Enhanced production of IL-17A during zymosan-induced peritonitis in obese mice

Neonatal cytokines associated with infant overweight and obesity at 1 year of age

OBJECTIVE

The incidence of childhood overweight and obesity has been increasing in recent years. Immune dysregulation has been demonstrated as a condition related to childhood obesity. Whether the neonatal immune status is related to infant overweight and obesity at 1 year of age is unclear.

METHODS

To explore the relationship between neonatal cytokines and infant overweight and obesity, we conducted a prospective study in Suzhou Municipal Hospital Affiliated to Nanjing Medical University from 2015 to 2016. 514 neonates were recruited and their dried blood spots were collected after birth. Infants were grouped into normal size groups and overweight and obesity groups based on BMI at 1 year of age. 27 neonatal cytokines levels were compared between the two groups.

RESULTS

370 infants were included in final analysis. Granulocyte colony stimulating factor (GCSF), interleukin-17A (IL17A) and platelet derived growth factor-BB (PDGF-BB) levels were independently associated with childhood overweight and obesity (OR =1.27, 95%CI 1.03, 1.57; OR =1.29, 95%CI: 1.06, 1.60; OR =0.69, 95%CI: 0.49, 0.96). Additionally, neonatal GCSF and IL17A levels were positively associated with increased BMI (β = 0.11, 95%CI: 0.02, 0.19; β = 0.07, 95%CI 0.01, 013) and BMI z-scores (β = 0.10, 95%CI: 0.02, 0.18; β = 0.06, 95%CI 0.01, 0.13). Neonatal PDGF-BB levels were negatively associated with BMI (β = -0.12, 95%CI: -0.23, -0.01) and BMI z-scores (β = -0.12, 95%CI: -0.23, -0.01). The inverse probability weighting (IPW) was performed to account for potential selection bias of this study, and the results were consistent with the above mentioned findings.

CONCLUSIONS

Neonatal GCSF, IL17A and PDGF-BB levels were correlated with infant overweight and obesity at 1 year of age, suggesting that early life immune status play a significant role of late obesity.

IL-17A, IL-17E and IL-17F as Potential Biomarkers for the Intensity of Low-Grade Inflammation and the Risk of Cardiovascular Diseases in Obese People

Low-grade inflammation is a factor that predisposes to many obesity-related comorbidities. The immune mechanisms controlling the inflammatory response related to the secretory activity of adipocytes and its consequences for the organism are still under investigation.

METHODS

84 obese adult volunteers (BMI ≥ 30 kg/m²) were tested by BIA. Serum samples were collected to analyze the concentrations of interleukins IL-17A, IL-17E and IL-17F. The subjects completed the original questionnaire, the FFQ-6 food consumption frequency questionnaire and the food diary.

RESULTS

The level of IL-17E and IL-17F was positively correlated with the BMI value and the level of IL-17E increased with the content of subcutaneous fat. Its increased blood concentration was also observed in individuals who declared that they were diagnosed with atherosclerosis and/or were taking beta-blockers. Products that were related with a low level of the above-mentioned interleukins were vegetables, groats, eggs, red meat, fast-food and alcohol. The level of these interleukins was positively correlated with the frequent consumption of confectionery and breakfast cereals. Nutrients that decreased the concentrations of IL-17 isoforms were potassium, iron, vitamins B6 and C, and folic acid.

CONCLUSIONS

Both IL-17E and IL-17F may be closely related to the intensity of low-grade inflammation and be biomarkers of cardiovascular disease risk. Food products or the nutrients they contain may affect the levels of the above-mentioned interleukins as well as IL-17A.

Diet-induced obesity in mice impairs host defense against Klebsiella pneumonia in vivo and glucose transport and bactericidal functions in neutrophils in vitro

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.

The impact of obesity on immune response to infection: Plausible mechanisms and outcomes

Emerging data suggest an association between obesity and infectious diseases. Although the mechanisms underlying this link are not well established, a number of potential factors may be involved. Indeed, the obesity-related vulnerability to infectious diseases could be due to chronic low-grade inflammation, hyperglycemia, hyperinsulinemia, and hyperleptinemia, which lead to a weakening of both the innate and adaptive immune responses. In addition, obesity results in anatomical-functional changes by the mechanical obstacle of excessive adipose tissue that blunt the respiratory mechanisms and predisposing to respiratory infections. Subjects with obesity are also at risk of skin folds and sweat more profusely due to the thick layers of subcutaneous fat, favoring the proliferation of microorganisms and slowing the repair of wounds down. All these factors make subjects with obesity more prone to develop nosocomial infections, surgical site, skin and soft tissue infections, bacteremia, urinary tract infections, and mycosis. Furthermore, infections in subjects with obesity have a worse prognosis, frequently prolonging hospitalization time as demonstrated for several flu viruses and recently for COVID-19. Thus, the aim of this manuscript is to provide an overview of the current clinical evidence on the associations between obesity and infectious diseases highlighting physio pathological insights involved in this link.

Corneal dysfunction precedes the onset of hyperglycemia in a mouse model of diet-induced obesity

PURPOSE

The purpose of this study was to use a mouse model of diet-induced obesity to determine if corneal dysfunction begins prior to the onset of sustained hyperglycemia and if the dysfunction is ameliorated by diet reversal.

METHODS

Six-week-old male C57BL/6 mice were fed a high fat diet (HFD) or a normal diet (ND) for 5-15 weeks. Diet reversal (DiR) mice were fed a HFD for 5 weeks, followed by a ND for 5 or 10 weeks. Corneal sensitivity was determined using aesthesiometry. Corneal cytokine expression was analyzed using a 32-plex Luminex assay. Excised corneas were prepared for immunofluorescence microscopy to evaluate diet-induced changes and wound healing. For wounding studies, mice were fed a HFD or a ND for 10 days prior to receiving a central 2mm corneal abrasion.

RESULTS

After 10 days of HFD consumption, corneal sensitivity declined. By 10 weeks, expression of corneal inflammatory mediators increased and nerve density declined. While diet reversal restored nerve density and sensitivity, the corneas remained in a heightened inflammatory state. After 10 days on the HFD, corneal circadian rhythms (limbal neutrophil accumulation, epithelial cell division and Rev-erbα expression) were blunted. Similarly, leukocyte recruitment after wounding was dysregulated and accompanied by delays in wound closure and nerve recovery.

CONCLUSION

In the mouse, obesogenic diet consumption results in corneal dysfunction that precedes the onset of sustained hyperglycemia. Diet reversal only partially ameliorated this dysfunction, suggesting a HFD diet may have a lasting negative impact on corneal health that is resistant to dietary therapeutic intervention.

IL-17A in the Psoriatic Patients' Serum and Plaque Scales as Potential Marker of the Diseases Severity and Obesity

The aim of the study was to evaluate concentrations of IL-17 in the serum and plaque scales of psoriatic patients. We analyzed their association with the clinical activity of the disease and with body mass index (BMI). Demographic data, medical history, serum, and scale from psoriatic plaques for assessment of IL-17 were collected from all the participants. The disease severity was assessed with PASI (Psoriasis Area and Severity Index), BSA (Body Surface Area), PGA (Physician Global Assessment), NAPSI (Nail Psoriasis Severity Index), and DLQI (Dermatology Quality of Life Index) scores. Obesity was diagnosed by calculating body mass index. Serum and scale concentration of IL-17 was determined with Human IL-17A High Sensitivity ELISA kit and Human IL-17 ELISA kit. In the psoriatic patients, BMI was statistically significantly higher than in the control group. Most of the patients presented BMI higher than normal. Our study confirms that overweight is a problem among psoriatic patients. A significant positive correlation between the IL-17 serum and scale concentrations and psoriasis severity indicates that IL-17 can be used as the marker of disease severity. More data from human studies can be crucial for understanding that relationship between IL-17, psoriasis, and obesity.

Serum leptin levels correlate negatively with the capacity of vitamin D to modulate the in vitro cytokines production by CD4+ T cells in asthmatic patients

Both obesity and low vitamin D levels have been associated with allergic asthma (AA) severity. In the present study, severity of AA was associated with obesity but to the in vitro IgE production. In those patients, higher levels of IL-5, IL-6 and IL-17 were quantified in CD4⁺ T-cell cultures as compared with patients with mild and moderate AA. In addition, the lowest IL-10 levels were detected in the cell cultures from patients with a worse prognosis. Interestingly, the occurrence of AA elevates the plasma levels of leptin, and this adipokine was positively correlated with the release of IL-5, IL-6 and IL-17, but inversely correlated with IL-10 production, by CD4⁺ T-cells from patients. In AA-derived CD4⁺ T-cell cultures, 1,25(OH)2D3 was less efficient at inhibiting IL-5, IL-6 and IL-17 production, and up regulating IL-10 release, as those from healthy subjects. Interestingly, the in vitro immunomodulatory effects of vitamin D were inversely correlated with serum leptin levels. In summary, our findings suggested that obesity, probably due to the overproduction of leptin, negatively impacts AA as it favors imbalance between Th2/Th17 and regulatory phenotypes. The deleterious effects of leptin may also be due to its ability to counter-regulate the immunosuppressive effects of vitamin D.

Impact of obesity on autoimmune arthritis and its cardiovascular complications

Obesity can instigate and sustain a systemic low-grade inflammatory environment that can amplify autoimmune disorders and their associated comorbidities. Metabolic changes and inflammatory factors produced by the adipose tissue have been reported to aggravate autoimmunity and predispose the patient to cardiovascular disease (CVD) and metabolic comorbidities. Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are autoimmune arthritic diseases, often linked with altered body mass index (BMI). Severe joint inflammation and bone destruction have a debilitating impact on the patient's life; there is also a staggering risk of cardiovascular morbidity and mortality. Furthermore, these patients are at risk of developing metabolic symptoms, including insulin resistance resulting in type 2 diabetes mellitus (T2DM). In addition, arthritis severity, progression and response to therapy can be markedly affected by the patient's BMI. Hence, a complex integrative pathogenesis interconnects autoimmunity with metabolic and cardiovascular disorders. This review aims to shed light on the network that connects obesity with RA, PsA, systemic lupus erythematosus and Sjӧgren's syndrome. We have focused on clarifying the mechanism by which obesity affects different cell types, inflammatory factors and traditional therapies in these autoimmune disorders. We conclude that to further optimize arthritis therapy and to prevent CVD, it is imperative to uncover the intricate relation between obesity and arthritis pathology.

Alterations in systemic levels of Th1, Th2, and Th17 cytokines in overweight adolescents and obese mice

BACKGROUND

Obesity represents a major problem for patients and health care systems in most industrialized countries. A chronic inflammatory state in obese individuals leads to disease conditions associated with activation of cellular immune mechanisms. Here, we sought to investigate the role of Th1-, Th2-, and Th17-related cytokines in overweight adolescents and mice on a high-fat diet.

METHODS

Plasma samples were obtained from 79 male adolescents aged 13-17 years. Thirty-seven of them had a body mass index (BMI) above the 90th age-specific percentile. Th1, Th2, and Th17 cytokines were measured using Bio-Plex multiplex technology (Bio-Rad, Hercules, USA). In an experimental approach, mice were fed with high-fat (HFD) or normal chow for 15 weeks.

RESULTS

Interleukin (IL)-17 concentrations were significantly decreased in overweight adolescents compared to lean controls [99.8 ± 7.3 pg/mL standard error of the mean (SEM) vs 146.6 ± 11.5 pg/mL SEM P = .001]. Levels of IL-17 correlated significantly with anthropometrical parameters of obesity. A concordant response was found in mice consuming a HFD for 15 weeks compared to controls (861 ± 165 pg/mL SEM vs 1575 ± 187 pg/ml SEM, P = .0183). However, a biphasic response was evident for most Th1, Th2, and Th17 cytokines as levels initially increased within the first 5 weeks on HFD and showed a decline afterwards.

CONCLUSIONS

In contrast to previous studies showing elevated levels of IL-17 in obese adults, we found a decreasing trend in overweight adolescents. This difference could possibly be related to the fact that disease conditions associated with obesity such as hypertension, vascular pathologies, diabetes, and a triggering of the Th1/Th17 axis were not yet present in overweight teenagers.

IL-17A-dependent gut microbiota is essential for regulating diet-induced disorders in mice

The gut microbiota plays a key role in obesity and related metabolic disorders, and multiple factors including diet, host genotype, and age regulate it. Many studies have examined the contribution of extrinsic factors to the regulation of the gut microbiota, but the importance of the host genetic constitution cannot be ignored. Interleukin 17A (IL-17A), a pro-inflammatory cytokine, is important in the defense against infection and diseases. Here, we investigated the association among IL-17, a high-fat diet (HFD), and the gut microbiota. Mice deficient in IL-17A were resistant to diet-induced obesity and related diseases. Compared with the Il-17a^-/- mice, wild-type (WT) mice challenged with HFD showed obvious weight fluctuations, such as those seen in type 2 diabetes, and hematological changes similar to those associated with metabolic syndrome. However, housing WT mice and Il-17a^-/- mice together significantly alleviated these symptoms in the WT mice. A metagenomic analysis of the mouse feces indicated that the microbial community compositions of these two groups differed before HFD feeding. The HFD mediated shifts in the gut microbial compositions, which were associated with the mouse phenotypes. We also identified potentially beneficial and harmful species present during this period, and drew networks of the most abundant species. A functional analysis indicated pathway changes in the WT and Il-17a^-/- mice when fed the HFD. Collectively, these data underscore the importance of the host factor IL-17A in shaping and regulating the gut microbiota, which conversely, influences the host health.

Exposure to an environmentally relevant mixture of organochlorine compounds and polychlorinated biphenyls Promotes hepatic steatosis in male Ob/Ob mice

Hepatic steatosis is recognized as an independent risk factor for the development of cardiovascular disease. While obesity and type 2 diabetes are well-established risk factors in the development of hepatic steatosis, recent studies have revealed exposure to mixtures of persistent organic pollutants (POPs), which are environmental contaminants in various fatty foods, can promote steatosis. Thus, the present study was designed to determine if exposure to a defined mixture of prevalent polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides or their metabolites promote hepatic steatosis in a genetically induced model of type 2 diabetes, the leptin-deficient ob/ob mouse. Male C57BL/6J wild type (WT) or ob/ob mice were administered an environmentally relevant mixture of PCBs and OCs for 7 weeks via oral gavage. Exposure to POPs did not significantly alter fasting serum glucose or insulin levels. However, POPs exposure significantly increased hepatic triglyceride content in ob/ob animals, while decreasing serum triglyceride levels. This POPs-mediated increase in hepatic triglyceride content did not appear to be associated with significantly increased inflammation in either the liver or adipose. Exposure to POPs significantly induced the expression of cytochrome P450 3a11 in WT animals, yet the expression of this cytochrome was significantly downregulated in ob/ob animals regardless of POPs exposure. Taken together, the present data indicate exposure to an environmentally relevant mixture of both PCBs and OC pesticides in ob/ob mice promotes hepatic steatosis while decreasing hypertriglyceridemia, which demonstrates exposure to a defined mixture of POPs alters systemic lipid metabolism in a genetically induced model of obesity and type 2 diabetes. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1399-1411, 2017.

Interleukin-17 as a factor linking the pathogenesis of psoriasis with metabolic disorders

Psoriasis is a systemic disease with numerous concomitant metabolic disorders. Apparently, T-helper 17 lymphocytes and interleukin (IL)-17 constitute an important element linking those disorders. The role of IL-17 has been confirmed by numerous studies, although it remains not completely understood, and the study results are controversial. Based on the studies performed so far, it is assumed that IL-17 contributes to development of atherosclerosis by means of: stimulation of production of proinflammatory compounds; induction of apoptosis of endothelial cells and heart muscle cells; stimulation of von Willebrand factor production; and induction of the matrix metalloproteinase-9 (atherosclerotic plaque rupture). On the other hand, IL-17 may exert protective activity due to inhibition of proatherogenic interferon-γ and vascular cell adhesion molecule-1, and production of type I collagen by smooth muscle cells. The role of IL-17 in the pathogenesis of obesity is as important as other proinflammatory cytokines. On the other hand, its deficiency increases diet-induced obesity and accelerates adipose tissue accumulation. Although the role of IL-17A in the pathogenesis of metabolic disorders in humans remains controversial, introduction of anti-IL-17A treatments brings hope that development of metabolic disorders in patients with psoriasis may be inhibited.

Free fatty acids sensitize dendritic cells to amplify TH1/TH17-immune responses

Obesity is associated with body fat gain and impaired glucose metabolism. Here, we identified both body fat gain in obesity and impaired glucose metabolism as two independent risk factors for increased serum levels of free fatty acids (FFAs). Since obesity is associated with increased and/or delayed resolution of inflammation observed in various chronic inflammatory diseases such as psoriasis, we investigated the impact of FFAs on human monocyte-derived and mouse bone marrow-derived dendritic cell (DCs) functions relevant for the pathogenesis of chronic inflammation. FFAs such as palmitic acid (PA) and oleic acid (OA) did not affect the pro-inflammatory immune response of DCs. In contrast, PA and OA sensitize DCs resulting in augmented secretion of TH1/TH17-instructive cytokines upon pro-inflammatory stimulation. Interestingly, obesity in mice worsened a TH1/TH17-driven psoriasis-like skin inflammation. Strong correlation of the amount of total FFA, PA, and OA in serum with the severity of skin inflammation points to a critical role of FFA in obesity-mediated exacerbation of skin inflammation. Our data suggest that increased levels of FFAs might be a predisposing factor promoting a TH1/TH17-mediated inflammation such as psoriasis in response to an inflammatory danger signal.

Interleukin-17A Differentially Induces Inflammatory and Metabolic Gene Expression in the Adipose Tissues of Lean and Obese Mice

The functions of interleukin-17A (IL-17A) in adipose tissues and adipocytes have not been well understood. In the present study, male mice were fed with a regular diet (n = 6, lean mice) or a high-fat diet (n = 6, obese mice) for 30 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were analyzed for IL-17A levels. SAT and VAT were treated with IL-17A and analyzed for inflammatory and metabolic gene expression. Mouse 3T3-L1 pre-adipocytes were differentiated into adipocytes, followed with IL-17A treatment and analysis for inflammatory and metabolic gene expression. We found that IL-17A levels were higher in obese SAT than lean SAT; the basal expression of inflammatory and metabolic genes was different between SAT and VAT and between lean and obese adipose tissues. IL-17A differentially induced expression of inflammatory and metabolic genes, such as tumor necrosis factor α, Il-6, Il-1β, leptin, and glucose transporter 4, in adipose tissues of lean and obese mice. IL-17A also differentially induced expression of inflammatory and metabolic genes in pre-adipocytes and adipocytes, and IL-17A selectively activated signaling pathways in adipose tissues and adipocytes. These findings suggest that IL-17A differentially induces inflammatory and metabolic gene expression in the adipose tissues of lean and obese mice.

The complex immunological and inflammatory network of adipose tissue in obesity

A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low-grade inflammation which is characterized by activation and infiltration of pro-inflammatory immune cells and a dysregulated production of high levels of pro-inflammatory cytokines. This pro-inflammatory milieu contributes to insulin resistance, type-2 diabetes, cardiovascular disease, and other related co-morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity-related diseases.

Interleukin-17A Gene Expression in Morbidly Obese Women

Data from recent studies conducted in rodent models and humans suggest that interleukin-17A (IL-17A) plays a role in the induction of inflammation in adipose tissue during obesity. The aim of this study was to assess the gene expression of IL-17A in adipose tissue of morbidly obese patients. We used RT-PCR to evaluate the expression of IL-17A and several adipo/cytokines in the visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of 10 normal-weight control women (BMI < 25 kg/m²) and 30 morbidly obese women (MO, BMI > 40 kg/m²). We measured serum levels of IL-17A and adipo/cytokines in MO and normal weight women. IL-17A expression was significantly higher in VAT than in SAT in MO patients (p = 0.0127). It was very low in normal-weight controls in both VAT and SAT tissues. We found positive correlations between IL-17A and IL-6, lipocalin-2 and resistin in VAT of MO patients. The circulating level of IL-17A was higher in the normal-weight group than the MO patients (p = 0.032), and it was significantly related to adiponectin and TNFRII levels. In conclusion, IL-17A expression in VAT is increased in morbidly obese women, which suggests a link between obesity and innate immunity in low-grade chronic inflammation in morbidly obese women.

Childhood obesity: immune response and nutritional approaches

Childhood obesity is characterized by a low-grade inflammation status depending on the multicellular release of cytokines, adipokines, and reactive oxygen species. In particular, the imbalance between anti-inflammatory T regulatory cells and inflammatory T helper 17 cells seems to sustain such a phlogistic condition. Alterations of gut microbiota since childhood also contribute to the maintenance of inflammation. Therefore, besides preventive measures and caloric restrictions, dietary intake of natural products endowed with anti-oxidant and anti-inflammatory activities may represent a valid interventional approach for preventing and/or attenuating the pathological consequences of obesity. In this regard, the use of prebiotics, probiotics, polyphenols, polyunsaturated fatty acids, vitamins, and melatonin in human clinical trials will be described.

AZD5363 Inhibits Inflammatory Synergy between Interleukin-17 and Insulin/Insulin-Like Growth Factor 1

In the United States, one-third of population is affected by obesity and almost 29 million people are suffering from type 2 diabetes. Obese people have elevated serum levels of insulin, insulin-like growth factor 1 (IGF1), and interleukin-17 (IL-17). Insulin and IGF1 are known to enhance IL-17-induced expression of inflammatory cytokines and chemokines, which may contribute to the chronic inflammatory status observed in obese people. We have previously demonstrated that insulin/IGF1 signaling pathway crosstalks with IL-17-activated nuclear factor-κB pathway through inhibiting glycogen synthase kinase 3β (GSK3β) activity. However, it is unclear whether GSK3α also plays a role and whether this crosstalk can be manipulated by AZD5363, a novel pan-Akt inhibitor that has been shown to increase glycogen synthase kinase 3 activity through reducing phosphorylation of GSK3α and GSK3β. In this study, we investigated IL-17-induced expression of C-X-C motif ligand 1 (Cxcl1), C-C motif ligand 20 (Ccl20), and interleukin-6 (Il-6) in wild-type, GSK3α^−/−, and GSK3β^−/− mouse embryonic fibroblast cells as well as in mouse prostate tissues by real-time quantitative PCR. We examined the proteins involved in the signaling pathways by Western blot analysis. We found that insulin and IGF1 enhanced IL-17-induced expression of Cxcl1, Ccl20, and Il-6, which was associated with increased phosphorylation of GSK3α and GSK3β in the presence of insulin and IGF1. AZD5363 inhibited the synergy between IL-17 and insulin/IGF1 through reducing phosphorylation of GSK3α and GSK3β by inhibiting Akt function. These findings imply that the cooperative crosstalk of IL-17 and insulin/IGF1 in initiating inflammatory responses may be alleviated by AZD5363.

Role of T cells in malnutrition and obesity

Nutritional status is critically important for immune cell function. While obesity is characterized by inflammation that promotes metabolic syndrome including cardiovascular disease and insulin resistance, malnutrition can result in immune cell defects and increased risk of mortality from infectious diseases. T cells play an important role in the immune adaptation to both obesity and malnutrition. T cells in obesity have been shown to have an early and critical role in inducing inflammation, accompanying the accumulation of inflammatory macrophages in obese adipose tissue, which are known to promote insulin resistance. How T cells are recruited to adipose tissue and activated in obesity is a topic of considerable interest. Conversely, T cell number is decreased in malnourished individuals, and T cells in the setting of malnutrition have decreased effector function and proliferative capacity. The adipokine leptin, which is secreted in proportion to adipocyte mass, may have a key role in mediating adipocyte-T cell interactions in both obesity and malnutrition, and has been shown to promote effector T cell function and metabolism while inhibiting regulatory T cell proliferation. Additionally, key molecular signals are involved in T cell metabolic adaptation during nutrient stress; among them, the metabolic regulator AMP kinase and the mammalian target of rapamycin have critical roles in regulating T cell number, function, and metabolism. In summary, understanding how T cell number and function are altered in obesity and malnutrition will lead to better understanding of and treatment for diseases where nutritional status determines clinical outcome.

Adipose tissue dendritic cells enhances inflammation by prompting the generation of Th17 cells

BACKGROUND

Obesity has become a global challenge for public health. It has been reported that obesity is associated with chronic inflammation. However, the mechanism for the chronic inflammation contributes to obesity remains elusive.

METHODOLOGY/PRINCIPAL FINDINGS

In our study, we found a novel CD11c+ dendritic cell subset existed in murine adipose tissues which was immature phenotype. Moreover, as compared to the lean controls, the number of CD11c+ DCs and CD4+IL-17+T cells were higher in adipose tissue of high fat diet (HFD) mice. Adipose tissues derived dendritic cells (ATDCs) displayed lower levels of CD40, CD80, CD86, MHCI and MHCII expression than splenic DCs (SPDCs). However, ATDCs showed higher levels of IL-6, TGF-β and IL-23 secretion. Moreover, our in vitro experiments demonstrated that ATDCs were capable of promoting Th17 cell generation.

CONCLUSIONS/SIGNIFICANCE

Our results indicate the existence of CD11c+ DCs in adipose tissues, which displays an immature phenotype but possessing pro-inflammatory function.

Leptin deficiency impairs maturation of dendritic cells and enhances induction of regulatory T and Th17 cells

Leptin is an adipose-secreted hormone that plays an important role in both metabolism and immunity. Leptin has been shown to induce Th1-cell polarization and inhibit Th2-cell responses. Additionally, leptin induces Th17-cell responses, inhibits regulatory T (Treg) cells and modulates autoimmune diseases. Here, we investigated whether leptin mediates its activity on T cells by influencing dendritic cells (DCs) to promote Th17 and Treg-cell immune responses in mice. We observed that leptin deficiency (i) reduced the expression of DC maturation markers, (ii) decreased DC production of IL-12, TNF-α, and IL-6, (iii) increased DC production of TGF-β, and (iv) limited the capacity of DCs to induce syngeneic CD4(+) T-cell proliferation. As a consequence of this unique phenotype, DCs generated under leptin-free conditions induced Treg or TH 17 cells more efficiently than DCs generated in the presence of leptin. These data indicate important roles for leptin in DC homeostasis and the initiation and maintenance of inflammatory and regulatory immune responses by DCs.

Insulin and IGF1 enhance IL-17-induced chemokine expression through a GSK3B-dependent mechanism: a new target for melatonin's anti-inflammatory action

Obesity is a chronic inflammation with increased serum levels of insulin, insulin-like growth factor 1 (IGF1), and interleukin-17 (IL-17). The objective of this study was to test a hypothesis that insulin and IGF1 enhance IL-17-induced expression of inflammatory chemokines/cytokines through a glycogen synthase kinase 3β (GSK3B)-dependent mechanism, which can be inhibited by melatonin. We found that insulin/IGF1 and lithium chloride enhanced IL-17-induced expression of C-X-C motif ligand 1 (Cxcl1) and C-C motif ligand 20 (Ccl20) in the Gsk3b(+/+) , but not in Gsk3b(-/-) mouse embryonic fibroblast (MEF) cells. IL-17 induced higher levels of Cxcl1 and Ccl20 in the Gsk3b(-/-) MEF cells, compared with the Gsk3b(+/+) MEF cells. Insulin and IGF1 activated Akt to phosphorylate GSK3B at serine 9, thus inhibiting GSK3B activity. Melatonin inhibited Akt activation, thus decreasing P-GSK3B at serine 9 (i.e., increasing GSK3B activity) and subsequently inhibiting expression of Cxcl1 and Ccl20 that was induced either by IL-17 alone or by a combination of insulin and IL-17. Melatonin's inhibitory effects were only observed in the Gsk3b(+/+) , but in not Gsk3b(-/-) MEF cells. Melatonin also inhibited expression of Cxcl1, Ccl20, and Il-6 that was induced by a combination of insulin and IL-17 in the mouse prostatic tissues. Further, nighttime human blood, which contained high physiologic levels of melatonin, decreased expression of Cxcl1, Ccl20, and Il-6 in the PC3 human prostate cancer xenograft tumors. Our data support our hypothesis and suggest that melatonin may be used to dampen IL-17-mediated inflammation that is enhanced by the increased levels of insulin and IGF1 in obesity.

Increased levels of interleukins 2 and 17 in the cerebrospinal fluid of patients with idiopathic intracranial hypertension

IIH is a condition of raised intracranial pressure of unknown pathogenesis, which is most commonly seen in young overweight women. This study was designed to confirm and extend previous reports by our and other groups showing increased inflammatory cytokine expression in patients with IIH. We analyzed the concentrations of 14 cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17, IL-22, IL-23, IFNγ, TNFα, TGFβ, and osteopontin) in the serum and cerebrospinal fluid (CSF) of 17 patients with IIH and 53 patients with other neurological conditions. Patients with IIH had highly elevated IL-2, IL-4, IL-10, IL-17 and IFNγ in the CSF compared to patients with multiple sclerosis or non-organic/non-inflammatory neurological conditions. No significant differences were seen between serum cytokine levels in four patient groups (IIH - multiple sclerosis - inflammatory neurological conditions - non-organic/non-inflammatory neurological conditions) and there were no correlations between serum and CSF cytokine levels. In IIH, levels of IL-2, IL-8 and IL-17 were significantly higher in CSF than serum; levels of IL-1β, IL-4, IL-22, IFNγ and TNFα were significantly higher in serum than CSF. For most cytokines, the CSF/serum cytokine ratio was significantly higher than the CSF/serum albumin ratio, indicating intrathecal synthesis of these cytokines in IIH. We conclude that IIH is associated with elevated levels of IL-17 and IL-2 in the CSF, suggesting the involvement of these cytokines in disease pathogenesis.

Physiological concentrations of leptin do not affect human neutrophils

Leptin is an adipokine that is thought to be important in many inflammatory diseases, and is known to influence the function of several leukocyte types. However, no clear consensus is present regarding the responsiveness of neutrophils for this adipokine. In this study a 2D DIGE proteomics approach was used as an unbiased approach to identify leptin-induced effects on neutrophils. Additionally chemotaxis and survival experiments were performed to reproduce results from literature showing putative effects of leptin on these neutrophil responses. Leptin did not induce any significant changes in the proteome provided leptin was added at physiologically relevant concentrations (250 ng). Our leptin batches were biologically active as they induced proliferation in LeptinR expressing Ba/F3 cells. At high concentrations (25000 ng) leptin induced a change in neutrophil proteome. Seventeen differently regulated spots were identified of which twelve could be characterized by mass spectrometry. Two of these identified proteins, SerpinB1 and p40 phox, were chosen for further analysis but leptin-induced expression analyzed by western blot were highly variable. Additionally leptin also induced neutrophil survival at these high concentrations. No leptin-induced chemotaxis of human neutrophils was detected at any concentration. In conclusion, physiological concentrations of leptin do not affect neutrophils. High leptin concentrations induced survival and changes in the neutrophils proteome, but this was most likely mediated by an indirect effect. However, it cannot be ruled out that the effects were mediated by a yet not-identified leptin receptor on human neutrophils.

A guanidine-rich regulatory oligodeoxynucleotide improves type-2 diabetes in obese mice by blocking T-cell differentiation

T lymphocytes exhibit pro-inflammatory or anti-inflammatory activities in obesity and diabetes, depending on their subtypes. Guanidine-rich immunosuppressive oligodeoxynucleotides (ODNs) effectively control Th1/Th2-cell counterbalance. This study reveals a non-toxic regulatory ODN (ODNR01) that inhibits Th1- and Th17-cell polarization by binding to STAT1/3/4 and blocking their phosphorylation without affecting Th2 and regulatory T cells. ODNR01 improves glucose tolerance and insulin sensitivity in both diet-induced obese (DIO) and genetically generated obese (ob/ob) mice. Mechanistic studies show that ODNR01 suppresses Th1- and Th17-cell differentiation in white adipose tissue, thereby reducing macrophage accumulation and M1 macrophage inflammatory molecule expression without affecting M2 macrophages. While ODNR01 shows no effect on diabetes in lymphocyte-free Rag1-deficient DIO mice, it enhances glucose tolerance and insulin sensitivity in CD4⁺ T-cell-reconstituted Rag1-deficient DIO mice, suggesting its beneficial effect on insulin resistance is T-cell-dependent. Therefore, regulatory ODNR01 reduces obesity-associated insulin resistance through modulation of T-cell differentiation.

Stress and obesity as risk factors in cardiovascular diseases: a neuroimmune perspective

Obesity is now growing at an alarming rate reaching epidemic proportions worldwide thus increasing morbidity and mortality rates for chronic disease. But although we have ample information on the complications associated with obesity, precisely what causes obesity remains poorly understood. Some evidence attributes a major role to a low-grade chronic inflammatory state (neurogenic inflammation) induced in obesity by inflammatory mediators produced and secreted within the expanded activated adipocyte pool. Adipose tissue is an endocrine organ that secretes numerous adipose tissue-specific or enriched hormones, known as adipokines, cytokine-like molecules thought to play a pathogenic role in cardiovascular diseases. The imbalance between increased inflammatory stimuli and decreased anti-inflammatory mechanisms may depend on chronic stress. Hence the positive correlation found between stress, obesity and cardiovascular diseases. The chronic inflammatory state associated with insulin resistance and endothelial dysfunction is highly deleterious for vascular function. This review focuses on the proposed neuroimmunodulatory mechanisms linking chronic (psychological) stress, obesity and cardiovascular diseases.

Fish and mammalian phagocytes differentially regulate pro-inflammatory and homeostatic responses in vivo

Phagocytosis is a cellular mechanism that is important to the early induction of antimicrobial responses and the regulation of adaptive immunity. At an inflammatory site, phagocytes serve as central regulators for both pro-inflammatory and homeostatic anti-inflammatory processes. However, it remains unclear if this is a recent evolutionary development or whether the capacity to balance between these two seemingly contradictory processes is a feature already displayed in lower vertebrates. In this study, we used murine (C57BL/6) and teleost fish (C. auratus) in vitro and in vivo models to assess the evolutionary conservation of this dichotomy at a site of inflammation. At the level of the macrophage, we found that teleost fish already displayed divergent pro-inflammatory and homeostatic responses following internalization of zymosan or apoptotic bodies, respectively, and that these were consistent with those of mice. However, fish and mice displayed significant differences in vivo with regards to the level of responsiveness to zymosan and apoptotic bodies, the identity of infiltrating leukocytes, their rate of infiltration, and the kinetics and strength of resulting antimicrobial responses. Unlike macrophages, significant differences were identified between teleost and murine neutrophilic responses. We report for the first time that activated murine, but not teleost neutrophils, possess the capacity to internalize apoptotic bodies. This internalization translates into reduction of neutrophil ROS production. This may play an important part in the recently identified anti-inflammatory activity that mammalian neutrophils display during the resolution phase of inflammation. Our observations are consistent with continued honing of inflammatory control mechanisms from fish to mammals, and provide added insights into the evolutionary path that has resulted in the integrated, multilayered responses that are characteristic of higher vertebrates.

Leptin as a link between the immune system and kidney-related diseases: leading actor or just a coadjuvant?

Food intake and nutritional status modify the physiological responses of the immune system to illness and infection and regulate the development of chronic inflammatory processes, such as kidney disease. Adipose tissue secretes immune-related proteins called adipokines that have pleiotropic effects on both the immune and neuroendocrine systems, linking metabolism and immune physiology. Leptin, an adipose tissue-derived adipokine, displays a variety of immune and physiological functions, and participates in several immune responses. Here, we review the current literature on the role of leptin in kidney diseases, linking adipose tissue and the immune system with kidney-related disorders. The modulation of this adipose hormone may have a major impact on the treatment of several immune- and metabolic-related kidney diseases.

Obesity and airway responsiveness: role of TNFR2

Obese mice exhibit innate airway hyperresponsiveness (AHR), a feature of asthma. Tumor necrosis factor alpha (TNFα) is implicated in the disease progression and chronic inflammatory status of both obesity and asthma. TNF acts via two TNF receptors, TNFR1 and TNFR2. To examine the role of TNFR2 in the AHR observed in obese mice, we generated obese Cpe(fat) mice that were either sufficient or deficient in TNFR2 (Cpe(fat) and Cpe(fat)/TNFR2(-/-) mice, respectively) and compared them with their lean controls (WT and TNFR2(-/-) mice). Compared to WT mice, Cpe(fat) mice exhibited AHR to aerosolized methacholine (measured using the forced oscillation technique) which was ablated in Cpe(fat)/TNFR2(-/-) mice. Bioplex or ELISA assay indicated significant increases in serum leptin, G-CSF, IL-7, IL-17A, TNFα, and KC in obese versus lean mice, as well as significant obesity-related increases in bronchoalveolar lavage fluid (BALF) G-CSF and IP-10, regardless of TNFR2 status. Importantly, BALF IL-17A was significantly increased over lean controls in Cpe(fat) but not Cpe(fat)/TNFR2(-/-) mice. Functional annotation clustering of significantly affected genes identified from microarray analysis comparing gene expression in lungs of Cpe(fat) and WT mice, identified blood vessel morphogenesis as the gene ontology category most affected by obesity. This category included several genes associated with AHR, including endothelin and trkB. Obesity increased pulmonary mRNA expression of endothelin and trkB in TNFR2 sufficient but not deficient mice. Our results indicate that TNFR2 signaling is required for the innate AHR that develops in obese mice, and suggest that TNFR2 may act by promoting IL-17A, endothelin, and/or trkB expression.

IL-17/IL-17 receptor system in autoimmune disease: mechanisms and therapeutic potential

IL-17 (interleukin-17), a hallmark cytokine of Th17 (T-helper 17) cells, plays critical roles in host defence against bacterial and fungal infections, as well as in the pathogenesis of autoimmune diseases. The present review focuses on current knowledge of the regulation, functional mechanisms and targeting strategies of IL-17 in the context of inflammatory autoimmune diseases. Evidence shows that IL-17 is highly up-regulated at sites of inflammatory tissues of autoimmune diseases and amplifies the inflammation through synergy with other cytokines, such as TNF (tumour necrosis factor) α. Although IL-17 was originally thought to be produced mainly by Th17 cells, a newly defined T-cell subset with a specific differentiation programme and tight regulation, several other cell types (especially innate immune cells) are also found as important sources for IL-17 production. Although IL-17 activates common downstream signalling, including NF-κB (nuclear factor κB), MAPKs (mitogen-activated protein kinases), C/EBPs (CCAAT/enhancer-binding proteins) and mRNA stability, the immediate receptor signalling has been shown to be quite unique and tightly regulated. Mouse genetic studies have demonstrated a critical role for IL-17 in the pathogenesis of variety of inflammatory autoimmune diseases, such as RA (rheumatoid arthritis) and MS (multiple sclerosis). Importantly, promising results have been shown in initial clinical trials of monoclonal antibodies against IL-17 or its receptor (IL-17R) to block IL-17-mediated function in treating autoimmune patients with psoriasis, RA and MS. Therefore targeting IL-17/IL-17R, IL-17-producing pathways or IL-17-mediated signalling pathways can be considered for future therapy in autoimmune diseases.

Role of IL-6 in the resolution of pancreatitis in obese mice

Obesity increases severity of acute pancreatitis and risk of pancreatic cancer. Pancreatitis and obesity are associated with elevated IL-6, a cytokine involved in inflammation and tumorigenesis. We studied the role of IL-6 in the response of lean and obese mice to pancreatitis induced by IL-12 + IL-18. Lean and diet-induced obese (DIO) WT and IL-6 KO mice and ob/ob mice pretreated with anti-IL-6 antibodies were evaluated at Days 1, 7, and 15 after induction of pancreatitis. Prolonged elevation of IL-6 in serum and visceral adipose tissue was observed in DIO versus lean WT mice, whereas circulating sIL-6R declined in DIO but not lean mice with pancreatitis. The severe inflammation and lethality of DIO mice were also observed in IL-6 KO mice. However, the delayed resolution of neutrophil infiltration; sustained production of CXCL1, CXCL2, and CCL2; prolonged activation of STAT-3; and induction of MMP-7 in the pancreas, as well as heightened induction of serum amylase A of DIO mice, were blunted significantly in DIO IL-6 KO mice. In DIO mice, production of OPN and TIMP-1 was increased for a prolonged period, and this was mediated by IL-6 in the liver but not the pancreas. Results obtained in IL-6 KO mice were confirmed in ob/ob mice pretreated with anti-IL-6 antibodies. In conclusion, IL-6 does not contribute to the increased severity of pancreatitis of obese mice but participates in delayed recovery from acute inflammation and may favor development of a protumorigenic environment through prolonged activation of STAT-3, induction of MMP-7, and sustained production of chemokines.

Terminal arteriolar network structure/function and plasma cytokine levels in db/db and ob/ob mouse skeletal muscle

OBJECTIVE

To investigate the terminal arteriolar network structure and function in relation to circulating plasma cytokine levels in db/db, ob/ob, and their genetic background control, C57/bl6, mice.

METHODS

Arteriolar network size and erythrocyte distribution were observed in the resting cremaster muscle (n = 45, pentobarbital 50 mg/kg i.p.). Structural remodeling and inflammatory state were related to 21 plasma cytokine levels.

RESULTS

db/db networks were shorter, had fewer branches, and smaller diameters than C57/bl6 controls. ob/ob networks were longer, with similar branch numbers, however with non-uniform diameters. Shunting of erythrocytes to the specific terminal arteriolar branches of the network (functional rarefaction) was prominent in db/db and ob/ob, with further evidence of shunting between networks seen as no flow to 50% of ob/ob arteriolar networks.

CONCLUSIONS

Altered levels of plasma cytokines are consistent with structural remodeling seen in db/db, and a pro-inflammatory state for both db/db and ob/ob. Differences in network structure alone predict overall reduced uniform oxygen delivery in db/db or ob/ob. Shunting probably increases heterogeneous oxygen delivery and is strain-dependent.

Role of interleukin 17 in inflammation, atherosclerosis, and vascular function in apolipoprotein e-deficient mice

OBJECTIVE

Interleukin 17A (IL17A) is involved in many inflammatory processes, but its role in atherosclerosis remains controversial. We examined the role of IL17A in mouse and human atherosclerosis.

METHODS AND RESULTS

Atherosclerosis was induced in apolipoprotein E (ApoE)(-/-) and IL17A/ApoE(-/-) mice using high-fat feeding, angiotensin II infusion, or partial carotid ligation. In ApoE(-/-) mice, 3 months of high-fat diet induced interferon-γ production by splenic lymphocytes, and this was abrogated in IL17A/ApoE(-/-) mice. IL17A/ApoE(-/-) mice had reduced aortic superoxide production, increased aortic nitric oxide levels, decreased aortic leukocyte and dendritic cell infiltration, and reduced weight gain after a high-fat diet compared with ApoE(-/-) mice. Despite these favorable effects, IL17A deficiency did not affect aortic plaque burden after a high-fat diet or angiotensin II infusion. In a partial carotid ligation model, IL17A deficiency did not affect percentage of stenosis but reduced outward remodeling. In this model, neutralization of the related isoform, IL17F, in IL17A/ApoE(-/-) mice did not alter atherosclerosis. Finally, there was no correlation between IL17A levels and carotid intima-media thickness in humans.

CONCLUSIONS

IL17 contributes to vascular and systemic inflammation in experimental atherosclerosis but does not alter plaque burden. The changes in plaque composition caused by IL17 might modulate plaque stability.

Suppressed cytokine production in whole blood cultures may be related to iron status and hepcidin and is partially corrected following weight reduction in morbidly obese pre-menopausal women

OBJECTIVE

Assess ex vivo whole-blood (WB) cytokine production and its association with iron status and serum hepcidin in obese versus non-obese women. Determine the change in ex vivo WB cytokine production 6 months after restrictive bariatric surgery in the obese group.

SUBJECTS

Seventeen obese (BMI: 46.6±7.9 kg/m²) and 19 non-obese (BMI: 22.5±3.0 kg/m²), pre-menopausal women; frequency matched for hemoglobin, age and race.

MEASUREMENTS

At baseline control and ex vivo stimulated IL-6, IL-10, IL-22, IFNγ, and TNFα from heparinized WB cultures, hemoglobin from finger-stick and transferrin receptor, hepcidin, CRP, IL-6, HOMA-IR from fasted serum samples and anthropometric parameters were assessed in the women. All parameters were reassessed 6-months following restrictive bariatric surgery in the obese women only.

RESULTS

Whole blood ex vivo LPS and ZY stimulated production of IL-6, TNFα, and IFNγ was reduced, IL-22 increased, and IL-10 was unaffected in obese compared with the non-obese women. Furthermore, ex vivo stimulated production of IL-6 and TNFα normalized, but IFNγ production remained unchanged with weight loss following restrictive bariatric surgery. In the obese women, serum transferrin receptor (a marker of iron status) and serum hepcidin were correlated with ex vivo stimulated IFNγ production at baseline.

CONCLUSION

Ex vivo LPS and ZY stimulated cytokine production from WB cultures was altered in pre-menopausal women with morbid obesity. Significant weight loss resulted in normalization of some but not all observed alterations. Furthermore, iron status and serum hepcidin were associated with ex vivo LPS and ZY stimulated IFNγ in obesity.

IL-17 in obesity and adipogenesis

The pro-inflammatory cytokine interleukin (IL)-17 (also known as IL-17) has been associated with induction of tissue inflammation. Obese individuals exhibit many symptoms of chronic low-grade inflammation, suggesting that IL-17 may impact adipose tissue. However, the role of IL-17 in obesity is largely unexplored. Emerging studies indicate that obesity selectively promotes expansion of the Th17 T-cell lineage, exacerbating disease in murine models of autoimmunity such as EAE and colitis. Human studies support this concept, as new clinical studies suggest that IL-17 is expressed at elevated levels in obese individuals. Conversely, however, an anti-adipogenic role for IL-17 is becoming evident, and therefore the interconnections between IL-17 and fat metabolism may be quite complex. Here, we consolidate the potential implications of IL-17 in relation to obesity and describe the emerging data regarding the role of IL-17 in adipose tissue.

Effect of major abdominal surgery on the host immune response to infection

PURPOSE OF REVIEW

The present review summarizes key studies on the effects of major abdominal surgery on the host response to infection published during the last 18 months.

RECENT FINDINGS

Surgical trauma causes stereotyped systemic proinflammatory and compensatory anti-inflammatory reactions. It is leukocyte reprogramming rather than general immune suppression. The list of recent findings is long. Preoperative infectious challenge was found to increase survival. Obesity is associated with increased production of interleukin-17A in peritonitis. Abdominal surgery alters expression of toll-like receptors (TLRs). The acute phase reaction down-regulates the transcription factor carbohydrate response element binding protein. Myosin light chain kinase activation is a final pathway of acute tight junction regulation of gut barrier and zonula occludens 1 protein is an essential effector. The brain is involved in regulating the immune and gut system. Elimination of lipopolysaccharide is challenging. Th1/Th2 ratio is lowered in patients with postoperative complications. Cholinergic anti-inflammatory pathways can inhibit tissue damage. The new substance PXL01 prevents adhesions. Postoperative infection causes incisional hernias. Hypothermia reduced human leukocyte antigen DR surface expression and delayed tumor necrosis factor clearance. Systems biology identified interferon regulatory factor 3 as the negative regulator of TLR signaling. Protective immunity could contribute defeating surgical infections.

SUMMARY

Systemic inflammation is the usual response to trauma. All organs seem to be involved and linked up in cybernetic systems aiming at reconstitution of homeostasis. Although knowledge is still fragmentary, it is already difficult to integrate known facts and new technologies are required for information processing. Defining criteria to develop therapeutic strategies requires much more insight into molecular mechanisms and cybernetics of organ systems.