Laszlo Takacs

Publications of Laszlo Takacs

• Chronic obstructive pulmonary disease-specific gene expression signatures of alveolar macrophages as well as peripheral blood monocytes overlap and correlate with lung function.

  Authors: Szilard Poliska, Eszter Csanky, Attila Szanto, Istvan Szatmari, Bertalan Mesko, Lajos Szeles, Balazs Dezso, Beata Scholtz, Janos Podani, Iain Kilty, Laszlo Takacs, Laszlo Nagy

  Respiration; international review of thoracic diseases. 03/2011; 81(6):499-510.

  Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by progressive airflow limitation and significant extrapulmonary (systemic) effects that lead to co-morbidChronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by progressive airflow limitation and significant extrapulmonary (systemic) effects that lead to co-morbid conditions, though the pathomechanism of COPD is largely undetermined. Alveolar macrophages (AM) derived from peripheral monocytes (MO) appear to play a key role in initiating and/or sustaining disease progression. To identify disease- and cell type-specific gene expression profiles and potential overlaps in those in order to diagnose COPD, characterize its progression and determine the effect of drug treatment. Global gene expression analysis was used for primary screening in order to obtain expression signatures of AMs and circulating MOs of COPD patients and healthy controls. The results of microarray analyses of AMs (20 controls and 26 COPD patients) and MOs (16 controls and 22 COPD patients) were confirmed and validated by real-time quantitative polymerase chain reaction. We have identified gene sets specifically associated with COPD in AMs and MOs. There were overlapping genes between the two cell types. Our data also show that COPD-specific gene expression signatures in AMs and MOs correlate with percent of predicted FEV(1). Disease-specific and overlapping gene expression signatures can be defined in lung-derived macrophages and also in circulating monocytes. Some of the validated expression changes in both cell types correlate with lung function and therefore could serve as biomarkers of disease progression.

• Analyses of association between PPAR gamma and EPHX1 polymorphisms and susceptibility to COPD in a Hungarian cohort, a case-control study.

  Authors: Andras Penyige, Szilard Poliska, Eszter Csanky, Beata Scholtz, Balazs Dezso, Ivan Schmelczer, Iain Kilty, Laszlo Takacs, Laszlo Nagy

  BMC medical genetics. 11/2010; 11:152.

  In addition to smoking, genetic predisposition is believed to play a major role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Genetic association studies of new candidate genesIn addition to smoking, genetic predisposition is believed to play a major role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Genetic association studies of new candidate genes in COPD may lead to improved understanding of the pathogenesis of the disease. Two proposed casual single nucleotide polymorphisms (SNP) (rs1051740, rs2234922) in microsomal epoxide hydrolase (EPHX1) and three SNPs (rs1801282, rs1800571, rs3856806) in peroxisome proliferator-activated receptor gamma (PPARG), a new candidate gene, were genotyped in a case-control study (272 COPD patients and 301 controls subjects) in Hungary. Allele frequencies and genotype distributions were compared between the two cohorts and trend test was also used to evaluate association between SNPs and COPD. To estimate the strength of association, odds ratios (OR) (with 95% CI) were calculated and potential confounding variables were tested in logistic regression analysis. Association between haplotypes and COPD outcome was also assessed. The distribution of imputed EPHX1 phenotypes was significantly different between the COPD and the control group (P = 0.041), OR for the slow activity phenotype was 1.639 (95% CI = 1.08- 2.49; P = 0.021) in our study. In logistic regression analysis adjusted for both variants, also age and pack-year, the rare allele of His447His of PPARG showed significant association with COPD outcome (OR = 1.853, 95% CI = 1.09-3.14, P = 0.0218). In haplotype analysis the GC haplotype of PPARG (OR = 0.512, 95% CI = 0.27-0.96, P = 0.035) conferred reduced risk for COPD. The "slow" activity-associated genotypes of EPHX1 were associated with increased risk of COPD. The minor His447His allele of PPARG significantly increased; and the haplotype containing the minor Pro12Ala and the major His447His polymorphisms of PPARG decreased the risk of COPD.

• Antigen identification and characterization of lung cancer specific monoclonal antibodies produced by mAb proteomics.

  Authors: Dongdong Wang, Marina Hincapie, Mariana Guergova-Kuras, Janos Kadas, Laszlo Takacs, Barry L Karger

  Journal of proteome research. 02/2010; 9(4):1834-42.

  A mass spectrometric (MS)-based strategy for antigen (Ag) identification and characterization of globally produced monoclonal antibodies (mAbs) is described. Mice were immunized with a mixture ofA mass spectrometric (MS)-based strategy for antigen (Ag) identification and characterization of globally produced monoclonal antibodies (mAbs) is described. Mice were immunized with a mixture of native glycoproteins, isolated from the pooled plasma of patients with nonsmall cell lung cancer (NSCLC), to generate a library of IgG-secreting hybridomas. Prior to immunization, the pooled NSCLC plasma was subjected to 3-sequential steps of affinity fractionation, including high abundant plasma protein depletion, glycoprotein enrichment, and polyclonal antibody affinity chromatography normalization. In this paper, to demonstrate the high quality of the globally produced mAbs, we selected 3 mAbs of high differentiating power against a matched, pooled normal plasma sample. After production of large quantities of the mAbs from ascites fluids, Ag identification was achieved by immunoaffinity purification, SDS-PAGE, Western blotting, and MS analysis of in-gel digest products. One antigen was found to be complement factor H, and the other two were mapped to different subunits of haptoglobin (Hpt). The 2 Hpt mAbs were characterized in detail to assess the quality of the mAbs produced by the global strategy. The affinity of one of the mAbs to the Hpt native tetramer form was found to have a K(D) of roughly 10(-9) M and to be 2 orders of magnitude lower than the reduced form, demonstrating the power of the mAb proteomics technology in generating mAbs to the natural form of the proteins in blood. The binding of this mAb to the beta-chain of haptoglobin was also dependent on glycosylation on this chain. The characterization of mAbs in this work reveals that the global mAb proteomics process can generate high-quality lung cancer specific mAbs capable of recognizing proteins in their native state.

• Lipid metabolite levels of prostaglandin D(2) and eicosapentaenoic acid recovered from bronchoalveolar lavage fluid correlate with lung function of chronic obstructive pulmonary disease patients and controls.

  Authors: Ezster Csanky, Ralph Rühl, Beata Scholtz, Attila Vasko, Laszlo Takacs, William M Hempel

  Electrophoresis. 03/2009;

  One-step global profiling of analyte (mRNA, protein, metabolite) biomarkers may soon replace conventional blood and histological/biopsy diagnostics technologies. It is important to establish whetherOne-step global profiling of analyte (mRNA, protein, metabolite) biomarkers may soon replace conventional blood and histological/biopsy diagnostics technologies. It is important to establish whether the numerous blood and other body fluid-derived potential novel diagnostics will be sufficiently efficacious and precise to replace, for example, imaging and functional diagnostic tests. Currently, imaging technologies and spirometry are indispensable for the diagnosis and management of chronic obstructive pulmonary disease (COPD). To validate the concept of using body fluid biomarkers in COPD and to address the question of whether biomarker levels correlate with lung function, we measured the level of a number of biologically relevant lipids and metabolites in the bronchoalveolar lavage (BAL) fluid of COPD and control subjects and examined whether these correlate with numeric parameters of lung function. Both the diagnosis and management of COPD rely on costly and labor intensive lung function tests. Thus, there is an imminent need to replace the current diagnostic approaches with simpler clinical assays. As a first step, we demonstrate proof of principle; the correlation of lipid biomarkers as measured by LC-MS with lung function. In the apparently BAL-accessible fluid compartment, the total recovered lipid metabolite amount, particularly prostaglandin D(2) and eicosapentaenoic acid show a remarkable linear correlation with lung function (R(2)>0.7). The study outcome is encouraging for the continuation of the work toward the measurement of lipid metabolite levels in more easily obtainable biological fluids such as sputum, exhaled air condensate, urine and plasma.

• Monoclonal antibody proteomics: discovery and prevalidation of chronic obstructive pulmonary disease biomarkers in a single step.

  Authors: Eszter Csanky, Petra Olivova, Eva Rajnavolgyi, William Hempel, Nadege Tardieu, Elesne Toth Katalin, Anne Jullien, Carole Malderez-Bloes, Mariana Kuras, Manuel X Duval, Laszlo Nagy, Beata Scholtz, William Hancock, Barry Karger, András Guttman, Laszlo Takacs

  Electrophoresis. 01/2008; 28(23):4401-6.

  We define mAb proteomics as the global generation of disease specific antibodies that permit mass screening of biomarkers. An integrated, high-throughput, disease-specific mAb-based biomarkerWe define mAb proteomics as the global generation of disease specific antibodies that permit mass screening of biomarkers. An integrated, high-throughput, disease-specific mAb-based biomarker discovery platform has been developed. The approach readily provided new biomarker leads with the focus on large-scale discovery and production of mAb-based, disease-specific clinical assay candidates. The outcome of the biomarker discovery process was a highly specific and sensitive assay, applicable for testing of clinical validation paradigms, like response to treatment or correlation with other clinical parameters. In contrast to MS-based or systems biology-based strategies, our process produced prevalidated clinical assays as the outcome of the discovery process. By re-engineering the biomarker discovery paradigm, the encouraging results presented in this paper clearly demonstrate the efficiency of the mAb proteomics approach, and set the grounds for the next steps of studies, namely, the hunt for candidate biomarkers that respond to drug treatment.