Immunoregulatory Effect of Calcitriol on Experimental Autoimmune Encephalomyelitis (EAE) Mice.

Previous studies noted an imbalance in T helper (Th) 17 and regulatory T cells (Tregs) in experimental autoimmune encephalomyelitis (EAE), a multiple sclerosis animal model. calcitriol, vitamin D's active form, was found to ameliorate EAE symptoms by favoring Tregss over Th17 cells, suggesting immunomodulatory effects. This study aimed to assess calcitriol's impact on EAE manifestations and cytokine profile in mice. In this study, we recruited twenty-eight C57BL/6 mice and divided them into 4 groups: healthy controls, EAE, EAE with calcitriol treatment, and healthy mice with calcitriol treatment. CD4+ T cells were isolated from splenocytes using magnetic-activated cell sorting. Real-time polymerase chain reaction was employed to quantify the genes associated with Th9 cells (i.e., SPI1 encoding PU.1 and IL9 encoding interleukin [IL]-9). Moreover, the levels of IL-17 and transforming growth factor beta (TGF-ß) were evaluated through enzyme-linked immunosorbent assay in the supernatant of CD4+ T cell culture stimulated by anti-CD3 and anti-CD28 antibodies for 72 hours. In the supernatant of CD4+ T cell cultures, the levels of interleukin-17 (IL-17) were significantly increased, while the levels of transforming growth factor beta (TGF-ß) were decreased in the EAE Group compared to the healthy control group. Calcitriol treatment reversed these changes and attenuated EAE symptoms, as confirmed in hematoxylin and eosin, and luxol fast blue stains. Notably, calcitriol increased IL9 gene expression in both EAE and healthy mice.  This study provides further evidence of the anti-inflammatory effects of calcitriol and its role in attenuating EAE.

Evaluation of cell adhesion molecules (LFA-1 and L-selectin) in ankylosing spondylitis patients after treatment with ß-D-mannuronic acid (M2000).

Background & objectives: To examine ß-D-mannuronic acid (M2000) effects on L-selectin shedding and leucocyte function-associated antigen-1 (LFA-1) expression as mechanisms of action of this drug in patients with ankylosing spondylitis (AS). Methods: To investigate the molecular consequences of ß-D-mannuronic acid on L-selectin shedding, flow cytometry method was used. Furthermore, the effect of it on LFA-1 gene expression was analyzed by using quantitative real time (qRT)-PCR technique. Results: The LFA-1 expression in patients with AS was higher than controls (P=0.046). The LFA-1 expression after 12 wk therapy with ß-D-mannuronic acid was meaningfully decreased (P=0.01). After 12 wk treatment with ß-D-mannuronic acid, the frequency of CD62L-expressing CD4+ T cells in patients with AS, was not considerably altered, compared to the patients before therapy (P=0.5). Furthermore, after 12 wk therapy with ß-D-mannuronic acid, L-selectin expression levels on CD4+ T-cells in patients with AS, were not remarkably changed, compared to the expression levels of these in patients before treatment (P=0.2). Interpretation & conclusions: The results of this study for the first time showed that ß-D-mannuronic acid can affect events of adhesion cascade in patients with AS. Moreover, ß-D-mannuronic acid presented as an acceptable benefit to AS patients and could aid in the process of disease management.

Immunosuppressive Effects of Two Probiotics, Lactobacillus paracasei DSM 13434 and Lactobacillus plantarum DSM 15312, on CD4+ T Cells of Multiple Sclerosis Patients.

T cells play an important role in the development and progression of multiple sclerosis (MS), an autoimmune disease of the central nervous system. In the present study, the immunomodulatory impacts of two Lactobacillus strains, L paracasei DSM 13434 and L plantarum DSM 15312, on the frequency and cytokine production of CD4+ T cells in MS patients were explored. Thirty MS patients were enrolled in this study. The CD4+ T cells were isolated, cultured, and exposed to the media containing cell-free supernatants of L plantarum (group1), L paracasei (group 2), the mixture group of cell-free supernatants of both probiotics (group 3), and vehicle (control) group (group 4). The frequencies of T helper (Th) 1, Th17, Th2, and T regulatory type 1 (Tr1) cells and mean fluorescent intensity (MFI) of the associated cytokines were assessed using flow cytometry. The levels of interleukin 17 (IL-17), transforming growth factor ß (TGF-ß), and interferon-gamma (IFN-γ) cytokines in supernatants of all groups were measured by enzyme-linked immunosorbent assay. The percentage of Th1 cells and the MFI of IFN-γ in Th1 cells (CD4+ IFN-γ+) in all three probiotic treatment groups were significantly decreased compared to the control group. However, no significant changes were observed in the proportion and MFI of Th2, Th17, and Tr1 cells. A significant decrease was observed in IL-17 secretion in the supernatant of cultured CD4+ T cells in all three treatment groups in comparison with control. The levels of TGF-ß and IFN-γ were not significantly different among any of the study groups.  Collectively, cell-free supernatants of the lactobacilli showed an in vitro anti-inflammatory effect. However, further studies are needed to prove the real effects of probiotics on MS.

Controversial role of γδ T cells in pancreatic cancer.

γδ T cells are rare lymphocytes with cogent impact on immune responses. These cells are one of the earliest cells to be recruited in the sites of infection or tumors and play a critical role in coordinating innate and adaptive immune responses. The anti-tumor activity of γδ T cells have been numerously reported; nonetheless, there is controversy among published studies regarding their anti-tumor vs pro-tumor effect- especially in pancreatic cancer. A myriad of studies has confirmed that activated γδ T cells can potently lyse a broad variety of solid tumors and leukemia/lymphoma cells and produce an array of cytokines; however, early γδ T cell-based clinical trials did not lead to optimal efficacy, despite acceptable safety. Depending on the local micromilieu, γδ T cells can differentiate into tumor promoting or suppressing cells such as Th1-, Th2-, or Th17-like cells and produce prototypical cytokines such as interferon-γ (IFNγ) and interleukin (IL)-4/-10, IL-9, or IL-17. In an abstruse tumor such as pancreatic cancer- also known as immunologically cold tumor- γδ T cells are more likely to switch to their immunosuppressive phenotype. In this review we will adduce the accumulated knowledge on these two controversial aspects of γδ T cells in cancers- with a focus on solid tumors and pancreatic cancer. In addition, we propose strategies for enhancing the anti-tumor function of γδ T cells in cancers and discuss the potential future directions.

Evaluation of the acute and 28-day sub-acute intravenous toxicity of α-l-guluronic acid (ALG; G2013) in mice.

α-l-Guluronic acid (ALG; G2013) has been previously introduced as a new anti-inflammatory agent with promising therapeutic effects. Thus, in the present study, we aimed to evaluate the acute and sub-acute toxicity of ALG through intravenous (i.v.) administration in Balb/C mice. ALG was administrated i.v. to the mice with doses of 300, 600, and 1000 mg/kg of body weight to investigate acute toxicity (single dose) and with doses of 25, 50, and 100 mg/kg of body weight to sub-acute toxicity study (daily injections for a period of 28 days). The mortality rate, food and water intake, behavior, body weight, gross necropsy, hematological and biochemical parameters as well as histopathological presentations of the vital organs (kidneys, liver, lungs, spleen, and heart) were examined in treated groups and compared to the healthy controls. The results of both acute and sub-acute studies showed that i.v. administrations of ALG did not affect the investigated parameters in both sexes, indicating that the LD50 of ALG was higher than 1000 mg/kg of body weight. As no difference was observed in toxicity profiles of investigated doses, no-observed-adverse-effect-level for i.v. administration of ALG in the sub-acute study was greater than 100 mg/kg body weight in both female and male mice. According to the finding, i.v. administration of ALG did not lead to any clinical sign in abovementioned doses, suggesting that ALG was well tolerated up to 1000 mg/kg. These pre-clinical findings support the application of ALG in the future clinical trials.

Immunomodulatory Effects of Calcitriol through DNA Methylation Alteration of FOXP3 in the CD4+ T Cells of Mice.

Vitamin D plays a variety of physiological functions, such as regulating mineral homeostasis. More recently, it has emerged as an immunomodulator player, affecting several types of immune cells, such as regulatory T (Treg) cells. It has been reported that vitamin D exerts some mediatory effects through an epigenetic mechanism. In this study, the impacts of calcitriol, the active form of vitamin D, on the methylation of the conserved non-coding sequence 2 (CNS2) region of the forkhead box P3 (Foxp3) gene promoter, were evaluated. Fourteen C57BL/6 mice were recruited in this study and divided into two intervention and control groups. The CD4+ T cells were isolated from mice splenocytes. The expression of Foxp3, IL-10, and transforming growth factor-beta (TGF-ß1) genes were relatively quantified by real-time PCR technique, and the DNA methylation percentage of every CpG site in the CNS2 region was measured individually by bisulfite-sequencing PCR. Vitamin D Intervention significantly (p<0.05) could increase the expression of Foxp3, IL-10, and TGF-ß1 gene in the CD4+ T cells of mice comparing with the control group. Meanwhile, methylation of the CNS2 region of Foxp3 promoter was significantly decreased in three of ten CpG sites in the vitamin D group compared to the control group. The results of this study showed that vitamin D can engage the methylation process to induce Foxp3 gene expression and probably Treg cytokines profile. Further researches are needed to discover the precise epigenetic mechanisms by which vitamin D modulates the immune system.

Effects of guluronic acid (G2013) on gene expression of TLR2, TLR4, MyD88, TNF-α and CD52 in multiple sclerosis under in vitro conditions.

Context: Multiple sclerosis (MS) is an autoimmune and chronic inflammatory disease of CNS. The α-L-guluronic acid (G2013) as novel NSAID with immunomodulatory effects has shown its positive effects in various investigations.Objective: Present research aimed to study the potency of G2013 on gene expression of TLR2, TLR4, MyD88, TNF-α and CD52 in PBMCs of MS patients under in vitro conditions. Materials and methods: 24 blood samples from MS patients and healthy controls were considered for RT-PCR and flow cytometry techniques under two different doses of G2013.Results: Our research indicated that this drug could significantly decrease the gene expression of TLR2, TLR4 and TNF-α compared to untreated group. Conclusion: Data demonstrated that the guluronic acid is able to modify the expression levels of TLR2, TLR4 and TNF-α genes to less than the pathogenic boarder line level, which it might be recommended for reducing the pathological process in multiple sclerosis.

IL-21 and IL-21-producing T cells are involved in multiple sclerosis severity and progression.

Multiple sclerosis is a common neuroinflammatory disease of the central nervous system causing nervous system defects and severe physical disability. IL-21 is a proinflammatory cytokine produced mainly by Th-17 and Tfh cells which its exact role in MS was not yet clearly understood. In the present study we aimed to investigate the possible correlation of IL-21 gene expression, methylation, and its serum levels with MS severity and progression. The results showed that IL-21 mRNA level and serum level were significantly increased in patient group compared with control group (p = 0.02 and p < 0.0001 respectively). Moreover, we found a strong positive correlation between IL-21 mRNA levels and EDSS scores (r = 0.637, P < 0.0001), IL-21 mRNA levels and Progression Index (r = 0.540, P < 0.0001), IL-21 serum levels and EDSS scores (r = 0.617, P < 0.0001), and IL-21 serum levels and Progression Index (r = 0.527, P < 0.0001) in MS patients. Additionally, we found that the methylation level of IL-21 promoter region was decreased in patient group compared with the control group (p < 0.0001). We also found that methylation level of IL-21 gene promoter is negatively correlated with the IL-21 mRNA level (r = -0.263, p = 0.02), serum level (r = -0.249, p = 0.03), EDSS scores (r = -0.276, p = 0.01) and Progression Index (r = -0.430, p = 0.0001). Data showed that the increased percentages of IL-21-producing Tfh-like, Th-17 and Th1 cells in patients are positively correlated with MS severity and progression. The results of our study suggest a pro-inflammatory and booster role for IL-21 in the MS pathogenesis and progression.

Assessment of immunological profile in ankylosing spondylitis patients following a clinical trial with guluronic acid (G2013), as a new NSAID with immunomodulatory properties.

The present research aims to study the effects of guluronic acid (G2013) on gene expression levels of the T-bet, GATA3, RORγt, AHR, and FOXP3 transcription factors and on gene expression of their related cytokines following oral administration of this drug in ankylosing spondylitis (AS) patients. In this trial (clinical trial identifier: IRCT2016091813739N4), 14 AS patients and 12 age- and sex-matched healthy individuals were enrolled. The level of transcription factors' gene expression and expression of their related cytokines were measured by quantitative real-time PCR, before and 3 months after G2013 therapy. Our data indicated that the gene expression levels of the T-bet and IFN-γ were not significantly reduced during 12 weeks of treatment with G2013 (p > 0.05). The findings showed that the gene expression levels of the GATA3 and IL-4 increased significantly during 12 weeks of treatment with G2013 (p < 0.05). In addition, gene expression levels of the RORγt, IL-17, AHR, and IL-22 decreased significantly during the 12-week treatment with G2013 (p < 0.05). Moreover, the gene expression level of the FOXP3 increased significantly during 12 weeks of treatment with G2013, but the gene expression level of IL-10 did not increase significantly (p < 0.05, p > 0.05, respectively). The present study showed that oral intake of G2013 was able to modify the severity of articular and inflammatory symptoms of AS through reducing the gene expression levels of the RORγt, IL-17, AHR, and IL-22 and increasing the gene expression levels of the GATA3, IL-4, and FOXP3.

MicroRNAs in rheumatoid arthritis.

The role of genetic and epigenetic factors in the development of rheumatic diseases has been an interesting field of research over the past decades all around the world. Research on the role of microRNAs (miRNAs) in rheumatoid arthritis (RA) has been active and ongoing, and investigations have attempted to use miRNAs as biomarkers in disease diagnosis, prognosis, and treatment. This review focuses on experimental researches in the field of miRNAs and RA to present the data available up to this date and includes researches searched by keywords "microRNA" and "rheumatoid arthritis" in PubMed from 2008 to January 2015. All references were also searched for related papers. miRNAs are shown to act as proinflammatory or anti-inflammatory agents in diverse cell types, and their role seems to be regulatory in most instances. Researchers have evaluated miRNAs in patients compared to controls or have investigated their role by overexpressing or silencing them. Multiple targets have been identified in vivo, in vitro, or in silico, and the researches still continue to show their efficacy in clinical settings.

Effect of all-transretinoic acid on Th17 and T regulatory cell subsets in patients with ankylosing spondylitis.

OBJECTIVE: We compared Th17 and T regulatory cells in patients with ankylosing spondylitis (AS) and in healthy controls. The effect of all-transretinoic acid (ATRA) was studied on cultured CD4+ T cells of patients with AS compared to controls. METHODS: Eighteen patients with AS and 18 age- and sex-matched healthy controls were included. CD4+ T cells were separated and cultured in conditions of anti-CD3 and anti-CD28 stimulation with and without ATRA. Intracellular and secreted cytokines, transcription factors, and gene expression were evaluated after 72 h. RESULTS: The frequency of CD4+IL-17+ T cells was significantly higher in patients with AS compared to controls, and ATRA could significantly decrease it. The frequency of forkhead box protein 3 (FOXP3)+ retinoic acid-related orphan receptor γt (RORγt) negative T-bet negative CD4+ cells was significantly lower in cases compared to controls. Intracellular and secreted interferon-γ (IFN-γ) was not significantly different between cases and controls. ATRA significantly increased intracellular IFN-γ in cases but not in controls. Tumor necrosis factor-α (TNF-α) secretion was significantly higher and interleukin 10 secretion was significantly lower in culture supernatant of cases compared to controls. ATRA could significantly decrease TNF-α secretion in cases. CONCLUSION: Our findings favor a pathogenic role for Th17 cells in AS. Th1 cells did not seem to contribute in the pathogenesis of this disease. The effect of ATRA as an immunomodulator on deviated immune cells was associated with decreased inflammatory markers. This association could be a reason for a clinical trial of ATRA in patients with AS.

Association between endoplasmic reticulum aminopeptidase-1 (ERAP-1) and susceptibility to ankylosing spondylitis in Iran.

Ankylosing spondylitis (AS) is an inflammatory arthritis, which affects mainly spine and sacroiliac joints. According to recent studies, ERAP1 is the second most common candidate gene for AS susceptibility after HLA-B27. The aim of this study was to determine the association of ERAP1 gene polymorphisms with AS in Iranian population.The study group comprised 387 Iranian AS patients and 316 healthy controls from Iran. Using Real Time PCR allelic discrimination method, we genotyped four SNPs (rs30187, rs469876, rs13167972 and rs27434) of ERAP1. We found that rs30187 and rs27434 were significantly associated with AS in Iranian population (P=6×10-5, P=7×10-3, respectively). The rs30187 T/T genotype was associated with AS compared with C/C genotype (P=1.5×10-5). The rs27434 G/G genotype was inversely associated with AS (P=5×10-3). Two specific haplotypes including: rs30187/ rs469876/ rs13167972/ rs27434 TAAA and CAGG were associated with increased and decreased risk of AS in Iranian population, respectively. These results indicated that ERAP1 SNPs and haplotypes were associated with AS in Iranian population.

Effect of all-trans retinoic acid (ATRA) on viability, proliferation, activation and lineage-specific transcription factors of CD4+ T cells.

All-trans retinoic acid (ATRA), as an active metabolite of vitamin A, has been shown to affect immune cells. This study was performed to evaluate the effect of ATRA on viability, proliferation, activation and lineage-specific transcription factors of CD4+ T cells. CD4+ T cells were separated from heparinized blood of healthy donors and were cultured in conditions, some with, some without ATRA. Viability was assessed by PI flowcytometry and proliferation was measured by MTT assay. CD69 expression was determined by flowcytometry as a measure of cell activation. Lineage-specific transcription factors (FOXP3, RORγt and T-bet) were examined by intracellular staining and flowcytometry. High doses of ATRA (0.1-1 mM) caused extensive cell death in both PBMCs and CD4+ T cells. Doses of ATRA equal to or lower than 10 µM did not adversely affect cell viability and proliferation in comparison to culture medium without ATRA. Doses of ATRA between 10 µM and 1nM significantly increased cell activation when compared to culture medium without ATRA. ATRA could increase FOXP3+ and also FOXP3+RORγt+ T cells while it decreased RORγt+ and T-bet+ T cells. This study showed that doses of ATRA up to 10 µM are safe when using with CD4+ T cells in terms of cell viability, proliferation and activation. We could also show that ATRA diverts the human immune response in neutral conditions (without adding polarizing cytokines) by increasing FOXP3+ cells and decreasing RORγt+ cells. ATRA could be regarded as a potential therapy in inflammatory conditions and autoimmunities.