[Expression of Th17 and IL-23 in Peripheral Blood and Their Relationship with Immunophenotype in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To observe the expression of helper T cells 17(Th17), interleukin 23 (IL-23) in peripheral blood in patients with acute myeloid leukemia (AML), to analyze the relationship between Th17, IL-23 in peripheral blood and immunophenotype. METHODS: 105 patients with AML in the hospital from January 2019 to January 2021 were prospectively selected as the research subjects, the expression of Th17 and IL-23 in peripheral blood of patients with AML was detected by flow cytometry; immunophenotype was detected and counted. The relationship between the expression of Th17, IL-23 in peripheral blood and immunophenotype of AML patients was analyzed. Draw ROC curve and analyze the predictive value of Th17 and IL-23 expression in peripheral blood to immunophenotype. RESULTS: The immunophenotype results of AML patients showed that myeloid antigen, lymphoid antigen and hematopoietic stem/progenitor cell marker antigen were positive expressed for various antigens in 105 AML patients, in myeloid antigens, CD13+ accounted for the highest proportion (93.33%), in lymphoid antigens, CD56+ accounted for the highest proportion (32.38%), and in hematopoietic stem/progenitor cell marker antigens, CD38+ accounted for the highest proportion (68.57%). The expression of Th17 in peripheral blood of AML patients with CD56+, CD7+, CD34+ and human leukocyte antigen DR+(HLA-DR+) were higher than that of AML patients with CD56-, CD7-, CD34-, HLA-DR-, the expression of IL-23 in peripheral blood of AML patients with CD56+, CD34+ and HLA-DR+ were higher than that of AML patients with CD56-, CD34-, HLA-DR-, the differences were statistically significant (P<0.05); compared the expression of Th17 and IL-23 in peripheral blood between other antibody positive and negative patients, there was no statistical significant difference (P>0.05). Logistic regression analysis showed that the high expression of Th17 in patients with AML was related to the positive expression of CD56, CD7, CD34 and HLA-DR in the detection of immunophenotype, the high expression of IL-23 was related to the positive expression of CD56, CD34 and HLA-DR in the detection of immunophenotype. The ROC curve showed that the AUC of expression levels of Th17 and IL-23 in peripheral blood alone and in combination for predicting CD56+, CD34+, HLA-DR+ and Th17 in peripheral blood for predicting CD7+ were mostly 0.5-0.7, which had certain predictive value, but the predictive performance was low. CONCLUSION: Myeloid antigen, lymphoid antigen and hematopoietic hematopoietic stem/progenitor cell marker antigen are positive expressed for various antigens in AML patients, the high expression of Th17 in peripheral blood of AML patients is related to the positive expression of CD56, CD7, CD34 and HLA-DR in detection of immunophenotyping, the high expression of IL-23 is related to the positive expression of CD56, CD34 and HLA-DR in the detection of immunophenotype.

Elevated Serum Interleukin-23 Levels in Patients with Oral and Cutaneous Lichen Planus.

Lichen planus is considered a chronic inflammatory disease which affects different sites, such as the skin, mucous membranes, hair, and nails. Based on the evidence, a complex cytokine network plays a crucial role in lichen planus pathogenesis. The study was aimed at assessing the serum IL-23 levels in the patients with cutaneous and oral lichen planus compared to healthy controls. Method. The study included 30 cutaneous lichen planus patients, 20 oral lichen planus patients, and 33 control subjects. Five milliliters of peripheral blood was obtained from each patient, and the serum was separated. IL-23 levels were determined using the ELISA kit, and the data were analyzed using the Mann-Whitney test. Results. IL-23 levels in the patient serum with oral lichen planus (P value ≤ 0.001) were significantly higher than in controls. Furthermore, there were significant differences in IL-23 serum levels in the patients with cutaneous lichen planus compared to the healthy controls (P value ≤ 0.001). Moreover, IL-23 serum levels were statistically different between patients with cutaneous lichen planus and patients with oral lichen planus (P value ≤ 0.001). Based on the mean concentration of interleukin-23, IL-23 levels were higher in the patients with oral lichen planus than in the patients with cutaneous lichen planus. Conclusions. Elevated serum IL-23 levels in the patients with oral lichen planus may indicate that IL-23 plays a crucial role in the pathogenesis of oral lichen planus. However, more research is needed with a larger sample size.

Mucosal IL23A expression predicts the response to Ustekinumab in inflammatory bowel disease.

BACKGROUND: Biologics against tumor necrosis factor-α (TNF) and the p40 subunit of interleukin (IL)-12 and IL-23 are increasingly used in inflammatory bowel disease (IBD) treatment. However, information on response prediction to these agents is limited. Thus, we aimed to identify factors for IBD treatment response prediction. METHODS: We conducted a retrospective study in 33 IBD subjects for anti-TNF and a prospective study of 23 IBD and 11 non-IBD subjects for ustekinumab (UST). Mucosal biopsy specimens were obtained before treatment with biologics. The expression of 18 immune-related genes encoding representative cytokines and transcription factors was analyzed by quantitative polymerase chain reaction. RESULTS: There was no difference between the treatment-resistant and -sensitive groups with regard to clinical characteristics. A higher expression of oncostatin M (OSM) and its receptor OSMR in the intestinal mucosa was most strongly associated with anti-TNF resistance, whereas lower IL23A expression was most strongly associated with UST resistance. In addition to the absolute expression levels of genes, concordant or discordant expression patterns of particular gene sets were associated with treatment sensitivity and resistance. CONCLUSIONS: The association of anti-TNF resistance and mucosal OSM and OSMR expression was consistent with the results of a previous study in a European cohort. Our observation that IBD subjects with higher mucosal IL23A expression were more likely to achieve remission by UST has not been previously reported. The response to biologics may thus be predicted in IBD patients through the analysis of mucosal gene expression levels and patterns.

IL-23/IL-17 axis and soluble receptors isoforms sIL-23R and sIL-17RA in patients with rheumatoid arthritis-presenting periodontitis.

BACKGROUND: Rheumatoid arthritis (RA) and periodontitis (P) are chronic inflammatory diseases characterized by joint and radiographic bone loss, respectively. IL-23 and IL-17 have an essential role in the immunopathogenesis of RA, and P. IL-23 stimulates Th17 cells through which produces IL-17, IL-21, and RANKL. IL-17 stimulates fibroblasts to produce RANKL, which initiates bone loss in the joints in RA and the periodontal tissue in periodontitis. The aim of this study was to determine the expression pattern of IL-23/IL-17 axis and soluble receptors isoforms sIL-23R and sIL-17RA of patients with RA presenting P (RAP). MATERIAL AND METHODS: Healthy subjects (HS) (n = 42), patients with P (n = 40), RA (n = 20), and patients with RAP (n = 40) were included. Plasma samples were obtained to evaluate the IL-23, IL-17A, sIL-23R, and sIL-17RA by ELISA technique. A nonparametric Mann-Whitney U test was used to compare the differences between groups. A Chi-square was used to compare gender, grade and stage of periodontitis, and DAS28-ESR between the groups. Spearman's rank correlation coefficient was used to study the association between the molecules and clinical parameters. RESULTS: IL-23 levels were increased in the RAP group, and lower sIL-23R levels were found in the RAP groups. However, IL-17A was lower in the P and RAP group but not in RA patients. RAP group showed a decrease IL-17A levels in advanced stages of the periodontal disease. CONCLUSION: These results suggest that IL-23 and IL-17A tend to downregulate their expression patterns when patients present both rheumatoid arthritis and periodontitis.

IL-38: A novel cytokine in systemic lupus erythematosus pathogenesis.

IL-38 is a newly identified cytokine that belongs to the IL-1 family. In our previous study, we found elevated plasma levels of IL-38 in patients with systemic lupus erythematosus (SLE). However, the clear relationship of IL-38 expression in plasma, peripheral blood mononuclear cells (PBMCs) and clinical and laboratory features needs elucidation. Additionally, we evaluated the possible role of IL-38 in regulating production of inflammatory cytokines in PBMCs in vitro. A pristane-induced murine lupus model was used to further demonstrate the effects of IL-38 on cytokines in vivo and discuss the significance of IL-38 in lupus development. The results showed that mRNA expression of IL-38 in PBMCs of patients with SLE was elevated compared with volunteers, and expression of IL-38 in both plasma and PBMCs was strongly related to clinical features, such as haematuria and proteinuria, and correlated with a SLEDAI score. Plasma levels of TNF-α, IL-1ß, IL-6 and IL-23 were elevated in patients with SLE and were related to plasma levels of IL-38. In vitro, PBMCs of patients with SLE stimulated with IL-38 showed a decreased expression of the four inflammatory cytokines compared with PBMCs of patients without treatment. Interestingly, IL-38 administration in lupus mice significantly reduced the development of lupus, such as reduced proteinuria, improved histological examinations of the kidneys and down-regulated inflammatory cytokines. In conclusion, IL-38 may suppress synthesis of pro-inflammatory cytokines and therefore regulate lupus pathogenesis.

High interleukin-18 and low FOXP3 mRNAs in peripheral blood of women with severe systemic lupus erythematosus: a cross-sectional study.

Gene expression analysis of peripheral blood cells may provide valuable information about the triggered molecular processes in systemic lupus erythematosus (SLE). The study aimed to quantify the mRNA in peripheral blood of seven target genes, including inflammatory cytokine genes (IL23A, IL12B, TNFA, IL18), and T regulatory-related genes (FOXP3, TGFB1, IL10) in patients with SLE and to correlate expression levels with disease activity and/or clinical manifestations. The relative quantification of target genes was performed using real-time polymerase chain reaction in peripheral blood obtained from 28 adult SLE females and 17 healthy women. The highest up-regulation in the blood of SLE patients was observed for IL23A with a median 9.54 (p < 0.0001), followed by TGFB1 (median: 2.07; p = 0.047) and IL10 (median: 1.84; p = 0.013). IL12B and TNFA were significantly down-regulated in patients compared to controls (median: 0.521; p = 0.0023, and median: 0.519; p = 0.0003, respectively). FOXP3 mRNA was lower among patients with higher degree of disease activity (median: 0.338; p = 0.029) and showed inverse correlation with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). IL18 mRNA correlated positively with the SLEDAI and was highly expressed during severe flares (median: 1.216; p = 0.021). IL18 up-regulation was associated with anti-dsDNA antibody positivity, while FOXP3 down-regulation with lupus nephritis. Our study pointed out the relationship of SLE disease activity and particular clinical manifestations with IL18 and FOXP3 expression, and the significant contribution of IL23A in the SLE immunopathogenesis. Hence, the peripheral blood cytokine mRNAs should be exploited as novel prognostic and diagnostic biomarkers.

Nonclinical safety of tildrakizumab, a humanized anti-IL-23p19 monoclonal antibody, in nonhuman primates.

Tildrakizumab (also known as MK-3222), is a high-affinity, humanized, immunoglobin G1κ monoclonal antibody targeting the p19 subunit of interleukin-23 recently approved for the treatment of moderate to severe plaque psoriasis in the US, Europe, and Australia. The safety profile of tildrakizumab was characterized in nonclinical studies using a pharmacologically relevant cynomolgus monkey model. In repeat-dose toxicity studies, cynomolgus monkeys were chronically treated with subcutaneous (SC) injections of 100 mg/kg of tildrakizumab every 2 weeks up to 9 months. Tildrakizumab was well tolerated, with no toxicological findings (including assessment of reproductive organs; hormonal effects; and cardiovascular, respiratory, and central nervous system function) at systemic exposures approximately 90 times higher than the recommended human dose of 100 mg. An embryofetal developmental study conducted in pregnant monkeys revealed no treatment-related effects to the developing fetus following SC administration of tildrakizumab 100 mg/kg. In a pre- and postnatal development study, 2 neonatal deaths due to potential viral infection at 100 mg/kg were considered of uncertain relationship to the treatment based on a lack of historical data on the occurrence of viral infection in neonate cynomolgus monkeys. The results of this comprehensive nonclinical safety program support the safe use of tildrakizumab.

Effect of 50-Hz Magnetic Fields on Serum IL-1ß and IL-23 and Expression of BLIMP-1, XBP-1, and IRF-4.

Investigations demonstrated that magnetic fields (MFs) change cytokine production and expression of some immune system genes. This alteration can affect the immune system function and may lead to some diseases. Therefore, this study investigated two important inflammatory cytokines, i.e., IL-1ß and IL-23 at two phases of pre- and post-immunization of the immune system. In addition, the expressions of three important genes in the humoral immunity, i.e., B lymphocyte-induced maturation protein-1 (BLIMP-1), X-box-binding protein-1 (XBP-1), and interferon regulatory factor-4 (IRF-4) were evaluated at post-immunization phase. Eighty adult male rats were divided into four experimental groups and a control. The experimental groups were exposed to 50 -Hz MFs with magnetic flux densities of 1, 100, 500, and 2000 µT, 2 h/day for 2 months. The animals were injected by human serum albumin (100 µg/rat) on days 31, 44, and 58 of exposure. The cytokine levels in serum were measured with enzyme-linked immunosorbent assay (ELISA), and the expression of genes was evaluated with reverse transcription quantitative polymerase chain reaction (RT-qPCR). Serum IL-1ß was decreased at pre-immunization phase after exposure to 1 and 100 µT of 50-Hz MFs. In contrast, serum IL-23 was increased at post-immunization phase in 100 µT group. No change was observed in serum IL-1ß and IL-23 in each group at pre-immunization phase compared with post-immunization. Furthermore, exposure to 100 µT downregulated expression of BLIMP-1, XBP-1, and IRF-4. In conclusion, exposure to 50-Hz MFs may decrease inflammation at short time and increase it at longer time exposures. In addition, 50-Hz MF exposure may decrease the humoral immune responses. It seems that 50-Hz MFs cause more alteration in immune system function at lower densities (100 µT).

NET Formation in Bullous Pemphigoid Patients With Relapse Is Modulated by IL-17 and IL-23 Interplay.

Background: DNA extracellular traps (ETs), released by neutrophils (NETs), or eosinophils (EETs), play a pathogenic role in several autoimmune disorders. However, to date, NETs have never been investigated in bullous pemphigoid (BP) with respect to clinical and immunological activities, both at baseline and at time of relapse which have been characterized with specific IL-17 and IL-23 patterns. Objective: We sought to assess whether ETs were associated with BP as well as the relative contribution of IL-17 axis cytokines to NET induction. Methods: Skin biopsy specimens were obtained from 11 patients with BP. Immuno-detection of neutrophils and eosinophils combined to DNA staining allowed us to investigate the in-situ presence of NETs and EETs using confocal scanning microscopy. NETs release was evaluated ex vivo by stimulating polymorphonuclear cells from BP patients with BP biological fluids in presence of IL-17A and IL-23 or of glucocorticoids. Results: At baseline, ETs were observed in BP lesions at the site of dermal-epidermal cleavage. Despite an important infiltrate of eosinophils, ETs were essentially associated with neutrophils in situ and were not related to BP clinical activity at diagnosis. In situ observation of NETs was associated in 6 among 8 patients with serum capacity of NET induction. Notably both blister fluid and sera from BP patients at diagnosis and at time of relapse could induce NET formation ex vivo. In contrast, a longitudinal investigation showed a decrease of NET formation with time of treatment in patients undergoing remission. Mimicking relapse, complementation of sera from BP patients with ongoing remission with either IL-17A or IL-23 increased NET formation. Conversely, IL-17A inhibited NET formation induced by serum from BP patients with relapse supplemented or not with IL-23. Finally, glucocorticoids also inhibited NET formation ex vivo in BP. Conclusion: NET formation is an associated phenomenon with BP. Furthermore, we showed that IL-23 favored NET formation, whereas the effects of IL-17A are environment dependent. Indeed, IL-17A displayed a protective effect on NET formation when associated with IL-23, showing for the first-time differential effects of these two cytokines in BP.

Colitis-Induced Th17 Cells Increase the Risk for Severe Subsequent Clostridium difficile Infection.

Clostridium difficile infection (CDI) is the number one hospital-acquired infection in the United States. CDI is more common and severe in inflammatory bowel disease patients. Here, we studied the mechanism by which prior colitis exacerbates CDI. Mice were given dextran sulfate sodium (DSS) colitis, recovered for 2 weeks, and then were infected with C. difficile. Mortality and CDI severity were increased in DSS-treated mice compared to controls. Severe CDI is dependent on CD4+ T cells, which persist after colitis-associated inflammation subsides. Adoptive transfer of Th17 cells to naive mice is sufficient to increase CDI-associated mortality through elevated IL-17 production. Finally, in humans, the Th17 cytokines IL-6 and IL-23 associate with severe CDI, and patients with high serum IL-6 are 7.6 times more likely to die post infection. These findings establish a central role for Th17 cells in CDI pathogenesis following colitis and identify them as a potential target for preventing severe disease.

IL-23 Gene and Protein Expression in Childhood Asthma.

BACKGROUND: Asthma is the chronic inflammation of airways characterized by eosinophilic infiltration, mucus overproduction, airway hyper-responsiveness and airway remodeling. These changes are induced mostly by cytokines which are produced by T helper (Th) 2 cells. Recently, the role of interleukin-23 (IL-23) in the pathogenesis of adult allergic asthma has been studied. OBJECTIVE: To explore IL-23 serum levels and its expression in persistent asthma compared with healthy children younger than five years old. METHOD: Blood samples of 40 children with mild and severe persistent asthma were compared to 34 healthy children regarding IL-23 serum levels and gene expression using enzyme-linked immunosorbentassay (ELISA) and real time quantitative polymerase chain reaction (PCR). RESULTS: The IL-23 gene expression level was significantly different in the 25 children with mild persistent asthma and the 15 children with severe persistent asthma compared to the control group (p=0.001). There was no significant difference in IL-23 gene expression level between the two groups of patients with mild and severe persistent asthma. A significant difference was seen in IL-23 serum levels between the 25 children with persistent asthma and control group (p=0.002). CONCLUSION: For pre-school children with history and physical exam in favor of asthma which cannot be tested by spirometry, IL-23 serum levels may be an auxiliary biomarker for the diagnosis of asthma.

Characterization of variations in IL23A and IL23R genes: possible roles in multiple sclerosis and other neuroinflammatory demyelinating diseases.

Multiple sclerosis is among the most serious inflammatory demyelinating diseases (IDD). Interleukin-23A (IL23A) regulates and coordinates the activities of immune cells by interacting with its receptor IL23R and plays key roles in the pathogenesis of immune inflammatory diseases. IDD, deemed to be a kind of autoimmune diseases, may involve IL23A in the pathogenesis. The aim of this work was to validate the hypothesized involvement of IL-23A and its receptor in IDD. We sequenced the IL-23A and IL-23R genes for 206 Chinese Han IDD patients and evaluated SNPs within or near those genes. The serum levels of IL23A in IDD participants were analyzed using ELISA. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using online software OEGE. Three variants rs2066808, rs2371494, rs11575248 in IL-23A gene and one variant rs1884444 in IL-23R gene were demonstrated to be associated with the risk of MS or other IDD diseases, and the expression level of serum IL-23A in the MS patients was also altered. We conclude that variants in IL-23A and IL-23R genes were associated with the risk of MS or other IDD diseases.

Interleukins 17 and 23 in patients with gastric neoplasms.

Recently there has been heightened interest in the potential significance of interleukin (IL)-17 and IL-23 in the development/progression of human malignancies. Here, we analyzed the systemic levels of these cytokines in 75 patients with different types of gastric neoplasms (carcinoma, gastrointestinal stromal tumors, neuroendocrine neoplasms, and lymphomas) and 42 healthy volunteers. We found that patients with all types of gastric neoplasms have significantly lower IL-23 levels. However, in comparison to the levels in healthy individuals, IL-17 concentrations were lower only in patients with types of gastric neoplasms other than carcinoma. Interestingly, IL-17 levels significantly differed between patients with early and advanced gastric carcinoma. No significant associations were detected between the systemic levels of examined interleukins and TNM staging. However, peripheral levels of IL-23 were correlated with the absolute numbers of circulating populations of bone marrow-derived mesenchymal and very small embryonic/epiblast-like stem cells in patients with gastric carcinoma. ROC curve analyses demonstrated that systemic levels of IL-17 seem to meet basic criteria for consideration as a helpful diagnostic marker in the detection of gastric carcinoma. In conclusion, our study provides translational evidence confirming the clinical significance of IL-17 and IL-23 in the pathogenesis of different types of gastric neoplasms in humans.

Altered Treg and cytokine responses in RSV-infected infants.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in children under 1 y of age in the USA. The host immune response is believed to contribute to RSV-induced disease. We hypothesize that severe RSV infection in infants is mediated by insufficient regulation of the host immune response of regulatory T cells (Tregs) resulting in immunopathology. METHODS: Blood and nasal aspirates from 23 RSV-infected and 17 control infants under 1 y of age were collected. Treg frequencies were determined by flow cytometry from peripheral blood mononuclear cells. Analysis of 24 cytokines was measured by multiplex assay on nasal aspirates. RESULTS: We demonstrate that the frequency of activated Tregs is significantly reduced in the peripheral blood of RSV-infected infants compared with age-matched controls. Surprisingly, T helper (Th)17 related cytokines including interleukin (IL)-1ß, IL-17A, and IL-23 were associated with a reduction in clinical symptoms of respiratory distress. In addition, the amount of IL-33 protein in nasal washes, a cytokine important in maintaining Treg homeostasis in mucosal tissues, was decreased in RSV-infected children. CONCLUSION: These results suggest that decreased Treg numbers and an inability to properly control the host inflammatory response results in severe RSV infection.

Up-regulated integrinα4ß1 on systemic lymphocytes and serum IL-17A in interstitial pneumonia.

BACKGROUND AND AIMS: In interstitial pneumonia (IP), lymphocytes play an important role in lung injury and the involvement of integrinα4ß1 on leukocytes has previously been reported in animal models. Although the integrinα4ß1 expression level is known to be up-regulated by inflammatory cytokines, the involvement of interleukin (IL)-17A is unclear. The purpose of this study is to address the possible involvement of integrinα4ß1 on circulating lymphocytes and its correlation with serum IL-17A in interstitial lung diseases (ILDs). METHODS: We measured the expression levels of integrinα4ß1 on peripheral lymphocytes and the serum concentration of IL-17A and IL-23 in subjects with ILDs (n = 27; 14 males and 13 females, 66.7 ± 7.8 years old) and control subjects (n = 10; 5 males and 5 females, 66.6 ± 4.6 years old). RESULTS: Recombinant IL-17A up-regulated expression levels of integrinα4ß1 on healthy human lymphocytes in an in vitro experiment. Expression levels of integrinα4ß1 were significantly higher in those with acute hypersensitivity pneumonitis (HP) and non-specific IP (NSIP) compared with control. Serum IL-17A concentration was also significantly increased in acute HP and NSIP subjects compared with control. And IL-17A concentration positively correlated with integrinα4ß1 expression level (P < 0.05). Serum IL-23 was below the minimal detectable level in all subjects. CONCLUSIONS: These findings suggest that up-regulated levels of integrinα4ß1 on systemic lymphocytes and elevated serum IL-17A might be involved in the extravasation of lymphocytes in IP.

Elevated serum levels of Interleukin-37 are associated with inflammatory cytokines and disease activity in rheumatoid arthritis.

Interleukin-37 (IL-37) is closely associated with several inflammatory diseases. However, the role of IL-37 in the pathogenesis of rheumatoid arthritis (RA) remains unclear. The aim of this study was to assess the associations between serum levels of IL-37 and disease activity, inflammatory cytokines, and bone loss in patients with RA. Serum cytokines levels were examined by Enzyme-linked immunosorbent assay (ELISA). Radiographic bone erosion was assessed using the van der Heijde-modified Sharp score and bone mineral density (BMD) was measured using DXA. Serum IL-37 levels in RA patients were significantly higher than those in HCs (p < 0.001), and were significantly positively correlated with clinical parameters of disease activity and serum levels of IL-17 and IL-23. In addition, serum IL-37 levels were significantly higher in patients with stage IV of radiographic bone erosion than those with stage III and stage I-II, and they were significantly higher in those with osteopenia and osteoporosis than in those with normal BMD. Our results suggest that serum IL-37 levels were increased in patients with RA and were positively associated with disease activity, IL-17/IL-23 and bone loss in RA, suggesting that IL-37 may play a critical role in the pathogenesis of RA.

IL-17A-producing T cells and associated cytokines are involved in the progression of gastric cancer.

Interleukin-17A-producing T cells (IL-17A+ T) (IL-17A+CD4+ Th17, IL-17A+CD8+ Tc17 and IL-17A+ γδT17 cells) and associated cytokines (IL-17A, IL-23 and IL-1ß) play crucial roles in inflammation-associated diseases, such as infection, autoimmunity and tumors. Th17 cells promote human gastric cancer (GC), although the source of intracellular IL­17A and the roles of Tc17 and γδT17 cells remain poorly understood. In this study, the frequencies of circulating Th17 and γδT17 cells in patients with GC were found to be significantly increased compared to those in healthy donors; however, Tc17 cells were decreased in these patients, and a negative relationship was found between the frequencies of Th17 and Tc17 cells. Moreover, the cytokine IL­17A was found to be produced mainly by Th17 cells in human peripheral blood. Similarly, serum cytokine levels and relative mRNA expression levels of IL­17A, IL­23 and IL­1ß were significantly increased in patients with GC, and the frequency of Th17 cells was closely associated with serum IL­17A concentrations in patients with GC. Additionally, Th17 cells and associated cytokines were present at significantly different levels during the progression and metastasis of GC, as were Tc17 and γδT17 cells. Taken together, these findings suggest that IL-17A+ T cells and associated cytokines might play crucial roles in human GC progression and metastasis and thus represent potential targets for treatment.

Epstein-Barr Virus and Human herpes virus 6 Type A DNA Enhance IL-17 Production in Mice.

Several studies have shown a potential association between the Herpesviridae members, the Epstein-Barr virus (EBV) and Human herpes virus 6 (HHV-6), and an increased risk of autoimmune disease development. Because of the ability of these viruses to cause recurrent infections, various viral antigens, including viral DNA, are consistently shed. These antigens may then play a role in triggering autoimmune processes or contributing to autoimmune mechanisms. Therefore, this study examined whether the DNA of EBV or that of HHV-6A is capable of triggering IL-17, the autoimmune-associated cytokine, in mice. BALB/c mice were intraperitoneally injected with various copy numbers of either EBV or HHV-6A DNA. One group was injected with sterile water (the DNA solvent), and another was left uninjected. A mouse group that was administered DNA obtained from Staphylococcus epidermidis was included to ensure that any observed effects would pertain to the viral DNA tested. Mice were sacrificed and their sera were examined using an enzyme-linked immunosorbent assay for IL-17 and IL-23, as pro-autoimmune cytokines, IL-10, as an anti-inflammatory cytokine, and IFN-γ, as a pro-inflammatory cytokine, on days 3, 6, and 9 post-injection. All mouse groups injected with different copy numbers of EBV DNA or HHV-6A DNA displayed higher IL-17 levels than did the group injected with water on days 3, 6, and 9 post-injection. The highest IL-17 levels appeared to coincide with a marked increase in IL-23 and a decrease in IL-10 levels. Unlike the S. epidermidis DNA, which increased IFN-γ levels but not IL-17 or IL-23 levels, the viral DNA tested increased all three mediators, indicating that triggering Th17 responses is a specific property of EBV and HHV-6A DNA. In conclusion, EBV and HHV-6A viral DNA are capable of enhancing the production of the pro-inflammatory cytokine IL-17, which has been shown to play a role in autoimmune diseases.

Identification and expression analysis of two interleukin-23α (p19) isoforms, in rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar.

Interleukin (IL)-23 is a heterodimeric IL-12 family cytokine composed of a p19 α-chain, linked to a p40 ß-chain that is shared with IL-12. IL-23 is distinguished functionally from IL-12 by its ability to induce the production of IL-17, and differentiation of Th17 cells in mammals. Three isoforms of p40 (p40a, p40b and p40c) have been found in some 3R teleosts. Salmonids also possess three p40 isoforms (p40b1, p40b2 and p40c) although p40a is missing, and two copies (paralogues) of p40b are present that have presumably been retained following the 4R duplication in this fish lineage. Teleost p19 has been discovered recently in zebrafish, but to date there is limited information on expression and modulation of this molecule. In this report we have cloned two p19 paralogues (p19a and p19b) in salmonids, suggesting that a salmonid can possess six potential IL-23 isoforms. Whilst Atlantic salmon has two active p19 genes, the rainbow trout p19b gene may have been pseudogenized. The salmonid p19 translations share moderate identities (22.8-29.9%) to zebrafish and mammalian p19 molecules, but their identity was supported by structural features, a conserved 4 exon/3 intron gene organisation, and phylogenetic tree analysis. The active salmonid p19 genes are highly expressed in blood and gonad. Bacterial (Yersinia ruckeri) and viral infection in rainbow trout induces the expression of p19a, suggesting pathogen-specific induction of IL-23 isoforms. Trout p19a expression was also induced by PAMPs (poly IC and peptidoglycan) and the proinflammatory cytokine IL-1ß in primary head kidney macrophages. These data may indicate diverse functional roles of trout IL-23 isoforms in regulating the immune response in fish.

Dysregulated serum IL-23 and SIRT1 activity in peripheral blood mononuclear cells of patients with rheumatoid arthritis.

Sirtuin 1 (Sirt1) is a class III histone deacetylase (HDAC) that modulates gene expression and is involved in the regulation of proinflammatory cytokines. Interleukin-23 (IL-23) is produced by activated macrophages and dendritic cells and could fuel the progression of rheumatoid arthritis (RA). The goal of our study was to evaluate serum IL-23 levels and both Sirt1 activity and expression in peripheral blood mononuclear cells (PBMCs) in patients with RA compared to healthy controls (HC) and to determine the relationship between Sirt1 activity/expression and IL-23 levels. We assessed apoptosis in PBMCs of RA patients and its association with Sirt1 expression and serum IL-23. Serum IL-23 levels were increased in RA patients in comparison with controls. We found a positive correlation between the levels of serum IL-23 and serum IL-6 in RA patients. Decreased cytoplasmic Sirt1 activity was observed in RA patients with severe disease compared to HC. The expression of Sirt1 protein was significantly decreased in PBMCs of RA patients compared to HC using western blotting. Serum IL-23 levels correlated positively with the cytoplasmic Sirt1 activity in RA patients. Apoptosis rate of PBMCs isolated from RA patients was increased compared to HC and correlated negatively with the expression of Sirt1 protein and serum IL-23 levels. Levels of serum IL-23 and Sirt1 activity and expression were disturbed in RA parallel to increased PBMC apoptosis. Our findings might provide the rationale for the development of new therapeutic approaches in RA.