Host–pathogen interactions in epidermolysis bullosa patients colonized with Staphylococcus aureus

Patients with the genetic blistering disease epidermolysis bullosa (EB) often have chronic wounds that can become colonized by different bacteria, especially the opportunistic pathogen Staphylococcus aureus. We therefore determined the S. aureus colonization rates in EB patients from the Netherlands by collecting swabs from their anterior nares, throats and wounds. Within a period of ∼2 years, more than 90% of the sampled chronic wounds of EB patients were found to be colonized by S. aureus. Molecular typing revealed that EB patients were not colonized by a single S. aureus type. Rather the S. aureus population structure in the sampled EB patients mirrored the local S. aureus population structure within the Netherlands. Furthermore, multiple types of S. aureus were found in close proximity to each other within individual chronic wounds, indicating that these S. aureus types are not mutually exclusive. Over time, strong fluctuations in the S. aureus types sampled from individual EB patients were observed. This high exposure to different S. aureus types is apparently reflected by high plasma levels of antistaphylococcal IgG's, especially in patients carrying multiple S. aureus types. It remains to be determined to what extent this strong immune response protects EB patients against serious staphylococcal infections. Lastly, further research is needed to define the impact of staphylococcal colonization of chronic wounds on the development, exacerbation and healing of such wounds in patients with EB.     

Regulation of cannabinoid receptor gene expression and endocannabinoid levels in lymphocyte subsets by interferon-β: a longitudinal study in multiple sclerosis patients

Evidence suggests the involvement of the cannabinoid system in the pathogenesis of multiple sclerosis (MS). We studied cannabinoid receptor (CB)1 and CB2 receptor gene expression in B, natural killer (NK) and T cells from MS patients before and after 1 year of interferon beta therapy, and compared these levels to those of healthy controls. We also measured the production of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and the gene expression of the endocannabinoid-degrading enzyme fatty acid amide hydrolase (FAAH) in these cells. Prior to interferon therapy, MS patients showed significantly elevated CB₂ expression in B cells, but not in T or NK cells. These levels decreased gradually within 6 months to 1 year of interferon treatment. CB₁ expression was elevated in all cell subsets, but only reached statistical significance in T cells; all levels decreased progressively over time. Before treatment, AEA but not 2-AG levels were significantly elevated in the three cell populations; after 1 year of treatment, all values decreased to control levels. The expression of FAAH was unchanged. The different expression of cannabinoid receptor genes and the increased level of AEA in lymphocytes point to a possible role of the cannabinoid system in MS immune response and its modulation by interferon.     

Interferon regulatory factor 5 gene variants and pharmacological and clinical outcome of Interferonβ therapy in multiple sclerosis

Interferon-β (IFNβ) therapy is effective in approximately half of the patients with relapsing-remitting multiple sclerosis (RRMS). Clinical non-responders were characterized by an increased expression of IFN response genes before the start of therapy, and a lack of a pharmacologically induced increase in IFN response gene activity. Because Interferon Regulatory Factor 5 (IRF5) is a master regulator of IFN-activity, we carried out a candidate gene study of IRF5 gene variants in relation to the pharmacological and clinical response upon IFNβ treatment. We found that patients with the IRF5 rs2004640-TT and rs47281420-AA genotype exerted a poor pharmacological response to IFNβ compared with patients carrying the respective G-alleles (P=0.0006 and P=0.0023, respectively). Moreover, patients with the rs2004640-TT genotype developed more magnetic resonance imaging (MRI)-based T2 lesions during IFNβ treatment (P=0.003). Accordingly, an association between MRI-based non-responder status and rs2004640-TT genotype was observed (P=0.010). For the rs4728142-AA genotype a trend of an association with more T2 lesions during IFNβ treatment and MRI-based non-responder status was observed (P=0.103 and P=0.154, respectively). The clinical relevance of the rs2004640-TT genotype was validated in an independent cohort wherein a shorter time to first relapse was found (P=0.037). These findings suggest a role for IRF5 gene variation in the pharmacological and clinical outcome of IFNβ therapy that might have relevance as biomarker to predict the response to IFNβ in multiple sclerosis.     

Maternal–fetal metabolic gene–gene interactions and risk of neural tube defects

Single-gene analyses indicate that maternal genes associated with metabolic conditions (e.g., obesity) may influence the risk of neural tube defects (NTDs). However, to our knowledge, there have been no assessments of maternal–fetal metabolic gene–gene interactions and NTDs. We investigated 23 single nucleotide polymorphisms among 7 maternal metabolic genes (ADRB3, ENPP1, FTO, LEP, PPARG, PPARGC1A, and TCF7L2) and 2 fetal metabolic genes (SLC2A2 and UCP2). Samples were obtained from 737 NTD case-parent triads included in the National Birth Defects Prevention Study for birth years 1999–2007. We used a 2-step approach to evaluate maternal–fetal gene–gene interactions. First, a case-only approach was applied to screen all potential maternal and fetal interactions (n = 76), as this design provides greater power in the assessment of gene–gene interactions compared to other approaches. Specifically, ordinal logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for each maternal–fetal gene–gene interaction, assuming a log-additive model of inheritance. Due to the number of comparisons, we calculated a corrected p-value (q-value) using the false discovery rate. Second, we confirmed all statistically significant interactions (q < 0.05) using a log-linear approach among case-parent triads. In step 1, there were 5 maternal–fetal gene–gene interactions with q < 0.05. The “top hit” was an interaction between maternal ENPP1 rs1044498 and fetal SLC2A2 rs6785233 (interaction OR = 3.65, 95% CI: 2.32–5.74, p = 2.09 × 10^− 8, q = 0.001), which was confirmed in step 2 (p = 0.00004). Our findings suggest that maternal metabolic genes associated with hyperglycemia and insulin resistance and fetal metabolic genes involved in glucose homeostasis may interact to increase the risk of NTDs.     

Association between vitamin D receptor polymorphisms and multiple sclerosis: systematic review and meta-analysis of case–control studies

Vitamin D receptor (VDR) polymorphisms have been studied as potential contributors to multiple sclerosis (MS). However, published studies differ with respect to study design and the significance of the effects detected. The aim of this study was to quantify the magnitude of the risk associated with the TaqI, BsmI, ApaI and FokI VDR polymorphisms in MS using a meta-analysis approach. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic search and meta-analysis of the literature. Subgroup analyses were performed to detect potential sources of heterogeneity from the selected study characteristics. The stability of the summary risk was evaluated using sensitivity analyses. The meta-analysis included a total of 3300 cases and 3194 controls from 13 case–control studies. There were no significant associations found between TaqI and BsmI polymorphisms and MS risk. The association between the ApaI polymorphism and MS risk was significant in the homozygous and codominant models (P=0.013 and P=0.031, respectively), suggesting that the AA ApaI genotype might be a significant MS risk factor. Publication year and age significantly affected the association between TaqI polymorphisms and MS (P=0.014 and P=0.010, respectively), which indicates a protective effect of the major T allele. The AA ApaI and FF FokI genotypes are significant risk factors for MS. The association between the TaqI polymorphism and MS risk is significantly affected by study characteristics.     

Is Chlamydia pneumoniae present in brain lesions of patients with multiple sclerosis?

We investigated the presence of Chlamydia pneumoniae in 81 normal and pathological specimens obtained from postmortem brain tissues of patients with multiple sclerosis and with other neurological or nonneurological diseases. The assays used included PCR amplification of all DNA samples in the initial study. Culture and a second PCR amplification of the organism in a subset of 19 brain specimens were also performed in two separate laboratories. All results were negative. Thus, this study on a large number of brain tissues suggests that C. pneumoniae is not involved in inflammatory demyelination.     

Involvement of germline DDX1–MYCN duplication in inherited nephroblastoma

This report concerns a 3-year-old girl with prenatal bilateral nephroblastomatosis and a family history of nephroblastoma. This girl had a chromosome 8 pericentric inversion inherited from her father. This inversion was observed in healthy individuals of the family and was absent in other individuals suffering from embryonic kidney tumor. We then supposed that another genetic anomaly predisposed her to tumorogenesis. Additional cryptic imbalances are reported in cases of apparently balanced chromosomal rearrangements with an abnormal phenotype. Array-CGH analysis showed a 569 kb duplication at 2p24.3 including the DDX1 and MYCN genes. This duplication was inherited from the patient's father who also had a nephroblastoma. A link between germline MYCN duplication and the occurrence of other embryonic cancers such as neuroblastoma has already been described. We supposed that germline DDX1–MYCN duplication could also be involved in the apparition of nephroblastomas.     

Impaired IFN-γ production and proliferation of NK cells in multiple sclerosis

NK cells are multicompetent lymphocytes of the innate immune system with a central role in host defense and immune regulation. Studies in experimental animal models of multiple sclerosis (MS) provided evidence for both pathologic and protective effects of NK cells. Humans harbor two functionally distinct NK-cell subsets exerting either predominantly cytotoxic (CD56(dim)CD16(+)) or immunoregulatory (CD56(bright)CD16(-)) functions. We analyzed these two subsets and their functions in the peripheral blood of untreated patients with relapsing-remitting MS compared with healthy blood donors. While ex vivo frequencies of CD56(bright)CD16(-) and CD56(dim)CD16(+) NK cells were similar in patients and controls, we found that cytokine-driven in vitro accumulation and IFN-γ production of CD56(bright)CD16(-) NK cells but not of their CD56(dim)CD16(+) counterparts were substantially diminished in MS. Impaired expansion of CD56(bright)CD16(-) NK cells was cell intrinsic because the observed effects could be reproduced with purified NK cells in an independent cohort of patients and controls. In contrast, cytolytic NK-cell activity toward the human erythromyeloblastoid leukemia cell line K562, the allogeneic CD4(+) T cell line CEM and allogeneic primary CD4(+) T-cell blasts was unchanged. Thus, characteristic functions of CD56(bright)CD16(-) NK cells, namely cytokine-induced NK cell expansion and IFN-γ production, are compromised in the NK cell compartment of MS patients.     

The blood–brain-barrier in multiple sclerosis: Functional roles and therapeutic targeting

In most regions of the central nervous system (CNS), the composition of the neuronal microenvironment is maintained by virtue of particular blood–brain-barrier (BBB) characteristics, to which vascular endothelial cells (ECs) contribute an important role. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS, characterized at tissue level by multifocal perivascular infiltrates, predominantly of lymphocytes and macrophages. Thus, lymphocyte recruitment into the brain across ECs of the BBB represents a critical event in disease pathogenesis, which is highly restricted and carefully regulated. In recent years, different investigations have identified the crucial components involved in leukocyte migration, providing new insights into mechanisms modulating neuroinflammatory reactions. In this review, several topics relating to these events are discussed, namely: (1) cellular and molecular characteristics of the BBB regulating permeability, as well as signals inducing EC differentiation in the brain and specific cell properties; (2) pathogenic mechanisms guiding the migration of different leukocyte populations through the BBB in MS; and (3) current knowledge on how different MS therapies targeting leukocytes migration across the BBB function. Furthermore, because the BBB has proven to be an important retaining wall preventing drug passage into the CNS, novel strategies directed at successful delivery of large molecules for effective treatment of various inflammatory conditions of the brain, both currently available or still under development, are discussed.     

Monocyte-derived tissue transglutaminase in multiple sclerosis patients: reflecting an anti-inflammatory status and function of the cells?

Background

Leukocyte infiltration into the central nervous system is an important feature of multiple sclerosis (MS) pathology. Among the infiltrating cells, monocytes comprise the largest population and are considered to play a dual role in the course of the disease. The enzyme tissue transglutaminase (TG2), produced by monocytes, plays a central role in monocyte adhesion/migration in animal models of MS. In the present study, we questioned whether TG2 expression is altered in monocytes from MS patients compared to healthy control (HC) subjects. Moreover, we determined the inflammatory status of these TG2-expressing monocytes, what inflammatory factor regulates TG2 expression, and whether TG2 can functionally contribute to their adhesion/migration processes.

Methods

Primary human monocytes from MS patients and HC subjects were collected, RNA isolated and subjected to qPCR analysis. Human THP-1 monocytes were lentivirally transduced with TG2 siRNA or control and treated with various cytokines. Subsequently, mRNA levels of inflammatory factors, adhesion properties, and activity of RhoA were analyzed in interleukin (IL)-4-treated monocytes.

Results

TG2 mRNA levels are significantly increased in monocytes derived from MS patients compared to HC subjects. In addition, correlation analyses indicated that TG2-expressing cells display a more anti-inflammatory, migratory profile in MS patients. Using THP-1 monocytes, we observed that IL-4 is a major trigger of TG2 expression in these cells. Furthermore, knockdown of TG2 expression leads to a pro-inflammatory profile and reduced adhesion/migration properties of IL-4-treated monocytes.

Conclusions

TG2-expressing monocytes in MS patients have a more anti-inflammatory profile. Furthermore, TG2 mediates IL-4-induced anti-inflammatory status in THP-1 monocytes, adhesion, and cytoskeletal rearrangement in vitro. We thus propose that IL-4 upregulates TG2 expression in monocytes of MS patients, driving them into an anti-inflammatory status.

     

Microbiota,diet, and the gut–brain axis in multiple sclerosis and stroke

Intestinal microbiota can influence the phenotype and function of immune cell responses through the dissemination of bacterial antigens or metabolites. Diet is one of the major forces shaping the microbiota composition and metabolism, contributing to host homeostasis and disease susceptibility. Currently, nutrition is a complementary and alternative approach to the management of metabolic and neurological diseases and cancer. However, the knowledge of the exact mechanism of action of diet and microbiota on the gut–brain communication is only developing in recent years. Here, we reviewed the current knowledge on the effect of diet and microbiota on the gut–brain axis in patients with two different central nervous system diseases, multiple sclerosis and stroke. We have also highlighted the open questions in the field that we believe are important to address to gain a deeper understanding of the mechanisms by which diet can directly or indirectly affect the host via the microbiota. We think this will open up new approaches to the treatment, diagnosis, and monitoring of various diseases.     

The alterations of cerebrospinal fluid TNF-alpha and TGF-beta2 levels in early relapsing–remitting multiple sclerosis

Immunologic Research - This study aimed to analyze serum and cerebrospinal fluid (CSF) concentrations of proinflammatory and anti-inflammatory cytokines produced by T regulatory (Treg) cells in...     

Glatiramer acetate-specific antibody titres in patients with relapsing / remitting multiple sclerosis and in experimental autoimmune encephalomyelitis

Glatiramer acetate (GA) is an immunomodulatory drug approved for the treatment of clinically isolated syndrome (CIS) and relapsing/remitting multiple sclerosis (RRMS). As an antigen-based therapy, GA induces GA-specific antibodies in treated patients and animals. GA-specific antibodies do not neutralize therapeutic effects on relapses and disability. Rather, it has been suggested that GA-specific antibodies may be associated with improved clinical outcomes. We evaluated antibody responses in eight patients with RRMS treated with GA for 15 months and antibody responses in GA-treated C57BL/6 mice before and after induction of experimental autoimmune encephalomyelitis (EAE). There were no significant differences from pretreatment levels of total IgE or GA-specific IgE in patients with RRMS. Total IgG1, IgG3 and GA-specific IgG4 were significantly increased at 15 months of GA treatment. Antibody type and titre were not associated with clinical outcomes, i.e. expanded disability status scale (EDSS) score, disease burden on magnetic resonance images (MRI) or clinical relapses. In contrast, mice with EAE showed a marked increase in GA-specific IgE and GA-specific IgG1 antibody responses. GA-treated mice demonstrated improved clinical symptoms and lower mortality than untreated controls. Our results suggest that antibody responses to GA are heterogeneous among patients with RRMS, with no apparent association between antibody response and clinical outcomes. Clinical improvements in EAE-induced GA-treated mice suggest that GA-specific IgE and IgG1 may contribute to GA treatment effects in EAE.     

Antibodies in sera from multiple sclerosis patients recognize Trichinella spiralis muscle larvae excretory–secretory antigens

Helminths, as complex pathogens, possess a large number of different epitopes, some of which may be similar to the epitopes of the host. Besides being the cause for the activation of self-reactive immune cells, molecular mimicry may also be the cause for the expansion of regulatory T cells, crucial for the host tolerance of self-antigens. Amelioration of experimental autoimmune encephalomyelitis (EAE), animal model of multiple sclerosis (MS), caused by Trichinella spiralis infection or application of its muscle larvae excretory-secretory products (ES L1), was achieved through activation of Th2 and regulatory responses. The present study aimed to reveal whether the cause of observed immunomodulation could be the existence of shared epitopes between ES L1 antigens and auto-antigens. Serum samples from 92 MS patients were tested in Western blot for the reactivity toward components of ES L1. Immunoglobulins from the sera of MS patients recognized several ES L1 components, but 45, 49 and 58 kDa proteins dominated others by the frequency of interaction. According to the logistic regression analysis, these interactions were statistically significantly associated with MS, regardless of the disease phenotype or severity. Selected molecules might share homology with self-antigens and as such are worthy of further investigation in terms of potential immunomodulatory capacity and involvement in the parasite’s provoked amelioration of EAE.     

Aging and cardiovascular diseases: The role of gene–diet interactions

In the study of longevity, increasing importance is being placed on the concept of healthy aging rather than considering the total number of years lived. Although the concept of healthy lifespan needs to be defined better, we know that cardiovascular diseases (CVDs) are the main age-related diseases. Thus, controlling risk factors will contribute to reducing their incidence, leading to healthy lifespan. CVDs are complex diseases influenced by numerous genetic and environmental factors. Numerous gene variants that are associated with a greater or lesser risk of the different types of CVD and of intermediate phenotypes (i.e., hypercholesterolemia, hypertension, diabetes) have been successfully identified. However, despite the close link between aging and CVD, studies analyzing the genes related to human longevity have not obtained consistent results and there has been little coincidence in the genes identified in both fields. The APOE gene stands out as an exception, given that it has been identified as being relevant in CVD and longevity. This review analyzes the genomic and epigenomic factors that may contribute to this, ranging from identifying longevity genes in model organisms to the importance of gene–diet interactions (outstanding among which is the case of the TCF7L2 gene).     

An association study between the genetic polymorphisms within GnRHI, LHβ and FSHβ genes and central precocious puberty in Chinese girls

Objectives: Gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are three hypothalamic–pituitary–gonadal axis expressing hormones. They play critical roles in the onset of puberty. Here we report the relationship between the three hormones and Central Precocious Puberty (CPP) in Chinese Han girls. Methods: We analyzed the single nucleotide polymorphisms (SNPs) of 5′-flanking regions of these genes by DNA sequencing in 27 CPP samples. Then the SNPs sites were genotyped by ligase detection reaction in a total of 283 Chinese Han CPP cases and 284 matched controls. Distributions of the polymorphisms and haplotypes were calculated for statistical evaluation. Results: Nine SNPs (One in GnRHI gene: −2003 C/T; Five in LHβ gene: −1456 C/G, −1424 C/G, −238 G/A, −164 G/A and −34 T/A; Three in FSHβ gene: −1825 T/C, −261 G/T and −132 T/A.) were found. A quantitative genetic association study was made. −1825 T/C in FSHβ gene was related with CPP with a weak effect (P = 0.025). A haplotype in the 5′-flanking region of LHβ gene was significantly associated with CPP in Chinese Han girls (P = 8.25 × 10⁻⁰⁹). However, analysis software showed that none of SNP was found in the regulating control element of these genes. Conclusions: Our finding implies that the polymorphisms in the 5′-flanking regions of FSHβ gene and LHβ gene probably were related to the puberty onset time of these girls. Further studies on the polymorphisms are needed for the exact mechanism.