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Circulating extracellular vesicles have emerged as potential new biomarkers in a wide variety of diseases. Despite the increasing interest, their isolation and purification from body fluids remains challenging. Here we studied human pre-prandial and 4 hours postprandial platelet-free blood plasma samples as well as human platelet concentrates. Using flow cytometry, we found that the majority of circulating particles within the size range of extracellular vesicles lacked common vesicular markers. We identified most of these particles as lipoproteins (predominantly low-density lipoprotein, LDL) which mimicked the characteristics of extracellular vesicles and also co-purified with them. Based on biophysical properties of LDL this finding was highly unexpected. Current state-of-the-art extracellular vesicle isolation and purification methods did not result in lipoprotein-free vesicle preparations from blood plasma or from platelet concentrates. Furthermore, transmission electron microscopy showed an association of LDL with isolated vesicles upon in vitro mixing. This is the first study to show co-purification and in vitro association of LDL with extracellular vesicles and its interference with vesicle analysis. Our data point to the importance of careful study design and data interpretation in studies using blood-derived extracellular vesicles with special focus on potentially co-purified LDL.

Health-related attitudes can be encouraged most effectively at young ages. Young generations would require more interactive methods in programs engaged in health promotion.The aim of the authors was to get an insight into the attitudes, experience and motivation of youngsters in connection with health promotion programs and the community service work.The questionnaires were filled in by high school students studying in Budapest and in the countryside (N = 898).44.4% of the students did not have lessons or extracurricular activities dealing with health promotion. Concerning health promotion programs, youngsters in Budapest had more positive experience, while female students showed a more adoptive attitude.It was concluded that in one of the most susceptible life stages, many youngsters either do not participate in programs dealing with health promotion, or participate in programs that are within the framework of school subjects or extracurricular activities building on traditional teaching methods.

The discovery of the biological relevance of non-coding RNA molecules represents one of the most significant advances in contemporary molecular biology. It has turned out that a major fraction of the non-coding part of the genome is transcribed. Beside small RNAs (including microRNAs) more and more data are disclosed concerning long non-coding RNAs of 200 nucleotides to 100 kb length that are implicated in the regulation of several basic molecular processes (cell proliferation, chromatin functioning, microRNA-mediated effects, etc.). Some of these long non-coding RNAs have been associated with human tumours, including H19, HOTAIR, MALAT1, etc., the different expression of which has been noted in various neoplasms relative to healthy tissues. Long non-coding RNAs may represent novel markers of molecular diagnostics and they might even turn out to be targets of therapeutic intervention. Orv. Hetil., 2012, 153, 1494–1501.

Decreased expression of the TCR ζ-chain has been reported in several autoimmune, inflammatory, and malignant diseases, suggesting that ζ-chain downregulation is common at sites of chronic inflammation. Although ζ-chain is critically important in T lymphocyte activation, the mechanism of the decreased ζ-chain expression is less clear. Src-like adaptor protein (SLAP) is a master regulator of T cell activation; previous data have reported that SLAP regulates immunoreceptor signaling. We have examined the mechanism and the functional consequences of CD3 ζ-chain downregulation. TNF treatment of human T lymphocytes (15–40 ng/ml) selectively downregulates CD3 ζ-chain expression in a dose-dependent manner (p < 0.05) and decreases activation-induced IL-2 expression (p < 0.01). Although blocking of the lysosomal compartment fails to restore TNF-induced CD3 ζ-chain downregulation, inhibition of the proteasome prevented the effect of TNF. Both SLAP expression and the colocalization of SLAP with CD3 ζ-chain was enhanced by TNF treatment (p < 0.05 and p < 0.01, respectively), whereas TNF-induced ζ-chain downregulation was inhibited by gene silencing of SLAP with small interfering RNA. SLAP levels of the CD4+ T lymphocytes isolated from patients with rheumatoid arthritis were more than 2-fold higher than that of the healthy donors’ (p < 0.05); moreover, TNF treatment did not alter the SLAP expression of the CD4+ cells of anti-TNF therapy-treated patients. Our present data suggest that TNF modulates T cell activation during inflammatory processes by regulating the amount of CD3 ζ-chain expression via a SLAP-dependent mechanism. These data provide evidence for SLAP-dependent regulation of CD3 ζ-chain in the fine control of TCR signaling.

Objective The conventional H1 and H2 histamine receptors have >10,000-fold lower avidity for histamine than H4 histamine receptor, which has been implicated in autoimmune diseases. This study was undertaken to compare H4 histamine receptor levels in the salivary glands (SGs) of healthy controls with those in the SGs of patients with primary Sjogren's syndrome (SS). Methods H4 histamine receptor messenger RNA (mRNA) was analyzed using real-time quantitative polymerase chain reaction, and the receptor protein was examined using immunostaining. Effects of the H4 histamine receptor agonist ST-1006 on cytokine synthesis by human SG (HSG) cells were analyzed using xMAP technology and enzyme-linked immunosorbent assay. Results Healthy SGs contained H4 histamine receptor mRNA. The receptor protein was localized to the acinar and ductal epithelial cells. H4 histamine receptor agonist stimulated HSG cells to produce the cytokines interleukin-8 and vascular endothelial growth factor. SS patients had low H4 histamine receptor levels. Conclusion H1 and H2 histamine receptor antagonists are not effective in the treatment of autoimmune diseases. However, such antagonists do not affect the newly discovered H4 histamine receptor. Dendritic cells and lymphocytes are nonprofessional histamine-producing cells, which produce histamine at 100–1,000-fold lower rates than mast cells do. Saliva contains only 0.31–12.4 ng/ml histamine, which is too low to stimulate H1 or H2 histamine receptor, but stimulates H4 histamine receptor half maximally. Our findings show that H4 histamine receptor is strongly expressed in tubuloacinar SG cells, which emphasizes the role of these cells in the pathogenesis of SS.

There are several clinical trials worldwide using bone marrow stromal cells (BMSCs) as a cellular therapy to modulate immune responses in patients suffering from various inflammatory conditions. A deeper understanding of the molecular mechanisms involved in this modulatory effect could help us design better, more effective protocols to treat immune mediated diseases. In this study, we demonstrated that human BMSCs express H1, H2, and H4 histamine receptors and they respond to histamine stimulation with an increased interleukin 6 (IL-6) production both in vitro and in vivo. Using different receptor antagonists, we pinpointed the importance of the H1 histamine receptor, while Western blot analysis and application of various mitogen-activated protein kinase inhibitors highlighted the role of p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase kinases in the observed effect. When BMSCs were pretreated with either histamine or degranulated human mast cells, they exhibited an enhanced IL-6-dependent antiapoptotic effect on neutrophil granulocytes. Based on these observations, it is likely that introduction of BMSCs into a histamine-rich environment (such as any allergic setting) or pretreatment of these cells with synthetic histamine could have a significant modulatory effect on the therapeutic potential of BMSCs. Disclosure of potential conflicts of interest is found at the end of this article.

Background: Histamine as an inflammatory mediator plays an important role in chronic allergic and asthmatic conditions. However, the role of genetic polymorphisms of the histamine receptor HRH4 (histamine receptor H4) gene in asthma susceptibility and endophenotypes has not been studied yet. Our aim was to investigate the possible association between single nucleotide polymorphisms (SNPs) in the HRH4 gene and asthma or some endophenotypes of asthma. Methods: Twenty-one SNPs of the HRH4 gene were genotyped in 313 asthmatic patients and 360 controls using Sequenom® iPLEX® Gold Genotyping Technology. Results: Genotype distribution of three HRH4 SNPs, namely rs17187619 [p = 0.002; odds ratio, OR (95% confidence interval, CI) = 2.4 (4.1–1.4)], rs527790 [p = 0.0002; OR (95% CI) = 3.3 (6.1–1.8)] and rs487202 [p = 0.00007; OR (95% CI) = 3.5 (6.6–1.9)] differed significantly between patients with or without infection-induced asthma. Haplotypes, which included the rs4800573–rs527790 CC allele combination, were found to be associated with infection-induced asthma [p = 0.0009, OR (95% CI) = 0.5 (0.4–0.8)]. The rs487202–rs574913 CA haplotype was more frequent among patients with infection-induced asthma [p = 0.0006, OR (95% CI) = 1.9 (1.3–2.6)]. None of the SNPs contributed directly to the risk of asthma. Conclusions: Our results suggest that genetic variation in the HRH4 gene might influence the pathogenesis of infection-induced asthma.

Background Galectins are potent immune regulators, with galectin-8 acting as a pro-apoptotic effector on synovial fluid cells and thymocytes and stimulator on T-cells. To set a proof-of-principle example for risk assessment in autoimmunity, and for a mutation affecting physiological galectin sensor functions, a polymorphism in the coding region of the galectin-8 gene (rs2737713; F19Y) was studied for its association with two autoimmune disorders, i.e. rheumatoid arthritis and myasthenia gravis. Methods A case–control analysis and a related quantitative trait-association study were performed to investigate the association of this polymorphism in patients (myasthenia gravis 149, rheumatoid arthritis 214 and 134 as primary and repetitive cohorts, respectively) and 365 ethnically matched (Caucasian) healthy controls. Distribution was also investigated in patients grouped according to their antibody status and age at disease onset. Comparative testing for lectin activity was carried out in ELISA/ELLA-based binding tests with both wild-type and F19Y mutant galectin-8 from peripheral blood mononuclear cell lysates of healthy individuals with different genotypes as well as with recombinant wild-type and F19Y mutant galectin-8 proteins. Results A strong association was found for rheumatoid arthritis, and a mild one with myasthenia gravis. Furthermore, the presence of the sequence deviation also correlated with age at disease onset in the case of rheumatoid arthritis. The F19Y substitution did not appear to affect carbohydrate binding in solid-phase assays markedly. General significance This is the first report of an association between a galectin-based polymorphism leading to a mutant protein and autoimmune diseases, with evidence for antagonistic pleiotropy.

As an outcome of The 2009 Nobel Prize in Physiology or Medicine, a connection has been highlighted between the length of telomeres and epigenetic effects, such as intensive changes in lifestyle and nutrition as well as behavioural and psychological factors. In this review, the various elements of molecular, cell biological, nutritional and lifestyle changes are introduced and discussed.

Membrane vesicles are membrane-covered cell fragments generated by all cell types. They comprise a recently recognized new system of intercellular communication, believed to play a pivotal role in information transfer between cells, as they display a large number of biomolecules enclosed within the membrane as well as in the membrane proper. The phenotype of the donor cell is reflected in the vesicular protein content, which also allows the identification of the original cell. Membrane vesicles have been implicated in several physiological and pathological processes, most notably in tumorigenesis. Tumor-derived vesicles may serve as prognostic markers, they were detected in blood plasma and in other body fluids. Their size varies between 30 and 1000 nm. All of them reflect the special potential of tumor cells for survival and for the expansion of the tumor, independently from cell-to-cell contact. Tumor-derived vesicles have the potential to facilitate the escape of tumor cells from immune surveillance through their protein and RNA content, at the same time they are involved in the establishment of a beneficial environment for newly formed and migrating tumor cells, influencing angiogenesis and the reorganization of the extracellular matrix. Elucidating the properties of tumor-derived vesicles should increase our understanding in tumor biology and open new perspectives in cancer treatment. Tumor-derived vesicles are involved in tumorigenesis at multiple level and drugs themselves can be expulsed from tumor cells via vesicles. Consequently, interfering with the formation, release and propagation of these vesicles can be a novel and alternative issue in cancer therapy. The present review is an overview of the roles of membrane vesicles in tumorigenesis showing also the potential to consider them as new targets in tumor therapy.

The clinical and molecular effects of whole-body polarized light treatment on children suffering from recurrent respiratory infection were studied. The incidence and duration of respiratory symptoms as well as the length of appropriate antibiotic therapy were measured. Simultaneously, the genome-wide gene expression pattern was examined by whole genome cDNA microarray in peripheral lymphocytes of children. Twenty of 25 children showed a marked clinical improvement, while in five of 25 had poor response or no changes. The gene expression pattern of the patients’ peripheral lymphocytes was compared in favorable and poor responders. The lymphocytes of the children with a documented improved clinical response to polarized light therapy showed a decrease in the expression of chemokine genes, such as CXCL1, CXCL2, CXCL3, and IL-8, and in that of the TNFα gene. On the contrary, a rapid elevation was found in the expression of the gene encoding for CYP4F2, a leukotriene B4-metabolizing enzyme. In children with poor clinical response to polarized light therapy, no similar changes were detected in the gene expression pattern of the lymphocytes. The improved clinical symptoms and modified gene expression profile of lymphocytes reveals an anti-inflammatory effect of whole-body polarized light irradiation.

The factors involved in the pathogenesis of Crohn's disease and ulcerative colitis, the two major types of inflammatory bowel disease (IBD) are summarized. Intestinal antigens composed of bacterial flora along with antigen presentation and impaired mucosal barrier have an important role in the initiation of IBD. The bacterial community may be modified by the use of antibiotics and probiotics. The dentritic cells recognize the antigens by cell surface Toll like receptor and the cytoplasmic CARD/NOD system. The balance between Th1/Th2/Th17 cell populations being the source of a variety of cytokines regulates the inflammatory mechanisms and the clearance of microbes. The intracellular killing and digestion, including autophagy, are important in the protection against microbes and their toxins. The homing process determines the location and distribution of the immune cells along the gut. All these players are potential targets of pharmacological manipulation of disease status.

Release of membrane vesicles, a process conserved in both prokaryotes and eukaryotes, represents an evolutionary link, and suggests essential functions of a dynamic extracellular vesicular compartment (including exosomes, microparticles or microvesicles and apoptotic bodies). Compelling evidence supports the significance of this compartment in a broad range of physiological and pathological processes. However, classification of membrane vesicles, protocols of their isolation and detection, molecular details of vesicular release, clearance and biological functions are still under intense investigation. Here, we give a comprehensive overview of extracellular vesicles. After discussing the technical pitfalls and potential artifacts of the rapidly emerging field, we compare results from meta-analyses of published proteomic studies on membrane vesicles. We also summarize clinical implications of membrane vesicles. Lessons from this compartment challenge current paradigms concerning the mechanisms of intercellular communication and immune regulation. Furthermore, its clinical implementation may open new perspectives in translational medicine both in diagnostics and therapy.

Histamine, produced by dendritic cells (DCs) or by other cells of the immune system, may have significant impact on DC activities. We investigated the influence of histamine and histamine H4 receptor (H4R) on some relevant functions of DCs. Histamine significantly decreased the antigen presentation capacity of splenic DCs, and this effect was reversed by a H4R antagonist. Furthermore, enhanced antigen presentation was detected in H4R-/- DCs. Prolonged histamine treatment during DC differentiation stimulated migration, albeit the increase was not significant. H4R-deficient DCs possessed significantly lower migration capacity than their wild-type counterparts. Monitoring in vivo and in vitro DC cytokine production revealed that a H4R agonist in combination with LPS, increased IL-1 beta mRNA expression, and a H4R antagonist reversed this effect. In H4R-deficient mice we detected decreased mRNA expression of some DC-derived cytokines including IFN-gamma and IL-10. Upon CFA stimulation, genotype-dependent differences were found in the expression of IL-6 and IFN-gamma. Our data suggest that H4R plays a crucial role in variety of functions of murine DCs.

Galectin-1 (LGALS1) and interleukin receptor 2β (IL2Rβ) are regulators of T-cell activation. Here we evaluated the association of regulatory region polymorphisms of the LGALS1 (rs4820293, rs4820294) and IL2Rβ (rs743777, rs228941) genes in 146 Caucasian myasthenia gravis patients compared to 291 ethnically matched controls. A significant difference was found in the distribution of the rs4820293/rs743777 polymorphism haplotypes (p0.01). The rs4820293 polymorphism, previously not described to be associated with any disease, does not affect LGALS1 expression in peripheral mononuclear cells and skeletal muscle. Pathway analysis revealed interaction between LGALS1 and IL2Rβ suggesting a role of these proteins in this rare disease.

Histidine decarboxylase (HDC), the unique enzyme responsible for histamine generation, is highly expressed in myeloid cells, but its function in these cells is poorly understood. Here we show that Hdc-knockout mice show a high rate of colon and skin carcinogenesis. Using Hdc-EGFP bacterial artificial chromosome (BAC) transgenic mice in which EGFP expression is controlled by the Hdc promoter, we show that Hdc is expressed primarily in CD11b +Ly6G+ immature myeloid cells (IMCs) that are recruited early on in chemical carcinogenesis. Transplant of Hdc-deficient bone marrow to wild-type recipients results in increased CD11b + Ly6G + cell mobilization and reproduces the cancer susceptibility phenotype of Hdc-knockout mice. In addition, Hdc-deficient IMCs promote the growth of tumor allografts, whereas mouse CT26 colon cancer cells downregulate Hdc expression through promoter hypermethylation and inhibit myeloid cell maturation. Exogenous histamine induces the differentiation of IMCs and suppresses their ability to support the growth of tumor allografts. These data indicate key roles for Hdc and histamine in myeloid cell differentiation and CD11b+Ly6G+IMCs in early cancer development. © 2011 Nature America, Inc. All rights reserved.

A 2009. évi orvosi Nobel-díjat a telomerák és a telomeráz enzim felfedezéséért és az ezekkel kapcsolatos úttörő kutatásokért három, Amerikában dolgozó tudós kapta megosztva. Nem régóta az is ismert, hogy bizonyos életmód- és táplálkozásbeli változások (Ornish-féle életmódváltozás), magatartásbeli, pszichológiai tényezők, valamint a telomerarövidülés között bizonyított kapcsolat létezik. Az összefoglalóban ezen összefüggések molekuláris, sejtbiológiai, életmódbeli és magatartási vonatkozásait, valamint ezek lehetséges összefüggéseit mutatják be.

Limited responsiveness to IFN-α in hepatitis C virus (HCV)-infected African-Americans compared to European Americans (AAs vs. EAs) hinders the management of HCV. Here, we studied healthy non-HCV-infected AA and EA subjects to test whether immune cell response to IFN-α is determined directly by race. We compared baseline and IFN-α-induced signal transducer and activator of transcription (STAT)-1, STAT-2, STAT-3, STAT-4, and STAT-5 protein and phosphorylation levels in purified T cells, global transcription, and a genomewide single-nucleotide polymorphism (SNP) profile of healthy AA and EA blood donors. In contrast to HCV-infected individuals, healthy AAs displayed no evidence of reduced STAT activation or IFN-α-stimulated gene expression compared to EAs. Although >200 genes reacted to IFN-α treatment, race had no impact on any of them. The only gene differentially expressed by the two races (NUDT3, P < 10 −7 ) was not affected by IFN-α and bears no known relationship to IFN-α signaling or HCV pathogenesis. Genomewide analysis confirmed the self-proclaimed racial attribution of most donors, and numerous race-associated SNPs were identified within loci involved in IFN-α signaling, although they clearly did not affect responsiveness in the absence of HCV. We conclude that racial differences observed in HCV-infected patients in the responsiveness to IFN-α are unrelated to inherent racial differences in IFN-α signaling and more likely due to polymorphisms affecting the hosts’ response to HCV, which in turn may lead to a distinct disease pathophysiology responsible for altered IFN signaling and treatment response.

In this study we investigated the role of histamine on the extramedullary hematopoiesis. Male histidine decarboxylase knockout (HDC−/−) mice and wild-type mice were used (n = 5/group). Groups of mice received sublethal total-body gamma irradiation at a single dose of 4 Gy. Spleen cells were studied at different time points post-irradiation by flow cytometry, colony forming unit (CFU) assay, and real-time PCR. For statistical analysis Student’s t test, ANOVA, and Holm-Sidak post-hoc test were used. By day 14 after irradiation, spleen cell counts increased almost eightfold in wild-type and not even fourfold in HDC−/− mice (P

CYP2C9 gene polymorphisms are widely studied in several ethnic groups, however they are less known in the Roma population. The aim of this work was to study the ethnic differences of the CYP2C9 allele distribution in a healthy Roma population in order to compare them with a healthy Hungarian population. A total of 535 Hungarian and 465 Roma volunteers were genotyped for the CYP2C9*2 (Arg144Cys) and CYP2C9*3 (Ile359Leu) allelic variants by PCR-RFLP assay. The frequencies of the CYP2C9*1, *2 and *3 alleles in the Hungarian population were 0.787, 0.125, and 0.088 and in Roma 0.727, 0.118, and 0.155, respectively. We found a significant difference in CYP2C9*3 prevalence between the Hungarian and Roma populations, which have therapeutic consequences (p

The orderly differentiation of cell lineages within gastric glands is regulated by a complicated interplay of local mucosal growth factors and hormones. Histamine secreted from enterochromaffin-like cells plays an important role in not only stimulated gastric acid secretion but also coordination of intramucosal growth and lineage differentiation. We have examined histidine-decarboxylase (HDC)-deficient mice, which lack endogenous histamine synthesis, to evaluate the influence of histamine on differentiation of fundic mucosal lineages and the development of metaplasia following induction of acute oxyntic atrophy. Stomachs from HDC-deficient mice and wild-type mice were evaluated at 8 wk and 12 mo of age. DMP-777 was administrated orally to 6-wk-old mice for 1 to 14 days. Sections of gastric mucosa were stained with antibodies against Mist1, intrinsic factor, H/K-ATPase, trefoil factor 2 (TFF2), chromogranin A, and Ext1 and for the cell cycle marker phospho-histone H3. HDC-deficient mice at 8 wk of age demonstrated a prominent increase in chief cells expressing Mist1 and intrinsic factor. Importantly Mist1-positive mature chief cells were present in the midgland region as well as at the bases of fundic glands, indicating a premature differentiation of chief cells. Mice dually deficient for both HDC and gastrin showed a normal distribution of chief cells in fundic glands. Treatment of HDC-deficient mice with DMP-777 led to loss of parietal cells and an accelerated and exaggerated emergence of mucous cell metaplasia with the presence of dual intrinsic factor and TFF2-expressing cells throughout the gland length, indicative of the emergence of spasmolytic polypeptide-expressing metaplasia (SPEM) from chief cells. These findings indicate that histamine, in concert with gastrin, regulates the appropriate differentiation of chief cells from mucous neck cells as they migrate toward the bases of fundic glands. Nevertheless, histamine is not required for emergence of SPEM following acute oxyntic atrophy.

Interleukin-6 (IL-6) is a member of the cytokine superfamily characterised by a wide variety of biological activities on various cell types. IL-6 exerts pleiotropic activities on hematopoiesis in the immune response and it is the main regulator of acute-phase protein synthesis in liver cells. According to structure-function studies, residues of helix A located at the N-terminal part and/or helix D of the C-terminal part of the protein are involved in the induction of acute-phase responses. Two groups of synthetic peptides corresponding to the 18-46 N-terminal and the 168-185 C-terminal regions of the IL-6 were prepared by solid-phase synthesis to identify structural requirements for induction of fibrinogen or complement factor B synthesis. These peptides were characterised by amino acid analysis, analytical reversed-phase high-performance liquid chromatography, fast atom bombardment mass spectrometry, and circular dichroism (CD) spectroscopy. CD results showed that under appropriate conditions both 18-46 and 168-185 related peptides are able to adopt markedly ordered conformation. We demonstrated that even octapeptides from the N-terminal part and truncated derivatives of the C-terminal region preserved some tendency to display the CD curve of periodic conformation. The ability of the peptides to induce de novo synthesis of acute-phase proteins was evaluated by measuring fibrinogen and complement factor B levels in the supernatants of human HepG2 cells. These results showed that residues 21-34 are critical for eliciting fibrinogen synthesis in the presence or absence of IL-6. In contrast, the full-length 168-185 peptide is required for the induction of complement factor B response.

Microvesicles (MVs) can derive from several cell types and their membranes contain cell surface elements. Their role is increasingly recognized in cell-to-cell communication, as they act as both paracrine and remote messengers, occurring in circulating form as well as in plasma. Successful pregnancy requires a series of interactions between the maternal immune system and the implanted fetus, such that the semi-allograft will not be rejected. These interactions occur at the materno-placental interface and/or at a systemic level. In the present study we identified for the first time the in vivo plasma pattern of the MVs of third-trimester, healthy pregnant women, their cellular origin, and their target cells using flow cytometry and confocal laser microscopy. We searched for the cellular target molecules of thrombocyte-derived MVs with the help of neutralizing antibodies. We examined the in vitro effects of MVs on STAT3 phosphorylation of primary lymphocytes and Jurkat cells. We found that both placental trophoblast-derived and maternal thrombocyte-derived MVs bind to circulating peripheral T lymphocytes, but not to B lymphocytes or NK cells. We were able to show that the P-selectin (CD62P)-PSGL-1 (CD162) interaction is one mechanism binding platelet-derived MVs to T cells. We were also able to demonstrate that MV-lymphocyte interactions induce STAT3 phosphorylation in T cells. Our findings indicate that both thrombocyte- and trophoblast-derived MVs may play an important role in the immunomodulation of pregnancy. We suggest that the transfer of different signals via MVs represents a novel form of communication between the placenta and the maternal immune system, and that MVs contribute to the establishment of stable immune tolerance to the semi-allograft fetus.

Experimental and clinical evidence for T cell involvement in the pathology of rheumatoid arthritis (RA) is compelling, and points to a local dysregulation of T cell function in the inflamed joint. Nitric oxide (NO) has been shown to regulate T cell function under physiological conditions, but overproduction of NO may contribute to lymphocyte dysfunction characteristic of RA. Several investigations in patients with RA have documented evidence of increased NO synthesis, but these studies have focused largely on macrophage-derived NO and its impact on innate immune and inflammatory responses. In this study, we set out to explore the contribution that T cells make to NO production. We find that T cells from RA patients produce2.5 times more NO than healthy donor T cells (p0.001). Although NO is an important physiological mediator of mitochondrial biogenesis, mitochondrial mass is similar in RA and control T cells. In contrast, increased NO production is associated with increased cytoplasmic Ca(2+) concentrations in RA T cells (p0.001). In vitro treatment of human peripheral blood lymphocytes, or Jurkat cells with TNF increases NO production (p=0.006 and p=0.001, respectively), whilst infliximab treatment in RA patients decreases T cell derived NO production within 6 weeks of the first infusion (p=0.005). Together, these data indicate that TNF induced NO production in T lymphocytes may contribute to perturbations of immune homeostasis in RA.

Ligand-supported homology models of the human histamine H4 receptor (hH4R) were developed based on the crystal structure of bovine rhodopsin and different known H4 ligands (histamine, OUP-16, JNJ7777120). Enrichment tests were performed to analyze whether our hH4R models can select known actives from random decoys. The impact of receptor conformation and the effect of different sets of random decoys, docking methods (FlexX, FlexX-Pharm) and scoring functions (FlexX-Score, D-Score, PMF-Score, G-Score, ChemScore) were investigated. We found that two agonists (histamine and OUP-16) form complementary interactions with Asp94 (3.32), Glu182 (5.46) and Thr323 (6.55), whereas JNJ7777120 interacts with Asp94 (3.32) and Glu182 (5.46) only. These results suggest a role of Thr323 (6.55) in ligand binding and presumably also in receptor activation. The models optimized in the presence of an agonist (histamine) and an antagonist (JNJ7777120) were compared in more detail. We conclude that the ligand used in the model building process can significantly influence the efficacy of virtual screening.

Pharmacogenomics, a fascinating, emerging area of biomedical research is strongly influenced by growing availability of genomic databases, high-throughput genomic technologies, bioinformatic tools and artificial computational modelling approaches. One main area of pharmacogenomics is the discovery of new drugs and drug targets with molecular genetic, genomic or even bioinformatic methods; the other is the study of how genomic differences influence the variability in patients' responses to drugs. From a genetic point of view, asthma is multifactorial, which means that the susceptibility to the disease is determined by interactions between multiple genes, and involves important non-genetic factors such as the environment for their expression. In this review, we summarize collective evidence from linkage and association studies that have consistently reported suggestive linkage or association of asthma or its associated phenotypes to polymorphic markers and single nucleotide polymorphisms in selected chromosomes. Genes that have been found implicated in the disease are potential new drug targets and several pharmacological investigations are underway to utilize these new discoveries. Next, we will focus on the inter-individual variability in anti-asthmatic drug responses and review the recent results in this topic.

In this review, we briefly described microRNA biogenesis, function and the principal approaches for studying the function of microRNAs (miRNA) in solid cancers. There are currently hundreds of confirmed miRNAs in humans, and computational predictions suggest that the total count might be more than thousand. The regulatory nature of miRNAs combined with the large number of presumptive target genes suggests that they are essential regulators of a wide range of cellular processes. To illustrate the importance of miRNA-mediated regulation in solid cancer some confirmed interactions were collected. Their relevance is described in detail in melanomas from the aspect of diagnosis, the potential application of miRNAs as biomarkers and as potential therapeutic tools.

Production of histamine in colon tumours has been described earlier. Histamine-mediated signals have been shown to be implicated in tumour growth, and the effects of histamine are largely determined locally by the histamine receptor expression pattern. We analysed histamine receptor expression in human colorectal cancer, adenoma and normal mucosa by quantitative reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and immunostaining. Real-time RT-PCR results revealed significantly decreased (p

We previously showed that transgenic enhancement of histamine production in B16-F10 melanomas strongly supports tumor growth in C57BL/6 mice. In the present study, gene expression profiles of transgenic mouse melanomas, secreting different amounts of histamine, were compared by whole genome microarrays. Array results were validated by real-time PCR, and genes showing histamine-affected behavior were further analyzed by immunohistochemistry. Regulation of histamine-coupled genes was investigated by checking the presence and functional integrity of all four known histamine receptors in experimental melanomas and by administering histamine H1 receptor (H1R) and H2 receptor (H2R) antagonists to tumor-bearing mice. Finally, an attempt was made to integrate histamine-affected genes in known gene regulatory circuits by in silico pathway analysis. Our results show that histamine enhances melanoma growth via H1R rather than through H2R. We show that H1R activation suppresses RNA-level expression of the tumor suppressor insulin-like growth factor II receptor (IGF-IIR) and the antiangiogenic matrix protein fibulin-5 (FBLN5), decreases their intracellular protein levels, and also reduces their availability in the plasma membrane and extracellular matrix, respectively. Pathway analysis suggests that because plasma membrane-bound IGF-IIR is required to activate matrix-bound, latent transforming growth factor-β1, a factor suggested to sustain FBLN5 expression, the data can be integrated in a known antineoplastic regulatory pathway that is suppressed by H1R. On the other hand, we show that engagement of H2R also reduces intracellular protein pools of IGF-IIR and FBLN5, but being a downstream acting posttranslational effect with minimal consequences on exported IGF-IIR and FBLN5 protein levels, H2R is rather irrelevant compared with H1R in melanoma. [Cancer Res 2008;68(6):1997–2005]

Multiple myeloma (MM) is a B-cell lymphoma of matured plasmacytic origin. There is a well described spectrum of cutaneous diseases in MM including cell infiltration and amyloid deposition [1]. Little is known about the basic processes involved that allow malignant plasma cells or lymphomas to grow outside the bone marrow environment. Several experimental models have been used to study this issue [2]. Hedvat et al. found altered gene expression profile pattern in plasma cells growing in extramedullary sites mostly involved in angiogenesis and adhesion [3]. Identification of other tumour-specific alterations required for extramedullary growth would confer better understanding of tumour metastasis. In an earlier study authors found that histidine decarboxylase (HDC)that is the only enzyme capable of histamine synthesisis absent from B-lymphocytes infiltrating the skin in a B-cell chronic lymphocytic leukemia patient who developed cutaneous infiltrations in the course of the disease. In contrast to this, those cells that remained in the bone marrow had their HDC activity been preserved [4]. There is evidence that besides histamine being a well known mediator of allergic reactions, may also be involved in certain types of cell proliferations like wound healing, embryonic development and tumor growth [5,6]. There are data confirming that a functioning HDC gene is important in maintaining immune homeostasis [7]. The relation of histamine metabolism and metastatising human plasma cell malignancies has not been examined so far. The case reported here served an appropriate occasion for that.

Melanomas containing more elastin are associated with higher stages of the disease. The interaction between elastin-derived peptides and melanoma cells appears to play an important role in the progression of melanomas. The effects of the elastin-derived peptides VGVAPG and VAPG have been investigated on the migration, invasion, adhesion and angiogenesis of human melanoma cells of different invasive potential. Elastin, tropoelastin and VGVAPG peptide were demonstrated at the invasion site of melanoma using histochemistry and immunohistochemistry. Not only the VGVAPG elastin-derived peptide, which exhibits the XGXXPG consensus sequence in its primary structure, but also the shorter VAPG bind directly to 3 cell surface receptors: galectin-3, integrin alpha v beta 3 and elastin-binding protein. Our results suggest that the increased levels of elastin-derived peptides facilitate the invasion of melanoma cells: (i) VGVAPG and VAPG elastin-derived peptides are chemotactic for melanoma cells; (ii) they can increase the migration of melanoma cells and the expression of CXCR-4 and CXCL-12 chemokines; (iii) they enhance the expression of the elastin-degrading MMP-2 and MMP-3; (iv) they increase the attachment of melanoma cells and the expression of different adhesion molecules; (v) they increase the expression of the lymphangiogenic VEGF-C and (vi) the galectin-3 receptor can mediate all these effects. Clinical and therapeutic aspects are also discussed.

Az öregedő lakosság ellátása egyre nagyobb kihívást jelent Európában. Az eredményesebb gyógyítás és megelőzés érdekében javítani kell a rendelkezésre álló technológiai eszközök felhasználását, hogy felgyorsuljon a betegségasszociált rizikófaktorok és gének azonosítása. E feladat megvalósításának azonban előfeltétele egy ellenőrzött minőségű, jól osztályozott és elegendően nagy betegminta-gyűjtemény/bank létrehozása, amelyben a DNS/szérum/plazma/sejtek/szövetek/RNS/fehérje fizikai tárolása egy információ alapú infrastruktúrával kombinálva garantálja a kutatók számára a minták és adatok széles körű hozzáférését. A Danubian Biobank egy olyan kezdeményezés, mely egyetemeket, oktató kórházakat és rehabilitációs klinikákat kapcsol össze a Duna mentén lévő, illetve az ezzel szomszédos államokban. A tudományos program fő célja a vascularis betegségek (pl. myocardialis infarktus, stroke, szívelégtelenség, artériás trombózis, veseelégtelenség), a metabolikus betegségek (pl. obesitas, diabétesz, metabolikus szindróma) és a neurodegeneratív betegségek (pl. demenciaszindrómák, Parkinson-kór) vizsgálata. A biobankprojekt egyes részfeladatainak megoldására munkacsoportok jöttek létre, hogy segítsék a betegek bevonásának, minták és adatok kezelésének, népegészségügyi, epidemiológiai, genetikai technológiai alkalmazásoknak és a kutatási stratégiáknak az összehangolását. A folyamatosság, illetve belső fejlesztés, optimalizálása érdekében a konzorcium, illetve az egyes munkacsoportok önmagukban is rendszeresen konferenciákat szerveznek, valamint az együttműködést finanszírozó pályázatokat készítenek.

Successful pregnancy is closely related to polarization toward a Th2 type immune response. As histamine is known to initiate Th2 dominance during inflammatory processes we raised the question whether histamine has any effect on the actual tuning of proper cytokine balance for the proceeding of the gestation. Histamine has multiple functions in the process of pregnancy, different studies have shown the direct and/or indirect presence of histamine action in the placenta as well. As HDC is the unique histamine producing enzyme in eukaryotes, we used HDC (so endogenous histamine)-deficient knockout mice as reliable model for studying histamine-related processes in vivo. We examined the placental histamine content and the expression of histamine receptors and Th1/Th2/Th3 type cytokines in the placenta. We showed for the first time the influence of histamine on the orchestrated regulation of placental cytokine expression. In the absence of local histamine the cytokine balance is shifted toward Th1 types at the maternal–placental interface, threatening pregnancy. We also measured splenic lymphocyte subpopulation ratios in pregnant and non-pregnant mice and found that in pregnancy they are independent of the presence of histamine.

The purpose of the present study was to investigate the influence of lack of histamine (HA) on tumor growth and functions of T cells in order further to illustrate the mechanism of immunological tolerance induction by HA. We assessed the phenotype and cytokine production of splenic lymphocytes in syngeneic HA-free (histidine decarboxylase knock-out) (HDC KO) and wild-type mice, inoculated subcutaneously with the LM2 murine breast cancer cell line. Relative quantification of target mRNA was performed with a TaqMan real-time RT-PCR assay. The CD4+CD25high+ Treg cell numbers were significantly smaller in the tumor-bearing KO mice than in the wild type ones measured by flow-cytometry. The expression of forkhead box P3 (Foxp3) decreased significantly and the copies of splenic Tbox-21 (T-bet) transcriptional factor mRNA was higher in HDC KO tumor-bearing mice than those of normal mice. The cytokine levels showed that a smaller number of interleukin-13-producing Th2 cells were elicited compared to interferon-γ-producing Th1 cells in the tumor-bearing HDC KO mice. In conclusion, the present study demonstrates that endogenous histamine stimulates the growth of breast adenocarcinoma tumor implants in mice by suppressing anti-tumor immunity. Keywords:: histidine decarboxylase knock-out (HDC KO), cytokine, regulatory T cell, histamine

Telomeres are protective heterochromatic structures that cap the end of linear chromosomes and play a key role in preserving genomic stability. Telomere length represents a balance between processes that shorten telomeres during cell divisions with incomplete DNA replication and the ones that lengthen telomeres by the action of telomerase, an RNA–protein complex with reverse transcriptase activity which adds telomeric repeats to DNA molecule ends. Telomerase activity and telomere length have a crucial role in cellular ageing and in the pathobiology of several human diseases attracting intense research. The last few decades have witnessed remarkable advances in our understanding about telomeres, telomere-associated proteins, and the biogenesis and regulation of the telomerase holoenzyme complex, as well as about telomerase activation and the telomere-independent functions of telomerase. Emerging data have revealed that telomere length can be modified by genetic and epigenetic factors, sex hormones, reactive oxygen species and inflammatory reactions. It has become clear that, in order to find out more about the factors influencing the rate of telomere attrition in vivo, it is crucial to explore both genetic and epigenetic mechanisms. Since the telomere/telomerase assembly is under the control of multiple epigenetic influences, the unique design of twin studies could help disentangle genetic and environmental factors in the functioning of the telomere/telomerase system. It is surprising that the literature on twin studies investigating this topic is rather scarce. This review aims to provide an overview of some important immune response- and epigenetics-related aspects of the telomere/telomerase system demanding more research, while presenting the available twin data published in connection with telomere research so far. By emphasising what we know and what we still do not know in these areas, another purpose of this review is to urge more twin studies in telomere research.

We examined the association of functional ABCB1 (MDR1) and ABCG2 (BCRP) polymorphisms with acute side effects of chemotherapy. Analyses were performed on clinical data from 138 patients treated with the ALL-BFM-95 protocol implying several substrates of these transporters. ABCB1 3435T>C, 2677G>T/A 1236C>T and ABCG2 421C>A genotypes were determined. A higher proportion of ABCB1 3435TT patients suffered excessive infectious complications than those harbouring at least one C allele (OR = 2.5, p = 0.03) during the whole half-year-long intensive phase of chemotherapy. Weaker associations were calculated when ABCB1 1236T-2677T-3435T haplotype homozygotes were tested against the remaining part of the population (OR = 2.3, p = 0.09). During the reinduction phase of therapy, the occurrence of severe leukocytopenia was similar among ABCB1 genotype groups. The frequency of any toxicities were not shown to differ according to the ABCG2 421C>A genotype. Our data suggest that the ABCB1 3435T>C genotype is associated with the infectious complications of the applied chemotherapy regimen.

Databases and computational tools are increasingly important in the study of allergies, particularly in the assessment of allergenicity and allergic cross-reactivity. ALLERDB database contains sequences of allergens and information on reported cross-reactivity between allergens. It focuses on analysis of allergenicity and allergic cross-reactivity of clinically relevant protein allergens. The official IUIS allergen data were extracted from the IUIS Allergen Nomenclature Sub-Committee website, and their sequence information from the public databases, and reference publications. The analysis tools assist allergen data analysis and retrieval, and include keyword searching, BLAST, prediction of allergenicity, modification of BLAST that displays cross-reactive allergens, and graphics representation of cross-reactivity data. ALLERDB is new brand of allergen databases with a rich set of tools for sequence comparison, pattern identification, and visualization of results. It is accessible at http://research.i2r.a-star.edu.sg/Templar/DB/Allergen.

Several data indicate a connection between Chlamydophila pneumoniae infection and asthma. Although C. pneumoniae is a common cause of infection, not all infected patients develop asthma. This suggests that certain individuals may be genetically predisposed to the chronic effects of C. pneumoniae infection on airway functions. We investigated the possible modifying effect of different polymorphisms on C. pneumoniae infection and on the susceptibility to asthma in 318 children, among those 144 had asthma and 174 had no asthmatic symptoms. C. pneumoniae-specific antibodies were measured by ELISA. Tumor necrosis factor-alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), and RANTES (regulated on activation normal T cell expressed and secreted) genotypes were determined by PCR-restriction fragment length polymorphism (RFLP). There were no significant differences in the percentage of children positive for C. pneumoniae-specific antibodies between cases and controls. None of the genotypes was associated with altered susceptibility to C. pneumoniae infection. Among asthmatic children carrying the TNFalpha -308A allele, there were significantly more patients positive for C. pneumoniae-specific IgG, than among control children carrying the same allele (20.1% versus 9.2% of asthmatic versus control children, respectively; p = 0.002; odds ratio = 3.52 (1.52-7.53); p = 0.005). This study indicates the possible roles of polymorphisms in the immune system in the susceptibility to asthma in children infected with C. pneumoniae.

The immune system is a complex functional network of diverse cells and soluble molecules orchestrating innate and adaptive immunity. Biological information, to run these intricate interactions, is not only stored in protein sequences but also in the structure of the glycan part of the glycoconjugates. The spatially accessible carbohydrate structures that contribute to the cell's glycome are decoded by versatile recognition systems in order to maintain the immune homeostasis of an organism. Microbial carbohydrate structures are recognized by pathogen associated molecular pattern (PAMP) receptors of innate immunity including C-type lectins such as MBL, the tandem-repeat-type macrophage mannose receptor, DC-SIGN or dectin-1 of dendritic cells, certain TLRS or the TCR of NKT cells. Natural autoantibodies, a long known effector branch of this network-based operation, are effective to home in on non-self and self-glycosylation also. The recirculating pool of mammalian immune cells is recruited to inflammatory sites by a reaction pathway involving the self-carbohydrate-binding selectins as initial recognition step. Galectins, further key sensors reading the high-density sugar code, exert regulatory functions on activated T cells, among other activities. Autoimmune diseases are being associated with defined changes of glycosylation. This correlation deserves to be thoroughly studied on the levels of structural mimicry and dysregulation as well as effector molecules to devise innovative anti-inflammatory strategies. This review briefly summarizes data on sensor systems for carbohydrate epitopes and implications for autoimmunity.

In this paper we show that, similar to the nervous system and the genetic system, the immune system provides a prototype for a ‘computing mechanism.’ We are presenting an immune response inspired algorithmic framework for spatial–temporal target detection applications using CNN technology (IEEE Trans. Circuits Syst. II 1993; 40(3):163–173; Foundations and Applications. Cambridge University Press: Cambridge, 2002). Unlike most analogic CNN algorithms (IEEE Trans. Circuits Syst. 1988; 35(10):1257–1290; Foundations and Applications. Cambridge University Press: Cambridge, 2002) here we will detect various targets by using a plethora of templates. These algorithms can be implemented successfully only by using a computer upon which thousands of elementary, fully parallel spatial–temporal actions can be implemented in real time. In our tests the results show a statistically complete success rate, and we are presenting a special example of recognizing dynamic objects. Results from tests in a 3D virtual world with different terrain textures are also reported to demonstrate that the system can detect unknown patterns and dynamical changes in image sequences. Applications of the system include in explorer systems for terrain surveillance. Copyright © 2006 John Wiley & Sons, Ltd.

Summary 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. Objective We hypothesized that pregnancy (a T helper-2 polarized state) of asthmatics will enhance the number of circulating T2 lymphocytes, but decrease the subset-producing IFN-γ (T1 lymphocytes) and thereby cause a culminating T2 dominance with possible clinical consequences. Methods IL-4- or IFN-γ-producing T lymphocytes were determined by flow cytometry in healthy (n=8) and asthmatic (n=13) non-pregnant women and healthy (n=18) and asthmatic (n=48) pregnant women of similar chronological and gestational (2nd–3rd trimester) age and asthma severity (Global Initiative for Asthma II–III). Results In the blood of non-pregnant women – healthy or asthmatic – the numbers of IL-4- and IFN-γ+ T cells were very low (

Histamine is known to act, at least in part, as a growth factor for several cell types, and as production of this biogen amine has been found to accelerate the rate of tissue proliferation in wound repair, embryogenesis and malignant growth. Abundant experimental and clinical data suggest that histamine augments in vivo tumour cell proliferation via histamine H2 receptors (H2R). Here, we report that exogenously added histamine stimulates Ets-1 (v-ets erythroblastosis virus E26 oncogene homolog 1) synthesis in human melanoma cells. Involvement of histamine receptors in the histamine induced ets-1 expression has been also studied. Our data show that these newly recognized actions of histamine are mediated by the H2R. Modification of local protooncogen Ets-1 level is likely being involved in the regulation of melanoma growth.

Background. Ets-1 controls the expression of critical genes involved in matrix remodeling. The matrix metal- loproteinase-3 (MMP-3) and urokinase type plasminogen acti- vator (uPA) are typical Ets-1 responsive genes. Recent studies have shown an increase in histamine synthesis and content in various human neoplasias. We hypothesized that the increased local histamine overproduction contributed to activation of matrix remodeling through the activation of MMP-3 expression of peritumoral fibroblasts by means of ets-1 regulation in head and neck squamous cell carcinomas (HNSCCs). Methods. Paraffin-embedded sections of 30 HNSCCs were immunostained for ets-1. The presence of ets-1 and MMP-3 mRNA in tumor samples was confirmed by reverse tran- scriptase-polymerase chain reaction (RT-PCR). To simulate stromal reaction in vitro, cultured human mucosal fibroblast was used. The level of ets-1 and MMP-3 mRNA was compared by use of RT-PCR, as was their protein with flow-cytometry, in the presence or absence of basic fibroblast growth factor (bFGF) (10 ng/mL) and histamine (1 AM). Results. Correlation between ets-1 expression and clini- copathologic background was not significant. In all cases, expression of ets-1 was seen in the stroma. In in vitro study, histamine upregulates production of ets-1 and MMP-3 in cul- tured fibroblast, and bFGF can stimulate histamine expression in fibroblast. Immunofluorescence staining supported the results of RT-PCR and flow cytometry. Conclusions. Ets-1 expression in HNSCCs has no prognos- tic value; however, ets-1 plays an important role in tumor-host interaction. Histamine may accelerate the spread of HNSCC through an ets-1-related mechanism. A 2005 Wiley Periodicals, Inc. Head Neck 27: 585-596, 2005

Proliferation of HL-60 and MOLT4 leukemia cells was inhibited by a c-myb antisense oligonucleotide (ASO) in the presence of a DNA uptake-stimulating protein (DNA uptake-stimulating factor, DUSF). The inhibitory effect was very mild in the absence of DUSF. Sense oligonucleotides or DUSF, alone or in combination, were found to be ineffective. Cellular expression of the c-myb protein was significantly more inhibited by the c-myb ASO in the presence than in the absence of DUSF. In the presence of DUSF, c-myb protein practically disappeared from the nuclei of HL-60 and MOLT4 cells treated with the ASO. Thus, DUSF appears to effectively stimulate the uptake of c-myb ASO into tumor cells in vitro, augmenting its antiproliferative effect by decreasing c-myb expression.

Histamine plays an important role in the regulation of various immunological functions. To evaluate the role of histamine in contact hypersensitivity, contact dermatitis was induced with dinitrofluorobenzene (DNFB) in histidine decarboxylase knockout (HDC-/-) histamine-deficient and wild-type mice. The DNFB-induced increase of the ear thickness was significantly higher in HDC-/- mice than in wild-type mice. Using flow cytometry, significantly lower percentages of CD4+ Th and CD8+ Tc cells, and significantly higher percentages of CD45R+ B cells were observed in the regional lymph nodes in HDC-/- mice than in wild-type mice. In the ear specimens of both groups, the majority of the infiltrating cells were neutrophils and macrophages at 24 and 48 h after challenge. Using immunohistochemistry, we observed significantly more CD45+ leukocytes in HDC-/- mice than in wild-type mice. The expression of Th1 (IL-2, IFN-gamma, TNF-alpha) and Th2 (IL-4) mRNAs was examined by quantitative real time RT-PCR in the ear samples. The levels of Th1 cytokine mRNAs both at 24 and 48 h after challenge and IL-4 mRNA at 48 h showed a significantly higher increase in HDC-/- mice than in wild-type mice. These results suggest that histamine plays a negative immunoregulatory role in DNFB-induced contact hypersensitivity.

Only recently, available microarray methods have been extended to the investigation of such complex pathophysiological conditions as inflammatory disease. Genome analysis gives the possibility of looking for susceptibility gene loci and their allelic combinations. By the analysis of mRNAs (transcriptome), novel players, functional groups of participants and regulatory pathways involved in the inflammation can be revealed. The possibility of comparing several samples is ideal to increase our knowledge about the kinetics of inflammation. The effects and post-receptor signalling events of individual pro- or anti-inflammatory mediators can also be tested. The use of human post mortem samples could yield otherwise inaccessible information on molecular mechanisms of chronic inflammatory diseases. However, the analysis and interpretation of a huge amount of data, the selection of appropriate experimental systems and time points may hide some pitfalls, which emphasize the need to confirm results with independent methods such as e.g. semi-quantitative Northern, real time PCR, RNA-ase protection assay as well as functional studies.

Natural antibodies (NA) are antibodies produced in the absence of known immunization with specific antigens. NA are found in the blood of healthy humans and mice. Histamine influences many aspects of the immune response, including antibody production. However, the role of histamine in the generation of NA has not yet been studied. In this work, we used an ELISA assay to characterize the self-antigen binding repertoires of NA in wild type (WT) mice and in histidine decarboxylase knock-out (HDC-KO) mice, unable to synthesize histamine. We now report that HDC-KO and WT mice differed in the patterns of autoreactivity of their IgM and IgG NA. The NA in HDC-KO sera manifested a larger repertoire of IgM autoantibodies than did the WT sera. The self-antigens bound by IgM from HDC-KO mice included structural proteins, enzymes associated with cellular metabolism, double-stranded and single-stranded DNA, and tissue-specific antigens like insulin. There were relatively fewer differences in the NA repertoire of IgG autoantibodies of the mice: notably, the HDC-KO sera reacted with glutamic acid decarboxylase (GAD), an antigen associated with autoimmune diabetes. These results demonstrate that endogenous histamine can influence the self-reactivity of the NA repertoire.