Anna Lundberg

Influence of early gut microbiota on the maturation of childhood mucosal and systemic immune responses

Introduction Among sensitized infants, those with high, as compared with low levels, of salivary secretory IgA (SIgA) are less likely to develop allergic symptoms. Also, early colonization with certain gut microbiota, e.g. Lactobacilli and Bifidobacterium species, might be associated with less allergy development. Although animal and in vitro studies emphasize the role of the commensal gut microbiota in the development of the immune system, the influence of the gut microbiota on immune development in infants is unclear.

Advice to follow a low-carbohydrate diet has a favourable impact on low-grade inflammation in type 2 diabetes compared with advice to follow a low-fat diet

Abstract Background. Inflammation may play an important role in type 2 diabetes. It has been proposed that dietary strategies can modulate inflammatory activity. Methods. We investigated the effects of diet on inflammation in type 2 diabetes by comparing a traditional low-fat diet (LFD) with a low-carbohydrate diet (LCD). Patients with type 2 diabetes were randomized to follow either LFD aiming for 55–60 energy per cent (E%) from carbohydrates (n = 30) or LCD aiming for 20 E% from carbohydrates (n = 29). Plasma was collected at baseline and after 6 months. C-reactive protein (CRP), interleukin-1 receptor antagonist (IL-1Ra), IL-6, tumour necrosis factor receptor (TNFR) 1 and TNFR2 were determined. Results. Both LFD and LCD led to similar reductions in body weight, while beneficial effects on glycaemic control were observed in the LCD group only. After 6 months, the levels of IL-1Ra and IL-6 were significantly lower in the LCD group than in the LFD group, 978 (664–1385) versus 1216 (974–1822) pg/mL and 2.15 (1.65–4.27) versus 3.39 (2.25–4.79) pg/mL, both P < 0.05. Conclusions. To conclude, advice to follow LCD or LFD had similar effects on weight reduction while effects on inflammation differed. Only LCD was found significantly to improve the subclinical inflammatory state in type 2 diabetes. Trial registration: ClinicalTrials.gov identifier: NCT01005498.

Lipopolysaccharide-Induced Immune Responses in Relation to the TLR4(Asp299Gly) Gene Polymorphism

ABSTRACT Altered microbial exposure is a possible explanation for the increase of allergies in the Western world. However, genetic factors influence microbially induced immune responses. We have investigated the TLR4(Asp299Gly) gene polymorphism and its possible association with receptor expression of circulating peripheral blood monocytes and the in vitro cytokine responses and phosphorylation of intracellular signaling proteins in peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide (LPS) from Escherichia coli and Salmonella enterica serotype Typhimurium. We studied 34 of the predominant haplotype TLR4 Asp299 (AA) and 8 heterozygote Asp299Gly (AG) individuals. TLR4 expression levels were similar in the two genotype groups. Serovar Typhimurium LPS induced interleukin-12p70 from PBMC, and the degree of phosphorylation of the intracellular signaling protein IκBα in PBMC was lower in the AG than the AA group (P = 0.03 and P = 0.04, respectively). These results were not seen, however, when PMBC were stimulated with E. coli-derived LPS. Based on these results, we propose that TLR4(Asp299Gly) gene polymorphism and the bacterial origin of LPS should be considered when environmental LPS exposure is evaluated in disease risk or protection.

Lutein exerts anti-inflammatory effects in patients with coronary artery disease

BACKGROUND AND AIMSnMany coronary artery disease (CAD) patients exhibit chronic low-grade inflammation. Carotenoids are anti-oxidants with potential anti-inflammatory properties. Here, we first assessed relationships between interleukin (IL)-6 and individual carotenoids in plasma from CAD patients. Based on the results, we proceeded to assess anti-inflammatory effects of one carotenoid, lutein, in peripheral blood mononuclear cells (PBMCs) from CAD patients.nnnMETHODSnLuteinxa0+xa0zeaxanthin (isomers with lutein being dominant), β-cryptoxanthin, lycopene, α- and β-carotene and IL-6 were measured in plasma from 134 patients with stable angina (SA) and 59 patients with acute coronary syndrome. In 42 patients, plasma measurements were also performed 3 months after coronary intervention. PBMCs from SA patients were pre-treated with lutein (1, 5 and 25xa0μM) for 24xa0h followed by 24xa0h incubationxa0±xa0lipopolysaccharide (LPS). Cell pellets were collected for IL-6, IL-1β and TNF mRNA and intracellular lutein. Cytokine secretion was measured in cell media.nnnRESULTSnOnly luteinxa0+xa0zeaxanthin were inversely correlated with IL-6 in SA patients at baseline (rxa0=xa0-0.366, pxa0<xa00.001) and follow-up (rxa0=xa0-0.546, pxa0<xa00.001). Exxa0vivo, lutein was taken up by PBMCs from SA patients in a dose- and time-dependent manner. Pre-treatment with lutein dose-dependently lowered LPS-induced secretion of IL-6, IL-1β (pxa0<xa00.01) and TNF (pxa0<xa00.05), and also reduced IL-6, IL-1β and TNF mRNA expression (pxa0<xa00.05).nnnCONCLUSIONSnClinical findings highlighted the inverse association between lutein and IL-6 in CAD patients. Anti-inflammatory effects of lutein in PBMCs from CAD patients were consolidated in exxa0vivo experiments. Taken together, these results show that lutein has the potential to play a role in resolution of chronic inflammation in CAD patients.

Activation-induced FOXP3 isoform profile in peripheral CD4+ T cells is associated with coronary artery disease

BACKGROUND AND AIMSnThe expression of FOXP3 isoforms affects regulatory T (Treg) cell function. Reduced Treg cell function has been associated with coronary artery disease (CAD). However, alternative splicing of FOXP3 in CAD has not been investigated.nnnMETHODSnFOXP3 splice variants and IL17A transcripts in peripheral blood mononuclear cells from stable CAD patients and healthy controls were quantified, and FOXP3 isoform expression in response to T cell receptor (TCR) stimulation or LDL was analyzed by flow cytometry.nnnRESULTSnCompared to healthy controls, CAD patients expressed significantly more FOXP3 transcripts that included exon 2, whereas alternative splicing of exon 7 in correlation with IL17A expression was reduced. Moreover, TCR stimulation, as well as exposure to LDL, decreased alternative splicing of FOXP3 in CD4+ T cells inxa0vitro.nnnCONCLUSIONSnOur results demonstrate that blood mononuclear cells in stable CAD patients express a ratio of FOXP3 isoforms that is characteristic for activated CD4+ T cells.

Stress-induced release of matrix metalloproteinase-9 in patients with coronary artery disease: The possible influence of cortisol

Stress and inflammation are both important risk factors for coronary artery disease (CAD). However, the susceptibility to stress-induced inflammation and its determinants have been little explored in patients with CAD. Here, our aim was to study the stress-induced inflammatory response, more precisely the early release of matrix metalloproteinase (MMP)-9, and its association with cortisol response in patients with CAD. Sixty-four patients underwent a standardized laboratory stress test. The stress-induced release of MMP-9 was closely associated with the release of other neutrophil-associated proteins, MMP-8 and myeloperoxidase (MPO). It also showed a large variation among patients, as did cortisol. Twenty minutes after stress, a negative association between changes in MMP-9 and cortisol was seen (p<0.01). In vitro, dexamethasone reduced the IL-8-mediated release of MMP-9 from neutrophils, indicating that glucocorticoids may exert rapid effects on neutrophil activation. Further characterization of patients revealed that stress-induced release of MMP-9 was related to leukocyte telomere shortening and increased ultrasound-assessed plaque occurrence in the carotid arteries, but not to other characteristics such as age, gender or psychological background factors. The susceptibility to stress-induced release of MMP-9 may thus have impact on disease phenotype. Stress tests can be useful to identify CAD patients in need of novel prevention and treatment strategies.

Overexpression of MMP-9 and Its Inhibitors in Blood Mononuclear Cells after Myocardial Infarction - Is It Associated with Depressive Symptomatology?

Background Matrix metalloproteinase (MMP)-9 may play a central role in the development and progression of atherosclerosis. Emerging evidence also indicates an association between MMP-9 and depressive symptomatology. Here, we investigated whether expression of MMP-9 and its inhibitors in blood mononuclear cells and plasma were related to depressive symptoms in patients with a recent myocardial infarction (MI). Methods and Results Blood sampling was performed between 6 and 18 months after MI in 57 patients. Forty-one clinically healthy subjects were included as controls. Gene expression of MMP-9 and its main tissue inhibitors TIMP-1 and -2 were analyzed in freshly isolated or cultured blood mononuclear cells. Corresponding protein levels were assessed in cell supernatants and plasma. In post-MI patients, mRNA levels of MMP-9 and TIMP-1 and -2 were significantly higher than in controls while protein levels in cell supernatants and plasma did not differ between groups. The Center for Epidemiological Studies - Depression (CES-D) scale was used to assess depressive symptomatology. Repeated assessments during the first 18 months after MI showed significantly higher CES-D scores in patients compared with controls. However, there were no relationships between depressive mood and any of the measurements of MMP-9 or TIMPs. Conclusion Our findings indicate that overexpression of MMP-9 and TIMPs in blood mononuclear cells and elevated depressive symptoms represent two unrelated phenomena after MI.

Annexin A1 in blood mononuclear cells from patients with coronary artery disease: Its association with inflammatory status and glucocorticoid sensitivity

Annexin A1 (AnxA1) is a key player in resolution of inflammation and a mediator of glucocorticoid actions. In atherosclerotic tissue, increased expression of AnxA1 has been associated with protective plaque-stabilizing effects. Here, we investigated the expression of AnxA1 in peripheral blood mononuclear cells (PBMCs) from patients with coronary artery disease (CAD). Blood was collected from 57 patients with stable CAD (SCAD) and 41 healthy controls. We also included a minor group (n = 10) with acute coronary syndrome (ACS). AnxA1 mRNA was measured in PBMCs. Expression of AnxA1 protein (total and surface-bound) and glucocorticoid receptors (GR) were detected in PBMC subsets by flow cytometry. Also, salivary cortisol, interleukin(IL)-6 and IL-10 in plasma, and LPS-induced cytokine secretion from PBMCs, with or without dexamethasone, were assessed. AnxA1 mRNA was found to be slightly increased in PBMCs from SCAD patients compared with controls. However, protein expression of AnxA1 or GRs in PBMC subsets did not differ between SCAD patients and controls, despite SCAD patients showing a more proinflammatory cytokine profile ex vivo. Only surface expression of AnxA1 on monocytes correlated with dexamethasone-mediated suppression of cytokines. In ACS patients, a marked activation of AnxA1 was seen involving both gene expression and translocation of protein to cell surface probably reflecting a rapid glucocorticoid action modulating the acute inflammatory response in ACS. To conclude, surface expression of AnxA1 on monocytes may reflect the degree of glucocorticoid sensitivity. Speculatively, “normal” surface expression of AnxA1 indicates that anti-inflammatory capacity is impaired in SCAD patients.

Glucocorticoid sensitivity and inflammatory status of peripheral blood mononuclear cells in patients with coronary artery disease

Abstract Objective: Mechanisms behind sustained inflammation in patients with coronary artery disease (CAD) are not clarified but hypothalamus-pituitary-adrenal (HPA) axis dysfunction may have a role. Here, we investigated whether inflammatory status of peripheral blood mononuclear cells (PBMCs) was associated with altered glucocorticoid sensitivity in CAD patients. Methods: In 55 CAD patients and 30 controls, mRNA levels of GR-α, GR-β, NF-κB, IκBα, MMP-9 and TIMP-1 were measured in PBMCs. Suppressive effects of dexamethasone on GR-α, GR-β, NF-κB, IκBα, MMP-9 and TIMP-1 mRNA levels were assessed in PBMCs ex vivo. Salivary cortisol was repeatedly measured over 3 days. Results: GR-α mRNA levels were higher in CAD patients than in controls, 0.50 (0.38–0.59) versus 0.26 (0.18–0.37), pu2009<u2009.001, while GR-β mRNA levels were equally low in both groups. GR-α mRNA expression was associated with inflammatory gene expression and, also, with flatter diurnal cortisol rhythm. In both patients and controls, dexamethasone suppressed gene expression of NF-κB, IκBα, MMP-9 and TIMP-1 (pu2009<u2009.001). Dexamethasone also reduced GR-α mRNA levels (pu2009<u2009.001), while LPS increased it (pu2009<u2009.001). Conclusions: PBMCs from CAD patients displayed an inflammatory gene expression profile. This was not explained by reduced glucocorticoid sensitivity. Instead, inflammation was associated with increased expression of GR-α mRNA, suggesting a hypocortisolemic state. Key messages u2009u2003•u2003Peripheral blood mononuclear cells from patients with coronary artery disease (CAD) display an inflammatory gene expression profile. u2009u2003•u2003This inflammatory state cannot be explained by reduced glucocorticoid sensitivity in CAD patients. u2009u2003•u2003Instead, the inflammatory gene expression profile is associated with upregulated levels of glucocorticoid receptor-α mRNA, suggesting a hypocortisolemic state.

Soluble Fas ligand is associated with natural killer cell dynamics in coronary artery disease

OBJECTIVEnApoptosis of natural killer (NK) cells is increased in patients with coronary artery disease (CAD) and may explain why NK cell levels are altered in these patients. Soluble forms of Fas and Fas ligand (L) are considered as markers of apoptosis. Here, we investigated whether plasma levels of Fas and FasL were associated with NK cell apoptosis and NK cell levels in CAD patients.nnnMETHODSnFas and FasL in plasma were determined by ELISA in 2 cohorts of CAD patients; one longitudinal study measuring circulating NK cells and apoptotic NK cells by flow cytometry 1 day, 3 months and 12 months after a coronary event and one cross-sectional study measuring NK cell apoptosis ex vivo. Both studies included matched healthy controls. Fas and FasL were also determined in supernatants from NK cells undergoing cytokine-induced apoptosis in cell culture.nnnRESULTSnIn the 12-month longitudinal study, plasma FasL increased by 15% (p<0.001) and NK cell levels by 31% (p<0.05) while plasma Fas did not change. Plasma FasL and NK cell levels were significantly related at 3 months and 12 months, r=0.40, p<0.01. Furthermore, plasma FasL, but not plasma Fas, correlated with NK cell apoptosis ex vivo in CAD patients, r=0.54, p<0.05. In vitro, cytokine-induced apoptosis of NK cells resulted in abundant release of FasL.nnnCONCLUSIONnIn CAD patients, FasL in plasma is associated with both apoptotic susceptibility of NK cells and dynamic changes in circulating NK cells. NK cells are also themselves a potential source of soluble FasL. Our findings link NK cell status to a soluble marker with possible atheroprotective effects thereby supporting a beneficial role of NK cells in CAD.