CNS Elevation of Vascular and Not Mucosal Addressin Cell Adhesion Molecules in Patients with Multiple Sclerosis

The mucosal addressin cell adhesion molecule (MAdCAM) and vascular cell adhesion molecule (VCAM) appear to play roles in the recruitment of leukocytes to specialized endothelium lining the gastrointestinal tract. The purpose of this study was to clarify the role of MAdCAM and VCAM in the central nervous system by comparing protein expression in patients with multiple sclerosis (MS) and control subjects by immunohistochemistry. Specific antibodies to human VCAM and MAdCAM were used to confirm expression in control and MS nervous system specimens by immunohistochemistry. VCAM immunoreactivity was detected in endothelial cells, perivascular tissue, and in some cases, leukocytes within the meninges, gray, and white matter, of both controls and MS patients. VCAM immunoreactivity was maximal in a patient with acute active plaques, but of lower intensity and reduced distribution in controls and those with chronic active or inactive MS plaques. In contrast, MAdCAM immunoreactivity could not be detected in brain tissue from unaffected or MS patients. Taken together, these data support a role of VCAM, but not MAdCAM in the development of MS.In recent years, interest and emergence has increased tremendously surrounding therapeutic approaches that interfere with normal leukocyte trafficking as alternative mechanisms to conventional immunosuppressive agents for inflammatory diseases. These include approaches that block leukocyte homing (such as natalizumab [Tysabri; Biogen Idec and Elan Pharmaceuticals], or sphingosine-1 phosphate-mediated egress from lymphoid tissue (fingolimod [Novartis]), or deplete specific populations of leukocytes (such as rituximab [Rituxan; Genentech and Biogen Idec]). In multiple sclerosis (MS), classically described as a chronic inflammatory disease of the central nervous system (CNS), focal autoreactive T-cell and macrophage infiltrates lead to demyelination and axonal loss.^1,2 Blood–brain barrier damage, prominent infiltration by activated CD4⁺ T cells and clonotypic CD8⁺ T cells, the presence of macrophages with phagocytosed myelin debris, reactive astrocytes and proliferating oligodendrocytes are characteristic of acute plaques. In chronic plaques, inflammation is less pronounced and generally restricted to the rim of the plaque, which exhibits gliosis, while the hypocellular center exhibits axonal and oligodendrocyte loss, and variable demyelination. In treatment of MS by natalizumab, the CNS restriction of CD4⁺, CD8⁺ T cells, CD19⁺ B lymphocytes, and CD138⁺ plasma cells by blocking α₄β₁ and α₄β₇ integrin mediated binding to endothelial cells expressing vascular cell adhesion molecule (VCAM), fibronectin, and MAdCAM has resulted in observations of improved outcome by magnetic resonance imaging, reductions in disease progression, and relapse in clinical studies. However, while the exaggerated recruitment of activated autoreactive leukocytes is one of the predisposing features that can lead to MS, CNS immune surveillance is also a critically important process. Natalizumab was temporarily withdrawn from the market in 2005 after three patients developed progressive multifocal leukoencephalopathy (PML)^3,4 and more recently, multiple cases of PML in efalizumab (anti-CD11a) and rituximab (anti-CD20)-treated individuals have been observed,^5,6 leading to the recent withdrawal of efalizumab by Genentech.PML is a rare, rapidly progressive and often fatal form of demyelinating disease caused by a reactivation of latent polyomavirus JC within a setting of immunosuppression. JC virus does not cause disease in healthy individuals. It was first described in 1958, and up to the early 1980s, reports of PML showed that it mainly occurred in AIDS patients or elderly individuals as a terminal complication of lymphoproliferative disorders.^7,8 Given that more than 70% of the adult population are carriers of the JC virus,⁹ the potential clinical implication of agents that either deplete immune cells or potentially interfere with the leukocyte trafficking in the CNS needs consideration.PF-00547659 has been recently described as a potent and selective anti-human MAdCAM monoclonal antibody that blocks the ability of α₄β₇ integrin-bearing leukocytes to home to specialized endothelium.¹⁰ Several studies have concluded that MAdCAM expression appears to be restricted to the endothelium of the gastrointestinal tract;^10,11 however, the observed expression in brain tissue under certain circumstances, the cloning of the receptor from CNS tissue,^12,13,14 as well as the observed effects of blocking anti-β₇ integrin or anti-MAdCAM antibodies in models of experimental autoimmune encephalomyelitis have suggested that MAdCAM may have an additional role in CNS immune surveillance in normal, as well as inflamed conditions.^15,16,17In the context of these observations, the purpose of this study was to characterize and compare the pattern as well as intensity of CNS MAdCAM expression with VCAM in control and MS brain tissue.     

Neuropathic Pain in Multiple Sclerosis Patients

Neuroscience and Behavioral Physiology - Among a multitude of pain syndromes (PS) of diverse locations and types of pathogenesis encountered in multiple sclerosis (MS) patients, most research...     

Biological Roles of Liver X Receptors in Immune Cells

Liver X receptors (LXRs) are members of the nuclear receptor superfamily that are activated by specific oxysterols. LXRs heterodimerize with retinoid X receptors to regulate positively the expression of a variety of target genes, many of which are involved in lipid and glucose metabolism. In the last few years, new targets of LXR activation have been identified with roles in the modulation of immune responses. Moreover, LXRs mediate repression of inflammatory pathways through mechanisms collectively known as transrepression. Here, we revise recent findings on the impact of LXR activation on immune responses, with an emphasis on advances in the understanding of the molecular mechanisms that mediate these effects.     

Response of Lymphocytes from Multiple Sclerosis Patients to Murine Brain Extract

Forty-seven patients with multiple sclerosis (MS), 21 subjects with neurological diseases other than MS (OND), 7 with miscellaneous diseases (MD) and 21 healthy individuals (HI) were examined by the standard procedure of blast transformation for the in vitro response to mouse brain (MB), mouse kidney (MK) and mouse lung (ML) tissue extracts. Increase cellular response to MB was limited to the MS and OND groups, whereas high and low values of stimulation index to MK and ML were similarly observed in all groups of individuals examined. No correlation was found between the clinical activity of the MS patients and the in vitro response to MB. The possibility that low sensitivity of the technique and complexity of the antigenic composition of MS are determining factors in the results obtained in these studies is discussed.     

Histocompatibility Determinants in Israeli Jewish Patients with Multiple Sclerosis

The distribution of 24 HLA antigens of the A and B loci was investigated in 197 Israeli Jewish patients with multiple sclerosis (MS) from various Jewish ethnic origins including central and eastern Europe, countries bordering the Mediterranean, the Middle East and from native-born Israelis. The results were compared with the HLA antigen frequencies in a control sample of 455 unrelated individuals representing the general Jewish population. The frequency of HLA-Bw40 among all MS patients (15%) was significantly greater (P less than 0.001) than among the controls (7%). In contrast to the findings in MS patients from other populations, there was no increased frequency of A3 and B7 and Dw2 was present in only one out of 28 patients. The study showed a similar distribution of HLA-A and -B locus antigens, especially of Bw40, in Jews of diverse ethnic origins represented in the control group.     

Oxidative Stress is Increased in Serum from Mexican Patients with Relapsing-Remitting Multiple Sclerosis

Objective: To determine the oxidative stress markers in serum from patients with relapsing-remitting multiple sclerosis. Methods: Blood samples from healthy controls and 22 patients 15 women (7 aged from 20 to 30 and 8 were > 40 years old) and 7 men (5 aged from 20 to 30 and 2 were > 40 years old) fulfilling the McDonald Criteria and classified as having Relapsing-Remitting Multiple Sclerosis accordingly with Lublin were collected for oxidative stress markers quantification. Results: Nitric oxide metabolites (nitrates/nitrites), lipid peroxidation products (malondialdehyde plus 4-hidroxialkenals), and glutathione peroxidase activity were significantly increased in serum of subjects with relapsing-remitting multiple sclerosis in comparison with that of healthy controls. These data support the hypothesis that multiple sclerosis is a component closely linked to oxidative stress.     

Upregulation of Immunoglobulin‐related Genes in Cortical Sections from Multiple Sclerosis Patients

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). Microarray‐based global gene expression profiling is a promising method, used to study potential genes involved in the pathogenesis of the disease. In the present study, we have examined global gene expression in normal‐appearing gray matter and gray matter lesions from the cortex of MS patients, and compared them with cortical gray matter samples from controls. We observed a massive upregulation of immunoglobulin (Ig)‐related genes in cortical sections of MS patients. Using immunohistochemistry, the activation of Ig genes seems to occur within plasma cells in the meninges. As synthesis of oligoclonal IgGs has been hypothesized to be caused by the activation of Epstein–Barr virus (EBV)‐infected B‐cells, we screened the brain samples for the presence of EBV by real‐time quantitative polymerase chain reaction (qPCR) and immunohistochemistry, but no evidence of active or latent EBV infection was detected. This study demonstrates that genes involved in the synthesis of Igs are upregulated in MS patients and that this activation is caused by a small number of meningeal plasma cells that are not infected by EBV. The findings indicate that the Ig‐producing B‐cells found in the cerebrospinal fluid (CSF) of MS patients could have meningeal origin.     

Movement-Related Somatosensory Activity Is Altered in Patients with Multiple Sclerosis

During active movement the somatosensory cortical responses are often attenuated. This attenuation is referred to as movement-related sensory gating. It is well known that patients with multiple sclerosis (MS) have sensory processing deficits, and recent work has also suggested that these patients display impaired motor control of the ankle musculature. The primary goal of the current study was to: (1) examine the movement-related somatosensory gating in patients with MS and demographically-matched controls, and (2) identify the relationship between the sensory gating and motor control of the ankle musculature. To this end, we used magnetoencephalography brain imaging to assess the neural responses to a tibial nerve electrical stimulation that was applied at rest (passive) and during an ankle plantarflexion motor task (active condition). All participants also completed an ankle isometric motor control task that was performed outside the scanner. Our results indicated that the controls, but not patients with MS, exhibited significantly reduced somatosensory responses during the active relative to passive conditions, and that patients with MS had stronger responses compared with controls during the active condition. Additionally, control of the ankle musculature was related to the extent of movement-related sensory attenuation, with poor motor control being associated with reduced gating. Overall, these results show that patients with MS do not attenuate the somatosensory cortical activity during motor actions, and that the inability to modulate somatosensory cortical activity is partially related to the poor ankle motor control seen in these patients.     

Measles Virus-Induced Migration Inhibition In Vitro of Leukocytes from Patients with Multiple Sclerosis

The migration inhibition in vitro induced by measles virus material on leukocytes from 17 patients with multiple sclerosis (MS) was compared with that of 8 patients with various other central nervous system diseases and that of 12 healthy blood donors. Significant differences could not be demonstrated. The results do not indicate that MS patients' leukocytes show an altered behaviour to measles virus material in the migration inhibition test.     

Comparison of Antibodies Against Different Viruses in Cerebrospinal Fluid and Serum Samples from Patients with Multiple Sclerosis

The occurrence of a local production in the central nervous system (CNS) of antibodies against different selected viruses was analyzed by comparison of titers in serum and cerebrospinal fluid samples from groups of 50 patients with multiple sclerosis from Finland, Norway, and Sweden. Measles antibodies were determined in hemagglutination inhibition, hemolysis inhibition, and nucleocapsid complement fixation tests; mumps, parainfluenza virus type 1, and rubella virus antibodies were determined in hemagglutination inhibition tests; and herpes simplex virus type 1 antibodies were determined in passive hemagglutination tests. For reference purposes tests were also made for adenovirus antibodies in penton hemagglutination enhancement tests and poliovirus antibodies in neutralization enhancement tests. Among the 150 multiple sclerosis patients, a local production of antibodies against measles virus was found in the CNS in 57%, against rubella virus in 19%, mumps virus in 15%, herpes simplex virus type 1 in 11%, and parainfluenza virus type 1 (Sendai) in 3%. A local production in the CNS of antibodies against any of the viruses studied was found in 71% of multiple sclerosis patients. These included 48, 16, and 7% that produced antibodies to one, two, and three or more viruses, respectively.     

Treatment of Multiple Sclerosis with Methylprednisolone and Mitoxantrone Modulates the Expression of CXC Chemokine Receptors in PBMC

Chemokines and their receptors are involved in the development of multiple sclerosis (MS). Methylprednisolone (MP) and mitoxantrone (MTX) are commonly used in the treatment of MS. In this study, we analyzed the expression of chemokine receptors CXCR1, CXCR2, CXCR3, CXCR4, and CXCR5 in peripheral blood mononuclear cells (PBMC) from MS patients before and after treatment with MP or MTX. We observed a significant upregulation of expression of CXCR1 and CXCR2 in untreated MS patients. Treatment of MS with MP stimulated further increase of expression of both receptors. Therapy for MS with MTX resulted in decrease of CXCR2 expression. There was a negative correlation between the expression of CXCR1 and CXCR2 and the cumulative dose of MTX received by patients. These results suggest that CXCR1 and CXCR2 may be involved in MS pathogenesis and that treatment of this disease with MP and MTX may influence expression of those receptors.     

Brain-Derived Neurotrophic Factor in Neuroimmunology: Lessons Learned from Multiple Sclerosis Patients and Experimental Autoimmune Encephalomyelitis Models

The concept of neuroprotective autoimmunity implies that immune cells, especially autoantigen-specific T cells, infiltrate the central nervous system (CNS) after injury and contribute to neuroregeneration and repair by secreting soluble factors. Amongst others, neurotrophic factors and neurotrophins such as brain-derived neurotropic factor (BDNF) are considered to play an important role in this process. New data raise the possibility that this concept could also be extended to neuroinflammatory diseases such as multiple sclerosis (MS) where autoantigen-specific T cells infiltrate the CNS, causing axonal/neuronal damage on the one hand, but also providing neuroprotective support on the other hand. In this review, we summarize the current knowledge on BDNF levels analyzed in MS patients in different compartments and its correlation with clinical parameters. Furthermore, new approaches in experimental animal models are discussed that attempt to decipher the functional relevance of BDNF in autoimmune demyelination.     

TNF-alpha Production by Peripheral Blood Monocytes in Multiple Sclerosis Patients and Healthy Controls

Background: Aberrant immune responses are evident in the pathogenesis of multiple sclerosis (MS) and it has been proposed that the spectrum of cytokines influence disease outcomes. Leptin and lipopolysaccharide (LPS) of Gram-negative bacteria are both potent cellular stimulators for production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). The aim of this study was to compare the TNF-α production by peripheral blood monocytes from MS patients with healthy controls.

Methods: Peripheral blood samples were stimulated with LPS or leptin. After blocking the Golgi apparatus, intracellular cytokine production was assessed using a monoclonal antibody against human TNF-α by the flow cytometry technique. Moreover, plasma level measurement of cytokines was performed using enzyme-linked immunosorbent assay (ELISA).

Results: Intracellular levels of TNF-α were 16.80?±?8.21 and 16.52?±?8.23in MS patients and healthy controls which showed no statistically significant difference between them (p?=?0.850). Leptin-stimulated and LPS-stimulated TNF-α production showed no significant difference between MS patients and the control group (p?=?0.263 and p?=?0.191, respectively). However, after treatment with leptin, a weak significant difference was shown between cases and control group (p?=?0.049). There were significant differences between cases and controls regarding serum levels of IL-6 and Toll-like receptor-4 (TLR-4) before and after stimulation with leptin and LPS, separately (p?<?0.05).

Conclusion: Taken together, we cannot definitely conclude that TNF-α does not play an important role in pathogenesis of MS. However, other characteristics of monocyte activation such as IL-6 or TLRs can elucidate implication of peripheral blood monocytes in MS pathogenesis.     

Correlation Between Interferon Production and Clinical Disease Activity in Patients with Multiple Sclerosis

We determined the interferon (IFN) serum levels and in vitro activated IFN production in eight patients with relapsing/remitting multiple sclerosis (MS), using a whole-blood test system and the mitogen concanavalin A and the viral antigen Newcastle disease virus for induction of the IFN production. During the overall study period of 12 months we observed, in relation to clinical disease progression, a biphasic increase in the individual IFN and IFN production. While mitogen-induced IFN synthesis showed a significant augmentation prior to the onset of a new relapse (P < 0.05), virus-induced IFN production showed a temporal delayed increase which was related to clinical remission (P < 0.01). The observed fluctuations in the individual production of both IFN subtypes were not reflected in the sera of the patients. Although the reason for the temporal different imbalance in the production of both IFN subtypes remains unknown, the observed association between increased IFN production and clinical remission emphasizes a possible role for type 1 IFNs in the resolution of the MS relapse.     

Flow Cytometric Analysis of In Vitro Proinflammatory Cytokine Secretion in Peripheral Blood from Multiple Sclerosis Patients

The cytokines, interferon- (IFN-), tumor necrosis factor- (TNF-rpar;, and interleukin-2 (IL-2) are important endogenous proinflammatory proteins and have been linked to disease activity in multiple sclerosis. In this study, we use flow cytometric methodology to compare the secretion of IFN-, IL-2, and TNF- from peripheral blood-derived T cells of multiple sclerosis patients to the secretion in healthy controls. The percentages of IFN-, IL-2, and TNF- secreting cells are not significantly different between multiple sclerosis patients and controls. However, the TNF- secreting CDS cell percentage is correlated with the IFN- and IL-2 secreting CD3 cell percentages in multiple sclerosis patients. In the controls, only the TNF- secreting CD3 cell percentage is correlated with IFN-. These findings show that correlated secretion of cytokines occurs in multiple sclerosis and suggest that concerted intercytokine interactions may play an important role in the disease.     

Lymphocyte Subpopulations in the Cerebrospinal Fluid and Peripheral Blood in Patients with Multiple Sclerosis

The cerebrospinal fluid (CSF) and blood of patients with multiple sclerosis (MS) were studied with respect to the frequency of lymphocytes with intracellular immunoglobulins of different Ig classes as well as the relative frequency of B and T lymphocytes. An increased number of Ig-positive cells were found in CSF (mean, 0.52%) when compared with blood (mean, 0.18%). In CSF there was a striking dominance of IgG-positive cells, very few IgA-positive cells, and almost no IgM-positive cells. The distribution in blood was approximately normal. The ratios between χ- and λ-positive cells in CSF were all outside the range in blood. In CSF there were fewer B cells (mean, 4.7%) and more T cells (mean, 74.2%) when compared with blood (mean, 11.5% and 61.8%, respectively). The values for MS blood were approximately the same as for normal controls. The increased number of IgG-containing cells in the CSF are in agreement with earlier studies, which showed a local immunoglobulin synthesis. The increased proportion of T lymphocytes in CSF of MS patients may indicate that these cells play a role in the pathogenesis of MS.