 secretion was noted. The effect of splenectomy as a trigger in fasting mice was determined by comparing splenectomized and non-splenectomized mice. Splenectomy significantly affected the expression of CD25 and CD4 CD25 and on secretion of TNFα, IFNg, and IL10. To determine the effect of keeping the cells in an out-of-body location on the expression of lymphocyte epitopes, tubes kept on top of the cages of the fasting mice were compared with tubes kept on top of empty cages. The results showed a significant change in the CD8 expression was noted. To determine the effect of keeping cells in an out-of-body location on cytokine secretion, tubes kept on cages were tested for cytokine levels significant decrease was noted in the secretion of TNFα and IFNg.

Conclusions

The study showed that a mouse could affect cells at a distance and alter the expression of surface markers and cytokine secretion following two types of triggers: fasting and/or splenectomy. The data characterized a system for the induction of correlations between two's immune system components without a transfer of mediators. It suggests that an out-of-body correlation can be induced between two components of the immune system.

A randomized double-blind placebo-controlled trial of low-dose interleukin-2 in relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is associated with regulatory T cells (Tregs) insufficiency while low-dose interleukin-2 (IL2LD) activates Tregs and reduces disease activity in autoimmune diseases.

METHODS

We aimed at addressing whether IL2LD improved Tregs from MS patients. MS-IL2 was a single-center double-blind phase-2 study. Thirty patients (mean [SD] age 36.8 years [8.3], 16 female) with relapsing-remitting MS with new MRI lesions within 6 months before inclusion were randomly assigned in a 1:1 ratio to placebo or IL-2 at 1 million IU, daily for 5 days and then fortnightly for 6 months. The primary endpoint was change in Tregs at day-5.

RESULTS

Unlike previous trials of IL2LD in more than 20 different autoimmune diseases, Tregs were not expanded at day-5 in IL2LD group, but only at day-15 (median [IQR] fold change from baseline: 1.26 [1.21-1.33] in IL2LD group; 1.01 [0.95-1.05] in placebo group, p < 0.001). At day-5, however, Tregs had acquired an activated phenotype (fold change of CD25 expression in Tregs: 2.17 [1.70-3.55] in IL2LD versus 0.97 [0.86-1.28] in placebo group, p < 0.0001). Regulator/effector T cells ratio remained elevated throughout treatment period in the IL2LD group (p < 0.001). Number of new active brain lesions and of relapses tended to be reduced in IL2LD treated patients, but the difference did not reach significance in this trial not powered to detect clinical efficacy.

CONCLUSION

The effect of IL2LD on Tregs in MS patients was modest and delayed, compared to other auto-immune diseases. This, together with findings that Tregs improve remyelination in MS models and recent reports of IL2LD efficacy in amyotrophic lateral sclerosis, warrants larger studies of IL2LD in MS, notably with increased dosages and/or modified modalities of administration.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov: NCT02424396; EU Clinical trials Register: 2014-000088-42.

Curcuma Longa Induces the Transcription Factor FOXP3 to Downregulate Human Chemokine CCR5 Expression and Inhibit HIV-1 Infection

HIV mutations occur frequently despite the substantial success of combination antiretroviral therapy, which significantly impairs HIV progression. Failure to develop specific vaccines, the occurrence of drug-resistant strains, and the high incidence of adverse effects due to combination antiviral therapy regimens call for novel and safer antivirals. Natural products are an important source of new anti-infective agents. For instance, curcumin inhibits HIV and inflammation in cell culture assays. Curcumin, the principal constituent of the dried rhizomes of Curcuma longa L. (turmeric), is known as a strong anti-oxidant and anti-inflammatory agent with different pharmacological effects. This work aims to assess curcumin's inhibitory effects on HIV in vitro and to explore the underpinning mechanism, focusing on CCR5 and the transcription factor forkhead box protein P3 (FOXP3). First, curcumin and the RT inhibitor zidovudine (AZT) were evaluated for their inhibitory properties. HIV-1 pseudovirus infectivity was determined by green fluorescence and luciferase activity measurements in HEK293T cells. AZT was used as a positive control that inhibited HIV-1 pseudoviruses dose-dependently, with IC50 values in the nanomolar range. Then, a molecular docking analysis was carried out to assess the binding affinities of curcumin for CCR5 and HIV-1 RNase H/RT. The anti-HIV activity assay showed that curcumin inhibited HIV-1 infection, and the molecular docking analysis revealed equilibrium dissociation constants of [Formula: see text]9.8[Formula: see text]kcal/mol and [Formula: see text]9.3[Formula: see text]kcal/mol between curcumin and CCR5 and HIV-1 RNase H/RT, respectively. To examine curcumin's anti-HIV effect and its mechanism in vitro, cell cytotoxicity, transcriptome sequencing, and CCR5 and FOXP3 amounts were assessed at different concentrations of curcumin. In addition, human CCR5 promoter deletion constructs and the FOXP3 expression plasmid pRP-FOXP3 (with an EGFP tag) were generated. Whether FOXP3 DNA binding to the CCR5 promoter was blunted by curcumin was examined using transfection assays employing truncated CCR5 gene promoter constructs, a luciferase reporter assay, and a chromatin immunoprecipitation (ChIP) assay. Furthermore, micromolar concentrations of curcumin inactivated the nuclear transcription factor FOXP3, which resulted in decreased expression of CCR5 in Jurkat cells. Moreover, curcumin inhibited PI3K-AKT activation and its downstream target FOXP3. These findings provide mechanistic evidence encouraging further assessment of curcumin as a dietary agent used to reduce the virulence of CCR5-tropic HIV-1. Curcumin-mediated FOXP3 degradation was also reflected in its functions, namely, CCR5 promoter transactivation and HIV-1 virion production. Furthermore, curcumin inhibition of CCR5 and HIV-1 might constitute a potential therapeutic strategy for reducing HIV progression.

The prognostic impact of the immune microenvironment in small-cell neuroendocrine carcinoma of the uterine cervix: PD-L1 and immune cell subtypes

Background

We investigate the correlation between programmed cell death-ligand 1 (PD-L1) and tumor-associated immune cell (TAIC) density in small-cell neuroendocrine carcinoma of the uterine cervix (SCNEC) and their correlation with clinicopathologic features.

Methods

PD-L1 and mismatch repair protein (MMR) expression in cancer cells and the density of TAIC were evaluated by immunohistochemistry in 89 SCNEC patients. The combined positive score (CPS), tumor proportion score (TPS), and immune cell score (ICS) of PD-L1 were measured, along with their correlation with clinicopathologic features in SCNEC patients using statistical analyses.

Results

CPS of PD-L1 ≥ 1 was seen in 68.5% of patients, positive TPS and ICS of PD-L1 were detected in 59.6% and 33.7% of patients, respectively. PD-L1CPS was higher in tumor-infiltrating immune cells (r = 0.387, p = 0.001) and positively correlated with programmed cell death-1 and forkhead box P3 + regulatory T cell (FOXP3 + Treg) infiltration (r = 0.443, p < 0.001; r = 0.532, p < 0.001). There was no statistical correlation between PD-L1 and MMR status. PD-L1CPS and PD-L1ICS positivity were independent prognostic factors, correlating with a favorable survival (HR (95%CI) = 0.363(0.139–0.950), p = 0.039 and HR (95% CI) = 0.199(0.050–0.802), p = 0.023, respectively). PD-L1ICS positivity was an independent indicator of recurrence in SCNEC patients and associated with better disease-free survival (HR (95% CI) = 0.124(0.036–0425), p = 0.001). TAIC and MMR levels had no statistical impact on survival results.

Conclusions

PD-L1 positivity was seen in over half of SCNEC tumors. It may work synergistically with FOXP3 + Treg and other infiltrating immune cells to support an adaptive immune response. PD-L1 positivity may be a favorable prognostic factor in SCNEC.

DNA Methyltransferase 3b Accelerates the Process of Atherosclerosis

Background

DNA methylation plays a key role in establishing cell type-specific gene expression profiles and patterns in atherosclerosis. The underlying mechanism remains unclear. Previous studies have shown that DNA methyltransferase 3b (DNMT3b) may play an important role in atherosclerosis. This study aimed to establish the regulatory role of DNMT3b in the development of atherosclerosis.

Methods

We constructed a viral vector carrying Dnmt3b shRNA to transduce ApoE-/- mice. Meanwhile, healthy human peripheral blood Treg cells were treated with inhibitor of DNMT3b (AZA and EGCG) or transduced with DNMT3b shRNA.

Results

It showed that Dnmt3b silencing attenuated atherosclerosis, including decreased lesion size and macrophage content and increased collagen and smooth muscle cells content in ApoE-/- mice. To further investigate the possible mechanisms, combined with previous studies by our group, we showed that Foxp3-TSDR methylation level was significantly reduced Foxp3 expression and peripheral blood Treg levels were significantly increased by Dnmt3b shRNA vector transduction in animals committed to western diet for 12 and 18 weeks. Consistently, inhibition of DNMT3b (AZA and EGCG) decreased the expression levels of DNMT3b, which can increase the expression levels of FOXP3, and increase the levels of TGF-β and IL-10 and decrease the levels of IL-β and IFN-γ. After transduction with DNMT3b shRNA, the effect was more obvious.

Conclusions

DNMT3b accelerated atherosclerosis, and may be associated with FOXP3 hypermethylation status in regulatory T cells.

Mucosal Immune Responses to Respiratory Syncytial Virus

Despite over half a century of research, respiratory syncytial virus (RSV)-induced bronchiolitis remains a major cause of hospitalisation in infancy, while vaccines and specific therapies still await development. Our understanding of mucosal immune responses to RSV continues to evolve, but recent studies again highlight the role of Type-2 immune responses in RSV disease and hint at the possibility that it dampens Type-1 antiviral immunity. Other immunoregulatory pathways implicated in RSV disease highlight the importance of focussing on localised mucosal responses in the respiratory mucosa, as befits a virus that is essentially confined to the ciliated respiratory epithelium. In this review, we discuss studies of mucosal immune cell infiltration and production of inflammatory mediators in RSV bronchiolitis and relate these studies to observations from peripheral blood. We also discuss the advantages and limitations of studying the nasal mucosa in a disease that is most severe in the lower airway. A fresh focus on studies of RSV pathogenesis in the airway mucosa is set to revolutionise our understanding of this common and important infection.

The Mechanism of Interleukin-35 in Chronic Hepatitis B

Interleukin-35 (IL-35) is a newly identified inhibitory cytokine. It has recently been found to play an extremely important role in chronic hepatitis B disease, which makes it likely to be a target for new therapies for hepatitis B malady. IL-35 modulates a variety of immune mechanisms to cause persistent viral infections, such as affecting the ratio of helper T cells, reducing the activity of cytotoxic T cells, hindering the antigen presentation capacity for dendritic cells, and increasing the transcription level of hepatitis B virus. On the other hand, IL-35 can control the inflammation caused by hepatitis B liver injury. Therefore, to seek a breakthrough in curing hepatitis B disease, the contradictory part of IL-35 in the occurrence and development of this sickness is worthy of further discussion and research. This article will systematically review the biological effects of IL-35 and the specific mechanisms affecting the disease.

The Functional Impact of Alternative Splicing and Single Nucleotide Polymorphisms in Rheumatoid Arthritis

Advances in genomics and proteomics aid the identification of genes associated with various diseases. Genome-Wide Association Studies (GWAS) have identified multiple loci as risk alleles for susceptibility to Rheumatoid Arthritis (RA). A bisection of RA risk can be attributed to genetic factors. Over 100 associated genetic loci that encompass immune regulatory factors have been found to be linked with RA. Aberrant Single Nucleotide Polymorphisms (SNPs) and alternative splicing mechanisms in such loci induce RA. These aberrations are viewed as potential therapeutic targets due to their association with a multitude of diseases. This review presents a few imperious genes whose alterations can cause severe bone deformities culminating in RA.

FoxP3-miR-150-5p/3p suppresses ovarian tumorigenesis via an IGF1R/IRS1 pathway feedback loop

Ovarian cancer (OC) causes more deaths than any other gynecological cancer. Many cellular pathways have been elucidated to be associated with OC development and progression. Specifically, the insulin-like growth factor 1 receptor/insulin receptor substrate 1 (IGF1R/IRS1) pathway participates in OC development. Moreover, accumulating evidence has shown that microRNA deregulation contributes to tumor initiation and progression. Here, our study aimed to investigate the molecular functions and regulatory mechanisms of miR-150, specifically, in OC. We found that the expression of miR-150-5p/3p and their precursor, mir-150, was downregulated in OC tissues; lower mir-150 levels were associated with poor OC patient outcomes. Ectopic mir-150 expression inhibited OC cell growth and metastasis in vitro and in vivo. Furthermore, both IRS1 and IGF1R were confirmed as direct targets of miR-150-5p/3p, and the miR-150-IGF1R/IRS1 axis exerted antitumor effects via the PI3K/AKT/mTOR pathway. Forkhead box protein 3 (FoxP3) positively regulated the expression of miR-150-5p/3p by binding to the mir-150 promoter. In turn, the PI3K/AKT/mTOR pathway downregulated FoxP3 and miR-150-5p/3p. Taken together, these findings indicate that a complex FoxP3-miR-150-IGF1R/IRS1-PI3K/AKT/mTOR feedback loop regulates OC pathogenesis, providing a novel mechanism for miR-150 as a tumor suppressor miRNA in OC.

A hemizygous mutation in the FOXP3 gene (IPEX syndrome) resulting in recurrent X-linked fetal hydrops: a case report

BACKGROUND

Fetal hydrops is excessive extravasation of fluid into the third space in a fetus, which could be due to a wide differential of underlying pathology. IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome primarily affects males. It is a monogenic primary immunodeficiency syndrome of X-linked recessive inheritance due to FOXP3 gene variants. It is characterised by the development of multiple autoimmune disorders in affected individuals.

CASE PRESENTATION

We present a rare cause of male fetal hydrops in the context of IPEX syndrome and discuss FOXP3 gene variants as a differential for 'unexplained' fetal hydrops that may present after the first trimester.

DISCUSSION AND CONCLUSIONS

In all similar cases, the pathological process begins during intrauterine life. Furthermore, there are no survivors described. Consequently, this variant should be considered as a severe one, associated with intrauterine life onset and fatal course, i.e., the most severe IPEX phenotype.

The role of FOXP3 rs3761548 and rs2294021 polymorphisms in pediatrics acute lymphoblastic leukemia: association with risk and response to therapy

FOXP3 X-linked gene has crucial roles in the development and function of regulatory T cells. We investigated the association of FOXP3 rs3761548, rs3761549 and rs2294021 single nucleotide polymorphisms (SNPs) with acute lymphoblastic leukemia (ALL) susceptibility and response to therapy. Genotyping was performed in 247 patients and 210 healthy subjects. We observed a higher frequency of rs3761548 A carriers and rs2294021 C carriers (p < 0.04) in male patients, and lower frequencies of rs3761548 AC genotype (p = 0.04) and rs2294021 CT genotype (p = 0.01) in female patients compared to controls. ACC (p = 0.04) and ATC haplotypes (p = 0.002) were associated with susceptibility to ALL. There was a significant correlation between the genotypes of rs3761548 and rs2294021 SNPs with event-free survival (EFS) and overall survival (OS). The rs3761548 A genotype in male patients was associated with increased risk of relapse (p < 0.0001), shorter EFS, increased death rate (p = 0.002) and shorter OS compared to C genotype (p = 0.001). Similar significant results were observed for the relation of rs2294021 C genotype with response to therapy in male patients. In females, patients with rs3761548 AC genotype had longer EFS (p = 0.02) and those with rs2294021 CT had longer EFS and OS (p < 0.005). According to haplotype analysis, patients carrying ACC or ATC haplotypes had the highest number of WBCs and shorter EFS or OS, and patients with CCT haplotype had the lowest number of WBCs and longer EFS or OS. These results provided evidence for the impact of these polymorphisms on susceptibility and response to therapy in children with ALL.

Accumulation of TNFR2-expressing regulatory T cells in malignant pleural effusion of lung cancer patients is associated with poor prognosis

Background

Regulatory T cells (Tregs) may represent a major cellular mechanism in immune suppression by dampening the anti-tumor response in malignant pleural effusion (MPE). Tumor necrosis factor receptor type II (TNFR2) has emerged as a novel identification for the maximally suppressive subset of Tregs in the tumor environment. At present, the significance of TNFR2 expression on Tregs in MPE remains unclear.

Methods

The distribution of TNFR2⁺cells in Tregs and effector T cells (Teffs) in MPE, peripheral blood (PB), and tuberculosis pleural effusion (TPE) were determined. The associations between TNFR2⁺Tregs frequencies present in MPE and the clinical and laboratorial characteristics of patients with lung cancer were investigated. The immunosuppressive phenotype of TNFR2⁺Tregs in MPE was analyzed. The effects of the TNF-TNFR2 interaction on the immunosuppressive function of Tregs was explored. The efficacy of targeting TNFR2 for MPE therapy was examined. The source of TNF in MPE was identified.

Results

We observed that markedly higher levels of TNFR2 were expressed in MPE Tregs compared with the levels expressed in MPE Teffs, PB Tregs, or in TPE Tregs. The frequencies of TNFR2⁺Tregs were positively correlated with the number of tumor cells in MPE, as well as the volume of MPE. High frequencies of TNFR2⁺Tregs in MPE indicated short survival time and poor performance status for MPE patients. Compared to TNFR2^-Tregs, TNFR2⁺Tregs expressed higher levels of immunosuppressive molecules cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed cell death-ligand 1 (PD-L1), and replicating marker Ki-67. Consequently, the proportions of interferon gamma (IFN-γ)-producing cytotoxic T lymphocytes (CTLs) were significantly increased after TNFR2 blockade. Furthermore, tumor necrosis factor (TNF), through interaction with TNFR2, enhanced the suppressive capacity of Tregs by up-regulating CTLA-4 and PD-L1 expression. Interestingly, T helper 1 (Th1) and T helper 17 (Th17) cells are the major source of TNF in MPE, suggesting that MPE Teffs may paradoxically promote tumor growth by boosting MPE Treg activity via the TNF-TNFR2 pathway.

Conclusions

Our data expanded the immunosuppressive mechanism present in MPE induced by Tregs, and provides novel insight for the diagnosis, disease evaluation, and treatment of MPE patients.

Synergistic anti-liver cancer effects of curcumin and total ginsenosides

BACKGROUND

Liver cancer is the sixth most frequently occurring cancer in the world and the fourth most common cause of cancer mortality. The pathogenesis of liver cancer is closely associated with inflammation and immune response in the tumor microenvironment. New therapeutic agents for liver cancer, which can control inflammation and restore cellular immunity, are required. Curcumin (Cur) is a natural anti-inflammatory drug, and total ginsenosides (TG) are a commonly used immunoregulatory drug. Of note, both Cur and TG have been shown to exert anti-liver cancer effects.

AIM

To determine the synergistic immunomodulatory and anti-inflammatory effects of Cur combined with TG in a mouse model of subcutaneous liver cancer.

METHODS

A subcutaneous liver cancer model was established in BALB/c mice by a subcutaneous injection of hepatoma cell line. Animals were treated with Cur (200 mg/kg per day), TG (104 mg/kg per day or 520 mg/kg per day), the combination of Cur (200 mg/kg per day) and TG (104 mg/kg per day or 520 mg/kg per day), or 5-fluorouracil combined with cisplatin as a positive control for 21 d. Tumor volume was measured and the protein expression of programmed cell death 1 and programmed cell death 1 ligand 1 (PD-L1), inflammatory indicators Toll like receptor 4 (TLR4) and nuclear factor-κB (NF-κB), and vascular growth-related factors nitric oxide synthases (iNOS) and matrix metalloproteinase 9 were analyzed by Western blot analysis. CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) were counted by flow cytometry.

RESULTS

The combination therapy of Cur and TG significantly inhibited the growth of liver cancer, as compared to vehicle-treated animals, and TG showed dose dependence. Cur combined with TG-520 markedly decreased the protein expression of PD-L1 (P < 0.0001), while CD4⁺CD25⁺Foxp3⁺ Tregs regulated by the PD-L1 signaling pathway exhibited a positive correlation with PD-L1. Cur combined with TG-520 also inhibited the cascade action mediated by NF-κB (P < 0.0001), thus inhibiting the TLR4/NF-κB signalling pathway (P = 0.0088, P < 0.0001), which is associated with inflammation and acts on PD-L1. It also inhibited the NF-κB-MMP9 signalling pathway (P < 0.0001), which is associated with tumor angiogenesis.

CONCLUSION

Cur combined with TG regulates immune escape through the PD-L1 pathway and inhibits liver cancer growth through NF-κB-mediated inflammation and angiogenesis.

Lymphocyte Immunosuppression and Dysfunction Contributing to Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS)

ABSTRACT

Persistent Inflammation, Immune Suppression, and Catabolism Syndrome (PICS) is a disease state affecting patients who have a prolonged recovery after the acute phase of a large inflammatory insult. Trauma and sepsis are two pathologies after which such an insult evolves. In this review, we will focus on the key clinical determinants of PICS: Immunosuppression and cellular dysfunction. Currently, relevant immunosuppressive functions have been attributed to both innate and adaptive immune cells. However, there are significant gaps in our knowledge, as for trauma and sepsis the immunosuppressive functions of these cells have mostly been described in acute phase of inflammation so far, and their clinical relevance for the development of prolonged immunosuppression is mostly unknown. It is suggested that the initial immune imbalance determines the development of PCIS. Additionally, it remains unclear what distinguishes the onset of immune dysfunction in trauma and sepsis and how this drives immunosuppression in these cells. In this review, we will discuss how regulatory T cells (Tregs), innate lymphoid cells, natural killer T cells (NKT cells), TCR-a CD4- CD8- double-negative T cells (DN T cells), and B cells can contribute to the development of post-traumatic and septic immunosuppression. Altogether, we seek to fill a gap in the understanding of the contribution of lymphocyte immunosuppression and dysfunction to the development of chronic immune disbalance. Further, we will provide an overview of promising diagnostic and therapeutic interventions, whose potential to overcome the detrimental immunosuppression after trauma and sepsis is currently being tested.

Functional analysis of clinical response to low-dose IL-2 in patients with refractory chronic graft-versus-host disease

Patients with chronic graft-versus-host disease (cGVHD) have a paucity of regulatory CD4 T cells (CD4Tregs) that mediate peripheral tolerance. In clinical trials, daily low-dose interleukin-2 (IL-2) has been administered safely for prolonged periods in patients with steroid-refractory cGVHD. Peripheral CD4Tregs expand dramatically in all patients during IL-2 therapy but clinical improvement was observed in ∼50% of patients. Here, we examined the impact of low-dose IL-2 therapy on functional T-cell markers and the T-cell repertoire within CD4Tregs, conventional CD4 T cells (CD4Tcons), and CD8⁺ T cells. IL-2 had profound effects on CD4Tregs homeostasis in both response groups including selective expansion of the naive subset, improved thymic output, and increased expression of Ki67, FOXP3, and B-cell lymphoma 2 within CD4Tregs. Similar changes were not seen in CD4Tcons or CD8 T cells. Functionally, low-dose IL-2 enhanced, in vitro, CD4Treg-suppressive activity in both response groups, and all patient CD4Tcons were similarly suppressed by healthy donor CD4Tregs. High-throughput sequencing of the T-cell receptor β (TCRβ) locus demonstrated that low-dose IL-2 therapy increased TCR repertoire diversity and decreased evenness within CD4Tregs without affecting CD4Tcons or CD8 T cells. Using clone-tracking analysis, we observed rapid turnover of highly prevalent clones in CD4Tregs as well as the conversion of CD4Tcons to CD4Tregs. After 12 weeks of daily IL-2, clinical responders had a greater influx of novel clones within the CD4Treg compartment compared with nonresponders. Further studies to define the function and specificity of these novel CD4Treg clones may help establish the mechanisms whereby low-dose IL-2 therapy promotes immune tolerance.

Early immune response against Fonsecaea pedrosoi requires Dectin-2-mediated Th17 activity, whereas Th1 response, aided by Treg cells, is crucial for fungal clearance in later stage of experimental chromoblastomycosis

Chromoblastomycosis (CBM) is a chronic worldwide subcutaneous mycosis, caused by several dimorphic, pigmented dematiaceous fungi. It is difficult to treat patients with the disease, mainly because of its recalcitrant nature. The correct activation of host immune response is critical to avoid fungal persistence in the tissue and disease chronification. CD4+ T cells are crucial for the development of protective immunity to F. pedrosoi infection. Here, we investigated T helper cell response dynamics during experimental CBM. Following footpad injection with F. pedrosoi hyphae and conidia, T cells were skewed towards a Th17 and Th1 phenotype. The Th17 population was the main Th cell subset found in the infected area during the early stages of experimental murine CBM, followed by Th1 predominance in the later stages, coinciding with the remission phase of the disease in this experimental model. Depletion of CD25+ cells, which leads to a reduction of Treg cells in the draining lymph node, resulted in decline in fungal burden after 14 days of infection. However, fungal cells were not cleared in the later stages of the disease, prolonging CBM clinical features in those animals. IL-17A and IFN-γ neutralization hindered fungal cell elimination in the course of the disease. Similarly, in dectin-2 KO animals, Th17 contraction in the course of experimental CBM was accompanied by fungal burden decrease in the first 14 days of infection, although it did not affect disease resolution. In this study, we gained insight into T helper subsets' dynamics following footpad injections of F. pedrosoi propagules and uncovered their contribution to disease resolution. The Th17 population proved to be important in eliminating fungal cells in the early stages of infection. The Th1 population, in turn, closely assisted by Treg cells, proved to be relevant not only in the elimination of fungal cells at the beginning of infection but also essential for their complete elimination in later stages of the disease in a mouse experimental model of CBM.

A New Immunological Prognostic Model Based on Immunohistochemistry for Extranodal Natural Killer/T-Cell Lymphoma Patients After Non-Anthracycline-Based Chemotherapy

Purpose

Programmed death ligand 1 (PD-L1) has been proposed as an important prognostic factor in many types of cancer. However, the role of predicting the prognosis of PD-L1 in extranodal natural killer/T-cell lymphoma (ENKTL) was controversial. Combining other biomarkers might enhance its predictive power. This study aims to evaluate the prognostic value of PD-L1 in conjunction with tumor-infiltrating FoxP3+Tregs for ENKTL after non-anthracycline-based chemotherapy.

Patients and Methods

A total of 81 patients with ENKTL were included in this study. Clinicopathological characteristics were collected, and prognostic significance of PD-L1 in neoplastic cells (nPD-L1) and tumor-infiltrating FoxP3+Tregs were evaluated.

Results

Patients with nPD-L1-positive had significantly inferior overall survival (OS) and progression-free survival (PFS) compared with nPD-L1-negative (3-year OS, 37.2% vs 67.3%, p = 0.014; 3-year PFS, 31.0% vs 61.8%, p =0.010, respectively). Patients who had low FoxP3+Tregs had significantly inferior OS and PFS compared with high FoxP3+Tregs (3-year OS, 36.4% vs 63.0%, p = 0.004; 3-year PFS, 31.7% vs 56.3%, p = 0.020, respectively). The results of multivariate analysis showed that nPD-L1 positivity (HR 6.629, 95% CI 1.966–22.350, p=0.002) and low FoxP3+Tregs (HR 7.317, 95% CI 2.154–24.855, p=0.001) were independent predictors of inferior OS. Using these 2 variables, we constructed a new prognostic model that singled out 3 groups with different risk profiles: group 1, no adverse factors; group 2, 1 adverse factor; and group 3, 2 adverse factors. The 3-year OS rates of group 1, group 2, and group 3 were 93.3%, 46.6% and 20.8%, respectively (p<0.001), and the 3-year PFS rates were 86.7%, 40.8% and 15.0%, respectively (p=0.001).

Conclusion

This study is the first to validate the prognostic value of nPD-L1 and tumor-infiltrating FoxP3+Tregs in ENKTL; the new immunological prognostic model might be used to stratify ENKTL patients in clinical trials for new therapeutic strategies.

The relationship between regulatory T cells and radiation therapy

Radiation therapy (RT) is an effective treatment for cancer. Approximately, 70% of cancer patients receive RT in China. The immune-modulating effect of radiation therapy have gained considerable interest in recent years and there have been multiple reports of synergy between radiation and immunotherapy. Regulatory T cells (Tregs) are a group of T cell subsets with immunosuppressive function, which is correlated with cancer. Tregs are involved in the pathogenesis, development, treatment and prognosis of tumors by cell-cell contact, cytokines, and cell metabolism. Based on the immunological characteristics of Tregs, this article reviews the interaction between RT and immune molecules, aiming to provide new ideas for RT combined with immunotherapy.

Maturation of Gut Microbiota and Circulating Regulatory T Cells and Development of IgE Sensitization in Early Life

Recent studies suggest that the cross-talk between the gut microbiota and human immune system during the first year of life is an important regulator of the later development of atopic diseases. We explored the changes in the gut microbiota, blood regulatory T cells, and atopic sensitization in a birth-cohort of Estonian and Finnish children followed from 3 to 36 months of age. We describe here an infant Treg phenotype characterized by high Treg frequency, the maturation of Treg population characterized by a decrease in their frequency accompanied with an increase in the highly activated Treg cells. These changes in Treg population associated first with the relative abundance of Bifidobacterium longum followed by increasing colonization with butyrate producing bacteria. High bifidobacterial abundance in the neonatal microbiota appeared to be protective, while colonization with Bacteroides and E. coli was associated with later risk of allergy. Estonian children with lower risk of IgE mediated allergic diseases than Finnish children showed an earlier maturation of the gut microbiota, detected as earlier switch to an increasing abundance of butyrate-producing bacteria, combined with an earlier maturation of Treg cell phenotype and total IgE production. The children with established allergic diseases by age 3 showed a decreased abundance of butyrate producing Faecalibacterium. These results suggest that as well as the maintenance of a bifidobacterial dominated gut microbiota is important during the first weeks of life, the overtake by butyrate producing bacteria seems to be a beneficial shift, which should not be postponed.

The expression of C-MYC in gastric adenocarcinoma is associated with PD-L1 and FOXP3 expression: C-MYC overexpression is a good prognostic factor

BACKGROUND

C-MYC appears to initiate and maintain tumorigenesis through modulation of immune regulatory molecules such as PD-L1. The aim of our research was to evaluate the clinical implication of C-MYC expression in gastric adenocarcinoma in relation to the expression of the immune regulatory molecules PD-L1 and FOXP3.

METHODS

Tissue samples were acquired from 182 cases of gastric adenocarcinoma that were surgically resected at Kyung Hee University Hospital at Gangdong from 2006 to 2012. Immunohistochemical staining for C-MYC, PD-L1, CD8 and FOXP3 was done.

RESULTS

C-MYC overexpression showed a significant correlation with smaller tumor size, lower T category, lower N category, lower recurrence rate, and less lymphatic invasion. And C-MYC overexpression was negatively correlated with PD-L1 expression. The tumoral FOXP3 was positively correlated with C-MYC overexpression and Tregs count. PD-L1 expression was positively correlated with Tregs, CD8 + T cells, and tumor infiltrating lymphocytes (TIL). Tregs count was positively correlated with CD8 + T cells and TIL. CD8 + T cells was positively correlated with TIL.

CONCLUSION

We discovered that the immune regulatory effect of C-MYC and PD-L1, and the tumor suppressor function of tumoral FOXP3 had a significant influence on the tumor microenvironment (Tregs, CD8 + T cells, and tumor infiltrating lymphocytes) in a complex manner. The C-MYC overexpression is a good prognostic factor in gastric adenocarcinoma.

Elevated Methylation of FOXP3 (Forkhead Box P3)-TSDR (Regulatory T-Cell-Specific Demethylated Region) Is Associated With Increased Risk for Adverse Outcomes in Patients With Acute Coronary Syndrome

Demethylation of the forkhead box P3 (FOXP3) corresponds with stability of FOXP3 expression and immunosuppressive function of regulatory T cells (Tregs). Previous studies have demonstrated that reduction in Tregs is associated with acute coronary syndrome (ACS). The aim of this study was to establish the relationship between methylation level of FOXP3-TSDR (Treg-specific demethylated region) and clinical outcomes of ACS. We first evaluated the prognostic significance of methylation levels of FOXP3-TSDR in patients with ACS (n=171). Then, we explored the possible mechanism of methylation levels of FOXP3-TSDR on clinical outcomes of ACS in vivo. We analyzed methylation of FOXP3-TSDR, percentage of Tregs in total peripheral blood, and atherosclerotic lesions in aortic root in ApoE^-/- mice (n=48; 6 groups). During the follow-up of 4.5±0.8 years, survival free of major adverse cardiovascular events was the lowest in the highest tertile of FOXP3-TSDR methylation (log-rank P=0.004). Multivariate analysis showed that FOXP3-TSDR methylation was independently and positively related to major adverse cardiovascular events (adjusted hazard ratio, 2.13; 95% CI, 1.21-3.75; P=0.009). We observed a duration-dependent increase in the methylation levels of FOXP3-TSDR in mice fed with Western diet at a period of 0, 3, 6, 9, 12, and 15 weeks. Elevated methylation levels of FOXP3-TSDR were significantly correlated of severity of atherosclerosis. We further found that FOXP3-TSDR methylation was inversely related to the percentages of Treg TGF-β (transforming growth factor-β) and IL (interleukin)-10 levels. Our results indicate that elevated methylation levels of FOXP3-TSDR are associated with increased risk for adverse outcomes in patients with ACS.

Elevated Circulating CD4+CD25-Foxp3+ Regulatory T Cells in Patients with Nonsmall Cell Lung Cancer

Purpose: CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cell-mediated immunosuppression has been implicated as a crucial mechanism of tumor immune cell escape in nonsmall cell lung cancer (NSCLC). However, little is known concerning the specific role of CD4⁺CD25^-Foxp3⁺ Treg cells in NSCLC. The aim of this study was to investigate the frequency of circulating CD4⁺CD25^-Foxp3⁺ Treg cells and their role in NSCLC. Methods: The frequencies of Treg, T helper (Th)1, Th2, and Th17 cells in peripheral blood were separately measured in 36 NSCLC patients and 20 healthy controls (HCs) using flow cytometry. Serum cytokine concentrations were determined using cytometric bead arrays. Results: The frequencies of circulating CD4⁺CD25⁺ T cells and CD4⁺CD25⁺Foxp3⁺ and CD4⁺CD25^-Foxp3⁺ Treg cells were significantly higher in advanced-stage NSCLC patients compared with patients with limited-stage NSCLC. The frequencies of circulating CD4⁺CD25⁺Foxp3⁺ and CD4⁺CD25^-Foxp3⁺ Treg cells were negatively correlated with interleukin (IL)-17, but positively correlated with serum IL-10 levels. In addition, the Th17/CD4⁺CD25^-Foxp3⁺ Treg cell ratios were negatively correlated with serum cytokeratin 19 fragment (CYFRA 21-1) concentrations in patients with NSCLC. Moreover, coculturing CD4⁺CD25^-Foxp3⁺ Treg cells and CD14⁺ monocytes in vitro resulted in a higher frequency of CD206⁺CD14⁺ M2-like monocytes compared with CD14⁺ monocytes. Conclusions: Elevated circulating CD4⁺CD25^-Foxp3⁺ Treg cells may be involved in the pathogenesis of NSCLC.

Significant association of CD4+CD25+Foxp3+ regulatory T cells with clinical findings in patients with systemic lupus erythematosus

Background

Regulatory T (Treg) cells are one of the important mechanisms in maintaining self-tolerance and immune homeostasis. CD4⁺CD25⁺Foxp3⁺Treg is considered to have a role in the pathogenesis of systemic lupus erythematosus (SLE). However, the data reported is controversial, and a conclusive result has not been given thus far. The aim of the present study is to evaluate the role of CD4⁺Treg in SLE further.

Methods

The peripheral blood T cells (PBMCs) from patients with SLE and healthy controls were isolated, and followed by the isolation of CD3⁺T cells. The PBMCs were tested for the expressions of CD25 and Foxp3 molecules on the surface of CD4⁺T cells, and CD3⁺T cells were tested for their cytokine expressions including IFN-γ, TGF-β, and IL-10, with the method of flow cytometry. The correlations of test results with clinical features of the disease were evaluated by linear correlation analysis.

Results

CD4⁺CD25⁺ Foxp3⁺Treg decreased in SLE patients and was correlated with the SLE Disease Activity Index (SLEDAI), and a few immunological abnormalities, including anti-dsDNA antibody positive, IgG increase and C3 decrease, and types of tissue damage, including leukocytopenia and kidney damage. IFN-γ⁺ cells in the CD4⁺CD25⁺T subset fresh-isolated from SLE patients increased slightly, but IFN-γ-producing response to stimulation in CD4⁺CD25⁺T subset of SLE decreased. The number of TGF-β-producing cells in the CD4⁺CD25⁺T subset from SLE patients also decreased. While the percentages of CD4⁺CD25⁺IL-10⁺T subset in the CD3⁺T cells increased in SLE, however, these changes of cytokine expressions did not show any significant correlations with SLEDAI.

Conclusions

There is clear and definite evidence from the present study indicating the important role of CD4⁺CD25⁺Foxp3⁺Treg in the pathogenesis of SLE, for the abnormalities in functional cytokine productions of the CD4⁺CD25⁺ T subset, and for the feasibility of a CD4⁺CD25⁺Foxp3⁺Treg- based immunotherapy in SLE.

The forkhead-box family of transcription factors: key molecular players in colorectal cancer pathogenesis

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide and the fourth most frequent cause of death having an oncological origin. It has been found that transcription factors (TF) dysregulation, leading to the significant expression modifications of genes, is a widely distributed phenomenon regarding human malignant neoplasias. These changes are key determinants regarding tumour’s behaviour as they contribute to cell differentiation/proliferation, migration and metastasis, as well as resistance to chemotherapeutic agents. The forkhead box (FOX) transcription factor family consists of an evolutionarily conserved group of transcriptional regulators engaged in numerous functions during development and adult life. Their dysfunction has been associated with human diseases. Several FOX gene subgroup transcriptional disturbances, affecting numerous complex molecular cascades, have been linked to a wide range of cancer types highlighting their potential usefulness as molecular biomarkers. At least 14 FOX subgroups have been related to CRC pathogenesis, thereby underlining their role for diagnosis, prognosis and treatment purposes.

This manuscript aims to provide, for the first time, a comprehensive review of FOX genes’ roles during CRC pathogenesis. The molecular and functional characteristics of most relevant FOX molecules (FOXO, FOXM1, FOXP3) have been described within the context of CRC biology, including their usefulness regarding diagnosis and prognosis. Potential CRC therapeutics (including genome-editing approaches) involving FOX regulation have also been included. Taken together, the information provided here should enable a better understanding of FOX genes’ function in CRC pathogenesis for basic science researchers and clinicians.

Terminally differentiated CD8+ T cells and CD57-FOXP3+CD8+ T cells are highly associated with the efficacy of immunotherapy using activated autologous lymphocytes

Treatment with activated autologous lymphocytes (AALs) has demonstrated mixed results for cancer treatment. Preliminary results revealed that the proportion of cluster of differentiation (CD)8⁺CD57⁺ T cells is significantly increased in AALs, indicating that they are able to determine treatment outcome. Therefore, the role of CD8⁺CD57⁺ T cells in AAL efficacy was investigated. T lymphocytes were isolated from 35 patients with stage IV gastric carcinomas (17 men and 18 women; aged 41-84 years) receiving immunotherapy using AALs (IAAL). Using fluorescence activated cell sorting, CD8, CD27, CD57, and forkhead box protein 3 (FOXP3) expression was investigated on CD8⁺ T cell populations in CD8⁺ T cell differentiation prior to and following in vitro culture. The association between these populations and progression-free survival (PFS) was analyzed using Cox univariate, and multivariate analyses and Kaplan-Meier survival analysis. CD57 expression was negative in early-differentiated CD8⁺ T cells (CD27⁺CD8⁺CD57^-), and positive in intermediate- (CD27⁺CD8⁺CD57⁺) and terminal- (CD27^-CD8⁺CD57⁺) differentiated CD8⁺ T cells. Univariate analysis revealed a significant association between terminal-CD8⁺ T cells and longer PFS times (P=0.035), whereas CD57^-FOXP3⁺CD8⁺ T cells were associated with shorter PFS times. Multivariate analysis revealed that CD57^-FOXP3⁺CD8⁺ T cells was an independent poor prognostic factor, whereas CD57⁺FOXP3⁺CD8⁺ T cells were not associated with PFS. Although IAAL increased the proportion of terminal-CD8⁺ T cells relative to the pre-culture proportions, patients with a high CD57^-FOXP3⁺CD8⁺ T cell percentage exhibited repressed terminal-CD8⁺ T cell induction, leading to poor patient prognosis. Terminally differentiated CD27^-CD8⁺CD57⁺ T cells were responsible for the effectiveness of AALs; however, CD57^-FOXP3⁺CD8⁺ T cells abrogated their efficacy, possibly by inhibiting their induction.

Matrix metalloproteinase 12 expression is associated with tumor FOXP3+ regulatory T cell infiltration and poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most fatal types of cancer worldwide due to its high rates of recurrence and metastasis. The molecular processes involved in HCC progression require further investigation to identify biomarkers for use in diagnosis and treatment. In the present study, the significance and prognostic value of matrix metallopeptidase 12 (MMP12) expression in human HCC was investigated. MMP12 mRNA expression was investigated using reverse transcription-quantitative polymerase chain reaction analysis of 42 pairs of tumor and non-tumor liver tissues obtained from patients with HCC following surgical treatment. Immunohistochemical staining was used to detect MMP12 and forkhead box P3 (FOXP3) expression in 158 paraffin-embedded HCC tissues. The prognostic value of MMP12 expression was determined using Kaplan-Meier analysis and the Cox proportional hazards model. MMP12 mRNA levels were significantly higher in liver tumor tissues compared with matched non-tumor liver tissues. MMP12 expression and FOXP3⁺ regulatory T cell (Treg) infiltration was positively correlated (r=0.302; P<0.001). MMP12 protein overexpression was positively correlated with tumor size (P=0.018), high serum alpha-fetoprotein levels (P=0.005) and poor overall survival time (P=0.012) in patients with HCC. Furthermore, MMP12 protein level was an independent predictive factor for overall survival time of patients with HCC who underwent curative resection. In conclusion, these results suggest that MMP12 may increase FOXP3⁺ Treg infiltration into tumor tissues, and promote tumor progression and immune evasion of HCC. The overexpression of MMP12 protein is, therefore, a valuable prognostic indicator in patients with HCC.

The role of regulatory T cells, interleukin-10 and in vivo scintigraphy in autoimmune and idiopathic diseases - Therapeutic perspectives and prognosis

Previous studies have demonstrated the expression of the CD25 marker on the surface of naturally occurring T cells (Tregs) of mice, which have a self-reactive cellular profile. Recently, expression of other markers that aid in the identification of these cells has been detected in lymphocyte subtypes of individuals suffering of autoimmune and idiopathic diseases, including: CD25, CTLA-4 (cytotoxic T-lymphocyte antigen 4), HLA-DR (human leukocyte antigen) and Interleukin 10 (IL-10), opening new perspectives for a better understanding of an association between such receptors present on the cell surface and the prognosis of autoimmune diseases. The role of these molecules has already been described in the literature for the modulation of the inflammatory response in infectious and parasitic diseases. Thus, the function, phenotype and frequency of expression of the a-chain receptor of IL-2 (CD25) and IL-10 in lymphocyte subtypes were investigated. Murine models have been used to demonstrate a possible correlation between the expression of the CD25 marker (on the surface of CD4 lymphocytes) and the control of self-tolerance mechanisms. These studies provided support for the presentation of a review of the role of cells expressing IL-2, IL-10, HLA-DR and CTLA-4 receptors in the monitoring of immunosuppression in diseases classified as autoimmune, providing perspectives for understanding peripheral regulation mechanisms and the pathophysiology of these diseases in humans. In addition, a therapeutic approach based on the manipulation of the phenotype of these cells and ways of scintigraphically monitoring the manifestations of these diseases by labeling their receptors is discussed as a perspective. In this paper, we have included the description of experiments in ex vivo regulation of IL-10 and synthesis of thio-sugars and poly-sugars to produce radiopharmaceuticals for monitoring inflammation. These experiments may yield benefits for the treatment and prognosis of autoimmune diseases.

Enhanced Suppressive Activity of Regulatory T Cells in the Microenvironment of Malignant Pleural Effusions

Cancer metastatic spread to serous cavity causes malignant pleural effusions (MPEs), indicating dismal prognosis. Tumor microenvironment can implement suppressive activity on host immune responses. Thus, we investigated the prevalence of Tregs and the relationship between them and TGF-β and IL-10 concentrations and measured expression of FOXP3, CTLA-4, CD28, and GITR genes, as well as protein expression of selected genes in benign effusions and MPEs. The percentage of Tregs was determined by means of multicolor flow cytometry system. TGF-β and IL-10 concentrations were measured using human TGF-β1 and IL-10 ELISA kit. Relative mRNA expression of studied genes was analyzed by real-time PCR. The frequency of Tregs was significantly higher in MPEs compared to benign effusions; however, the level of TGF-β and IL-10 in analyzed groups was comparable, and no correlation between concentrations of TGF-β and IL-10 and percentage of Tregs was observed. Relative mRNA expression of all the genes was higher in CD4⁺CD25⁺ compared to CD4⁺CD25⁻ cells. In CD4⁺CD25⁺ cells from MPEs, relative mRNA expression of FOXP3, CTLA-4, and CD28 genes was significantly higher than in benign effusions; however, the level of CD4⁺CD25⁺CTLA-4⁺ cells in analyzed groups showed no significant differences. We found numerous genes correlations in an entire CD4⁺CD25⁺ cell subset and CD4⁺CD25⁺ cells from MPEs. Enhanced suppressive activity of Tregs is observed in the microenvironment of MPEs. Understanding of relations between cellular and cytokine immunosuppressive factors in tumor microenvironment may determine success of anticancer response.

Regulatory and Mechanistic Actions of Glucocorticoids on T and Inflammatory Cells

Glucocorticoids (GCs) play an important role in regulating the inflammatory and immune response and have been used since decades to treat various inflammatory and autoimmune disorders. Fine-tuning the glucocorticoid receptor (GR) activity is instrumental in the search for novel therapeutic strategies aimed to reduce pathological signaling and restoring homeostasis. Despite the primary anti-inflammatory actions of GCs, there are studies suggesting that under certain conditions GCs may also exert pro-inflammatory responses. For these reasons the understanding of the GR basic mechanisms of action on different immune cells in the periphery (e.g., macrophages, dendritic cells, neutrophils, and T cells) and in the brain (microglia) contexts, that we review in this chapter, is a continuous matter of interest and may reveal novel therapeutic targets for the treatment of immune and inflammatory response.

PD-L1 Expression Is Associated with FOXP3+ Regulatory T-Cell Infiltration of Soft Tissue Sarcoma and Poor Patient Prognosis

Background: Programmed death ligand-1(PD-L1) functions as a negative mediator of immune response through different pathways in anti-tumor immunity. Recent studies have reported that PD-L1 plays a pivotal role in the function of regulatory T-cells (Tregs). Although increases in FOXP3+ Tregs infiltration and PD-L1 expression have been revealed in several cancers, their correlation with soft tissue sarcoma remains unknown.

Methods: We included 163 cases of soft tissue sarcoma who were diagnosed and underwent extensive and radical resection at the Sun Yat-sen University Cancer Center, Guangzhou, China, from 2000-2010. PD-L1 and FOXP3 expression was evaluated by immunohistochemistry. Correlation between their expressions and associations with clinicopathological features were studied.

Results: Among 163 STS samples, 19 (11.7%) exhibited PD-L1 positivity, and 41 (25.2%) cases expressed high FOXP3+ Treg infiltration. Significant correlation between PD-L1 expression and FOXP3+Treg infiltration in STS was identified (r=0.450, p<0.001). In univariate analysis, PD-L1 expression was significantly associated with high tumor grade and the age of patients, while the presence of FOXP3+ in tumor infiltrating Tregs was significantly associated with the age of patients, high tumor stage, higher tumor grade and tumor depth. Multivariate analysis revealed PD-L1 and FOXP3 as independent prognostic indicators significantly associated with OS and DFS.

Conclusions: Our study revealed that PD-L1 and FOXP3+Tregs may work synergistically in promoting immune evasion of the tumors in soft tissue sarcoma. A combined strategy to block PD-L1/PD-1 with simultaneous depletion of Tregs may show promise in enhancing the therapeutic efficacy of these patients.

Preliminary study on decreasing the expression of FOXP3 with miR-155 to inhibit diffuse large B-cell lymphoma

The aim of the present study was to analyze the association between the transcription factor forkhead box P3 (FOXP3) and diffuse large B-cell lymphoma (DLBCL), and investigate the effect of microRNA-155 (miR-155) on the generation and development of FOXP3 in DLBCL. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) technique was used to determine the expression of FOXP3 in the human DLBCL cell lines Ly1, Ly8 and Ly10, and in normal B cells. An immunohistochemical method was used to determine FOXP3 expression in 60 DLBCL tumor and adjacent tissues, and a retrospective analysis of FOXP3 expression in tumor tissues and clinical data was performed. The lentiviral transfection technique was used to silence the miR-155 gene in mouse A20 cells to analyze the influence of miR-155 on FOXP3 in DLBCL. The A20 cell line with a silenced miR-155 gene was used to perform a tumorigenicity assay in BALB/c mice, and to compare the tumorigenicity rate and the tumor growth rate. The results identified that the expression of the transcription factor FOXP3 in the human DLBCL cell lines was increased compared with normal B cells; FOXP3 in human DLBCL tumor issues was increased compared with the tumor-adjacent tissue, and the increased expression of FOXP3 was identified as an indicator of poor prognosis of patients with DLBCL in the middle and late period; FOXP3 level decreased subsequent to silencing miR-155 in A20 cells; A20 cells with the low-expression miR-155 gene were used to determine the tumorigenicity in BALB/c mice and it was identified that the tumorigenicity of the low-expression miR-155 gene group was decreased compared with the untransfected group. Therefore, miR-155 may be a regulatory factor of FOXP3, and miR-155 may be associated with the metastasis and prognosis of patients with DLBCL.

Interleukin 4 promotes the development of ex-Foxp3 Th2 cells during immunity to intestinal helminths

Pelly et al. use novel mouse reporter systems to show that a proportion of Th2 cells develop from Foxp3-expressing cells in an IL-4–dependent manner, highlighting the potential to subvert T reg cell–mediated suppression in favor of type 2 immunity.

Immunity to intestinal helminth infections requires the rapid activation of T helper 2 cells (Th2 cells). However, simultaneous expansion of CD4⁺Foxp3⁺ regulatory T cells (T reg cells) impedes protective responses, resulting in chronic infections. The ratio between T reg and effector T cells can therefore determine the outcome of infection. The redifferentiation of T reg cells into Th cells has been identified in hyperinflammatory diseases. In this study, we asked whether ex–T reg Th2 cells develop and contribute to type-2 immunity. Using multigene reporter and fate-reporter systems, we demonstrate that a significant proportion of Th2 cells derive from Foxp3⁺ cells after Heligmosomoides polygyrus infection and airway allergy. Ex-Foxp3 Th2 cells exhibit characteristic Th2 effector functions and provide immunity to H. polygyrus. Through selective deletion of Il4ra on Foxp3⁺ cells, we further demonstrate IL-4 is required for the development of ex-Foxp3 Th2 cells. Collectively, our findings indicate that converting T reg cells into Th2 cells could concomitantly enhance Th2 cells and limit T reg cell–mediated suppression.

FOXP3-Positive Regulatory T Cells and Kidney Allograft Tolerance

Normal immune homeostasis is achieved by several mechanisms, and prominent among them is immunoregulation. Although several types of regulatory lymphocyte populations have been described, CD4 T cells expressing the FOXP3 transcription factor (FOXP3-positive regulatory T cells [FOXP3+ Tregs]) are the best understood. This population of cells is critical for maintaining self-tolerance throughout the life of the organism. FOXP3+ Tregs can develop within the thymus, but also under select circumstances, naive peripheral T cells can be induced to express FOXP3 and become stable Tregs as well. Abundant evidence from animal systems, as well as limited evidence in humans, implicates Tregs in transplant tolerance, although whether these Tregs recognize allo- or self-antigens is not clear. New translational approaches to promote immunosuppression minimization and/or actual tolerance are being designed to exploit these observations. These include strategies to boost the generation, maintenance, and stability of endogenous Tregs, as well as adoptive cellular therapy with exogenous Tregs.

The mechanisms tumor cells utilize to evade the host's immune system

The immune system plays an essential role in the tumor progression; not only can it inhibit tumor growth but it can also promote tumor growth by establishing a favorable environment. Tumor cells utilize several strategies to evade the host's immune system, including expression of immunosuppressive molecules such as PD-L1, IDO and siglec-9. In addition, tumor cells not only regulate the recruitment and development of immunosuppressive forces to influence the tumor microenvironment but also shift the phenotype and function of normal immune cells from a possibly anti-tumor state to a pro-tumor state. As a result, tumor cells evade the host's immune system, leading to metastasis and/or recurrent disease.

Lifelong training improves anti-inflammatory environment and maintains the number of regulatory T cells in masters athletes

PURPOSE

The purpose of this study was to quantify and characterize peripheral blood regulatory T cells (Tregs), as well as the IL-10 plasma concentration, in Masters athletes at rest and after an acute exhaustive exercise test.

METHODS

Eighteen Masters athletes (self-reported training: 24.6 ± 1.83 years; 10.27 ± 0.24 months and 5.45 ± 0.42 h/week per each month trained) and an age-matched control group of ten subjects (that never took part in regular physical training) volunteered for this study. All subjects performed an incremental test to exhaustion on a cycle ergometer. Blood samples were obtained before (Pre), 10 min into recovery (Post), and 1 h after the test (1 h).

RESULTS

Absolute numbers of Tregs were similar in both groups at rest. Acute exercise induced a significant increase in absolute numbers of Tregs at Post (0.049 ± 0.021 to 0.056 ± 0.024 × 10⁹/L, P = 0.029 for Masters; 0.048 ± 0.017 to 0.058 ± 0.020 × 10⁹/L, P = 0.037 for control) in both groups. Treg mRNA expression for FoxP3, IL-10, and TGF-β in sorted Tregs was similar throughout the trials in both groups. Masters athletes showed a higher percentage of subjects expressing the FoxP3 (100% for Masters vs. 78% for Controls, P = 0.038) and TGF-β (89% for Masters vs. 56% for Controls, P = 0.002) after exercise and a higher plasma IL-10 concentration (15.390 ± 7.032 for Masters vs. 2.411 ± 1.117 for control P = 0.001, ES = 2.57) at all timepoints. KLRG1 expression in Tregs was unchanged.

CONCLUSION

Our findings showed that Masters athletes have elevated anti-inflammatory markers and maintain the number of Tregs, and may be an adaptive response to lifelong training.

Micro-RNA 10a Is Increased in Feline T Regulatory Cells and Increases Foxp3 Protein Expression Following In Vitro Transfection

CD4⁺CD25⁺Foxp3⁺ T regulatory (Treg) cells are activated during the course of lentiviral infection and exhibit heightened suppressor function when compared to Treg cells from uninfected controls. Foxp3 is essential to Treg cell function and multiple studies have documented that lentivirus-activated Treg cells exhibit heightened Foxp3 expression when compared to Treg cells from uninfected controls. Our hypothesis was that lentivirus-induced micro-RNAs (miRNAs) contribute to heightened Treg cell suppressor function by stabilizing Foxp3 expression. We demonstrated that CD4⁺CD25⁺ T cells from both feline immunodeficiency virus infected (FIV⁺) cats and uninfected control cats exhibit increased miRNA 10a and 21 levels compared to autologous CD4⁺CD25- T cells but there was no difference in the levels of these miRNAs when Treg cells from FIV⁺ cats were compared to Treg cells from uninfected controls. Further, there was no increase in Foxp3 mRNA following transfection of miRNA 10a or 21 into a feline cell line. However, transfection with miRNA 10a resulted in increased Foxp3 protein expression.

Platelets modulate the immune response following trauma by interaction with CD4+ T regulatory cells in a mouse model

CD4+ T regulatory cells (Tregs) play a pivotal role in the anti-inflammatory immune response following trauma. The mechanisms of CD4+ Treg activation are mostly unknown. Here, we hypothesize that platelets regulate CD4+ Treg activation following trauma. In a murine burn injury model (male C57Bl/6N mice), depletion of platelets or CD4+ Tregs was conducted. Draining lymph nodes, blood and spleen were harvested 2 h and 7 days after trauma. CD4+ Treg activation was measured using phospho- and conventional flow cytometry. Platelet activation was analyzed using thromboelastometry and flow cytometry. Trauma differentially activates CD4+ T cells, early after trauma only CD4+ Tregs are activated. Following burn injury, platelets augment the activation of CD4+ Tregs. This effect could only be seen early after trauma. While CD4+ Tregs influence hemostasis early following trauma, platelet activation markers were unchanged. Beyond their role in hemostasis, platelets are able to modulate the immunologic host response to trauma-induced injury by augmenting the activation of CD4+ Tregs. CD4+ Treg activation following trauma is considered protective. In addition, CD4+ Tregs are capable of modulating the hemostatic function of platelets. For the first time, we could show reciprocal activation of platelets and CD4+ Tregs as part of the protective immune response following trauma.

Foxp3 promoter methylation impairs suppressive function of regulatory T cells in biliary atresia

Biliary atresia (BA) is characterized by progressive inflammation of the biliary system leading to liver cirrhosis, necessitating liver transplantation in pediatric patients. Various cell types have been reported to participate in the proinflammatory response in rhesus rotavirus (RRV)-induced BA mouse models, including T helper (Th) 1, Th2, Th17, CD8⁺ T cells, and natural killer cells. The immune suppressive regulatory T (Treg) cells, on the contrary, were reported not to function properly. The underlying mechanism is largely unknown. Focusing on the impaired suppressive function of Treg, we found methylation status of CpG islands within the Foxp3 promoter region of Treg cells in BA patients and murine models were both increased. Moreover, by injecting 5-aza-2'-deoxycytidine (Aza) as DNA-methylation inhibitor to RRV-infected mice, BA phenotypes were alleviated. Furthermore, Treg cells isolated from "RRV+Aza"-injected mice had better suppressive function than Treg cells from mice injected with RRV only, both in vivo and ex vivo. Thus we concluded that aberrant increased methylation status of "Foxp3 promoter" in Treg cells leads to impaired Treg suppressive function, exacerbating inflammatory injury in BA.

PD-L1 Expression Is Associated with Tumor FOXP3(+) Regulatory T-Cell Infiltration of Breast Cancer and Poor Prognosis of Patient

Background: Expression of PD-L1 has been estimated to predict the therapeutic potential of PD-L1 inhibition in solid tumors. Recent studies have demonstrated that PD-L1 plays a critical role in regulatory T-cell (Treg) development and functional maintenance. Although increases in FOXP3⁺Treg infiltration and PD-L1 expression have been revealed in several malignancies, their correlation in human breast tumors is as yet unclear.

Methods: Whole-tissue sections from 501 patients with breast cancer were examined for PD-L1 and FOXP3 expression by immunohistochemistry. Correlation between their expressions and the association with clinicopathological features, intrinsic tumor subtypes and patient's prognosis were studied.

Results: PD-L1 expression and FOXP3⁺Treg infiltrates in tumor tissue demonstrated a high correlation (r_s=0.334, p<0.001) in this cohort of breast cancer patients. High PD-L1 expression and increased FOXP3⁺Treg infiltrates were both associated with high histological grade, negative ER and PR status, and aggressive intrinsic tumor subtypes, especially the basal-like subtype. Tumors with concomitant high expressions of the two markers had the worst prognosis. Multivariate analysis proved both markers to be the independent predictors for decreased overall survival of patients, particularly in the basal-like subtype.

Conclusions: The results suggest that PD-L1 and FOXP3⁺Tregs may work synergistically and their up-regulated expressions promote tumor immune evasion in breast cancer. Combinatorial immunotherapeutic approaches aiming on blocking PD-L1 and depleting Tregs might improve therapeutic efficacy in breast cancer patients, especially those with basal-like carcinoma.

A genome-wide association study of fetal response to type 2 porcine reproductive and respiratory syndrome virus challenge

Control of porcine reproductive and respiratory syndrome (PRRS) is economically important for the swine industry worldwide. As current PRRS vaccines do not completely protect against heterologous challenge, alternative means of control, including enhanced genetic resilience, are needed. For reproductive PRRS, the genetic basis of fetal response to PRRS virus (PRRSV) infection is poorly understood. Genome-wide association studies (GWAS) were done here using data from 928 fetuses from pregnant gilts experimentally challenged with type 2 PRRSV. Fetuses were assessed for viral load in thymus (VLT), viral load in endometrium (VLE), fetal death (FD) and fetal viability (FV), and genotyped at a medium density. Collectively, 21 candidate genomic regions were found associated with these traits, seven of which overlap with previously reported QTLs for pig health and reproduction. A comparison with ongoing and related transcriptomic analyses of fetal response to PRRSV infection found differentially expressed genes within 18 candidate regions. Some of these genes have immune system functions, and have been reported to contribute to host response to PRRSV infection. The results provide new evidence about the genetic basis of fetal response to PRRSV challenge, and may ultimately lead to alternative control strategies to reduce the impact of reproductive PRRS.

Evaluation of transcription factor that regulates T helper 17 and regulatory T cells function in periodontal health and disease

Background:

The differentiation of naοve T helper (Th) cells towards Th17 and regulatory T cells (Treg) is regulated by the transcription factors retinoic acid related orphan receptor gamma transcription (RORYt) and Forkhead box p3 (Foxp3), respectively. An imbalance in the activity of these transcription factors could result in the dysregulation of Th17/Treg response.

Materials and Methods:

Total RNA was isolated from gingival tissue obtained from 10 patients, each from periodontally healthy and diseased groups. The gene expression of RORYt and Foxp3 was measured by real-time reverse transcription polymerization chain reaction using total RNA isolates from gingival tissues group when compared to the healthy group, while Foxp3 demonstrated a 6.68 ± 0.03 fold decrease of expression in diseased group when compared to healthy group.

Conclusion:

Our results indicate a functional imbalance in the Th17/Treg response in periodontal disease group when compared to the periodontally healthy group.

CD4(+)CD25(-)Foxp3(+) T cells play a role in tuberculous hydrothorax rather than malignant hydrothorax

BACKGROUND

Foxp3(+) T cells regulate inflammation and tumorigenesis. However, little is known about the role of different subsets of Foxp3(+) T cells in malignant or tuberculous hydrothorax.

METHODS

The numbers of CD4(+)CD25(+)Foxp3(+), CD4(+)CD25(-)Foxp3(+) T cells and the levels of some inflammatory cytokines in patients with tuberculous hydrothorax, malignant hydrothorax, and healthy controls (HCs) were examined by flow cytometry and ELISA. The potential association between the numbers of different subsets of Foxp3 + T cells and the values of clinical measures were analyzed.

RESULTS

The numbers of peripheral blood CD4(+)CD25(+)Foxp3(+) T cells were greater in malignant hydrothorax patients than in HCs, but fewer than those of hydrothorax in patients. The percentages of circulating IL-10(+) or LAP(+) CD4(+)CD25(+)Foxp3(+) T cells were higher than in the hydrothorax in patients with malignant hydrothorax. The numbers of circulating CD4(+)CD25(-)Foxp3(+) T cells were significantly fewer in patients with tuberculous hydrothorax than in HCs, and both the numbers of circulating CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) T cells were significantly fewer than in the hydrothorax in patients. Significantly higher percentages of circulating IL-10(+) or LAP(+) CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) T cells were detected in tuberculous hydrothorax patients. The numbers of CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(+) T cells were associated with hydrothorax adenosine deaminase (ADA) levels in tuberculous hydrothorax patients, while CD4(+)CD25(+)Foxp3(+) T cells were associated with carcino-embryonic antigen (CEA) in malignant hydrothorax patients. The concentrations of serum IL-6 and TGF-β in the patients were significantly higher than that in the HCs, but lower than that in the corresponding hydrothorax. A similar pattern of IL-10 was observed in different groups, except that there was no significant difference in the levels of serum IL-10 between the tuberculous hydrothorax patients and HCs.

CONCLUSIONS

CD4(+)CD25(-)Foxp3(+) T cells, which have lower inhibitory function than CD4(+)CD25(+)Foxp3(+) T cells, may play a role in tuberculous hydrothorax.

The Regulatory T Cell Lineage Factor Foxp3 Regulates Gene Expression through Several Distinct Mechanisms Mostly Independent of Direct DNA Binding

The lineage factor Foxp3 is essential for the development and maintenance of regulatory T cells, but little is known about the mechanisms involved. Here, we demonstrate that an N-terminal proline-rich interaction region is crucial for Foxp3’s function. Subdomains within this key region link Foxp3 to several independent mechanisms of transcriptional regulation. Our study suggests that Foxp3, even in the absence of its DNA-binding forkhead domain, acts as a bridge between DNA-binding interaction partners and proteins with effector function permitting it to regulate a large number of genes. We show that, in one such mechanism, Foxp3 recruits class I histone deacetylases to the promoters of target genes, counteracting activation-induced histone acetylation and thereby suppressing their expression.

The suppressive activity of regulatory T cells provides the immune system with a mechanism to prevent detrimental immune responses, such as autoimmunity, attack of the beneficial commensal microbiota and rejection of the fetus. Intriguingly, expression of a single lineage factor Foxp3 is sufficient to completely reprogram T cells from a pro-inflammatory to a suppressive phenotype. Here, we show that Foxp3 alters the expression of thousands of genes through several independent mechanisms. In many cases, its own ability to bind to DNA appears to be dispensable, but rather it binds indirectly to the DNA by interaction with other transcription factors. Foxp3 then in turn recruits other proteins that affect gene expression through chromatin modification. For example, Foxp3 indirectly binds to the IL-2 promoter via interaction with the transcriptional activators c-Rel, AML-1 and NFAT. This leads to the Foxp3 mediated recruitment of class I histone deacetylases HDAC1, 2 and 3, which in turn counteracts the activation-induced hyper-acetylation of the promoter, thereby switching the gene off. In a way, Foxp3 hijacks pre-existing regulatory mechanism to reverse the transcriptional expression status of the target gene. By dissecting Foxp3 on a molecular level, we also show that this is only one of several independent mechanism utilised by Foxp3.

New insights into the resolution of inflammation

The goal of treating chronic inflammatory diseases must be to inhibit persistent inflammation and restore tissue function. To achieve this we need to improve our understanding of the pathways that drive inflammation as well as those that bring about its resolution. In particular, resolution of inflammation is driven by a complex set of mediators that regulate cellular events required to clear inflammatory cells from sites of injury or infection and restore homeostasis. Indeed, it may be argued that dysfunctional resolution may underpin the aetiology of some chronic inflammatory disease and that a novel goal in treating such diseases is to develop drugs based on the mode of endogenous pro-resolution factors in order to drive on-going inflammation down a pro-resolution pathway. And while we are improving our understanding of the resolution of acute and chronic inflammation, much remains to be discovered. Here we will discuss the key endogenous checkpoints necessary for mounting an effective yet limited inflammatory response and the crucial biochemical pathways necessary to prevent its persistence and trigger its resolution. In doing so, we will provide an update on what is known about resolution of acute inflammation, in particular its link with adaptive immunity.

Anti-Inflammatory Effects and Joint Protection in Collagen-Induced Arthritis after Treatment with IQ-1S, a Selective c-Jun N-Terminal Kinase Inhibitor

c-Jun N-terminal kinases (JNKs) participate in many physiologic and pathologic processes, including inflammatory diseases. We recently synthesized the sodium salt of IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime) and demonstrated that it is a high-affinity JNK inhibitor and inhibits murine delayed-type hypersensitivity. Here we show that IQ-1S is highly specific for JNK and that its neutral form is the most abundant species at physiologic pH. Molecular docking of the IQ-1S syn isomer into the JNK1 binding site gave the best pose, which corresponded to the position of cocrystallized JNK inhibitor SP600125 (1,9-pyrazoloanthrone). Evaluation of the therapeutic potential of IQ-1S showed that it inhibited matrix metalloproteinase 1 and 3 gene expression induced by interleukin-1β in human fibroblast-like synoviocytes and significantly attenuated development of murine collagen-induced arthritis (CIA). Treatment with IQ-1S either before or after induction of CIA resulted in decreased clinical scores, and joint sections from IQ-1S-treated CIA mice exhibited only mild signs of inflammation and minimal cartilage loss compared with those from control mice. Collagen II-specific antibody responses were also reduced by IQ-1S treatment. By contrast, the inactive ketone derivative 11H-indeno[1,2-b]quinoxalin-11-one had no effect on CIA clinical scores or collagen II-specific antibody titers. IQ-1S treatment also suppressed proinflammatory cytokine and chemokine levels in joints and lymph node cells. Finally, treatment with IQ-1S increased the number of Foxp3(+)CD4(+)CD25(+) regulatory T cells in lymph nodes. Thus, IQ-1S can reduce inflammation and cartilage loss associated with CIA and can serve as a small-molecule modulator for mechanistic studies of JNK function in rheumatoid arthritis.