21 research outputs found

    Design and study protocol of the maternal smoking cessation during pregnancy study, (M-SCOPE)

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    <p>Abstract</p> <p>Background</p> <p>Maternal smoking is the most significant cause of preventable complications during pregnancy, with smoking cessation during pregnancy shown to increase birth weight and reduce preterm birth among pregnant women who quit smoking. Taking into account the fact that the number of women who smoke in Greece has increased steadily throughout the previous decade and that the prevalence of smoking among Greek females is one of the highest in the world, smoking cessation should be a top priority among Greek health care professionals.</p> <p>Methods/Design</p> <p>The Maternal Smoking Cessation during Pregnancy Study (M-SCOPE), is a Randomized Control Trial (RCT) that aims to test whether offering Greek pregnant smokers a high intensity intervention increases smoking cessation during the third trimester of pregnancy, when compared to a low intensity intervention. Prospective participants will be pregnant smokers of more than 5 cigarettes per week, recruited up to the second trimester of pregnancy. Urine samples for biomarker analysis of cotinine will be collected at three time points: at baseline, at around the 32<sup>nd </sup>week of gestation and at six months post partum. The control group/low intensity intervention will include: brief advice for 5 minutes and a short leaflet, while the experimental group/intensive intervention will include: 30 minutes of individualized cognitive-behavioural intervention provided by a trained health professional and a self-help manual especially tailored for smoking cessation during pregnancy, while counselling will be based on the ''5 As.'' After childbirth, the infants' birth weight, gestational age and any other health related complications during pregnancy will be recorded. A six months post-partum a follow up will be performed in order to re-assess the quitters smoking status.</p> <p>Discussion</p> <p>If offering pregnant smokers a high intensity intervention for smoking cessation increases the rate of smoking cessation in comparison to a usual care low intensity intervention in Greek pregnant smokers, such a scheme if beneficial could be implemented successfully within clinical practice in Greece.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier <a href="http://www.clinicaltrials.gov/ct2/show/NCT01210118">NCT01210118</a></p

    Pathogenicity of a human thyroglobulin peptide (2340–2359) in mice with high or low genetic susceptibility to thyroiditis

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    We have previously identified a 20-mer peptide of human thyroglobulin (hTg), p2340 (aa2340–2359), which induced experimental autoimmune thyroiditis (EAT) in AKR/J (H-2k) and HLA-DR3 transgenic mice. In this study, we investigated the thyroiditogenic potential of p2340 in ‘high responder’ CBA/J (H-2k) and SJL/J (H-2s) or ‘low responder’ C57BL/6 (H-2b) and BALB/c (H-2d) mice. Mice were immunized subcutaneously with 100 nmol of p2340 in complete Freund's adjuvant (CFA) and both the proliferative capacity of their lymph node cells in the presence of p2340 or intact Tg and the production of peptide-specific antibodies were investigated. The p2340 peptide was found to contain B-cell and non-dominant T-cell epitope(s) in all strains tested. Moreover, it elicited EAT in CBA/J (2/6, infiltration index (I.I.) 1) and SJL/J (5/5, I.I. 1-3) mice after direct challenge and in BALB/c (4/7, I.I. 1) and C57BL/6 (1/5, I.I. 1) after adoptive transfer of p2340-primed lymph node cells. P2340 is the first Tg peptide found to be pathogenic in low as well as high responder mouse strains and thus will allow us to investigate mechanisms of EAT induction in a genetically resistant host

    Natural autoimmunity in oligoarticular juvenile idiopathic arthritis

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    Abstract Oligoarticular juvenile idiopathic arthritis (oligo-JIA) is classically thought of as an antigen-driven lymphocyte-mediated autoimmune disease. Considering the major immunoregulatory role of natural antibodies (NAbs) in homeostasis and autoimmune pathogenesis, we designed this study to further elucidate their role in oligo-JIA pathogenesis. To this end, 70 children with oligo-JIA and 20 healthy matched controls were enrolled in the study. Serum IgM and IgA antibodies against human G-actin, human IgG F(ab΄)2 fragments and the hapten TriNitroPhenol (TNP) were measured by in-house enzyme-immunoassays. In addition, total concentration for serum IgM and IgA was also measured by ELISA and in cases where significant differences were observed between groups, the ratio of NAbs levels to the total IgM and IgA concentrations was used for comparisons. The ratios of IgA anti-TNP, anti-actin and anti-F(ab΄)2 levels to total serum IgA concentration were found to be significantly increased in patients with oligo-JIA compared to healthy subjects. Significantly elevated levels of IgM anti-TNP antibodies were also found in children with inactive oligo-JIA compared to those of children with active disease and healthy controls. In the presence of anterior uveitis, IgM anti-TNP levels were significantly higher than in patients without uveitis or in healthy controls. Backward regression analysis revealed than the disease activity and the presence of anterior uveitis independently affect IgM anti-TNP levels. Our findings are in accordance with the hypothesis that NAbs contribute to the pathogenesis of autoimmune diseases and provide additional evidence that disturbances in natural autoimmunity may contribute to the as yet unclarified pathogenesis of oligo-JIA.</jats:p

    Changes in N-Glycosylation Induced By Somatic Hypermutation Modulate the Antigen Reactivity of the Immunoglobulin Receptors in CLL Stereotyped Subset #201

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    The IGHV4-34 gene is intrinsically autoreactive due to carrying a germline(GL)-encoded (super)antigenic motif binding various self (and exogenous) antigens, while it is one of the few IGHV genes that contain a GL-encoded N-glycosylation (N-glyc) site. IGHV4-34 is overrepresented in chronic lymphocytic leukemia (CLL), particularly in cases expressing B cell receptor immunoglobulin (BcR IG) with a significant load of somatic hypermutation (SHM; 'mutated' CLL, M-CLL). Moreover, a large fraction of IGHV4-34 M-CLL cases are clustered in different stereotyped subsets, of which the best studied is subset #4, the largest within M-CLL, defined by the expression of IgG-switched IGHV4-34/IGKV2-30 BcR IG with a distinctive SHM imprint. Considerably smaller than subset #4 is subset #201, defined by the expression of IGHV4-34/IGLV1-44 BcR IG of the IgMD isotype. Subset #201 is noteworthy owing to recurrent replacement SHMs that frequently lead to the creation of novel N- glyc motifs within the VH domain. This may be functionally relevant, considering that N-linked glycosylation is a widespread post-translational modification that is largely SHM-induced during antigen-specific immune responses and can modulate antibody (Ab) affinity towards antigen. That said, nothing is yet known about the antigen reactivity of subset #201 BcR IG and whether/how it could be affected through SHM-induced changes of N-linked glycosylation. In order to obtain insight into this issue, 4 subset #201 clonotypic IGs were expressed as recombinant monoclonal Abs (mAbs) of the mu isotype in HEK293 human cells, in either the authentic SHM state ('wildtype', WT-mAbs) or after reverting specific SHMs that altered N-glyc sites (R-mAbs) by site-directed mutagenesis. Since not all N-glyc motifs are eventually glycosylated, we used the NetNglyc 1.0 Server (http://www.cbs.dtu.dk/services/NetNGlyc/) for the prediction of N-glycan occupancy. Binding to MEC1 B CLL, Jurkat T and HEK293 cells was assessed by flow cytometry. Reactivity against nuclear Hep-2 cell extract, nDNA, actin, myosin, thyroglobulin (TG), β-amyloid, carbonic anhydrase, F(ab')2 and the non-self hapten trinitrophenyl was tested by ELISA. Non-subset #201 M-CLL mAbs (n=14, including 3 subset #4 mAbs), were used as controls. None of the subset #201 WT-mAbs displayed reactivity in any of the ELISAs. However, unlike most CLL mAbs, all subset #201 WT-mAbs bound to live MEC1 cells, while also exhibiting reactivity to HEK293 cells that was significantly higher when compared to non-subset #201 M-CLL (p=0.0095) or subset #4 (p=0.05); additionally, 1/4 subset #201 mAb displayed weak binding to Jurkat T cells. Three of 4 subset #201 mAbs bore a novel N-glyc site introduced by SHM in codons VL CDR1 36-38 of the clonotypic lambda light chains. Reversion to the GL in one such mAb resulted in enhanced binding to all 3 cell lines [fold change (FC) of binding of the R- vs WT-mAb to MEC1, Jurkat and HEK293: 1.3, 7.9 and 3.3, respectively) and in strong anti-TG activity. The GL-encoded N-glyc site in VH CDR2 57-59, that has been reported to be mostly unoccupied, was targeted by SHM in 2/4 subset #201 mAbs: reversion to GL decreased binding to both MEC1 and HEK293 cells (FC: -8 and -1.4 respectively). Finally, in 2/4 cases, SHM at codons VH FR3 67-68 inserted an N-glyc site that, however, is not predicted to acquire N-glycans. Reversion to GL enhanced the binding of one of these mAbs to MEC1 and HEK293 cells (FC: 2.1 and 5.6, respectively). The same mAb bore an additional predicted N-glyc site introduced by SHM at VH FR3 90-92; reversion of this change to GL augmented binding to both MEC1 and HEK293 cells (FC: 4.1 and 9.7, respectively). Double reversion of both aforementioned SHMs conferred further increased binding than any of the single reversions, implying a synergistic effect. Acquisition of novel N-glyc sites is not an intrinsic characteristic of either M-CLL in general or IGHV4-34 M-CLL in particular and its high incidence in subset #201 implies a selective process likely due to distinct (auto)antigenic pressure. Indeed, subset #201 mAbs exhibit an antigen reactivity profile that differs from that of typical polyreactive mAbs, including natural autoantibodies and other CLL mAbs, binding selectively to viable lymphoblastoid cell line cells and human HEK293 epithelial cells. These results further emphasize the importance of SHM in shaping the distinct (auto)antigenic recognition profile of CLL mAbs. Disclosures Chatzidimitriou: Janssen: Honoraria. Stamatopoulos:Abbvie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. </jats:sec

    Natural autoimmunity in oligoarticular juvenile idiopathic arthritis

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    Abstract Background Oligoarticular juvenile idiopathic arthritis (oligo-JIA) is considered as an antigen-driven lymphocyte-mediated autoimmune disease. Natural antibodies (NAbs) are pre-immune antibodies produced in the absence of exogenous antigen stimulation, participating in both, innate and adaptive immunity. Considering their major immunoregulatory role in homeostasis and autoimmune pathogenesis, we designed this study to further elucidate their role in oligo-JIA pathogenesis. Methods Seventy children with persistent oligo-JIA and 20 healthy matched controls were enrolled in the study. Serum IgM and IgA antibodies against human G-actin, human IgG F(ab΄)2 fragments and the hapten TriNitroPhenol (TNP) as well as the total concentration of serum IgM and IgA were measured by in-house enzyme-immunoassays. Kolmogorov–Smirnov normality test, Kruskal–Wallis H and Mann–Whitney tests were used to assess data distribution, and significant differences of non-parametric data between groups of the study. Backward regression analysis was used to analyze the effect of multiple factors (age, gender, disease activity, anti-nuclear antibody positivity, presence of uveitis) on continuous dependent variables (activities and activity/ concentration ratios of IgM and IgA NAbs). Results The ratios of IgA anti-TNP, anti-actin and anti-F(ab΄)2 levels to total serum IgA concentration were found to be significantly increased in patients with oligo-JIA compared to healthy subjects. Significantly elevated levels of IgM anti-TNP antibodies were also found in children with inactive oligo-JIA compared to those of children with active disease and of healthy controls. In the presence of anterior uveitis, IgM anti-TNP levels were significantly higher than in patients without uveitis or in healthy controls. Backward regression analysis revealed that the disease activity and the presence of anterior uveitis independently affect IgM anti-TNP levels. Conclusuions Our findings are in accordance with the hypothesis that NAbs contribute to the pathogenesis of autoimmune diseases and provide additional evidence that disturbances in natural autoimmunity may contribute to the as yet unclarified pathogenesis of oligo-JIA

    Detailed Functional Characterization of Splenic Marginal Zone Lymphoma: Uncovering Links between the Epigenetic and the Signaling Machinery

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    Splenic marginal-zone lymphoma (SMZL) ontogeny and evolution is a complex process, involving, amongst others, (super)antigenic stimulation, molecular deregulation of genes involved in the physiological differentiation of splenic marginal zone B cells (e.g. NOTCH2 and KLF2), and epigenetic alterations leading to silencing of different tumor suppressor genes and overexpression of oncogenes, including the PRC2-complex (EZH2, EED, and SUZ12). However, despite important recent progress, advances in the fundamental understanding of SMZL have not yet been translated in improved patient management, highlighting the need for further molecular investigations. In this context, here we aimed at detailed characterization of: (i) epigenetic modifiers, particularly the histone methyltransferase EZH2, a marker of clinical aggressiveness and druggable target in lymphoma; (ii) immune signaling capacity of SMZL B cells; and, (iii) antigen reactivity profile of the SMZL clonotypic B Cell Receptor immunoglobulin (BcR IG). Quantification of EZH2 mRNA levels using quantitative Real-time PCR (n=26 SMZL patients) and protein levels using western blotting (WB) (n=14) revealed that EZH2 was expressed in all cases yet in a heterogeneous manner (2^-ΔCt range: 0.079-1.38; ΕΖΗ2+ cells: 3.11%-44.8%). Interestingly, higher proliferation rates (Ki67+ cells) were observed in cases with high EZH2 protein levels (n=4) compared to cases with low EZH2 (n=6) (FD=2.6; p&amp;lt;0.05). Stimulation of SMZL CD19+ B cells (n=8) through i) the BcR with anti-IgM ii) Toll-Like receptor 9 (TLR9) with CpG and iii) BcR/TLR for 60 minutes affected pBTK, pERK and pNF-kB levels as revealed by WB and flow cytometry (FCM). Although, great heterogeneity was observed in the responses between different cases, categorization of SMZL cases based on EZH2 levels showed that, at basal level, EZH2high cases expressed higher pBTK, pERK and pNF-κB compared to EZH2low cases (FC=2.4, FC=6,1, FC=12.7, respectively; p&amp;lt;0.05 for all comparisons). BcR and TLR9 activation and, especially, co-stimulation with anti-IgM/CpG induced the expression of pBTK, pERK and pNF-κB in EZH2low cases, while the opposite was observed in EZH2high cases. Moreover, stimulation through both the BcR and BcR/TLR9 for 24 hours could also induce EZH2 expression compared to the unstimulated control cells (FC=1.6; p&amp;lt;0.05 for both comparisons). To gain insight into the type of antigenic stimuli that could activate BcR signaling through the BcR we investigated the antigen binding profile of 10 SMZL clonotypic BcR IGs expressed as recombinant human IgM monoclonal antibodies (mAbs). Cases were representative of the most common IGHV genes in SMZL (IGHV1-2*04, IGHV4-34 and IGHV3-23). Reactivity (at 15 μg/ml) against various autoantigens was evaluated by ELISA. Five of 9 (56%), 4/7 (57%), 5/10 (50%), 2/9(22%), 2/9 (22%), 3/9 (33%), 3/8 (38%), 4/8 (50%) and 4 of 9 (44%) SMZL IgM mAbs displayed reactivity against native DNA, nuclear Hep-2 cell extract, actin, myosin, thyroglobulin, β-amyloid, carbonic anhydrase, F(ab')2 and the hapten trinitrophenyl respectively, with optical density (OD) values greater than the cut-off point. Moreover, 5/10 (50%) SMZL IgM mAbs recognized more than 2 antigens and were characterized as polyreactive. Each of these SMZL mAbs exhibited a distinct antigen polyreactivity profile, while heterogeneity was observed even amongst cases expressing the same gene or cases with similar IGHV gene mutational load. Recognition of epitopes on the surface of viable MEC1 B and HEK293 cells was assessed by FCΜ. Two of 3 and 5/11 mAbs bound to viable MEC1 B cells and HEK293 cells, respectively: binding to HEK293 cells was more pronounced for minimally mutated/unmutated versus mutated mAbs (p&amp;lt;0.05). Importantly, stimulation of SMZL CD19+ B cells with the SMZL BcR cognate antigens actin and myosin resulted in regulation of pERK/pPLCγ2 in 3/6 and 1/2 cases, respectively, as revealed by WB. Overall, SMZL cells can be activated by microenvironmental signals albeit in a different manner depending on EZH2 levels, highlighting links between the epigenetic and the signaling machinery with potential therapeutic implications. Moreover, the recognition of a wide range of autoantigens by the SMZL mAbs indicates that SMZL B cell clones may arise from polyreactive B cells, likely resident in the normal splenic marginal zone. Disclosures Stamatopoulos: Janssen: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. </jats:sec
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