Role of Peripheral Blood Mononuclear Cells in the Predisposition of Obese Individuals to Inflammation and Infection

ObjectiveTo compare the production of pro- and anti-inflammatory cytokines by peripheral blood mononuclear cells (PBMC) from obese but otherwise healthy individuals to that of normal-weight volunteers.Methods25 healthy normal-weight subjects and 41 obese individuals were enrolled. Weight and height were measured twice. PBMC were examined for their capacity to generate pro-inflammatory (TNF-α, IFN-γ, IL-1β, IL-6, IL-2) and anti-inflammatory IL-10 and IL-1ra) cytokines.ResultsPBMC from obese individuals, compared to those from subjects with normal weight showed an increased production of the pro-inflammatory cytokines IL-2 (6.7 ± 0.4. vs. 4.9 ± 0.3 ng/ml; p = 0.003), TNF-α (505 ± 45 vs. 277 ± 32 pg/ml; p = 0.001), and IFN-γ (93.8 ± 6.0 vs. 73.9 ± 2.7 ng/ml; p = 0.0016). However, PBMC from obese individuals produced a lower amount of the anti-inflammatory cytokine IL-10 (651 ±72 pg/ml) versus those from subjects with normal weight (951 ± 133 pg/ml; p = 0.039).ConclusionsThe findings imply that obese individuals are in a ‘low-grade inflammatory state’, presumed to be connected with metabolic and cardiovascular co morbidities. The surplus of pro-inflammatory cytokines produced by circulating mononuclear cells of obese individuals, together with those secreted by adipocytes and non-fat cells in the adipose tissue, may contribute to the predisposition of obese patients to inflammation and infections.Key Words: Obesity, Peripheral blood mononuclear cells, Cytokines, Inflammation, Infection     

Effect of glutamine on apoptosis of intestinal epithelial cells of severe acute pancreatitis rats receiving nutritional support in different ways

Objective: To investigate the effect of glutamine (Gln) on pro-inflammatory cytokines (TNF-α, IL-2 and IL-10) and the balance between pro-inflammatory cytokines and anti-inflammatory cytokines in severe acute pancreatitis (SAP) rats receiving nutritional support in different ways. Methods: Male SD rats (n=80) were randomly assigned into 5 groups: sham group, SAP+ parenteral nutrition (PN) group, SAP+ enteral nutrition (EN) group, SAP+EN+Gln group and SAP+PN+Gln group. At the same time, rats in 5 groups were sacrificed at 4 and 7 days after nutritional support. ELISA was employed to detect the pro-inflammatory cytokines including TNF-α, IL-2 and IL-10. Results: The serum TNF-α in the EN+Gln group after 7-day treatment was significantly lower than that in the EN, PN and PN+Gln groups at corresponding time point (P<0.05). The serum IL-2 in the EN+Gln group after 7-day treatment was markedly higher than that in the EN, PN and PN+Gln groups at corresponding time point (P<0.01). After 7-day treatment, the serum IL-2 in the EN+Gln and EN groups were markedly higher than that after 4-day treatment (P<0.01), but the serum IL-2 in the PN group was significantly lower than that after 4-day treatment (P<0.01). The serum IL-10 after 7-day treatment was markedly lower than that after 4-day treatment in all groups (P<0.01), and PN group had the lowest serum IL-10. Serum IL-10 in the EN+Gln group was significantly higher than that in the PN and PN+Gln groups at both time points (P<0.01). The serum IL-10 in the EN group was significantly higher than that in the PN group after 4-day treatment (P<0.01), but the serum IL-10 in the EN group was comparable to that in the PN group after 7-day treatment. The serum IL-10/TNF-α in the EN+Gln group was only slightly higher than that in the control group at both time points. The serum IL-10/TNF-α in the EN group was significantly lower than that in the EN+Gln group at both time points (P<0.05). The serum IL-10/TNF-α in the PN group was markedly lower than that in the EN group and EN+Gln group (P<0.05 and P<0.01, respectively).Conclusion: EN in combination with Gln are superior to EN alone, PN alone and PN in combination with Gln in regulating inflammation in SAP rats, and the EN has more potent capability to regulate the balance between pro-inflammation and anti-inflammation than PN.     

The chronic blockade of angiotensin I-converting enzyme eliminates the sex differences of serum cytokine levels of spontaneously hypertensive rats

Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.     

Production of chemokines in Kawasaki disease, Henoch-Schönlein purpura and acute febrile illness

We compared the production of three chemokines; interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1) and growth-related oncogene-α (Gro-α) that attracts monocytes or neutrophils, or both, in peripheral blood at acute stage of Kawasaki disease (n=29), Henoch-Schönlein purpura (n=15) and acute febrile illnesses (n=12). The production of the chemokines was assayed by ELISA. The plasma levels of IP-10 were markedly elevated in Kawasaki disease (538.6±336.4 pg/mL) and acute febrile illnesses (417.1±262.2 pg/mL) compared with in Henoch-Schönlein purpura (58.7±95.7 pg/mL) (p<0.05). The MCP-1 levels were elevated in Kawasaki disease (443.0±473.1 pg/mL) and acute febrile illnesses (328.6±261.1 pg/mL) compared with in Henoch-Schönlein purpura (82.9±79.0 pg/mL) (p<0.05). The Gro-α levels were elevated only in acute febrile illnesses (134.3±153.6 pg/mL) compared with in Kawasaki disease (31.8±22.1 pg/mL) or Henoch-Schönlein purpura (29.4±53.3 pg/mL) (p<0.05). According to these results, monocytes may play an important role in Kawasaki disease. In acute febrile illnesses, both monocytes and neutrophils may play an important role. By contrast, Henoch-Schönlein purpura may not be associated with the role of monocytes and neutrophils. Further studies using a larger number of cases are needed.     

Role of Th1 and Th2 Cytokines in Immune Response to Uncomplicated Plasmodium falciparum Malaria

The relative balance between Th1 and Th2 cytokines appears crucial, since the role of cytokines has been evaluated in several studies by comparison of clinically heterogeneous groups of patients. The aim of this study is to determine the role of proinflammatory Th1 cytokines, interleukin-12 (IL-12) and gamma interferon (IFN-γ), and anti-inflammatory Th2 cytokines, IL-4 and IL-10, in a homogeneous group of patients with uncomplicated Plasmodium falciparum malaria. Levels of IL-12, IFN-γ, Il-4, and IL-10 in serum for 20 adult patients and 15 healthy control subjects were determined by an immunoenzymatic assay. Serum levels of Th1 cytokines, IL-12 (8.6 ± 2.8 pg/ml; controls, 3.2 ± 0.7 pg/ml) and IFN-γ (39.2 ± 67.6 pg/ml; controls, 8.4 ± 6.3 pg/ml), were significantly increased at admission; 3 days later, levels of IL-12 in serum remained significantly high (8.8 ± 2.6 pg/ml), whereas IFN-γ levels returned to control values. The anti-inflammatory response of Th2 cytokines (IL-10 and IL-4) was distinct. Levels of IL-10 in serum were not significantly increased at day 0 and day 3 (306.6 ± 200.4 pg/ml and 56.6 ± 38.4 pg/ml, respectively; controls, 17.4 ± 9.0 pg/ml). In contrast, levels of IL-4 in serum were not increased on admission (3.4 ± 1.2 pg/ml; controls, 2.4 ± 0.8 pg/ml), but at day 3 a moderate and significant increase of IL-4 levels was observed (4.5 ± 1.7 pg/ml). In conclusion, the increase of Th1 cytokine IL-12 and IFN-γ levels during the acute phase of uncomplicated P. falciparum malaria may reflect an early and effective immune response regulated by proinflammatory Th1 cytokines, and in particular IFN-γ may play a role in limiting progression from uncomplicated malaria to severe and life-threatening complications.     

The Role of Keratinocyte-derived Chemokine in Hemorrhage-induced Acute Lung Injury in Mice

Dominant inflammatory cytokines might be different depending on the underlying causes of acute lung injury (ALI). The role of kertinocyte-derived chemokine (KC), a potent chemoattractant for neutrophils, has not been clearly established in hemorrhage-induced ALI. In this study, lung injury and cytokine expressison were evaluated in LPS- or hemorrhage-induced ALI models of BALB/c mice. The myeloperoxidase activities at 4 hr after hemorrhage and LPS-injection were 47.4±13.0 and 56.5±16.4 U/g, respectively. NF-κB activity peaked at 4 hr after hemorrhage, which was suppressed to the control level by anti-high mobility group B1 (HMGB1) antibody. Lung expressions of TNF-α, MIP-2, and IL-1β were increased by LPS injection. However, there was only a minimal increase in IL-1β and no expressions of TNF-α or MIP-2 in hemorrhage-induced ALI. In contrast, lung KC increased significantly at 4 hr after hemorrhage compared to control levels (83.1±12.3 vs. 14.2±1.6 pg/mL/mg by ELISA) (P<0.05). By immunohistochemical staining, lung neutrophils stained positive for KC. Increased KC was also observed in bronchoalveolar lavage fluid and plasma. KC plays an important role in hemorrhage-induced ALI.     

Serum titres of anti-glutamic acid decarboxylase-65 and anti-IA-2 autoantibodies are associated with different immunoregulatory milieu in newly diagnosed type 1 diabetes patients

Several studies correlated genetic background and pancreatic islet-cell autoantibody status (type and number) in type 1A diabetes mellitus (T1AD), but there are no data evaluating the relationship among these markers with serum cytokines, regulatory T cells and β cell function. This characterization has a potential importance with regard to T1AD patients'' stratification and follow-up in therapeutic prevention. In this study we showed that peripheral sera cytokines [interleukin (IL)-12, IL-6, II-1β, tumour necrosis factor (TNF)-α, IL-10] and chemokines (CXCL10, CXCL8, CXCL9, CCL2) measured were significantly higher in newly diagnosed T1AD patients when compared to healthy controls (P < 0·001). Among T1AD, we found a positive correlation between CXCL10 and CCL-2 (r = 0·80; P = 0·000), IL-8 and TNF-α (r = 0·60; P = 0·000); IL-8 and IL-12 (r = 0·57; P = 0·001) and TNF-α and IL-12 (r = 0·93; P = 0·000). Glutamic acid decarboxylase-65 (GAD-65) autoantibodies (GADA) were associated negatively with CXCL10 (r = −0·45; P = 0·011) and CCL2 (r = −0·65; P = 0·000), while IA-2A showed a negative correlation with IL-10 (r = −0·38; P = 0·027). Human leucocyte antigen (HLA) DR3, DR4 or DR3/DR4 and PTPN22 polymorphism did not show any association with pancreatic islet cell antibodies or cytokines studied. In summary, our results revealed that T1AD have a proinflammatory cytokine profile compared to healthy controls and that IA-2A sera titres seem to be associated with a more inflammatory peripheral cytokine/chemokine profile than GADA. A confirmation of these data in the pre-T1AD phase could help to explain the mechanistic of the well-known role of IA-2A as a more specific marker of beta-cell damage than GADA during the natural history of T1AD.     

The relationship between thyroid function,serum monokine induced by interferon gamma and soluble interleukin‐2 receptor in thyroid autoimmune diseases

Interactions between cytokines play an important role in the development of thyroid autoimmunity. Using enzyme-linked immunosorbent assay we investigated serum concentrations of soluble interleukin-2 receptor (sIL-2R), interferon-gamma, tumour necrosis factor (TNF)-α, interleukin (IL)-10, CD30, monokine induced by interferon-gamma (MIG), cytotoxic T lymphocyte antigen-4 and markers of apoptosis decoy receptor 3 and Bcl-2 in 28 patients with hyperthyroid Graves'' disease (GD), 24 patients with untreated Hashimoto''s thyroiditis (HT) and 15 healthy controls. TNF-α, IL-10 and sIL-2R were higher in GD compared with HT and controls (TNF-α: 8·79 in GD versus 2·54 pg/ml in HT, P = 0·01; IL-10: 10·00 versus 3·10 versus 3·10 pg/ml, P₁ < 0·001, P₂ = 0·005; sIL-2R: 1·26 versus 0·64 versus 0·46 ng/ml, P < 0·001). MIG and CD30 were higher in HT compared with controls (649·22 ± 262·55 versus 312·95 ± 143·35 pg/ml, P = 0·037, 6·57 ± 2·35 versus 3·03 ± 1·04 U/ml, P = 0·036 respectively). In GD sIL-2R decreased when the euthyroid state was achieved (1·31 ± 0·64 versus 0·260 ± 0·11, n = 12, P < 0·001). sIL-2R correlated positively with free thyroxine (FT4) (R = 0·521, P = 0·000) and negatively with thyroid stimulating hormone (TSH) (R = −0·472, P = 0·00132). MIG correlated negatively with FT4 (R = −0·573, P = 0·00234) and positively with TSH (R = 0·462, P = 0·0179). The results suggest that serum concentrations of sIL-2R and MIG are related to thyroid function rather than to activation of autoimmunity.     

Effect of betamethasone on neuropathic pain and cerebral expression of NF-kappaB and cytokines

Glucocorticoids have been used to treat neuropathic pain for many years, but the underlying mechanisms are still unknown. Recent studies indicate that pathological pain states may be mediated by cytokines. We, therefore, examined the effect of betamethasone on neuropathic pain and the relationship between pain behavior and the expression of cytokines in the brain. Rats were given epidural injections of betamethasone (Diprospan) after L5 spinal nerve transection. Mechanical allodynia and thermal hyperalgesia were evaluated on post-operative days 1, 3, 7, 14 and 21 with von Frey and Hargreaves tests. Cerebral expression of NF-kappaB, TNFalpha, IL-1beta and IL-10 was quantified using electrophoretic mobility shift assay (EMSA) or enzyme-linked immunosorbent assay (ELISA). We found that spinal nerve injury caused long-lasting mechanical and thermal hyperalgesia in the hind paw and stimulated the expression of NF-kappaB, TNFalpha, IL-1beta and IL-10 in the brain. A single epidural injection of betamethasone at the time of nerve injury partially inhibited the development of neuropathic hyperalgesia and reduced the subsequent elevated levels of pro-inflammatory cytokines in the brain, while stimulating the expression of the anti-inflammatory cytokine IL-10. These data support our hypothesis that pro-inflammatory cytokines in the brain may mediate the hyperalgesic effects of spinal nerve injury and that the long-acting anti-hyperalgesic effects of epidural glucocorticoid treatment are due to an inhibitory effect on pro-inflammatory cytokine levels and a stimulatory effect on anti-inflammatory cytokine levels in the brain.     

The activating effect of IFN-γ on monocytes/macrophages is regulated by the LIF–trophoblast–IL-10 axis via Stat1 inhibition and Stat3 activation

Interferon gamma (IFN-γ) and leukemia inhibitory factor (LIF) are key gestational factors that may differentially affect leukocyte function during gestation. Because IFN-γ induces a pro-inflammatory phenotype in macrophages and because trophoblast cells are principal targets of LIF in the placenta, we investigated whether and how soluble factors from trophoblast cells regulate the effects of IFN-γ on macrophage activation. IFN-γ reduces macrophage motility, but enhances Stat1 activation, pro-inflammatory gene expression and cytotoxic functions. Soluble factors from villous cytotrophoblasts (vCT+LIF cells) and BeWo cells (BW/ST+LIF cells) that were differentiated in the presence of LIF inhibit macrophage Stat1 activation but inversely sustain Stat3 activation in response to IFN-γ. vCT+LIF cells produce soluble factors that induce Stat3 activation; this effect is partially abrogated in the presence of neutralizing anti-interleukin 10 (IL-10) antibodies. Moreover, soluble factors from BW/ST+LIF cells reduce cell proliferation but enhance the migratory responses of monocytes. In addition, these factors reverse the inhibitory effect of IFN-γ on monocyte/macrophage motility. BW/ST+LIF cells also generate IFN-γ-activated macrophages with enhanced IL-10 expression, but reduced tumor-necrosis factor alpha (TNF-α), CD14 and CD40 expression as well as impaired cytotoxic function. Additional assays performed in the presence of neutralizing anti-IL-10 antibodies and exogenous IL-10 demonstrate that reduced macrophage cytotoxicity and proliferation, but increased cell motility result from the ability of trophoblast IL-10 to sustain Stat3 activation and suppress IFN-γ-induced Stat1 activation. These in vitro studies are the first to describe the regulatory role of the LIF–trophoblast–IL-10 axis in the process of macrophage activation in response to pro-inflammatory cytokines.     

Mycoplasma pneumoniae Infection Affects the Serum Levels of Vascular Endothelial Growth Factor and Interleukin-5 in Atopic Children

Purpose

Previous studies have outlined mechanisms by which Mycoplasma pneumonia (M. pneumonia) infection may promote allergic lung inflammation and airway remodeling, and increasing evidence from human studies suggests that atypical bacterial infections contribute to asthma exacerbation, chronic asthma, and disease severity with changes in cytokine expression. The present study evaluated changes in serum levels of vascular endothelial growth factor (VEGF) and interleukin (IL)-5 in atopic children with Mycoplasma pneumoniae pneumonia.

Methods

We recruited a total of 72 children with pneumonia. The patients were divided into 4 groups: atopic children with M. pneumonia pneumonia (group I, n=24), non-atopic children with M. pneumonia pneumonia (group II, n=23), atopic children with viral pneumonia (group III, n=13), and non-atopic children with viral pneumonia (group IV, n=12). Serum levels of IL-5, IL-13, VEGF, and tumor necrosis factor-α were measured at admission and at recovery using enzyme-linked immunosorbent assays.

Results

Serum levels of VEGF and IL-5 were elevated in group I compared with the other groups at both admission phase and clinical recovery phase. In group I, serum levels of VEGF and IL-5 were higher at recovery phase than at admission phase (VEGF: 1,102.2±569.4 vs. 874.9±589.9 pg/mL, respectively; IL-5: 150.5±63.9 vs. 120.2±46.7 pg/mL, respectively).

Conclusions

The serum levels of VEGF and IL-5 were more increased in atopic children with M. pneumonia pneumonia than in the other groups. In this group, the serum levels of VEGF and IL-5 were more increased at recovery phase than at admission phase. The results of this study suggest that increases in VEGF and IL-5 may contribute to the development of hypersensitivity during M. pneumonia infection. These cytokines may act through their respective pro-inflammatory pathways to aggravate the allergic status and induce airway hypersensitivity during M. pneumonia pneumonia in atopic children.     

Prognostic values of serum IP-10 and IL-17 in patients with pulmonary tuberculosis

Objective: To identify patients at high risk of relapse after anti-tuberculosis (TB) therapy or with poor long-term outcomes. Methods: Fifty-one patients with pulmonary TB: 7 were classified as high association with both cavitations on initial chest radiography and positive sputum smear/cultures after two months of anti-TB treatment (HA group); 19 medium association (MA, one risk alone); and 25 low association (LA, neither risk). Serum interferon (IFN)-γ-inducible protein 10 (IP-10), interleukin-17 (IL-17), and C-reactive protein levels were investigated. Results: There was a trend towards higher serum IP-10 levels (p = 0.042) for HA patients throughout the 6-month treatment period. Month-2 IP-10 levels were higher in the HA than in the MA/LA group (656.2 ± 234.4 vs. 307.6 ± 258.5 pg/ml, adjusted p = 0.005). Receiver operating characteristic curves showed that the risk of relapse was well-captured by month-2 IP-10 levels at a cut-off value of 431 pg/ml (AUC=0.857, 95% CI 0.75–0.97, p = 0.003). Month-2 serum IL-17 levels were lower in non-survivors than survivors (15.7 ± 2.9 pg/ml vs. 24.6 ± 8.2 pg/ml, p = 0.001). Multivariate analysis demonstrated that a month-2 serum IL-17 level of ≤ 17 pg/ml (p = 0.026) was independently associated with all-cause mortality. Conclusions: Serum IP-10 and IL-17 levels after 2 months of anti-TB treatment may be biomarkers for estimating risk of both cavitation and delayed sputum conversion, and for predicting long-term mortality, respectively.     

Tumour necrosis factor‐α plus interleukin‐10 low producer phenotype predicts acute kidney injury and death in intensive care unit patients

Genetic polymorphism studies of cytokines may provide an insight into the understanding of acute kidney injury (AKI) and death in intensive care unit (ICU) patients. The aim of this study was to investigate whether the genetic polymorphisms of −308 G < A tumour necrosis factor (TNF)-α, −174 G > C interleukin (IL)-6 and −1082 G > A IL-10 may predispose ICU patients to the development of AKI and/or death. In a prospective nested case–control study, 303 ICU patients and 244 healthy individuals were evaluated. The study group included ICU patients who developed AKI (n = 139) and 164 ICU patients without AKI. The GG genotype of TNF-α (low producer phenotype) was significantly lower in the with AKI than without AKI groups and healthy individuals (55 versus 62 versus 73%, respectively; P = 0·01). When genotypes were stratified into four categories of TNF-α/IL-10 combinations, it was observed that low TNF-α plus low IL-10 producer phenotypes were more prevalent in patients with AKI, renal replacement therapy and death (P < 0·05). In logistic regression analysis, low TNF-α producer plus low IL-10 producer phenotypes remained as independent risk factors for AKI and/or death [odds ratio (OR) = 2·37, 95% confidence interval (CI): 1·16–4·84; P = 0·02] and for renal replacement therapy (RRT) and/or death (OR = 3·82, 95% CI: 1·19–12·23; P = 0·02). In this study, the combination of low TNF-α plus low IL-10 producer phenotypes was an independent risk factor to AKI and/or death and RRT and/or death in critically ill patients. Our results should be validated in a larger prospective study with long-term follow-up to emphasize the combination of these genotypes as potential risk factors to AKI in critically ill patients.     

Estrogen enhances the functions of CD4(+)CD25(+)Foxp3(+) regulatory T cells that suppress osteoclast differentiation and bone resorption in vitro

Cross-talk has been shown to occur between the immune system and bone metabolism pathways. In the present study, we investigated the impact of CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cells on osteoclastogenesis and bone resorption. Treg cells that were isolated and purified from peripheral blood mononuclear cells (PBMCs) of healthy adults inhibited both the differentiation of osteoclasts (OCs) from human embryo bone marrow cells (BMCs) and the pit formation in a dose-dependent manner. In cell cocultures, the production levels of both interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-β1) were proportionally upregulated as the ratio of Treg cells to BMCs was increased, and the inhibition of OC differentiation and bone resorption by Treg cells was completely reversed by anti-IL-10 and anti-TGF-β1 antibodies. Treatment of BMC and Treg cell cocultures with 17β-estradiol (E2) at concentrations between 10⁻⁷ and 10⁻⁹ mol/l suppressed OC differentiation and bone resorption more efficiently than it did in cultures of BMCs alone; this enhanced suppression occurred via the stimulation of Treg cell IL-10 and TGF-β1 expression. These data suggest that Treg cells suppress OC differentiation and bone resorption by secreting IL-10 and TGF-β1. E2 enhances the suppressive effects of Treg cells on OC differentiation and bone resorption by stimulating IL-10 and TGF-β1 secretion from these cells. Therefore, Treg cell-derived IL-10 and TGF-β1 are likely involved in the regulation of E2 on bone metabolism and represent potential therapeutic targets for the treatment of postmenopausal osteoporosis (PMO).     

Regulation and production of IL-8 by human proximal tubular epithelial cells in vitro

A number of inflammatory kidney diseases are associated with interstitial nephritis and influx of leucocytes in the renal interstitium. Potentially the influx of neutrophils in the interstitium may be induced by the chemotactic cytokine IL-8. In the present study we have analysed the production of IL-8 by cultured human proximal tubular epithelial cells (PTEC) in response to a number of proinflammatory cytokines. Primary cell lines of proximal tubular epithelium obtained from ten different kidneys, and cultured under serum-free conditions, were found to produce IL-8 to different degrees from not detectable levels up to 10·8±1·5 ng IL-8 per 1×10⁵ cells in 72 h. Gel filtration chromatography of PTEC supernatant indicated that the size of IL-8 of PTEC is 15·1 and 8·1 kD, and is chemotactically active for polymorphonuclear neutrophils (PMN). Addition of 0·5 ng/ml rIL-1α or 1000 U/ml recombinant tumour necrosis factor-alpha (TNF-α) to the culture media of PTEC induced an up-regulation of IL-8 production up to 6·3-fold and 3·0-fold, respectively. The up-regulation by IL-1α and TNF-α was dose- and time-dependent. In contrast, 500 U/ml recombinant interferon-gamma (rIFN-γ) down-regulated the production of IL-8 3·4-fold. Northern blot analysis showed that IL-1α and TNF-α increased the expression of IL-8 mRNA, whereas IFN-γ reduced IL-8 mRNA expression. Taken together, these experiments indicate that human PTEC are a potential source of IL-8 in the kidney, and that IL-8 produced in the proximal tubule can be induced by various proinflammatory cytokines.     

Impairment of the hematological response and interleukin-1β production in protein-energy malnourished mice after endotoxemia with lipopolysaccharide

The objectives of this study were to determine if protein-energy malnutrition (PEM) could affect the hematologic response to lipopolysaccharide (LPS), the interleukin-1β (IL-1β) production, leukocyte migration, and blood leukocyte expression of CD11a/CD18. Two-month-old male Swiss mice were submitted to PEM (N = 30) with a low-protein diet (14 days) containing 4% protein, compared to 20% protein in the control group (N = 30). The total cellularity of blood, bone marrow, spleen, and bronchoalveolar lavage evaluated after the LPS stimulus indicated reduced number of total cells in all compartments studied and different kinetics of migration in malnourished animals. The in vitro migration assay showed reduced capacity of migration after the LPS stimulus in malnourished animals (45.7 ± 17.2 × 10⁴ cells/mL) compared to control (69.6 ± 7.1 × 10⁴ cells/mL, P ≤ 0.05), but there was no difference in CD11a/CD18 expression on the surface of blood leukocytes. In addition, the production of IL-1β in vivo after the LPS stimulus (180.7 pg·h⁻¹·mL⁻¹), and in vitro by bone marrow and spleen cells (41.6 ± 15.0 and 8.3 ± 4.0 pg/mL) was significantly lower in malnourished animals compared to control (591.1 pg·h⁻¹·mL⁻¹, 67.0 ± 23.0 and 17.5 ± 8.0 pg/mL, respectively, P ≤ 0.05). The reduced expression of IL-1β, together with the lower number of leukocytes in the central and peripheral compartments, different leukocyte kinetics, and reduced leukocyte migration capacity are factors that interfere with the capacity to mount an adequate immune response, being partly responsible for the immunodeficiency observed in PEM.     

Alterations in immune cell subsets and their cytokine secretion profile in childhood idiopathic thrombocytopenic purpura (ITP)

Immune thrombocytopenic purpura (ITP) is acquired autoimmune disease in children characterized by the breakdown of immune tolerance. This work is designed to explore the contribution of different lymphocyte subsets in acute and chronic ITP children. Imbalance in the T helper type 1 (Th1)/Th2 cytokine secretion profile was investigated. The frequency of T (CD3⁺, CD4⁺, CD8⁺) and B (CD19⁺) lymphocytes, natural killer (NK) (CD16⁺56⁺) and regulatory T (T_reg) [CD4⁺CD25^+highforkhead box protein 3 (FoxP3)⁺] cells was investigated by flow cytometry in 35 ITP children (15 acute and 20 chronic) and 10 healthy controls. Plasma levels of Th1 cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF-α)] and Th2 [interleukin (IL)-4, IL-6 and IL-10)] cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The percentage of T_reg (P < 0·001) and natural killer (NK) (P < 0·001) cells were significantly decreased in ITP patients compared to healthy controls. A negative correlation was reported between the percentage of T_reg cells and development of acute (r = −0·737; P < 0·01) and chronic (r = −0·515; P < 0·01) disease. All evaluated cytokines (IFN-γ, TNF-α, IL-4, IL-6 and IL-10) were elevated significantly in ITP patients (P < 0·001, P < 0·05, P < 0·05, P < 0·05 and P < 0·001, respectively) compared to controls. In conclusion, our data shed some light on the fundamental role of immune cells and their related cytokines in ITP patients. The loss of tolerance in ITP may contribute to the dysfunction of T_regs. Understanding the role of T cell subsets will permit a better control of autoimmunity through manipulation of their cytokine network.     

Increased Transforming Growth Factor-beta1 in Alcohol Dependence

Ethanol and its metabolite acetaldehyde increase transforming growth factor beta1 (TGF-β1) expression in animal studies. TGF-β1 is related with the hepatic stellate cell (the key element of hepatic fibrogenesis) and the radial glia (the key element of neuronal migration). Blood samples were collected from 41 patients with alcohol dependence, TGF-β1 levels measured by ELISA were compared with 41 normal subjects. Plasma TGF-β1 levels in the patients with alcohol dependence (1,653.11±532.45 pg/mL) were significantly higher than those of healthy subjects (669.87±366.53 pg/mL) (P=0.000). Patients with or without liver pathology showed no difference in TGF-β1 (P=0.36). Increased TGF-β1 may mediate deleterious effect of alcohol such as hepatic fibrosis and suppressed neuronal developments in alcohol dependence patients.