The effect of interferon beta-1b on lymphocyte-endothelial cell adhesion

Interferon-β decreases LPS-induced neutrophil recruitment to cardiac fibroblasts

Introduction: Cardiac fibroblasts (CF) are crucial cells in damaged heart tissues, expressing TLR4, IFN-receptor and responding to lipopolysaccharide (LPS) and interferon-β (IFN-β) respectively. While CF interact with immune cells; however, their relationship with neutrophils remains understudied. Additionally, theimpact of LPS and IFN-β on CF-neutrophil interaction is poorly understood. Methods: Isolated CF from adult rats were treated with LPS, with or without IFN-β. This study examined IL-8 secretion, ICAM-1 and VCAM-1 expression, and neutrophil recruitment, as well as their effects on MMPs activity. Results: LPS triggered increased IL-8 expression and secretion, along with elevated ICAM-1 and VCAM-1 expression, all of which were blocked by TAK-242. Pre-treatment with IFN-β countered these LPS effects. LPS treated CF showed higher neutrophil recruitment (migration and adhesion) compared to unstimulated CF, an effect prevented by IFN-β. Ruxolitinib blocked these IFN-β anti-inflammatory effects, implicating JAK signaling. Analysis of culture medium zymograms from CF alone, and CF-neutrophils interaction, revealed that MMP2 was mainly originated from CF, while MMP9 could come from neutrophils. LPS and IFN-β boosted MMP2 secretion by CF. MMP9 activity in CF was low, and LPS or IFN-β had no significant impact. Pre-treating CF with LPS, IFN-β, or both before co-culture with neutrophils increased MMP2. Neutrophil co-culture increased MMP9 activity, with IFN-β pre-treatment reducing MMP9 compared to unstimulated CF. Conclusion: In CF, LPS induces the secretion of IL-8 favoring neutrophils recruitment and these effects were blocked by IFN-. The results highlight that CF-neutrophil interaction appears to influence the extracellular matrix through MMPs activity modulation.

The Spatio-Temporal Expression Profiles of CD4 + T Cell Differentiation and Function-Related Genes During EAE Pathogenesis

Multiple sclerosis is a CD4⁺ T cell-mediated autoimmune disease of the central nervous system. The unbalance of the cytokines and transcription factors critical for CD4⁺ T cell differentiation and function is probably the main reason that causes MS. We detected the mRNA expression changes of key cytokines and transcription factors which are critical for Th1, Th2, Th17, and Treg cell differentiation and function in different tissues during EAE pathogenesis. We fund that each gene not only has its own featured expression changes, but also has interaction with one another, which composes a network of immunity. Understanding the roles of key cytokines and transcription factors in these processes will help to understand disease pathogenesis and supply indications for disease therapy.

Elevated endothelial microparticle—monocyte complexes induced by multiple sclerosis plasma and the inhibitory effects of interferon-β1b on release of endothelial microparticles, formation and transendothelial migration of monocyte-endothelial microparticle complexes

Monocyte migration through the disrupted cerebral endothelial cell (EC) junctions plays an essential role in formation of multiple sclerosis (MS) demyelinating lesions. During pathogenesis of MS, activated ECs release endothelial microparticles (EMP), which possibly facilitate transendothelial migration (TEMIG) of monocytes. To assess functional roles of EMP in MS, specifically, their (i) interaction with monocytes, (ii) effect on monocyte TEMIG in an in vitro model of the brain microvascular endothelial cells (BMVEC), (iii) phenotypic profiles of EMP elicited by MS plasma and (iv) the effects of IFN-b1b on release of EMP and on TEMIG of monocytes (mono) and monocytes:EMP complexes (mono:EMP) through the BMVEC. The effect of IFN-b1b on the release of EMP and the TEMIG of mono and mono:EMP was assessed by preincubating BMVEC cultures of IFN-b1b prior to addition of plasma. Three EMP phenotypes, CD54, CD62E and CD31 were assayed. Plasma specimens from 20 patients with relapsing—remitting MS (11 in exacerbation, MS-E, and 9 in remission, ME-R) and 10 healthy controls were studied. Incubation of BMVEC with MS-E plasma yielded elevated levels of EMPCD54, EMP62E and EMPCD31 relative to MS-R and control plasmas. MS-E but not MS-R or control plasma also augmented TEMIG of monocytes, respectively. Mono:EMP complexes further augmented TEMIG relative to mono alone, but only in the presence of MS-E plasma; there was no significant effect with MS-R or control plasmas. The presence of IFN-b1b inhibited TEMIG of mono and mono:EMP by 20% and 30%, respectively. MS-E but not MS-R plasma elicited release of activation-derived EMP and enhanced TEMIG of mono and mono:EMP. IFN-b1b inhibited TEMIG and release of EMP, suggesting a role of EMP and a novel therapeutic mechanism for IFN-β1b in MS.

Anti-metastatic functions of type 1 interferons: Foundation for the adjuvant therapy of cancer

The anti-tumorigenic effects that type 1 interferons (IFN1) elicited in the in vitro studies prompted consideration of IFN1 as a potent candidate for clinical treatment. Though not all patients responded to IFN1, clinical trials have shown that patients with high risk melanoma, a highly refractory solid malignancy, benefit greatly from intermediate IFN1 treatment in regards to relapse-free and distant-metastasis-free survival. The mechanisms by which IFN1 treatment at early stages of disease suppress tumor recurrence or metastatic incidence are not fully understood. Intracellular IFN1 signaling is known to affect cell differentiation, proliferation, and apoptosis. Moreover, recent studies have revealed specific IFN1-regulated genes that may contribute to IFN1-mediated suppression of cancer progression and metastasis. In concert, expression of these different IFN1 stimulated genes may impede numerous mechanisms that mediate metastatic process. Though, IFN1 treatment is still utilized as part of standard care for metastatic melanoma (alone or in combination with other therapies), cancers find the ways to develop insensitivity to IFN1 treatment allowing for unconstrained disease progression. To determine how and when IFN1 treatment would be most efficacious during disease progression, we must understand how IFN1 signaling affects different metastasis steps. Here, we specifically focus on the anti-metastatic role of endogenous IFN1 and parameters that may help to use pharmaceutical IFN1 in the adjuvant treatment to prevent cancer recurrence and metastatic disease.

TIP30 inhibits oligodendrocyte precursor cell differentiation via cytoplasmic sequestration of Olig1

Differentiation of oligodendrocyte precursor cells (OPCs) is a prerequisite for both developmental myelination and adult remyelination in the central nervous system. The molecular mechanisms underlying OPC differentiation remain largely unknown. Here, we show that the thirty-kDa HIV-1 Tat interacting protein (TIP30) is a negative regulator in oligodendrocyte development. The TIP30(-/-) mice displayed an increased myelin protein level at postnatal day 14 and 21. By using a primary OPC culture system, we demonstrated that overexpression of TIP30 dramatically inhibited the stage progression of differentiating OPCs, while knockdown of TIP30 enhanced the differentiation of oligodendroglial cells remarkably. Moreover, overexpression of TIP30 was found to sequester the transcription factor Olig1 in the cytoplasm and weaken its nuclear translocation due to the interaction between TIP30 and Olig1, whereas knockdown of TIP30 led to more Olig1 localized in the nucleus in the initiation stage during OPC differentiation. In the cuprizone-induced demyelination model, there was a dramatic increase in NG2-expressing cells with nuclear location of Olig1 in the corpus callosum during remyelination. In contrast, within chronic demyelinated lesions in multiple sclerosis, TIP30 was abnormally expressed in NG2-expressing cells, and few nuclear Olig1 was observed in these cells. Taken together, our findings suggest that TIP30 plays a negative regulatory role in oligodendroglial differentiation.

Extracellular Vesicles in Multiple Sclerosis: What are They Telling Us?

Extracellular vesicles (EVs) are membrane-bound particles secreted by almost all cell types. They are classified depending on their biogenesis and size into exosomes and microvesicles or according to their cell origin. EVs play a role in cell-to-cell communication, including contact-free cell synapsis, carrying active membrane proteins, lipids, and genetic material both inside the particle and on their surface. They have been related to several physiological and pathological conditions. In particular, increasing concentrations of EVs have been found in many autoimmune diseases including multiple sclerosis (MS). MS is a central nervous system (CNS) demyelinating disease characterized by relapsing of symptoms followed by periods of remission. Close interaction between endothelial cells, leukocytes, monocytes, and cells from CNS is crucial for the development of MS. This review summarizes the pathological role of EVs in MS and the relationship of EVs with clinical characteristics, therapy, and biomarkers of the disease.

Cytohesin-1 regulates human blood neutrophil adhesion to endothelial cells through β2 integrin activation

Cytohesin-1 is a guanine nucleotide exchange factor for ADP ribosylation factor 6 (Arf6) in human blood neutrophils and differentiated PLB-985 neutrophil-like cells. Cytohesin-1 regulates adhesion and the transendothelial migration of monocytes, dendritic cells and T lymphocytes through activation of the β2 integrin LFA-1. In this study we investigated the role of cytohesin-1 in neutrophil and neutrophil-like cell adhesion to HUVECs, immobilized ICAM-1, and the α4β1 and α5β1 integrin extracellular matrix ligand fibronectin. We show that cytohesin-1 knockdown or inhibition with secinH3 inhibits fMLF-mediated cell adhesion to HUVECs and immobilized ICAM-1, whereas cytohesin-1 over-expression has the opposing effect. Binding of PLB-985 cells to HUVECs correlated with expression of the high-affinity β2 integrin epitope recognized by mAb24. Adhesion to HUVECs was inhibited by soluble ICAM-1, anti-ICAM-1, anti-CD11a and anti-CD18, but not anti-CD11b, blocking antibodies. We also demonstrate that cytohesin-1 knockdown promotes fMLF-mediated cell adhesion to fibronectin whereas cytohesin-1 over-expression has the opposing effect. Crosstalk between β1 and β2 integrins also exists since inhibition of β1 integrin functions with blocking antibodies enhanced adhesion of PLB-985 over-expressing cytohesin-1 to ICAM-1. We suggest that cytohesin-1 is a key regulator of neutrophil adhesion to endothelial cells and to components of extracellular matrix, which may influence cell emigration through its dual opposing effect on β2 and β1 integrin activation.

Reduced expression of β2 integrin genes in rat peripheral leukocytes by inhibiting postprandial hyperglycemia

β(2) integrins (CD11s/CD18) promote the attachment of leukocytes to vascular endothelial cells. We performed in this study sucrose loading to rats with moderate postprandial hyperglycemia with/without once-daily dosing of the α-glucosidase inhibitor, miglitol, for 4 days under 4-h fasting conditions. The streptozotocin (STZ)-treated rats showed moderate postprandial hyperglycemia on days 1 and 4. The gene expression was higher for CD11a with fasting and 3-h postprandial on day 1, and with fasting on day 4, for CD11b with fasting on day 1 and 3-h postprandial on day 4, and for CD18 with fasting on days 1 and 4 in peripheral leukocytes from the STZ-treated rats than in peripheral leukocytes from the saline-treated rats. Miglitol reduced postprandial hyperglycemia and the gene expression of CD11a with fasting and of CD11b 3-h postprandial on day 4. These results indicate that inhibiting postprandial hyperglycemia reduced the mRNA expression of β(2) integrins in peripheral leukocytes of moderately postprandial hyperglycemic rats.

T-cell based immunotherapy in experimental autoimmune encephalomyelitis and multiple sclerosis

One of the reasons multiple sclerosis (MS) has been considered a T-cell mediated autoimmune disease is that a similar experimental disease can be induced in certain rodents and primates by immunization with myelin antigens, leading to T-cell-mediated inflammatory demyelination in the CNS. In addition, most if not all pharmacological treatments available for MS are biologically active on T cells. In this article we review the principles of T-cell-based immunotherapies and the specific actions of current and novel treatments on T-cell functions, when these are known. For both licensed and innovative agents, we also discuss biological actions on other immune cell types. Finally, we offer a brief perspective on expected changes in the use of MS immunotherapies in the near future.

Experimental autoimmune encephalomyelitis-induced upregulation of tumor necrosis factor-alpha in the dorsal root ganglia

Background: Multiple sclerosis (MS) is a chronic, neurological disease characterized by targeted destruction of central nervous system (CNS) myelin. The autoimmune theory is the most widely accepted explanation of disease pathology. Circulating Th1 cells become activated by exposure to CNS-specific antigens such as myelin basic protein. The activated Th1 cells secrete inflammatory cytokines, which are pivotal for inflammatory responses. We hypothesize that enhanced production of inflammatory cytokines triggers cellular events within the dorsal root ganglia (DRG) and/or spinal cord, facilitating the development of neuropathic pain (NPP) in MS. NPP, the second worst disease-induced symptom suffered by patients with MS, is normally regulated by DRG and/or spinal cord.

Objective: To determine gene and protein expression levels of tumor necrosis factor-alpha (TNFα) within DRG and/or spinal cord in an animal model of MS.

Methods: Experimental autoimmune encephalomyelitis (EAE) was induced in adolescent female Lewis rats. Animals were sacrificed every 3 days post-disease induction. DRG and spinal cords were harvested for protein and gene expression analysis.

Results: We show significant increases in TNFα expression in the DRG and of EAE animals at peak disease stage, as assessed by clinical symptoms.

Conclusion: Antigen-induced production of inflammatory cytokines such as TNFα within the DRG identifies a potential novel mechanism for MS-induced NPP.

Interferon (IFN)-ß1a and IFN-ß1b Block IFN-?-Induced Disintegration of Endothelial Junction Integrity and Barrier

Recent clinical trials indicate the efficacy of interferon (IFN)-beta 1b in reducing relapse rate in relapsing-remitting multiple sclerosis (MS), whereas a surge of IFN-gamma precedes and provokes acute relapses. Disruption of the cerebral endothelial barrier and transendothelial migration of inflammatory cell migration into the brain play a significant role in pathogenesis of MS and may be driven by this surge in IFN-gamma. However, the molecular mechanisms underlying the beneficial effects of IFN-beta 1b against the deleterious effects of IFN-gamma on the barrier formed by the junctional proteins remain to be characterized. The authors investigated the effects of IFN-beta 1b, IFN-beta 1a, and IFN-gamma on the integrity of two endothelial junctional proteins, occludin and vascular endothelial-cadherin (VE-cadherin). Human umbilical vein endothelial cell (HUVEC) layers were treated with IFN-beta 1b, IFN-beta 1a, IFN-gamma, IFN-beta 1b plus IFN-gamma, or IFN-beta 1a plus IFN-gamma. IFN-beta 1b, IFN-beta 1a, and IFN-gamma effects on occludin and VE-cadherin integrity and electrical resistance were assessed by Western blotting and immunofluorescence. IFN-gamma significantly reduced occludin expression and produced gaps in endothelial monolayers. VE-cadherin expression was decreased to a lesser extent in endothelial cells exposed to IFN-gamma. IFN-beta 1b significantly attenuated the IFN-gamma-induced decrease in occludin and VE-cadherin expression. The protective effects of IFN-beta 1a on IFN-gamma-treated endothelial cells were similar to those of IFN-beta 1b. IFN-gamma also significantly reduced endothelial monolayer electrical resistance; this effect was blocked by either IFN-beta 1a or IFN-beta 1b. IFN-beta 1a and IFN-beta 1b effectively prevent the IFN-gamma-induced disintegration of the endothelial tight junctions and sustain barrier against the effects of IFN-gamma. The protective effects of IFN-beta on occludin and VE-cadherin stability appear to represent molecular mechanisms for the therapeutic effects of the IFN-beta on blood brain barrier in MS.

Interferon-beta up-regulates the expression of co-stimulatory molecules CD80, CD86 and CD40 on monocytes: significance for treatment of multiple sclerosis

Interferon (IFN)-beta reduces the biological activity of multiple sclerosis (MS), a presumably T cell-mediated autoimmune disease of central nervous system (CNS) myelin. Co-stimulatory molecules are necessary for full T cell activation and differential expression of co-stimulatory molecules on antigen-presenting cells is thought to influence the type of effector T cell response (Th1/Th2). In this study we investigated the effects of IFN-beta on the expression of co-stimulatory molecules on lymphocytes and monocytes as a potential mechanism of action of IFN-beta in MS. Peripheral blood mononuclear cells (PBMCs) were stimulated with IFN-beta in vitro and expression of CD80, CD86, CD40 and HLA was examined by flow cytometry and reverse-transcription polymerase chain reaction. Whereas IFN-beta had no effect on the expression of these molecules on T and B lymphocytes there was a significant increase on monocytes. Correspondingly, the expression of mRNA increased after 6-18 h. This in vitro response was also observed in untreated MS patients and patients receiving treatment with IFN-beta. The increase of co-stimulatory molecules on monocytes was not mediated by interleukin (IL)-10. When IFN-beta-stimulated monocytes were used to stimulate autologous T cells an increased secretion of IL-13 was observed. In biopsies taken from IFN-beta-induced skin reactions after subcutaneous injection increased expression of CD80 mRNA was detected, indicating that IFN-beta also up-regulates this co-stimulatory molecule in vivo. These data provide the background for further studies of IFN-beta-induced changes of co-stimulatory molecules in MS patients.

The effects of interferon-beta on interleukin-10 in multiple sclerosis patients

The incidence of the neuropathological lesions and the severity of the clinical symptoms in multiple sclerosis (MS) are correlated with the amount of the transferred autoreactive T cells. The balance between the T helper 1 (Th1) and T helper 2 (Th2) cytokine phenotypes may affect the activity of the disease in MS patients. Interleukin-10 (IL-10) is a cytokine secreted by Th2 cells. Thus, it has been thought that inducing IL-10 may have therapeutic effects in the treatment of MS patients. In this study, in order determine whether different types of prophylaxis change the secretion of IL-10, we measured the levels of IL-10 in relapsing-remitting type multiple sclerosis (RRMS) patients receiving interferon-beta 1b (IFN-beta 1b) or azathioprine (AZA). Our study consisted of RRMS patients (n=45) and healthy subjects (n=15) as control group. Patients were categorized into three groups as those receiving either IFN-beta 1b or AZA and those not receiving prophylaxis. Each group was compared with the control group. Serum IL-10 levels were determined using ELISA method. IL-10 levels of those receiving IFN-beta 1b were found to be significantly higher than that of other groups. These results support that the ability of inducing anti-inflammatory cytokine IL-10 plays a role in the clinical advantage of IFN-beta 1b in MS treatment.

Interferon-beta-1a induces increases in vascular cell adhesion molecule: implications for its mode of action in multiple sclerosis

We investigated soluble vascular cell adhesion molecule-1 (sVCAM) levels and MRI lesions over 24 weeks in 15 Relapsing Remitting MS (RRMS) patients randomized prospectively to receive once-weekly (qw) IFN-beta-1a 30 mug intramuscularly (IM) (Group I, 8 patients) or three-times-weekly (tiw) IFN-beta-1a 44 mug subcutaneously (SC) (Group II, 7 patients). Both groups demonstrated a significant increase in sVCAM during treatment when compared to pre-treatment levels. Patients on IFN-beta-1a 44 mug SC tiw had a significant (p<0.0001) mean increase in sVCAM of 321.9 ng/ml which was significantly greater (p<0.0001) than with IFN-beta-1a 30 mug IM qw (68.6 ng/ml). There was a negative correlation between combined unique (CU) MRI lesions and sVCAM levels within the IFN-beta-1a 44 mug SC tiw group (slope=-0.00106, p=0.009). We postulate that the mode of action of IFN-beta therapy in MS may involve the induction of an increase in sVCAM. sVCAM could bind VLA-4 on T-cells and intercept their adhesion to the blood brain barrier (BBB). This mechanism is consistent with the observed clinical effect of IFN-beta in reducing MRI contrast enhancing lesions.

Tumor necrosis factor alpha modulates airway smooth muscle function via the autocrine action of interferon beta

Current evidence suggests that tumor necrosis factor alpha (TNFalpha) and the family of interferons (IFNs) synergistically regulate many cellular responses that are believed to be critical in chronic inflammatory diseases, although the underlying mechanisms of such interaction are complex, cell-specific, and not completely understood. In this study, TNFalpha in a time-dependent manner activated both janus tyrosine kinase 1 and Tyk2 tyrosine kinase and increased the nuclear translocation of interferon-regulatory factor-1, STAT1, and STAT2 in human airway smooth muscle cells. In cells transfected with a luciferase reporter, TNFalpha stimulated gamma-activated site-dependent gene transcription in a time- and concentration-dependent manner. Using neutralizing antibodies to IFNbeta and TNFalpha receptor 1, we show that TNFalpha-induced secretion of IFNbeta mediated gamma-activated site-dependent gene expression via activation of TNFalpha receptor 1. In addition, neutralizing antibody to IFNbeta also completely abrogated the activation of interferon stimulation response element-dependent gene transcription induced by TNFalpha. Secreted IFNbeta acted as a negative regulator of TNFalpha-induced interleukin-6 expression, while IFNbeta augmented TNFalpha-induced RANTES (regulated on activation normal T cell expressed and secreted) secretion but had little effect on TNFalpha-induced intercellular adhesion molecule-1 expression. Furthermore TNFalpha, a modest airway smooth muscle mitogen, markedly induced DNA synthesis when cells were treated with neutralizing anti-IFNbeta. Together these data show that TNFalpha, via the autocrine action of IFNbeta, differentially regulates the expression of proinflammatory genes and DNA synthesis.

Adhesion molecules and matrix metalloproteinases in Multiple Sclerosis: effects induced by Interferon-beta

In Multiple Sclerosis (MS) pathology, early inflammation involves leukocyte migration across the blood-brain barrier (BBB) within the central nervous system. In this process, adhesion molecules (AMs), both membrane-bound and soluble-circulating forms, and matrix metalloproteinases (MMPs) certainly play a regulatory role. In MS, recombinant Interferon-beta (rIFNbeta) is effective in reducing gadolinium contrast-enhancing lesions on magnetic resonance imaging and this suggests that it may reduce BBB damage or even restore its integrity by different mechanisms that include interference with both AM and MMP pathways. This review will highlight the effects induced by rIFNbeta, both in vitro and in vivo, on cell-bound and soluble forms of AMs and on MMPs.

Cytokines in multiple sclerosis: methodological aspects and pathogenic implications

Multiple sclerosis (MS) is one of the leading causes of disability among young adults of Caucasian origin. One hundred and fifty years after the first description of the disease, the cause of MS remains unknown. Ironically, the few hypotheses concerning MS pathogenesis that are valid today were first proposed over a hundred years ago. However, equipped with the advanced technology of molecular biology and imaging systems, we are at present progressively uncovering dues to understanding the pathogenesis of the disease. It is dearly evident that aberrant immune responses occur in MS, and it is likely that the spectrum of cytokines produced decisively influences disease outcome. The detrimental consequences of IFN-gamma and the beneficial effects of IFN-beta treatment in MS support this hypothesis. However, there are still major gaps in our knowledge of the involvement of cytokines in MS. Numerous studies have addressed the question of cytokine levels in MS, often with conflicting results; elevated, normal and decreased levels of almost all cytokines have been reported. This scenario most probably reflects methodological dilemmas as well as the complex biology of cytokines. Here we focus on possible reasons for the discrepancies of results reported on cytokines in MS and summarize findings obtained in particular by the application of enzyme-linked immunospot (ELISPOT) assays to cytokine studies in MS.

Interferon-beta directly influences monocyte infiltration into the central nervous system

Interferon-beta (IFN-beta) has beneficial effects on the clinical symptoms of multiple sclerosis (MS) patients, but its exact mechanism of action is yet unknown. We here suggest that IFN-beta directly modulates inflammatory events at the level of cerebral endothelium. IFN-beta treatment resulted in a marked reduction of perivascular infiltrates in acute experimental allergic encephalomyelitis (EAE), the rat model for MS, which was coupled to a major decrease in the expression of the adhesion molecules ICAM-1 and VCAM-1 on brain capillaries. In vitro, IFN-beta reduced the mRNA levels and protein expression of adhesion molecules of brain endothelial cell cultures and diminished monocyte transendothelial migration. Monocyte adhesion and subsequent migration was found to be predominantly regulated by VCAM-1. These data indicate that IFN-beta exerts direct antiinflammatory effects on brain endothelial cells thereby contributing to reduced lesion formation as observed in MS patients.

Production of IL-1beta and IL-1Ra as risk factors for susceptibility and progression of relapse-onset multiple sclerosis

Interleukin-1beta (IL-1beta) is present in multiple sclerosis (MS) lesions. Interleukin-1 receptor antagonist (IL-1Ra) moderates the induction of experimental autoimmune encephalomyelitis (EAE). Here, we show that families that are characterized by high IL-1beta over IL-1Ra production ratio are at 2.2-fold (95% CI, 1.0-4.8; p=0.05) increased risk to have a patient relative with relapse-onset MS than families with a low ratio. It is also related to the reduction of volumetric magnetization transfer ratio (MTR) histogram height, a measure of parenchymal integrity (p=0.04). Those families who combine a high IL-1beta over IL-1Ra ratio with a high tumor necrosis factor (TNF) over IL-10 production ratio have a 6.2-fold (95% CI, 1.8-21; p=0.002) increased risk. Innate production of IL-1beta and IL-1Ra is not related to the outcome of primary progressive MS. Taq1 polymorphism in the IL-1beta gene and the variable number of tandem repeats (VNTR) polymorphism of 86-base pairs within the IL-1Ra gene cannot explain these findings.

Glial cell influence on the human blood-brain barrier

The blood-brain barrier (BBB) is a specialized structure of the central nervous system (CNS) that restricts immune cell migration and soluble molecule diffusion from the systemic compartment into the CNS. Astrocytes and microglia are resident cells of the CNS that contribute to the formation of the BBB. In this article, we consider the influence of these glial cells on the immune regulatory functions of the microvascular endothelium, with special emphasis on the human BBB. A series of in vitro studies demonstrate that soluble factors produced by glial cells, under basal culture conditions, help restrict development of inflammation within the CNS. These soluble factor effects include upregulating expression of molecules including HT7, UEA-1 lectin-binding sites, and angiotensin receptors that help define the phenotype of endothelial cells. These factors also induce tight junction formation between brain endothelial cells, contributing to the restricted permeability of the BBB. In contrast, these factors have little effect on expression of molecules by ECs that either promote lymphocyte migration, such as chemokines and adhesion molecules or molecules that are required for competent antigen presentation, such as MHC and co-stimulatory molecules. Glial cells that become activated in response to signals derived from the immune system or generated within the CNS, produce an array of inflammatory molecules that increase permeability and promote lymphocyte trafficking and persistence. These observations emphasize the bidirectional nature of neural-immune interactions; this dynamic system should be amenable to therapeutic interventions.

Matrix metalloproteinase and cytokine profiles in monocytes over the course of stroke

Stroke is a common cause of death and disability in our society. Stroke is associated with changes in immune responses within the central nervous system as well as systemically. The cells contributing to such changes as well as the factors contributing to formation of the inflammatory infiltrate observed in stroke remain to be clarified. In this study, blood monocytes and corresponding mononuclear cells (MNC) were separated and examined in parallel within 4 days and 1-3 months after onset of ischemic stroke. Numbers of TNF-alpha-, IL-12-, IL-6-, and IL-10-secreting cells and of cells expressing mRNA for matrix metalloproteinase (MMP)-1, -2, -7, -9 and tissue inhibitor of MMP (TIMP)-1 were studied. The TNF-alpha-, IL-12-, and IL-6-secreting monocytes and MNC were elevated during the acute phase compared to healthy controls. Such differences were not observed when stroke patients were examined during convalescence. The IL-10-secreting monocytes did not change over the course of stroke. Levels of monocytes expressing MMP-1, MMP-7 and TIMP-1 mRNA were elevated in the acute phase of stroke patients compared to convalescence and healthy controls, as were levels of MMP-1, -2, -7, -9 and TIMP-1 mRNA expressing blood MNC. The MMP-2 and -9 activity as measured by zymography also was higher in MNC supernatants in the acute phase of stroke compared to convalescence. The high levels of proinflammatory cytokines and MMPs in blood monocytes and MNC further demonstrate the presence of systemic aberrations in the acute phase of stroke. Such changes may contribute to the influx of blood-borne cells into the ischemic lesions during the acute phase of stroke.

T lymphocytes conditioned with Interferon beta induce membrane and soluble VCAM on human brain endothelial cells

Vascular cell adhesion molecule (VCAM)-1 plays a critical role in mediating inflammatory cell adhesion and migration. Factors regulating the expression of membrane (m)VCAM and its cleaved counterpart soluble (s)VCAM are poorly understood. We previously demonstrated that serum sVCAM levels are increased in multiple sclerosis (MS) patients treated with interferon beta 1b (IFNbeta1b), which correlated with a reduction in gadolinium enhancing lesions on magnetic resonance imaging. However, subsequent studies have shown that IFNbeta does not directly induce VCAM expression on endothelial cells. We demonstrate here that co-culture with IFNbeta-conditioned T cells induces mVCAM on human brain endothelial cells (HBEC). Further, rapid shedding of sVCAM occurs, which mirrors the response after in vivo IFNbeta treatment. The VCAM induction is mediated partially through tumor necrosis factor (TNF)alpha and can be abrogated by sTNF receptor. VCAM could also be induced on astroglioma lines using IFNbeta-conditioned T cells, which suggests the effect is not specific for HBEC. Kinetic studies demonstrated an increase in the sVCAM to mVCAM ratio over time, which may contribute to the ultimate therapeutic effect of IFNbeta in patients. These data have important implications for understanding the events occurring at the blood brain barrier in vivo, and for determining the mechanism of action of IFNbeta in MS.

Multiple sclerosis: pro- and anti-inflammatory cytokines and metalloproteinases are affected differentially by treatment with IFN-beta

Interferon-beta (IFN-beta) has a beneficial influence on the course of multiple sclerosis (MS) and has become standard treatment of this disease, though its mechanisms of action are incompletely understood. This study examines the effect of IFN-beta treatment on the cytokines IL-6, TNF-alpha, IFN-gamma and IL-10; the metalloproteinases MMP-3, -7 and -9 and the tissue inhibitor of metalloproteinase-1 (TIMP-1). IFN-beta treatment resulted in decreased numbers of mononuclear cells (MNC) secreting IL-6 and TNF-alpha and expressing mRNA of MMP-3 and MMP-9 compared to pretreatment levels. On the contrary, numbers of IL-10 secreting MNC and TIMP-1 mRNA expressing were augmented during IFN-beta therapy. Whether the down-regulatory effects on pro-inflammatory and upregulatory effects on anti-inflammatory molecules are a direct result of IFN-beta on the immune system or secondary to clinical stabilization of MS pathology induced by IFN-beta remains to be evaluated.

Adhesion of mononuclear cells from multiple sclerosis patients to cerebral vessels in cryostat sections of normal human brain

Leukocyte extravasation across the blood-brain barrier is a critical event in the pathogenesis of multiple sclerosis (MS). This complex multistep process includes the adhesion of leukocytes to the endothelial cells of the central nervous system microvasculature. To investigate this phenomenon in MS, we developed a modified version of the frozen-section assay. Peripheral blood mononuclear cells (PBM) from 26 MS patients, 26 healthy controls and 10 patients with other inflammatory non- neurological diseases (OIND) were co-incubated with cryostat sections of normal brain white matter, immunohistochemically labelled with anti-CD45 antibody and counterstained with Giemsa stain. CD45-positive PBM adherent to transected microvasculature were counted with an automated image analyzer. MS patients showed an increased number of vessel-bound PBM (48.8 +/- 36.4) with respect to healthy controls (27.4 +/- 20.7, P = 0.01) and OIND patients (22.6 +/- 7.8, P = 0.01). Significant differences were also obtained counting the number of vessel-bound PBM as a percent of total vascular cells between MS patients (12.7 +/- 7.2%) and healthy controls (6.9 +/- 5.4%, P = 0.002) or OIND patients (7.4 +/- 4.4%, P = 0.03). We confirm that PBM from MS patients show an increased potential of binding to cerebral vessels. The frozen-section assay provides a unique tool to study in situ the molecular interactions of leukocytes with brain vascular structures.

Leukocyte traffic in the central nervous system: the participants and their roles

While the central nervous system has long been considered immunologically privileged, over the past decade it has become evident that a wide variety of leukocyte types traffic through the nervous system. It is also apparent that the rules governing the trafficking of these disparate cell types are different for each. Some arrive, and probably depart, continuously as part of normal physiology. Others only appear to seek a specific antigen or in response to tissue damage. In this review the nature and function of individual cell types are discussed and our current knowledge regarding the parameters governing their entry into the CNS is examined.

Comparative study of the pharmacodynamic and pharmacologic effects of Betaseron and AVONEX

The aim of this 1 week study was to compare the biologic effects induced by Betaseron and AVONEX using their approved dose, route, and schedule. Sixteen healthy volunteers were randomly assigned to receive either a single i.m. dose of AVONEX (6 million International Units [MIU]) or, every other day s.c. doses of Betaseron (8 MIU). Common side effects associated with interferon-beta (IFN-beta) treatment and biologic response parameters (neopterin, beta2-microglobulin, interleukin-10 [IL-10], and MxA protein levels in blood) were measured. Ibuprofen was administered to all subjects throughout the study. Fever, chills, and myalgia occurred most frequently and with the greatest severity between 6 and 12 h after the first dose of either IFN-beta. Despite the additional dosing of subjects in the Betaseron group, the incidence, duration, and severity of the side effects were not significantly different from those in the AVONEX group. Biologic response parameters reached similar maximum concentrations in both treatment groups. In the Betaseron group, neopterin and beta2-microglobulin levels remained significantly greater than baseline throughout the 7 day study, whereas those in the AVONEX group were elevated only through day 5. Betaseron treatment significantly increased IL-10 levels above baseline, but AVONEX treatment did not. The overall induction of neopterin, beta2-microglobulin, and IL-10 (as measured by area under the concentration-time curve) was significantly greater in the Betaseron group than the AVONEX group (p = 0.031). The results of this study demonstrate that the approved Betaseron dosing regimen, in combination with ibuprofen use, provided a significantly greater and more consistently elevated biologic response compared with that of AVONEX and did so with a side effects profile comparable to that of once a week AVONEX dosing.

Correlation of soluble adhesion molecules in blood and cerebrospinal fluid with magnetic resonance imaging activity in patients with multiple sclerosis

Several studies have reported a positive correlation between levels of soluble adhesion molecules in serum or cerebrospinal fluid and cranial MRI activity. We performed a cross-sectional study in 46 patients with newly diagnosed MS and determined levels of soluble intercellular adhesion molecule-I (sICAM-I) as well as vascular cell adhesion molecule-I (sVCAM-I) in correlation to the number and area of gadolinium enhancing lesions on cranial magnetic resonance images (MRI). The data revealed a significant positive correlation between sVCAM-I serum levels and gadolinium enhancing lesions. In addition, CSF to serum ratios for sICAM-I and sVCAM-I correlated to MRI activity. In patients with a single enhancing lesion (SEL) there was a negative correlation between the QsCAM and the distance of the SEL to the ventricles. As these adhesion molecules are stable and markers of disease activity in MS, we further investigated sVCAM-I serum levels during treatment with interferon beta-Ib (Betaferon). Significant increases in serum levels for sVCAM-I in patients receiving Betaferon were associated with a favourable treatment response after 1 year in 17 out of 19 patients and correlated to decreased MRI activity, whereas stable or reduced sVCAM-I levels occurred more often in non-responders (five out of six patients). Therefore it can be hypothesized that soluble adhesion molecules are released from cerebral endothelial cells as an early immunoregulatory activity of the immune system to reduce cellular traffic across the blood brain barrier and this is further enhanced by IFN-beta treatment.

Influence of IFN-beta1b (Betaferon) on cytokine mRNA profiles in blood mononuclear cells and plasma levels of soluble VCAM-1 in multiple sclerosis

Inflammatory cell infiltration within the central nervous system (CNS) and upregulation of both pro- and anti-inflammatory cytokines are characteristic for multiple sclerosis (MS). Treatment with interferon-beta 1b (IFN-beta1b) reduces the number and severity of MS relapses. To examine whether treatment with IFN-beta1b affects levels of cytokine mRNA expressing blood mononuclear cells (MNC) we employed in-situ hybridization with synthetic oligonucleotide probes to detect and enumerate IFN-gamma, TNF-alpha, IL-10, TGF-beta and perforin mRNA expressing cells in MS patients before treatment with IFN-beta1b and during treatment for 3-6 weeks and for 3-6 months. Numbers of blood MNC spontaneously expressing TNF-alpha and IL-10 mRNA were lower after 3-6 months of treatment, while numbers of IFN-gamma, TGF-beta and perforin mRNA expressing MNC were not affected by treatment. IFN-beta1b had no influence on levels of MBP-reactive IFN-gamma, TNF-alpha, TGF-beta, IL-10 or perforin mRNA expressing blood MNC determined after 3-6 weeks or 3-6 months of treatment. Parallel measurements of plasma concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) revealed elevated levels after 3-6 weeks of treatment and these levels remained higher after 3-6 months of treatment. The results suggest that IFN-beta1b treatment upregulates plasma levels of sVCAM-1, but has little effects on numbers of blood MNC expressing mRNA of the pro- and anti-inflammatory cytokines under study.Copyright Lippincott-Raven Publishers

Effects of beta-IFN-1b treatment in MS patients on adhesion between PBMNCs, HUVECs and MS-HBECs: an in vivo and in vitro study

The in vivo effects on the expression of adhesion molecules and on the adhesion between mononuclear cells and multiple sclerosis human brain endothelial cells (MS-HBECs) were investigated at the beginning of beta-IFN-1b treatment of MS patients. MS-HBECs were isolated from a surgical specimen obtained from an MS patient undergoing brain surgery for vascular aneurysm. 48 h after the first single administration of beta-IFN-1b, PBMNCs of 10 MS patients were analyzed for HLA-DR, CD11a, CD18 and VLA-4 expression and the adhesion between PBMNCs and both stimulated and unstimulated MS-HBECs evaluated. sICAM-1 and sVCAM-1 dosage in the serum of the patients was checked as well. The experiments were repeated using HUVECs in order to detect possible endothelial organ-specific differences. The experiments were also performed after six months of beta-INF-1b treatment on HUVECs. No significant effects on mononuclear cells/endothelium adhesion were detected at 48 h, but adhesion of PBMNCs to HUVECs decreased at six months. An increase in HLA-DR and VLA-4 and a decrease of CD18 was detected in monocytes. The serum level of sVCAM-1 increased at T2 and was still higher than at T0 at six months. The effect of the beta-IFN-1b treatment on both MS-HBECs and HUVECs, was selectively studied in vitro by testing the expression of cytokine-induced adhesion molecules HLA-DR, ICAM-1 and VCAM-1. The in vitro experiments confirmed that beta-IFN-1b is able to antagonize gamma-IFN-induced HLA-DR expression on MS human brain endothelial cells without relevant effects on VCAM-1 and ICAM-1.