Zsolt István Komlósi

INCREASED INTERFERON-GAMMA- AND INTERLEUKIN-4-SYNTHESIZING SUBSETS OF CIRCULATING T LYMPHOCYTES IN PREGNANT ASTHMATICS

Background Pregnancy frequently interferes with the course of bronchial asthma, and asthmatic pregnant women experience less successful pregnancies. T lymphocytes synthesizing IL‐4 or IFN‐γ are important in allergic mechanisms of the airways as well as in materno‐fetal immunity.

Galectin-9 in allergic airway inflammation and hyper-responsiveness in mice.

Background: Galectin-9 (Gal-9) is a member of the growing family of β-galactoside-binding lectins. Gal-9 is an eosinophil chemoattractant and inducer of Th1 cell apoptosis. These effects suggest its potential role in the pathogenesis of asthma. Our aim was to study the expression of Gal-9 in an ovalbumin (OVA)-induced mouse model of allergic asthma. Methods: To investigate the significance of Gal-9 in allergic inflammation and airway hyperresponsiveness (AHR), a group of BALB/c mice was sensitized and challenged with OVA (GOVA). Another group of animals was allergized with OVA and also treated with dexamethasone (DEX) (GOVA+DEX). The control group (GPBS) received phosphate-buffered saline instead of OVA as placebo. Airway reactivity to intravenous methacholine was assessed. Results: The percentage of Gal-9-positive cells and their intracellular Gal-9 content and Th1/Th2 cytokine levels in the bronchoalveolar lavage (BAL) were determined by flow cytometry. Gal-9 mRNA expression and protein level were measured in the lung tissue by real-time RT-PCR and Western blot. In GOVA mice, airway inflammation and mucus hypersecretion developed. DEX treatment inhibited the main features of experimental asthma. The number of Gal-9-positive lymphocytes, eosinophil and neutrophil granulocytes and the levels of Th2 cytokines were higher in the BAL of GOVA compared to GPBS or GOVA+DEX mice. Moreover, Gal-9 protein level was elevated in the lungs of GOVA mice. Conclusions: These results suggest that Gal-9 plays a role as a mediator contributing to the development of allergic airway inflammation. Gal-9 may serve as a recruiter of eosinophil granulocytes and promoter of Th2 dominance.

Gene expression profiling of experimental asthma reveals a possible role of paraoxonase-1 in the disease

In this study, we aimed to identify novel genes involved in experimental and human asthma, importance of which has not yet been recognized. In an ovalbumin-induced murine model of asthma, we applied microarray gene expression analysis at different time points after allergen challenges. Advanced statistical methods were used to relate gene expression changes to cellular processes and to integrate our results into multiple levels of information available in public databases. At 4 h after the first allergen challenge, gene expression pattern reflected mainly an acute, but non-atopic, inflammatory response and strong chemotactic activity. At 24 h after the third allergen challenge, gene set enrichment analysis revealed significant over-representation of gene sets corresponding to T(h)2-type inflammation models. Among the top down-regulated transcripts, an anti-oxidant enzyme, paraoxonase-1 (PON1), was identified. In human asthmatic patients, we found that serum PON1 activity was reduced at exacerbation, but increased parallel with improving asthma symptoms. PON1 gene polymorphisms did not influence the susceptibility to the disease. Our observations suggest that an altered PON1 activity might be involved in the pathogenesis of asthma, and serum PON1 level might be used for following up the effect of therapy.

Lipopolysaccharide exposure makes allergic airway inflammation and hyper-responsiveness less responsive to dexamethasone and inhibition of iNOS.

Allergic airway disease can be refractory to anti‐inflammatory treatment, whose cause is unclarified. Therefore, in the present experiment, we have tested the hypothesis that co‐exposure to lipopolysacharide (Lps) and allergen results in glucocorticoid‐resistant eosinophil airway inflammation and hyper‐responsiveness (AHR). Ovalbumin (Ova)‐sensitized BALB/c mice were primed with 10 μg intranasal Lps 24 h before the start of Ova challenges (20 min on 3 consecutive days). Dexamethasone (5 mg/kg/day) was given on the last 2 days of Ova challenges. AHR, cellular build‐up, cytokine and nitrite concentrations of bronchoalveolar lavage fluid (BALF) and lung histology were examined. To assess the role of iNOS‐derived NO in airway responsiveness, mice were treated with a selective inhibitor of this enzyme (1400W) 2 h before AHR measurements. More severe eosinophil inflammation and higher nitrite formation were found in Lps‐primed than in non‐primed allergized mice. After Lps priming, AHR and concentrations of T‐helper type 2 cytokines in BALF were decreased, but still remained significantly higher than in controls. Eosinophil inflammation was partially, while nitrite production and AHR were observed to be largely dexamethasone resistant in Lps‐primed allergized animals. 1400W effectively and rapidly diminished the AHR in Ova‐sensitized and challenged mice, but failed to affect it after Lps priming plus allergization. In conclusion, Lps inhalation may exaggerate eosinophil inflammation and reduce responsiveness to anti‐inflammatory treatment in allergic airway disease.

Cisplatin nephrotoxicity aggravated by cardiovascular disease and diabetes in lung cancer patients

Ageing lung cancer patients may be at increased risk of Cisplatin (Cp) nephrotoxicity, because of comorbidities leading to accelerated ageing of the kidneys. Therefore, the Cp-induced impairement of renal function was compared between no comorbidity (NC) and hypertension plus ischaemic heart disease (CD) patients or others having diabetes mellitus plus ischaemic heart disease (DMIH). In a preliminary study, glomerular filtration rate (GFR) was measured by clearance of technetium 99m-labelled diethylene-thiamine penta-acetate in 38 lung cancer patients with normal serum creatinine concentration ([creat]). Then, the incidence of nephrotoxicity was analysed retrospectively over 1st–4th cycles of Cp treatment among 242 lung cancer patients with initially normal [creat]. GFR was repeatedly estimated using calculated creatinine clearance. Pre-treatment GFR was 57±3 mL·min−1·m−2 in those with normal (n = 15) and 42±2 mL·min−1·m−2 in those with pathologically increased (n = 23) [creat] any time following their 2nd–4th Cp cycle (p<0.05). The retrospective analysis revealed that Cp-induced nephrotoxicity developed in 7.5% of the NC (n = 80), in 20.9% of the CD (n = 110) and in 30.8% of the DMIH (n = 52) subgroups. Within the overall dropout rate from further Cp chemotherapy, nephrotoxicity was responsible in 14% of NC, 38% in CD and 75% in DMIH patients. A major portion of our ageing lung cancer patients suffered from comorbidities leading to reduced renal resistance to Cp nephrotoxicity.

Human CD40 ligand–expressing type 3 innate lymphoid cells induce IL-10–producing immature transitional regulatory B cells

Background: Type 3 innate lymphoid cells (ILC3s) are involved in maintenance of mucosal homeostasis; however, their role in immunoregulation has been unknown. Immature transitional regulatory B (itBreg) cells are innate‐like B cells with immunosuppressive properties, and the in vivo mechanisms by which they are induced have not been fully clarified. Objective: We aimed to investigate the ILC3–B‐cell interaction that probably takes place in human tonsils. Methods: ILC3s were isolated from peripheral blood and palatine tonsils, expanded, and cocultured with naive B cells. Tonsillar ILC3s and regulatory B cells were visualized with immunofluorescence histology. ILC3 frequencies were measured in tonsil tissue of allergic and nonallergic patients and in peripheral blood of allergic asthmatic patients and healthy control subjects. Results: A mutually beneficial relationship was revealed between ILC3s and B cells: ILC3s induced IL‐15 production in B cells through B cell–activating factor receptor, whereas IL‐15, a potent growth factor for ILC3s, induced CD40 ligand (CD40L) expression on circulating and tonsillar ILC3s. IL‐15–activated CD40L+ ILC3s helped B‐cell survival, proliferation, and differentiation of IL‐10–secreting, PD‐L1–expressing functional itBreg cells in a CD40L‐ and B cell–activating factor receptor–dependent manner. ILC3s and regulatory B cells were in close connection with each other in palatine tonsils. ILC3 frequency was reduced in tonsil tissue of allergic patients and in peripheral blood of allergic asthmatic patients. Conclusion: Human CD40L+ ILC3s provide innate B‐cell help and are involved in an innate immunoregulatory mechanism through induction of itBreg cell differentiation, which takes place in palatine tonsils in vivo. This mechanism, which can contribute to maintenance of immune tolerance, becomes insufficient in allergic diseases. GRAPHICAL ABSTRACT Figure. No caption available.

Association Study with 77 SNPs Confirms the Robust Role for the rs10830963/G of MTNR1B Variant and Identifies Two Novel Associations in Gestational Diabetes Mellitus Development

Context Genetic variation in human maternal DNA contributes to the susceptibility for development of gestational diabetes mellitus (GDM). Objective We assessed 77 maternal single nucleotide gene polymorphisms (SNPs) for associations with GDM or plasma glucose levels at OGTT in pregnancy. Methods 960 pregnant women (after dropouts 820: case/control: m99’WHO: 303/517, IADPSG: 287/533) were enrolled in two countries into this case-control study. After genomic DNA isolation the 820 samples were collected in a GDM biobank and assessed using KASP (LGC Genomics) genotyping assay. Logistic regression risk models were used to calculate ORs according to IADPSG/m’99WHO criteria based on standard OGTT values. Results The most important risk alleles associated with GDM were rs10830963/G of MTNR1B (OR = 1.84/1.64 [IADPSG/m’99WHO], p = 0.0007/0.006), rs7754840/C (OR = 1.51/NS, p = 0.016) of CDKAL1 and rs1799884/T (OR = 1.4/1.56, p = 0.04/0.006) of GCK. The rs13266634/T (SLC30A8, OR = 0.74/0.71, p = 0.05/0.02) and rs7578326/G (LOC646736/IRS1, OR = 0.62/0.60, p = 0.001/0.006) variants were associated with lower risk to develop GDM. Carrying a minor allele of rs10830963 (MTNR1B); rs7903146 (TCF7L2); rs1799884 (GCK) SNPs were associated with increased plasma glucose levels at routine OGTT. Conclusions We confirmed the robust association of MTNR1B rs10830963/G variant with GDM binary and glycemic traits in this Caucasian case-control study. As novel associations we report the minor, G allele of the rs7578326 SNP in the LOC646736/IRS1 region as a significant and the rs13266634/T SNP (SLC30A8) as a suggestive protective variant against GDM development. Genetic susceptibility appears to be more preponderant in individuals who meet both the modified 99’WHO and the IADPSG GDM diagnostic criteria.

Frequencies of four ATP-binding cassette transporter G8 polymorphisms in patients with ischemic vascular diseases.

ATP-binding cassette transporter G8 (ABCG8) was found to participate in plant sterol and cholesterol (CHOL) transport; however, the potential associations of ABCG8 genetic variants and ischemic vascular diseases are largely unknown. Determinations of allele frequencies of four common ABCG8 polymorphisms (D19H, Y54C, T400K, and A632V) were carried out in 241 unrelated patients with ischemic stroke, 148 patients with coronary heart disease, and 191 blood donors (controls). Allele frequencies of the investigated polymorphisms in patient groups showed no significant differences compared with controls. There was a tendency toward reduced 54YY-genotype frequency among male patients with stroke. On stratification by age at disease onset, male patients with stroke under the age of 50 (n = 62) showed significantly reduced 54YY-frequency compared with male controls (n = 92; 24.2% vs. 41.3%; odds ratio: 0.45 [95% confidence intervals: 0.22-0.93]; p = 0.038). No such associations were found among women. In healthy controls, CHOL levels of individuals with the 54YY genotype (n = 71; median: 4.51 mM, 25th-75th percentiles: 4.19-5.43) were significantly reduced compared with 54YC and 54CC individuals combined (n = 120; median: 4.95 mM, 25th-75th percentiles: 4.42-5.88, p = 0.009). Further, we identified a new ABCG8-variant, T401S, in a control subject. In conclusion, ABCG8 54YY-genotype may be a potential protecting factor against ischemic stroke in young men and may influence plasma CHOL levels.

Increased synthesis of vascular endothelial growth factor in allergic airway inflammation in histidine decarboxylase knockout (HDC(-/-)) mice.

ABSTRACT Histamine and vascular endothelial growth factor (VEGF) have been implicated in the pathogenesis of allergic asthma; they enhance inflammation, vascular permeability, and mucus secretion. Histamine was suggested to alter the level of VEGF via the H2 receptors. Here the authors have applied histidine decarboxylase gene-targeted (HDC−/−) mice, lacking histamine, to investigate the effect of histamine deficiency on VEGF expression in an animal model of asthma. HDC−/− and wild-type (WT) mice were sensitized and challenged with ovalbumin (OVA). VEGF mRNA expression and protein level were determined in the lung. Number of VEGF-positive immune cells of bronchoalveolar lavage (BAL) and their intracellular VEGF content were measured by flow cytometry. VEGF protein level in the lung and in the BAL cells was increased in OVA treated (HDC−/−ova as well as in WTova) animals compared to their controls. However, there was no difference in the VEGF levels between HDC−/− or WT animals, either in the lung or in the BAL cells. In conclusion, increased VEGF production of the lung or BAL immune cells can be induced by allergen provocation independently from the genetic background of the animals. These data suggest that VEGF-mediated allergic processes can persist in the absence of histamine.