Effect of Lactobacillus sakei OK67 in Reducing Body and Visceral Fat in Lifestyle-Modified Overweight Individuals: A 12-Week, Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

Obesity is a global health problem that affects the quality of life. It is a multidimensional chronic risk factor for major medical conditions, such as cardiovascular diseases, diabetes, and cancer. This clinical trial evaluated the efficacy of Lactobacillus sakei OK67 (DW2010), a lactic acid bacterium, in reducing body and visceral fat in overweight individuals (body mass index ≥25 kg/m2 and <30 kg/m2), aged 20-60 years. A total of 100 subjects placed in a lifestyle modification program were randomly assigned to receive either DW2010 (2.0 g/day, 1.0 × 1010 CFU) or a placebo for 12 weeks. The efficacy of DW2010 was evaluated by measuring body fat mass using dual-energy X-ray absorptiometry and visceral fat area using computed tomography. After 12 weeks, the change in body fat in the DW2010 group was not markedly different from that in the placebo group. However, visceral fat area decreased more in the DW2010 group than in the placebo group (p = 0.035). During the clinical trial, no major adverse events were reported. Moreover, no statistical differences were observed in the biochemical parameters of the DW2010 and placebo groups. Overall, we concluded that the intake of DW2010 for 12 weeks is safe and potentially reduces visceral fat in lifestyle-modified overweight subjects.

Genetic Parameters for Different Measures of Feed Efficiency and Their Relationship to Production Traits in Three Purebred Pigs.

Residual feed intake (RFI) gained attention as a potential alternative to the feed conversion ratio (FCR). Thus, this study aimed to estimate genetic parameters for different feed efficiency (FE) traits (FCR, RFI1 to RFI5) and their genetic correlation to on-test daily weight gain (ADG), backfat (BFT), loin muscle area (LMA), lean percentage (LP), and total feed intake (FI) for 603 Male Duroc (DD), 295 Landrace (LL), and 341 Yorkshire (YY). The common spatial pen effect was also estimated in these traits. Five RFI measures were estimated by regressing daily feed intake on initial testing age (ITA), initial testing weight (IBW), and ADG for RFI1; other models were the same as RFI1 except for additional BFT for RFI2; LMA for RFI3; BFT and LMA for RFI4; BFT, LMA, and average metabolic body weight (AMBW) instead of IBW for RFI5. Genetic parameters estimated using two animal models and the REML method showed moderate heritability for FCR in all breeds (0.22 and 0.28 for DD, 0.31 and 0.39 for LL, 0.17 and 0.22 for YY), low heritability for the majority of RFI measures in DD (0.15 to 0.23) and YY (0.14 to 0.20) and moderate heritability for all RFI measures in LL (0.31 to 0.34). Pen variance explained 7% to 22% for FE and 0% to 9% for production traits' phenotypic variance. The genetic correlation revealed that selection against less complex RFI1 in DD and LL and RFI2 in YY would bring the most advantageous reduction to FI (0.71 for DD, 0.49 for LL, 0.43 YY) without affecting ADG in all breeds (0.06 for DD, -0.11 for LL, 0.05 for YY), decrease in BFT, and increase in LP in DD (0.51 in BFT, -0.77 in LP) and LL (0.45 in BFT, -0.83 in LP). Therefore, inclusion of these breed-specific RFI measures in the future selection criteria would help improve feed efficiency in the swine industry.

Single-Step Genomic Evaluation for Meat Quality Traits, Sensory Characteristics, and Fatty-Acid Composition in Duroc Pigs.

Meat quality and carcass characteristics have gained the attention of breeders due to their increasing economic value. Thus, this study investigated the genomic prediction efficiencies of genomic best linear unbiased prediction (GBLUP) and single-step GBLUP (ssGBLUP) for traits associated with meat quality, sensory characteristics, and fatty-acid composition. A total of 1237 Duroc finishing pigs with 654 individuals genotyped using the Illumina Porcine SNP 60k marker panel were used in this study. Prediction accuracy and bias for GBLUP and ssGBLUP were evaluated using a five-replicates of five-fold cross-validation. Estimation of genetic parameters for traits associated with meat quality, including lightness, yellowness, redness, pH at 24 h post-mortem, moisture content, fat content, water-holding capacity, cooking loss except for shear force (0.19), as well as fatty-acid composition (palmitic, stearic, oleic, linoleic, and linolenic fatty acids), revealed moderate to high heritability estimates ranging from 0.25 to 0.72 and 0.27 to 0.50, respectively, whereas all traits related to sensory characteristics (color, flavor, tenderness, juiciness, and palatability) showed low heritability estimates ranging from 0.08 to 0.14. Meanwhile, assessment of genomic prediction accuracy revealed that ssGBLUP exhibited higher prediction accuracy than GBLUP for meat quality traits, fatty-acid composition, and sensory characteristics, with percentage improvements ranging from 1.90% to 56.07%, 0.73% to 23.21%, and 0.88% to 11.85%, respectively. In terms of prediction bias, ssGBLUP showed less bias estimates than GBLUP for the majority of traits related to meat quality traits, sensory characteristics, and fatty-acid composition of Duroc meat. In this study, ssGBLUP outperformed GBLUP in terms of prediction accuracy and bias for the majority of traits. Through selection and breeding, our findings could be used to promote meat production with improved nutritional value.

Safety, tolerability and pharmacokinetics and pharmacodynamics of HL2351, a novel hybrid fc-fused interleukin-1 receptor antagonist, in healthy subjects: A first-in-human study.

AIMS: We performed a first-in-human study with HL2351, a novel hybrid Fc-fused interleukin (IL)-1 receptor antagonist, to evaluate its tolerability, pharmacokinetics and pharmacodynamics (PD) after a single subcutaneous (SC) administration in healthy subjects. METHODS: A randomized, double-blind, placebo- and active-controlled, dose-escalation study was conducted. Eligible subjects randomly received a single SC administration of HL2351 (1, 2, 4, 8 and 12 mg/kg) or placebo in a ratio of 8:2. Subjects in the active-controlled group received a single SC administration of anakinra at 100 mg. Serial blood samples were collected for pharmacokinetics and PD analyses. An ex-vivo activation test was performed to evaluate the PD using peripheral blood mononuclear cells treated with IL-1ß. Anti-HL2351 antibodies were determined at baseline and 29 days postdose. Tolerability was assessed throughout the study. RESULTS: HL2351 was eliminated more slowly than anakinra (terminal half-life: 27.21-45.28 vs 3.97 h). Serum concentrations of HL2351 were increased dose-proportionally. The mean apparent clearance of HL2351 were 0.6, 0.66, 0.75, 0.51, 0.65 L/h at 1, 2, 4, 8 and 12 mg/kg, respectively. The percent inhibition of IL-6 expression varied widely (range: 0-92.1%), showing no clear trend or discernible difference between HL2351, anakinra and placebo. HL2351 was well tolerated after a single SC administration. CONCLUSION: HL2351 was well tolerated and showed linear pharmacokinetic characteristics after a single SC administration at doses up to 12 mg/kg in healthy subjects. HL2351 remained in the body 7-11 times longer than anakinra. HL2351 can be developed as a potential therapeutic alternative to anakinra.

The Mediating Role of Parental Support in the Relationship between Life Stress and Suicidal Ideation among Middle School Students.

BACKGROUND: Youth suicide is increasingly being recognized as a major social problem in South Korea. In this study, we aimed to explore the effects of parental support on the relationship between life stress and suicidal ideation among middle-school students. METHODS: This study analyzed data from a cross-sectional study on mental health conducted by the South Korea National Youth Policy Institute between May and July of 2013. Questionnaire responses from 3,007 middle-school students regarding stress factors, thoughts of suicide during the past year, and parental support were analyzed in terms of 3 subscale elements: emotional, academic, and financial support. RESULTS: Among the participants, 234 male students (7.8%) and 476 female students (15.8%) reported experiencing suicidal ideation in the past year. Life stress significantly influenced suicidal ideation (P<0.001), and parental support and all of the subscale elements had a significant influence on decreasing suicidal ideation. As shown in model 1, life stress increased suicidal ideation (adjusted odds ratio [aOR], 1.318; P<0.001), and, in model 2, the effect of life stress on suicidal ideation decreased with parental support (aOR, 1.238; P<0.001). CONCLUSION: Parental support was independently related to a decrease in suicidal ideation, and life stress was independently related to an increase in suicidal ideation. Parental support buffered the relationship between life stress and suicidal ideation.

Effect of a herbal extract powder (YY-312) from Imperata cylindrica Beauvois, Citrus unshiu Markovich, and Evodia officinalis Dode on body fat mass in overweight adults: a 12-week, randomized, double-blind, placebo-controlled, parallel-group clinical trial.

BACKGROUND: YY-312 is a herbal extract powder from Imperata cylindrica Beauvois, Citrus unshiu Markovich, and Evodia officinalis Dode, which have health promoting effects, including body fat reduction. We aimed to evaluate the efficacy and safety of YY-312 for body fat reduction in overweight adults. METHODS: This was a 12-week, randomized, double-blind, placebo-controlled, parallel-group clinical trial performed in overweight Korean adults aged 19-60 years with a body mass index of 25.0-29.9 kg/m2. The daily dose of YY-312 was 2400 mg (containing 1800 mg of active herbal extract and 600 mg of cyclodextrin). Primary outcomes were reductions in body fat mass (BFM) and body fat percentage (BF%) after 12 weeks. Secondary outcomes included reductions in body weight and waist circumference (WC) after 12 weeks. RESULTS: After 12 weeks, BFM (1.6 kg vs. 0.1 kg; P = 0.023) and BF% (1.5% vs. -0.2%; P = 0.018) decreased significantly more in the YY-312 group than in the placebo group, as did body weight (2.7 kg vs. 1.0 kg; P = 0.014) and WC (2.2 cm vs. 0.8 cm; P = 0.049). All safety parameters were within normal limits; no serious adverse events occurred in either group. CONCLUSIONS: In a 12-week clinical trial in overweight adults, YY-312 resulted in significantly greater reduction in body fat vs. placebo, while being safe and well tolerated. TRIAL REGISTRATION: cris.nih.go.kr: ( KCT0001225 ).

IL-1 receptor antagonist (IL-1Ra)-Fc ameliorate autoimmune arthritis by regulation of the Th17 cells/Treg balance and arthrogenic cytokine activation.

INTRODUCTION: IL-1ß signalling has a critical role in the pathogenesis of various types of inflammatory arthritis including rheumatoid arthritis (RA). We aimed to investigate the therapeutic effects of human IL-1 receptor antagonist with Fc fragment (hIL-1Ra-Fc) on autoimmune arthritis and to identify the possible mechanisms by which hIL-1RA-Fc exerts anti-arthritic effects in a murine model of RA and patients with rheumatoid arthritis. METHODS: Collagen-induced arthritis (CIA) murine model was established in DBA/1J mice. The levels of various cytokines were determined by using enzyme-linked immunosorbent assay. The mouse joints were assessed for clinical arthritis score and histologic features. Th17 cells and Treg cells were stained by using antibodies specific for CD4, IL-17, CD25, and FoxP3. Osteoclastogenesis was determined by TRAP staining and real-time PCR. RESULTS: hIL-1RA-Fc reduced the arthritis incidence, histological inflammation and cartilage score in the CIA model. The expression of proinflammatory cytokines, VEGF and RANK, was reduced in the affected joint of hIL-1Ra-Fc-treated mice. hIL-1Ra-Fc-treated mice showed decreased number of Th17 cells with increased number of Treg cells in spleens. hIL-1Ra-Fc reduced Th17 cell differentiation by inactivation of STAT3 signalling, and reciprocally induced Treg cell differentiation through STAT5 signalling. In addition, the expression of IL-17, TNF-α, RANKL, and VEGF was decreased, while Foxp3 gene expression was increased in PBMCs of RA patients after administration of hIL-1Ra-Fc. CONCLUSION: The anti-arthritis effects of hIL-1RA-Fc are associated with regulation of balance between Th17 cells and Treg cells and suppression of osteoclastogenesis and angiogenesis in the affected joints.

The cutoff value of waist circumference for predicting metabolic risks in pre- and post-menopausal korean women: analysis of 2010 korean national health and nutrition examination survey data.

BACKGROUND: With metabolic syndrome (MS) being a major risk factor for cardiovascular disease, and central obesity being a major predisposing factor for MS, intensive research is currently being performed on cutoff values according to race and sex. Menopause is an especially significant factor in designating cutoff values for female central obesity, as menopause brings sudden bodily changes that induce central obesity and increased prevalence of MS. Therefore this study aimed to investigate the cutoff values for the obesity index and its validity in predicting the criteria for MS in Korean women according to menstrual status. METHODS: The study focused on 3,103 women 20 years of age or older participating in the 2007 Korea National Health and Nutrition Examination Survey. Definitions of non-adipose components of MS were defined by the International Diabetes Federation, and menstrual status was judged on the basis of survey results. The sensitivity, specificity, and positive and negative predictive values of the central obesity index (body mass index [BMI], waist circumference [WC], waist-to-height ratio [WHtR]) according to menstrual status for two or more non-adipose components of MS were calculated based on the Youden index. RESULTS: Area under the curve (AUC) values predicting the presence of two or more metabolic risk factors were higher in pre-menopausal women, with AUC values for BMI, WC, and WHtR being, in pre- and post-menopausal women, 23.1 kg/m(2) vs. 23.9 kg/m(2), 76.1 cm vs. 82.5 cm, and 0.49 vs. 0.53, respectively. The WC cut off (76 cm) for pre-menopausal women was found to be more sensitive and more effective at screening for MS risks than the cutoff value given by the Korea Society for the Study of Obesity. CONCLUSION: The central obesity index showed better predictability for MS risk in pre-menopausal women. Because the central obesity index cutoff values are lower in pre-menopausal women, the possibility of metabolic risk can be considered for pre-menopausal women with WC lower than 85 cm. Assessment and control of other risks are needed accordingly for preventing the development of MS.

TWEAK promotes osteoclastogenesis in rheumatoid arthritis.

Bone destruction is critical in the functional disability of patients with rheumatoid arthritis (RA). Osteoclasts, specialized bone-resorbing cells regulated by cytokines, such as receptor activator of NF-κB ligand (RANKL), are primarily implicated in bone destruction in RA. The aim of the study was to examine whether tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, has osteoclastogenic activity in patients with RA and in animal models, including mice with collagen-induced arthritis (CIA) and IL-1 receptor antagonist knockout (IL-1RaKO) mice. TWEAK was increased in the synovium, synovial fluid, and serum of patients with RA and in the synovium of CIA mice and IL-1RaKO mice. TWEAK induced RANKL expression in mixed joint cells and splenocytes from CIA mice, IL-1RaKO mice, and fibroblast-like synoviocytes from patients with RA. Both osteoclast precursor cells and osteoclasts express TWEAK receptor fibroblast growth factor-inducible 14. In addition, TWEAK enhanced in vitro osteoclastogenesis without the presence of RANKL-providing cells and by inducing RANKL expression in fibroblast-like synoviocytes. Moreover, treatment with fibroblast growth factor-inducible 14-Fc inhibited RANKL-induced osteoclastogenesis, indicating that endogenous TWEAK also has osteoclastogenic activity. Our data demonstrated that TWEAK promotes osteoclastogenesis in RA, suggesting that therapeutic strategies targeting TWEAK could be effective for treatment of patients with RA, especially in preventing bone destruction.

New diagnostic criteria for obesity and overweight in Korean children and adolescents using 2007 Korean National Growth Charts.

The diagnostic criteria (KCDC Criteria) to define obesity and overweight of Korean children and adolescents were newly presented in the 2007 Korean National Growth Charts. The KCDC Criteria were criticized for several problems caused by upward shift of body mass index (BMI) percentile curves of the growth charts. This study was conducted to establish new diagnostic criteria (New Criteria) for obesity and overweight in Korean children and adolescents that would be less affected by a change of BMI distribution in the reference population of the Growth Charts. The BMI values for ages 2-18 years corresponding to Asia-Pacific adult BMI cutoffs of obesity (25.0 kg/m(2)) and overweight (23.0 kg/m(2)) were calculated with L, M and S values presented in the 2007 Korean National Growth Charts. Additionally, we examined the frequencies of obesity and overweight among children and adolescents who participated in the 2005 National Growth Survey based on both New Criteria and KCDC Criteria. The Z-scores corresponding to BMIs of 25 and 23 kg/m(2) at 18-years-of-age were 0.99 and 0.41 in boys, and 1.34 and 0.71 in girls, respectively. The BMI values corresponding to these Z-scores from age 2 to 18 years were determined as new BMI cutoffs for obesity and overweight. The frequencies of obesity and overweight estimated by New Criteria were greater by 2 times in boys and 1.5 times in girls than those by KCDC Criteria. We suggest that New Criteria could be a good alternative that can resolve problems caused by upward shift of BMI percentile curves of the 2007 Korean National Growth Charts.

Socioeconomic Indicators Associated with Initiation and Cessation of Smoking among Women in Seoul.

BACKGROUND: While smoking prevalence in Korean men has been decreasing, it is increasing in Korean women. Little is known about women's smoking inequalities in Korea. This study was conducted to investigate the association of socioeconomic indicators with the initiation and cessation of smoking among Korean women. METHODS: This was a cross-sectional study on 9,089 women aged 25-64 years from the 2008 Seoul Community Health Survey. The data on smoking and socioeconomic status were obtained through face-to-face interviews. Smoking initiation rate was defined as the proportion of the individuals who had started smoking at least one cigarette among all subjects. Smoking cessation rate was calculated by dividing the number of individuals who had quit smoking by the number of ever smokers. Education level, total family income and occupation were investigated as socioeconomic indicators. RESULTS: Education level was significantly associated with both initiation and cessation of smoking. Lower educated women had a higher likelihood of smoking initiation (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.17 to 2.51) but lower likelihood of smoking cessation (OR, 0.38; 95% CI, 0.22 to 0.66) than higher educated women. Smoking initiation rate was higher in manual workers (OR, 1.65; 95% CI, 1.20 to 2.27) than in non-manual workers. However, there were no significant differences of both initiation and cessation of smoking according to total household income. CONCLUSION: This study shows that there are smoking inequalities among Korean women. It is thought that education level and occupation are important determinants of women's smoking status.

The Relationship between Serum Gamma-glutamyltransferase Level and Overweight in Korean Urban Children.

BACKGROUND: Recently, it has been reported that gamma-glumyltransferase (GGT) is associated with various cardiovascular risk factors including overweight in adults. However, there are few studies on the relationship between GGT and cardiovascular risk factors in children. The aim of this study was to assess the relationship between serum GGT level and overweight in Korean urban children. METHODS: This study was a cross-sectional study using data on 390 4th grade students of elementary schools in Gunpo, Korea. Children were divided into 4 groups according to gender-specific quartiles of serum GGT level. Body mass index, waist circumference and body fat percentage were quantified as adiposity indices. RESULTS: All adiposity indices in children of the highest GGT level quartile were higher than those in children of the lowest quartile. Adjusted odd ratios on overweight of the highest quartile of GGT level compared to the lowest quartile were 14.40 (95% confidence interval [CI], 4.43 to 46.83) in boys and 2.94 (95% CI, 1.06 to 8.16) in girls. CONCLUSION: This study shows that high serum GGT level is related with overweight in Korean urban children and this relationship is stronger in boys compared to girls.

Related factors of insulin resistance in Korean children: adiposity and maternal insulin resistance.

Increased adiposity and unhealthy lifestyle augment the risk for type 2 diabetes in children with familial predisposition. Insulin resistance (IR) is an excellent clinical marker for identifying children at high risk for type 2 diabetes. This study was conducted to investigate parental, physiological, behavioral and socio-economic factors related to IR in Korean children. This study is a cross-sectional study using data from 111 children aged 7 years and their parents. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated using fasting glucose and insulin level as a marker of IR. All children's adiposity indices (r = 0.309-0.318, all P-value = 0.001) and maternal levels of fasting insulin (r = 0.285, P-value = 0.003) and HOMA-IR (r = 0.290, P-value = 0.002) were positively correlated with children's HOMA-IR level. There was no statistical difference of children's HOMA-IR level according to children's lifestyle habits and socioeconomic status of families. An increase of 1 percentage point in body fat was related to 2.7% increase in children's HOMA-IR (P-value < 0.001) and an increase of 1% of maternal level of HOMA-IR was related to 0.2% increase in children's HOMA-IR (P-value = 0.002). This study shows that children's adiposity and maternal IR are positively associated with children's IR.

The relationship between low maternal education level and children's overweight in the Korean society.

SUMMARY: This study was conducted to investigate the relationship between socioeconomic status of family and children's adiposity in the Korean society. Data were obtained from 429 2nd-grade students of elementary schools in Gwacheon, Korea in 2006. Body mass index, body fat percentage and waist circumference were measured as indices of children's adiposity. Parental educational level and total household income were surveyed as markers of SES of family. The maternal education level was most closely related to children's overweight among marker of SES. The adjusted odds ratio (OR) of low-educated mother on the children's overweight was 2.67 (95% CI: 1.21-5.89). Increased OR of low-educated mother on children's overweight was observed only in low-income families [adjusted OR: 6.14 (95% CI: 1.94-19.46)]. This study showed that low maternal education level was significantly related to children's overweight in the current Korean society. However, this relationship between the maternal education level and children's overweight was observed only in low-income families.:

IL-23 induces receptor activator of NF-kappaB ligand expression on CD4+ T cells and promotes osteoclastogenesis in an autoimmune arthritis model.

IL-23, a clinically novel cytokine, targets CD4(+) T cells. Recent IL-1Ra(-/-) mouse studies have demonstrated that IL-23 indirectly stimulates the differentiation of osteoclast precursors by enhancing IL-17 release from CD4(+) T cells. IL-17, in turn, stimulates osteoclastogenesis in osteoclast precursor cells. In this study, we found that IL-23 up-regulates receptor activator of NF-kappaB ligand expression by CD4(+) T cells, and thus contributes to osteoclastogenesis. This indirect pathway is mediated by NF-kappaB and STAT3. We have also demonstrated that IL-23 can influence osteoclastogenesis positively under the special conditions in the IL-1-dominant milieu of IL-1Ra(-/-) mice. We propose that IL-23-enhanced osteoclastogenesis is mediated mainly by CD4(+) T cells. The results of this study show that IL-23 is a promising therapeutic target for the treatment of arthritis-associated bone destruction.

IL-17 induces the production of IL-16 in rheumatoid arthritis.

The purpose of this study was to investigate the expression of IL-16 in the rheumatoid synovium and the role of inflammatory cytokines and Toll-like receptor (TLR) ligands in IL-16 production by fibroblast-like synoviocytes (FLS) of rheumatoid arthritis (RA) patients. Immunohistochemical staining was performed with a monoclonal antibody to IL-16 in synovial tissues from patients with RA and likewise in patients with osteoarthritis (OA). FLS were isolated from RA synovial tissues and stimulated with IL-15, IL-1beta, IFN-gamma, and IL-17. The IL-16 mRNA level was assessed by semiquantitative RT-PCR and real time (RT) PCR and a comparison was made between IL-16 mRNA levels produced by RA-FLS and OA-FLS. Production of IL-16 was identified by a western blot assay, and IL-16 production after stimulation by specific ligands of TLR2 and TLR4 was assessed by RT-PCR. While immunohistochemical staining demonstrated strong expression of IL-16 mRNA in synovial tissues from patients with RA, similar findings were not present in the OA group. Moreover, mRNA expression of IL-16 by RA-FLS increased after treatment with IL-17 but not with IL-15, IL-1beta, and IFN-gamma. Specifically, IL-17 increased IL-16 mRNA level by RA-FLS and peripheral blood mononuclear cells in a dose-dependent manner. However, IL-17 did not stimulate IL-16 production in OA-FLS. Peptidoglycan, a selective TLR2 ligand, also increased production of IL-16 by RA-FLS dose- dependently, whereas LPS, a selective TLR4 ligand, had no such stimulatory effect. The results from our data demonstrate that IL-17 and TLR2 ligands stimulate the production of IL-16 by RA-FLS.

Dysfunctional interferon-alpha production by peripheral plasmacytoid dendritic cells upon Toll-like receptor-9 stimulation in patients with systemic lupus erythematosus.

BACKGROUND: It is well known that interferon (IFN)-alpha is important to the pathogenesis of systemic lupus erythematosus (SLE). However, several reports have indicated that the number of IFN-alpha producing cells are decreased or that their function is defective in patients with SLE. We studied the function of plasmacytoid dendritic cells (pDCs) under persistent stimulation of Toll-like receptor (TLR)9 via a TLR9 ligand (CpG ODN2216) or SLE serum. METHODS: The concentrations of IFN-alpha were determined in serum and culture supernatant of peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy controls after stimulation with CpG ODN2216 or SLE serum. The numbers of circulating pDCs were analyzed by fluoresence-activated cell sorting analysis. pDCs were treated with CpG ODN2216 and SLE serum repeatedly, and levels of produced IFN-alpha were measured. The expression of IFN-alpha signature genes and inhibitory molecules of TLR signaling were examined in PBMCs from SLE patients and healthy control individuals. RESULTS: Although there was no significant difference in serum concentration of IFN-alpha and number of circulating pDCs between SLE patients and healthy control individuals, the IFN-alpha producing capacity of PBMCs was significantly reduced in SLE patients. Interestingly, the degree which TLR9 ligand-induced IFN-alpha production in SLE PBMCs was inversely correlated with the SLE serum-induced production of IFN-alpha in healthy PMBCs. Because repeated stimulation pDCs with TLR9 ligands showed decreased level of IFN-alpha production, continuous TLR9 stimulation may lead to decreased production of IFN-alpha in SLE PBMCs. In addition, PBMCs isolated from SLE patients exhibited higher expression of IFN-alpha signature genes and inhibitory molecules of TLR signaling, indicating that these cells had already undergone IFN-alpha stimulation and had become desensitized to TLR signaling. CONCLUSION: We suggest that the persistent presence of endogenous IFN-alpha inducing factors induces TLR tolerance in pDCs of SLE patients, leading to impaired production of IFN-alpha.

Oral administration of type-II collagen suppresses IL-17-associated RANKL expression of CD4+ T cells in collagen-induced arthritis.

The receptor activator of nuclear factor kappaB ligand (RANKL) is an osteoclastogenic mediator, which is mainly expressed by stromal cells and osteoblast. However, T cells can also be an important provider for RANKL in special condition such as autoimmune arthritis. We examined the RANKL expression of hyporesponsive CD4+ T cells induced by oral feeding with type II collagen in collagen-induced arthritis (CIA) mice. The potential of RANKL expression in CD4+ T cells was downregulated in tolerance, as compared with CIA. One of possible explanations for this phenomenon is that CII-specific T cell activation was intrinsically impaired in oral tolerance, which caused suppression of RANKL expression of CD4+ T cells. We also investigated the extrinsic role of cytokine in this process. IL-17, well-known pro-inflammatory cytokine was upregulated in CIA and downregulated in tolerance. IL-17 had a potential to stimulate T cells to express RANKL in dose-dependent manner. IL-17-associated RANKL expression of CD4+ T cells was downregulated in oral tolerance, suggesting that the induction of tolerance ameliorates IL-17-induced RANKL expression of T cells in murine CIA. We also discovered that CIA - T cells could enhance osteoclastogenesis but not oral tolerance - T cells. Oral tolerance might be promising therapeutic option in viewpoints of modulating autoreactivity of CII which can induce not only IL-17 production but also RANKL expression in CD4+ T cells.

Indoleamine 2,3-dioxygenase-expressing dendritic cells are involved in the generation of CD4+CD25+ regulatory T cells in Peyer's patches in an orally tolerized, collagen-induced arthritis mouse model.

INTRODUCTION: The present study was devised to understand the role of systemic indoleamine 2,3-dioxygenase (IDO) in the tolerance induction for orally tolerized mice in collagen-induced arthritis (CIA). We examined whether IDO-expressing dendritic cells (DCs) are involved in the generation of CD4+CD25+ regulatory T cells during the induction of oral tolerance in a murine CIA model. METHODS: Type II collagen was fed six times to DBA/1 mice beginning 2 weeks before immunization, and the effect on arthritis was assessed. To examine the IDO expression, the DCs of messenger RNA and protein were analyzed by RT-PCR and Flow cytometry. In addition, a proliferative response assay was also carried out to determine the suppressive effects of DCs through IDO. The ability of DCs expressing IDO to induce CD4+CD25+ T regulatory cells was examined. RESULTS: CD11c+ DCs in Peyer's patches from orally tolerized mice expressed a higher level of IDO than DCs from nontolerized CIA mice. IDO-expressing CD11c+ DCs were involved in the suppression of type II collagen-specific T-cell proliferation and in the downregulation of proinflammatory T helper 1 cytokine production. The suppressive effect of IDO-expressing CD11c+ DCs was mediated by Foxp3+CD4+CD25+ regulatory T cells. CONCLUSION: Our data suggest that tolerogenic CD11c+ DCs are closely linked with the induction of oral tolerance through an IDO-dependent mechanism and that this pathway may provide a new therapeutic modality to treat autoimmune arthritis.

Murine thymic stromal lymphopoietin promotes the differentiation of regulatory T cells from thymic CD4(+)CD8(-)CD25(-) naïve cells in a dendritic cell-independent manner.

Human thymic stromal lymphopoietin (TSLP) activates dendritic cells (DCs), which promote the proliferation and differentiation of CD4+ T cells. However, murine TSLP (mTSLP) can act directly on CD4+ T cells and bring about their differentiation. We studied the role of mTSLP in the generation of CD4+CD25+FoxP3+ T cells from thymocytes. mTSLP promoted the differentiation of CD4+ single-positive thymocytes into CD4+CD25+FoxP3+ T cells. Although we cannot exclude an effect of TSLP mediated through DCs due to co-stimulatory effects, mTSLP appears to act directly on thymocytes. T-cell receptor and TSLP receptor signaling act synergistically on thymocytes to generate CD4+CD25+FoxP3+ T cells. mTSLP may play an important role in maintaining immune tolerance by promoting the conversion of thymocytes into natural regulatory T cells via escape from negative selection.