The helminth Trichuris suis suppresses TLR4-induced inflammatory responses in human macrophages.

Recent clinical trials in patients with inflammatory diseases like multiple sclerosis (MS) or inflammatory bowel disease (IBD) have shown the beneficial effects of probiotic helminth administration, although the underlying mechanism of action remains largely unknown. Potential cellular targets may include innate immune cells that propagate inflammation in these diseases, like pro-inflammatory macrophages. We here investigated the effects of the helminth Trichuris suis soluble products (SPs) on the phenotype and function of human inflammatory (granulocyte-macrophage colony-stimulating factor (GM-CSF)-differentiated) macrophages. Interestingly, we here show that T. suis SPs potently skew inflammatory macrophages into a more anti-inflammatory state in a Toll-like receptor 4 (TLR4)-dependent manner, and less effects are seen when stimulating macrophages with TLR2 or -3 ligands. Gene microarray analysis of GM-CSF-differentiated macrophages further revealed that many TLR4-induced inflammatory mediators, including interleukin (IL)-12B, CCL1 and CXCL9, are downregulated by T. suis SPs. In particular, we observed a strong reduction in the expression and function of P2RX7, a purinergic receptor involved in macrophage inflammation, leading to reduced IL-1ß secretion. In conclusion, we show that T. suis SPs suppress a broad range of inflammatory pathways in GM-CSF-differentiated macrophages in a TLR4-dependent manner, thereby providing enhanced mechanistic insight into the therapeutic potential of this helminth for patients with inflammatory diseases.

CNS myelin induces regulatory functions of DC-SIGN-expressing, antigen-presenting cells via cognate interaction with MOG.

Myelin oligodendrocyte glycoprotein (MOG), a constituent of central nervous system myelin, is an important autoantigen in the neuroinflammatory disease multiple sclerosis (MS). However, its function remains unknown. Here, we show that, in healthy human myelin, MOG is decorated with fucosylated N-glycans that support recognition by the C-type lectin receptor (CLR) DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) on microglia and DCs. The interaction of MOG with DC-SIGN in the context of simultaneous TLR4 activation resulted in enhanced IL-10 secretion and decreased T cell proliferation in a DC-SIGN-, glycosylation-, and Raf1-dependent manner. Exposure of oligodendrocytes to proinflammatory factors resulted in the down-regulation of fucosyltransferase expression, reflected by altered glycosylation at the MS lesion site. Indeed, removal of fucose on myelin reduced DC-SIGN-dependent homeostatic control, and resulted in inflammasome activation, increased T cell proliferation, and differentiation toward a Th17-prone phenotype. These data demonstrate a new role for myelin glycosylation in the control of immune homeostasis in the healthy human brain through the MOG-DC-SIGN homeostatic regulatory axis, which is comprised by inflammatory insults that affect glycosylation. This phenomenon should be considered as a basis to restore immune tolerance in MS.

Cerebrospinal fluid anti-whole myelin antibodies are not correlated to magnetic resonance imaging activity in multiple sclerosis.

BACKGROUND: The role of antimyelin antibodies as biomarker in multiple sclerosis is subject of debate. Here antimyelin antibody reactivity against native myelin is studied in CSF and serum. OBJECTIVE: To compare antimyelin antibody reactivity between patients with multiple sclerosis (MS) and patients with other neurological diseases in CSF and serum. In addition, MRI measures were studied in relation to antimyelin antibody reactivity. METHODS: 77 MS patients (13 primary progressive, 27 secondary progressive and 37 relapsing remitting), 26 patients with other non-inflammatory neurological diseases and 9 patients with inflammatory neurological diseases other than MS were included. A myelin flow cytometry assay was used to detect anti-myelin antibody levels which were expressed as mean fluorescence intensity (myelin-MFI). MRI outcome measures were new or persistent T2 lesions, gadolinium enhancing T1 lesions and brain atrophy which were assessed by normalized brain volumes. RESULTS: There was no significant difference between myelin-MFI values in serum and CSF between MS patients and controls (Mann-Whitney test p=0.19 and p=0.51). Myelin-MFI values in CSF were not correlated with number of T2 lesions (Spearman r=-0.023, p=0.85), number of gadolinium enhancing T1 lesions (Spearman r=-0.066, p=0.588) or normalized brain volume (Spearman r=-0.065, p=0.594). CONCLUSIONS: These results do not confirm an association between anti-myelin antibody reactivity and the presence of MS or MRI measures of disease activity.

Increased plasma 8,12-iso-iPF2alpha- VI levels in relapsing multiple sclerosis patients are not predictive of disease progression.

BACKGROUND: Oxidative stress plays an important role in multiple sclerosis (MS). Isoprostanes are biomarkers for oxidative stress and have been related to neurological disease progression. OBJECTIVE: To study whether plasma isoprostane levels were related to disease progression in MS. METHODS: Plasma levels of 8,12-iso-iPF2alpha-VI were determined in 17 patients with clinically isolated syndrome (CIS), 41 relapsing-remitting MS (RRMS) patients and 5 primary progressive MS (PPMS) patients and related to MRI and clinical disease parameters. RESULTS: Isoprostane levels were similar in CIS (60.9, interquartile range (IQR): 47.7-77.7 pg/ml) and RRMS patients (65.3, IQR: 51.9-82.8 pg/ml). The plasma levels were lower in PPMS patients (42.5, IQR: 37.1-49.9) pg/ml, p<0.05) compared to CIS and RRMS patients in this cohort, which was not confirmed in a second cohort. Baseline isoprostane levels were not related to clinical progression defined by conversion form CIS to RRMS or change in Expanded Disability Status Scale (EDSS) or MS Functional Composite (MSFC) scores during six years of follow-up (CIS + RRMS), nor to change in volume of gadolinium enhancing lesions, T2 lesion load or T1 hypointense lesion load during 2.8 years of follow-up (CIS + RRMS). CONCLUSION: These results do not support a strong role of 8,12-iso-iPF2alpha-VI in the prediction of disease progression in MS.

Identification of biomarkers for diagnosis and progression of MS by MALDI-TOF mass spectrometry.

INTRODUCTION: Body fluid biomarkers for clinical subtyping and monitoring of disease progression are of considerable interest in multiple sclerosis (MS). Proteomics tools are optimal for the unbiased simultaneous detection of large series of peptides and proteins. OBJECTIVES: To identify novel candidate biomarkers discriminating patients with MS from patients with other neurological diseases (OND), and for subtyping of relapsing-remitting (RR), secondary progressive (SP) and primary progressive (PP) MS patients using a high-throughput MALDI-TOF-based mass spectrometry method. METHODS: Paired cerebrospinal fluid (CSF) and serum samples of 41 RRMS, 30 SPMS, 13 PPMS patients and 25 patients with OND were analysed. RESULTS: Out of a total of 100 detected peptides in CSF and 200 peptides in serum, 11 peptides were differentially regulated in serum and two in CSF between patients with MS and the OND control group. Eleven peptides were differentially regulated in both serum and CSF between relapse-onset MS and PPMS patients. Lastly, four peptides were differentially regulated in serum and two in CSF between RRMS and SPMS patients. Specific peaks regulated in MS were tentatively identified as fragments of secretogranin III and complement C3. The peak intensity of the CSF peptide ion with m/z value 8607.7 correlated to atrophy (r = -0.27, p < 0.005), black hole volumes (r = 0.31, p < 0.008) and total lesion load (r = 0.34, p < 0.003). A serum peptide with m/z value of 872.4 elevated in SPMS correlated to Expanded Disability Status Scale (r = 0.341, p < 0.005) and atrophy (r = -0.286, p < 0.028). CONCLUSIONS: Using high-throughput body fluid profiling by MALDI-TOF mass spectrometry, small proteins and peptides were detected as promising candidate biomarkers for diagnosis and disease progression of MS.

The release of cytokines by macrophages is not affected by myelin ingestion.

Macrophages play an important role in demyelination in multiple sclerosis (MS). Activated macrophages ingest myelin particles, thereby acquiring a foamy appearance. Foamy macrophages in MS lesions were described as being anti-inflammatory. Therefore, these cells might play a role in modulating the inflammatory state of an active lesion. Here, we investigated the mechanism by which myelin uptake leads to skewing of macrophages toward an anti-inflammatory phenotype. Macrophages were incubated with myelin, leading to the development of foamy macrophages. Afterwards, the cells were stimulated with the TLR-4 ligand lipopolysaccharide (LPS), and cytokine production was determined. Interestingly, foamy macrophages appeared to have a reduced cytokine secretion and were LPS insensitive only when generated with one of the myelin preparations. The factor responsible for the different outcomes between different myelin batches turned out to be LPS. We demonstrated that LPS contamination induced insensitivity to LPS in foamy macrophages. On the contrary, foamy macrophages generated in the presence of LPS-free myelin were able to secrete cytokines upon activation. To conclude, myelin-laden macrophages were not LPS insensitive, indicating that they had not acquired an anti-inflammatory phenotype.

Change in body mass can overrule the effects of maternal testosterone on primary offspring sex ratio of first eggs in homing pigeons.

The phenomenon of primary offspring sex ratio adjustment is being extensively studied, yet knowledge of the underlying proximate mechanism is still mainly hypothetical. Female birds are the heterogametic sex, thus potentially controlling the sex of the gamete to be fertilized. In several bird species, independent studies showed effects of maternal plasma testosterone, corticosterone, or condition on primary offspring sex ratio. Our objective was to investigate the causal relation between these two maternal hormones, body condition, and offspring sex ratio in homing pigeons (Columba livia domestica). Following our earlier study, we again implanted females with testosterone and determined embryo sex of first eggs. To identify the pathway of sex ratio adjustment, we repeatedly measured not only maternal plasma testosterone and mass but also plasma corticosterone, cholesterol, and glucose, all indicators of body condition. We also calculated the temporal change in these parameters, which has been proposed to be a more accurate predictor of offspring sex ratio compared with the absolute values. Furthermore, we analyzed testosterone concentrations in outer yolk layers, which potentially influence the first meiotic division of the gamete. We found no relation between plasma parameter and embryo sex of first eggs; testosterone treatment did not affect any of the measured parameters. However, females that increased in mass produced more male embryos, irrespective of treatment group. Outer yolk layer testosterone concentrations did not differ between treatment groups or between male and female eggs. We propose that not only the absolute values but also the complex interactions between maternal hormones and body condition ultimately affect the mechanism of primary offspring sex manipulation.

Abundant extracellular myelin in the meninges of patients with multiple sclerosis.

BACKGROUND: In multiple sclerosis (MS) myelin debris has been observed within MS lesions, in cerebrospinal fluid and cervical lymph nodes, but the route of myelin transport out of the brain is unknown. Drainage of interstitial fluid from the brain parenchyma involves the perivascular spaces and leptomeninges, but the presence of myelin debris in these compartments has not been described. AIMS: To determine whether myelin products are present in the meninges and perivascular spaces of MS patients. METHODS: Formalin-fixed brain tissue containing meninges from 29 MS patients, 9 non-neurological controls, 6 Alzheimer's disease, 5 stroke, 5 meningitis and 7 leucodystrophy patients was investigated, and immunohistochemically stained for several myelin proteins [proteolipid protein (PLP), myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase)]. On brain material from MS patients and (non)neurological controls, PLP immunostaining was used to systematically investigate the presence of myelin debris in the meninges, using a semiquantitative scale. RESULTS: Extensive extracellular presence of myelin particles, positive for PLP, MBP, MOG and CNPase in the leptomeninges of MS patients, was observed. Myelin particles were also observed in perivascular spaces of MS patients. Immunohistochemical double-labelling for macrophage and dendritic cell markers and PLP confirmed that the vast majority of myelin particles were located extracellularly. Extracellular myelin particles were virtually absent in meningeal tissue of non-neurological controls, Alzheimer's disease, stroke, meningitis and leucodystrophy cases. CONCLUSIONS: In MS leptomeninges and perivascular spaces, abundant extracellular myelin can be found, whereas this is not the case for controls and other neurological disease. This may be relevant for understanding sustained immunogenicity or, alternatively, tolerogenicity in MS.

Combination of CSF N-acetylaspartate and neurofilaments in multiple sclerosis.

OBJECTIVE: Axonal degeneration is the likely cause of disease progression in multiple sclerosis (MS). Our previous results indicated that neuron-specific N-acetylaspartate (NAA) is a candidate CSF biomarker for disease progression in MS. The aim of this study was to explore the potential of NAA as an early biomarker of axonal damage in MS. Next, we wanted to know the additional value of measurement of NAA compared to other candidate markers for axonal damage, such as neurofilament subunits and tau protein. METHODS: Levels of NAA, neurofilament light, neurofilament heavy, and tau were determined in CSF of patients with clinically isolated syndrome (CIS, n = 38), relapsing-remitting MS (RRMS, n = 42), secondary progressive MS (SPMS, n = 28), and primary progressive MS (PPMS, n = 6); patients without neurologic disease (ND, n = 28); noninflammatory neurologic controls (n = 18); and inflammatory neurologic controls (n = 39). RESULTS: CSF NAA levels were decreased in patients with SPMS compared to ND controls, patients with CIS, and patients with RRMS. CSF NAA levels in patients with CIS and RRMS were similar to those in ND subjects. All axonal damage proteins showed specific patterns of changes and relations with disease activity measures. The neurofilament light chain levels were already increased in patients with CIS, especially in patients who converted to MS. The neurofilament heavy chain levels were highest in the patients with SPMS. Tau levels were similar in MS and ND. CONCLUSIONS: CSF N-acetylaspartate (NAA) levels were not different from patients without neurologic disease in early stages of multiple sclerosis, though decreased as the disease progressed. Combining CSF NAA and neurofilament levels yields information on different phases of axonal pathology.

Testosterone has a long-term effect on primary sex ratio of first eggs in pigeons--in search of a mechanism.

Despite accumulating evidence that birds, in which females are the heterogametic sex, are able to manipulate primary offspring sex ratio, the underlying mechanism remains elusive. Steroid hormones, which govern female reproduction and are also accumulated by the developing follicle could potentially affect primary sex ratio by differential follicle development in relation to future sex and meiotic drive, or by sex specific influence on oocyte abortion or fertilization. So far, experimental results on the involvement of maternal testosterone (T) in offspring sex manipulation are ambiguous. To investigate the effect of T on primary sex ratio and elucidate underlying mechanisms, we elevated circulating T levels in female homing pigeons (Columba livia). During the course of the experiment females produced three clutches--before and during T implantation, and one year after implant removal. Intriguingly, first eggs, but not second eggs of T females were significantly male biased relative to sham-implanted controls. One year after cessation of the treatment the male bias was still present, indicating long-term effects on female reproductive physiology. T treatment did not affect maternal body condition, nor was body condition correlated with offspring sex ratio. Our data on timing of oviposition, lack of infertile eggs, and yolk weight indicate a possible role for sex specific follicle abortion, perhaps in combination with meiotic drive. However, despite T treatment elevating maternal plasma levels, egg yolk T concentrations did not differ between treatment groups and did not vary with embryo sex, suggesting that yolk T is not involved in meiotic drive.

An in vitro model for de- and remyelination using lysophosphatidyl choline in rodent whole brain spheroid cultures.

The process of demyelination occurring in diseases as multiple sclerosis is usually investigated in animal models. A major drawback of animal models is that only one condition can be tested per animal, necessitating many animals and systemic effects are factors to be considered. The aim of the study was to develop a reproducible in vitro model for de- and remyelination using whole brain spheroid cultures and lysophosphatidyl choline (LPC). In spheroid cultures, single cell suspensions of embryonic day 15 rodent brain cells reaggregate under constant rotation. Three-dimensional contacts form between the central nervous system cell types present. Multilayered myelin is maximal in four-week old cultures. A week of repeated exposure to LPC led to 30% loss of MBP protein concentration and 2',3'-cyclic nucleotide 3'-phosphodiesterase activity measurements in both rat and mouse spheroids and 56% loss in the number of myelin sheets, with partial remyelination after a week of recovery. The number of dividing cells was increased after LPC exposure and oligodendrocytes were shown to be among the dividing cells. Microglia and astrocytes were not affected and neurons were relatively spared. This suggests that LPC toxicity is specific for myelin and oligodendrocytes. LPC toxicity could be decreased using cholesterol and simvastatin, suggesting that LPC works through altering membrane composition. Thus, in different rodent species and using different read-outs, we could reproducibly show de- and remyelination in spheroid cultures after LPC exposure. This model for demyelination with potential for remyelination offers possibilities for testing novel therapies and studying mechanisms of remyelination.

Severe oxidative damage in multiple sclerosis lesions coincides with enhanced antioxidant enzyme expression.

Reactive oxygen species (ROS) and subsequent oxidative damage may contribute to the formation and persistence of multiple sclerosis (MS) lesions by acting on distinct pathological processes. ROS initiate lesion formation by inducing blood-brain barrier disruption, enhance leukocyte migration and myelin phagocytosis, and contribute to lesion persistence by mediating cellular damage to essential biological macromolecules of vulnerable CNS cells. Relatively little is known about which CNS cell types are affected by oxidative injury in MS lesions. Here, we show the presence of extensive oxidative damage to proteins, lipids, and nucleotides occurring in active demyelinating MS lesions, predominantly in reactive astrocytes and myelin-laden macrophages. Oxidative stress can be counteracted by endogenous antioxidant enzymes that confer protection against oxidative damage. Here, we show that antioxidant enzymes, including superoxide dismutase 1 and 2, catalase, and heme oxygenase 1, are markedly upregulated in active demyelinating MS lesions compared to normal-appearing white matter and white matter tissue from nonneurological control brains. Particularly, hypertrophic astrocytes and myelin-laden macrophages expressed an array of antioxidant enzymes. Enhanced antioxidant enzyme production in inflammatory MS lesions may reflect an adaptive defense mechanism to reduce ROS-induced cellular damage.

Serum homocysteine levels in relation to clinical progression in multiple sclerosis.

BACKGROUND: Elevated homocysteine levels are associated with various neurodegenerative diseases and have even been identified as a risk factor for some of these. Homocysteine levels may be elevated in patients with multiple sclerosis (MS) but large studies are lacking and the relation with disease progression remains to be determined. AIM: The aim of the study was to investigate homocysteine levels in patients with MS and in controls, and to study the relationship between homocysteine levels and clinical progression in MS. METHODS: Serum homocysteine levels were compared between MS subtypes (n = 219) and controls (n = 152). Homocysteine levels were associated with baseline and follow-up clinical severity scores. RESULTS: The results showed that serum homocysteine values were similar in patients with MS and controls. Baseline scores on the Expanded Disability Status Scale were higher in patients with secondary progressive MS (SPMS) in the top compared with the bottom quartile of homocysteine levels (p = 0.02). The baseline scores on the Multiple Sclerosis Functional Composite (MSFC) and Paced Auditory Serial Addition Test (PASAT), which measures cognitive functioning, were lower in patients with SPMS in the top compared with the bottom quartile of homocysteine levels (MSFC, p = 0.02; PASAT, p = 0.02). High homocysteine levels were associated with a decline in PASAT scores during follow-up in patients with primary progressive MS (p = 0.009). CONCLUSION: Serum total homocysteine levels are associated with several measures of disease progression in MS but are not elevated in patients with MS compared with controls. The association of homocysteine levels with cognition in patients with progressive MS raises the question of whether homocysteine directly impacts on MS or reflects a more general neurodegenerative process.

Targeting the tetraspanin CD81 blocks monocyte transmigration and ameliorates EAE.

Leukocyte infiltration is a key step in the development of demyelinating lesions in multiple sclerosis (MS), and molecules mediating leukocyte-endothelial interactions represent prime candidates for the development of therapeutic strategies. Here we studied the effects of blocking the integrin-associated tetraspanin CD81 in in vitro and in vivo models for MS. In an in vitro setting mAb against CD81 significantly reduced monocyte transmigration across brain endothelial cell monolayers, both in rodent and human models. Interestingly, leukocyte as well as endothelial CD81 was involved in this inhibitory effect. To assess their therapeutic potential, CD81 mAb were administered to mice suffering from experimental autoimmune encephalomyelitis (EAE). We found that Eat2, but not 2F7 mAb directed against mouse CD81 significantly reduced the development of neurological symptoms of EAE when using a preventive approach. Concomitantly, Eat2 treated animals showed reduced inflammation in the spinal cord. We conclude that CD81 represents a potential therapeutic target to interfere with leukocyte infiltration and ameliorate inflammatory neurological damage in MS.

Over-expression of a gibberellin 2-oxidase gene from Phaseolus coccineus L. enhances gibberellin inactivation and induces dwarfism in Solanum species.

Gibberellins (GAs) are endogenous hormones that play a predominant role in regulating plant stature by increasing cell division and elongation in stem internodes. The product of the GA 2-oxidase gene from Phaseolus coccineus (PcGA2ox1) inactivates C(19)-GAs, including the bioactive GAs GA(1 )and GA(4), by 2beta-hydroxylation, reducing the availability of these GAs in plants. The PcGA2ox1 gene was introduced into Solanum melanocerasum and S. nigrum (Solanaceae) by Agrobacterium-mediated transformation with the aim of decreasing the amounts of bioactive GA in these plants and thereby reducing their stature. The transgenic plants exhibited a range of dwarf phenotypes associated with a severe reduction in the concentrations of the biologically active GA(1) and GA(4). Flowering and fruit development were unaffected. The transgenic plants contained greater concentrations of chlorophyll b (by 88%) and total chlorophyll (11%), although chlorophyll a and carotenoid contents were reduced by 8 and 50%, respectively. This approach may provide an alternative to the application of chemical growth retardants for reducing the stature of plants, particularly ornamentals, in view of concerns over the potential environmental and health hazards of such compounds.

24S-hydroxycholesterol in relation to disease manifestations of acute experimental autoimmune encephalomyelitis.

Levels of the brain-specific cholesterol metabolite 24S-hydroxycholesterol are proposed as possible biomarkers for multiple sclerosis (MS). It is not yet clear for which aspect of the MS disease manifestations 24S-hydroxycholesterol is a reflection. We studied the relation of serum levels of 24S-hydroxycholesterol and other sterols to the disease characteristics of acute experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Serum was analyzed for cholesterol precursors, oxysterols, and plant sterols during the course of disease development. Significantly increased levels of the cholesterol metabolites 24S-hydroxycholesterol and 27-hydroxycholesterol were observed on day 9, before the onset of clinical signs. The serum levels of these oxysterols gradually increased up to 193% and 415%, respectively, at day 17, when clinical symptoms had recovered. Total cholesterol levels were slightly but significantly decreased on day 9 and day 17 in treated animals. Serum levels of cholesterol precursors and plant sterols decreased gradually from day 11 and day 14, respectively. Immunostaining of the 24S-hydroxycholesterol-forming enzyme Cyp46 was shown in macrophage infiltrates. In vitro experiments confirmed the presence of Cyp46 in macrophages and showed a decreased expression after LPS treatment. The data indicate that changes in serum oxysterols occur early in EAE and can be formed by macrophages. These early changes indicate an important role for oxysterols in the development of EAE.

Drosophila melanogaster, a model system for comparative studies on the responses to real and simulated microgravity.

A key requirement to enhance our understanding of the response of biological organisms to different levels of gravity is the availability of experimental systems that can simulate microgravity and hypergravity in ground-based laboratories. This paper compares the results obtained from analysing gene expression profiles of Drosophila in space versus those obtained in a random position machine (RPM) and by centrifugation. The correlation found validates the use of the RPM simulation technique to establish the effects of real microgravity on biological systems. This work is being extended to investigate Drosophila development in another gravity modifying instrument, the levitation magnet.

[The Nobel Prize in Physiology or Medicine 2007 for the development of 'knockout' technology]. / Nobelprijs Fysiologie of Geneeskunde 2007 voor de ontwikkeling van de 'knock-out'-technologie.

The Nobel Prize in Physiology or Medicine 2007 has been awarded to Mario R. Capecchi (University ofUtah, Salt Lake City, USA), O. Smithies (University of North Carolina, Chapel Hill, USA), and Sir Martin J. Evans (Cardiff University, Cardiff, UK) 'for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells'. Transgenic mice are often used to study the function of a single gene. The Nobel Prize winners succeeded in silencing the targeted gene in an embryonic stem cell. They went on to introduce it into a blastocyst and then implanted it in a surrogate mother mouse. The blastocyst grew into a genetically modified mouse, better known as a 'knockout' mouse.

A subtype of multiple sclerosis defined by an activated immune defense program.

Given the heterogeneous nature of multiple sclerosis (MS), we applied DNA microarray technology to determine whether variability is reflected in peripheral blood (PB) cells. In this study, we studied whole-blood gene expression profiles of 29 patients with relapsing-remitting MS (RRMS) and 25 age- and sex-matched healthy controls. We used microarrays with a complexity of 43K cDNAs. The data were analyzed using sophisticated pathway-level analysis in order to provide insight into the deregulated peripheral immune response programs in MS. We found a remarkable elevated expression of a spectrum of genes known to be involved in immune defense in the PB of MS patients compared to healthy individuals. Cluster analysis revealed that the increased expression of these genes was characteristic for approximately half of the patients. In addition, the gene signature in this group of patients was comparable with a virus response program. We conclude that the transcriptional signature of the PB cells reflects the heterogeneity of MS and defines a sub-population of RRMS patients, who exhibit an activated immune defense program that resembles a virus response program, which is supportive for a link between viruses and MS.

Multiple pathways of maternal effects in black-headed gull eggs: constraint and adaptive compensatory adjustment.

We investigated in the black-headed gull whether female deposition of antioxidants and immunoglobulins (enhancing early immune function), and testosterone (suppressing immune function and increasing early competitive skills) correlate suggesting that evolution has favoured the mutual adjustment of different pathways for maternal effects. We also took egg mass, the position of the egg in the laying sequence and offspring sex into account, as these affect offspring survival. Yolk antioxidant and immunoglobulin concentrations decreased across the laying order, while yolk testosterone concentrations increased. This may substantially handicap the immune defence of last-hatched chicks. The decrease in antioxidant levels was greater when mothers had a low body mass and when the increase in testosterone concentrations was relatively large. This suggests that female black-headed gulls are constrained in the deposition of antioxidants in last-laid eggs and compensate for this by enhanced testosterone deposition. The latter may be adaptive since it re-allocates the chick's investment from costly immune function to growth and competitive skills, necessary to overcome the consequences of hatching late from an egg of reduced quality.