Immunoregulatory effects of interferon-beta and interacting cytokines on human vascular endothelial cells. Implications for multiple sclerosis autoimmune diseases

Protective effect of scorpion venom oligopeptides in human umbilical vein endothelial cells under benzo(α)pyrene exposure

Inflammation and oxidative stress play pivotal role in the process of atherosclerosis. Scorpion venom is widely used as anti-cancer agent, however, the anti-inflammatory and antioxidant activities of scorpion venom peptides (SVPs) are rarely explored. In the current study, seven novel SVPs were isolated in a protective activity tracking isolation method in a cell model of benzo(α)pyrene (BaP)-induced human umbilical vein endothelial cells (HUVECs). The current study showed that SVP-1 [Tyr-Thr-Trp-Glu-Ala] significantly attenuated BaP-induced reactive oxygen species (ROS) over-production and inflammatory cytokines (IL-6, IL-1β, TNF-α, NO and PGE2) over-expression. Furthermore, SVP-1 attenuated BaP-induced adhesion molecules over-expression and inhibited the NF-κB and AhR signalling pathways activation. Collectively, the present study, for the first time, shows that SVPs inhibit the NF-κB and AhR signalling pathways in HUVECs under BaP-exposure, which strongly suggests the therapeutic potential of SVPs against atherosclerosis.

Use of interferon beta in multiple sclerosis: rationale for early treatment and evidence for dose- and frequency-dependent effects on clinical response

The current approach to the use of interferon (IFN) beta in the treatment of multiple sclerosis (MS) is, in general, conservative. However, recent findings about early events in MS and data on dose-response relationships with IFN beta indicate that such an approach may be suboptimal. Four lines of evidence suggest that delays in the initiation of therapy with IFN beta may be detrimental: I) axonal damage secondary to inflammation starts very early in the course of MS; 2) pathological events occurring early in MS are predictive of the future course of the disease; 3) inflammatory activity in relapsing MS is not confined to episodes of clinical impairment, but often starts before the first such episode and generally continues during remissions; and 4) the immune-mediated activity that underlies MS may become more difficult to control as the disease progresses. An early treatment strategy is also supported by data from two recently published clinical studies. In addition, preclinical and clinical results suggest that the beneficial effects of IFN may be dose- and frequency-dependent Taken together, these findings indicate that treatment with IFN beta should be started as early as possible in the course of MS, and suggest that, in order to maximize patient benefit, the highest possible dose of IFN beta should be chosen. Multiple Sclerosis (2002) 8, 2-9

Cellular crosstalk between airway epithelial and endothelial cells regulates barrier functions during exposure to double-stranded RNA

INTRODUCTION

The epithelial and endothelial barriers of the airway mucosa are critical for regulation of tissue homeostasis and protection against pathogens or other tissue damaging agents. In response to a viral infection, epithelial cells must signal to the endothelium to initiate immune cell recruitment. This is a highly temporal regulated process; however, the mechanisms of this cross-talk are not fully understood.

METHODS

In a close-contact co-culture model of human airway epithelial and endothelial cells, cellular crosstalk was analyzed using transepithelial electrical resistance (TER) measurements, immunofluorescence, electron microscopy, and ELISA. Viral infections were simulated by exposing airway epithelial cells apically to double-stranded RNA (Poly(I:C)). Using a microfluidic culture system, the temporal release of mediators was analyzed in the co-culture model.

RESULTS

Within 4 h of challenge, double-stranded RNA induced the release of TNF-α by epithelial cells. This activated endothelial cells by triggering the release of the chemoattractant CX3CL1 (fractalkine) by 8 h post-challenge and expression of adhesion molecules E-selectin and ICAM-1. These responses were significantly reduced by neutralising TNF-α.

CONCLUSION

By facilitating kinetic profiling, the microfluidic co-culture system has enabled identification of a key signaling mechanism between the epithelial and endothelial barriers. Better understanding of cell-cell cross-talk and its regulatory mechanisms has the potential to identify new therapeutic strategies to control airway inflammation.

PEGylated interferon beta-1a: meeting an unmet medical need in the treatment of relapsing multiple sclerosis

Multiple sclerosis is a chronic autoimmune disease of the central nervous system for which a number of disease-modifying therapies are available, including interferon beta (Avonex®, Rebif®, and Betaseron/Betaferon®), glatiramer acetate (Copaxone®), and an anti-VLA4 monoclonal antibody (Tysabri®). Despite the availability and efficacy of these protein and peptide drugs, there remains a significant number of patients who are untreated, including those with relatively mild disease who choose not to initiate therapy, those wary of injections or potential adverse events associated with therapy, and those who have stopped therapy due to perceived lack of efficacy. Since these drugs have side effects that may affect a patient's decision to initiate and to remain on treatment, there is a need to provide a therapy that is safe and efficacious but that requires a reduced dosing frequency and hence a concomitant reduction in the frequency of side effects. Here we describe the development of a PEGylated form of interferon beta-1a that is currently being tested in a multicenter, randomized, double-blind, parallel-group, placebo-controlled study in relapsing multiple sclerosis patients, with the aim of determining the safety and efficacy of 125 microg administered via the subcutaneous route every 2 or 4 weeks.

Effect of IFN-beta therapy on the frequency and function of CD4(+)CD25(+) regulatory T cells and Foxp3 gene expression in relapsing-remitting multiple sclerosis (RRMS): a preliminary study

Interferon-beta (IFN-beta) is an immunomodulatory drug of choice to control relapsing-remitting multiple sclerosis (RR-MS), although its function is still unclear. A reduced suppressive function of CD4(+)CD25(+) regulatory T cells (T(reg)) has been shown in RR-MS patients. In this study, to understand the effect of IFN-ss on CD4(+)CD25(+) regulatory T cells, we analyzed the frequency and function of these cells and Foxp3 gene expression before and after treatment. We evaluated the frequency and function of CD4(+)CD25(+)Foxp3(+) regulatory T cells by flow cytometry and co-culture inhibition test respectively and gene expression of Foxp3 by real-time PCR in a longitudinal follow-up study in 18 relapsing-remitting MS patients. Our data revealed that IFN-beta significantly improved frequency and suppressive function of T(reg) cells (P<0.05) without any significant effect on gene expression of Foxp3 after 6 months. The results of the present study indicate that IFN-beta therapy in some of patients with RR-MS may restore function of regulatory T cells and control the unchecked immune cascade activity. Larger longitudinal studies on more MS patients are required to confirm our findings.

High-dose, high-frequency recombinant interferon beta-1a in the treatment of multiple sclerosis

BACKGROUND

There is at present no cure for multiple sclerosis (MS), and existing therapies are designed primarily to prevent lesion formation, decrease the rate and severity of relapses and delay the resulting disability by reducing levels of inflammation.

OBJECTIVE

The aim of this review was to assess the treatment of relapsing MS with particular focus on subcutaneous (s.c.) interferon (IFN) beta-1a.

METHOD

The literature on IFN beta-1a therapy of MS was reviewed based on a PubMed search (English-language publications from 1990) including its pharmacodynamics and pharmacokinetics, clinical efficacy in relapsing MS as shown in placebo-controlled studies and in comparative trials, efficacy in secondary progressive MS, safety and tolerability, and the impact of neutralizing antibodies.

CONCLUSION

The literature suggests that high-dose, high-frequency s.c. IFN beta-1a offers an effective option for treating patients with relapsing MS, with proven long-term safety and tolerability, and has a favourable benefit-to-risk ratio compared with other forms of IFN beta.

Impaired autoimmune T helper 17 cell responses following DNA vaccination against rat experimental autoimmune encephalomyelitis

Background

We have previously shown that vaccination with DNA encoding the encephalitogenic peptide myelin oligodendrocyte glycoprotein (MOG)_91–108 (pMOG) suppresses MOG_91–108-induced rat Experimental Autoimmune Encephalomyelitis (EAE), a model for human Multiple Sclerosis (MS). The suppressive effect of pMOG is dependent on inclusion of CpG DNA in the plasmid backbone and is associated with early induction of Interferon (IFN)-β.

Principal Findings

In this study we examined the mechanisms underlying pMOG-induced protection. We found that in the DNA vaccinated cohort proinflammatory Interleukin (IL)-17 and IL-21 responses were dramatically reduced compared to in the control group, but that the expression of Foxp3 and Tumor Growth Factor (TGF)-β1, which are associated with regulatory T cells, was not enhanced. Moreover, genes associated with Type I IFNs were upregulated. To delineate the role of IFN-β in the protective mechanism we employed short interfering RNA (siRNA) to IFN-β in the DNA vaccine. SiRNA to IFN-β completely abrogated the protective effects of the vaccine, demonstrating that a local early elaboration of IFN-β is important for EAE protection. IL-17 responses comparable to those in control rats developed in rats injected with the IFN-β-silencing DNA vaccine.

Conclusions

We herein demonstrate that DNA vaccination protects from proinflammatory Th17 cell responses during induction of EAE. The mechanism involves IFN-β as IL-17 responses are rescued by silencing of IFN-β during DNA vaccination.

Interferon-beta reduces the mouse liver fibrosis induced by repeated administration of concanavalin A via the direct and indirect effects

Type I interferons (IFNs), IFN-alpha and IFN-beta, are widely used for treating chronic hepatitis C. Although retrospective studies have suggested that type I IFNs have direct antifibrotic effects, little is known about these mechanisms. The present study was designed to clarify the preventive mechanisms of type I IFNs in the progression of fibrosis for the establishment of a more effective therapy. A murine fibrosis model comprising immunological reactions was induced by the administration of concanavalin A (0.3 mg/body) into mice once a week for 4 weeks. Liver injury and the degree of fibrosis were determined by measuring the serum alanine aminotransferase activities and liver hydroxyproline contents with or without IFN-beta pretreatment. IFN-beta suppressed the hepatocellular injury and increased the hydroxyproline content induced by repeated concanavalin A injections, but had no effect on established fibrosis. Furthermore, IFN-beta reduced the expressions of transforming growth factor-beta, basic fibroblast growth factor, collagen type I A2 and tissue inhibitor of metalloproteinase 1 messenger RNAs, which are related to the progression of liver fibrosis. The IFN-beta reduced the liver injury and fibrosis induced by immunological reactions. These data suggest that type I IFNs suppress the progression of cirrhosis through inhibition of repeated hepatocellular injury and/or factors that promote the liver fibrosis induced by hepatitis virus infection.

Cytokine-mediated modulation of MMPs and TIMPs in multipotential neural precursor cells

Recent studies have implicated the inflammatory process during experimental allergic encephalomyelitis (EAE) in triggering migration and differentiation of transplanted neural precursors cells (NPCs) into the inflamed white matter. The pro-inflammatory cytokines tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma are key factors in the pathogenesis of brain inflammation in EAE and were shown to enhance NPCs migration in vitro. As cell migration is dependent on extracellular matrix remodeling, involving proteolytic enzyme members of the matrix metalloproteinase (MMPs) family, we characterized the profile of expression of MMPs and their endogenous inhibitors (TIMPs) in rat NPCs, and evaluated the effects of TNF-alpha, IFN-gamma and IFN-beta, a clinically proven modulator of brain inflammation, on the expression of these molecules. Newborn rat striatal NPCs were expanded in spheres as nestin+, PSA-NCAM+ and NG2(-) cells, which can differentiate into astrocytes, oligodendrocytes and neurons. NPCs' gelatinase activities of MMP-2 and MMP-9, as determined by zymography, were increased by TNF-alpha, and to a lesser extent by IFN-gamma. Semi-quantitative RT-PCR indicated that TNF-alpha also upregulated MMP-9 mRNA levels. IFN-beta suppressed the TNF-alpha-induced levels of secreted MMP-9 and MMP-2, while enhancing the expression of TIMP-1 and TIMP-2 mRNA. These results suggest that MMPs activity is induced in NPCs by pro-inflammatory cytokines to mobilize them for promoting reparative processes. IFN-beta, on the other hand, appears to have an anti-proteolytic influence that may attenuate such NPC-mediated repair processes.

Mechanisms of action for treatments in multiple sclerosis: Does a heterogeneous disease demand a multi-targeted therapeutic approach?

The etiology of multiple sclerosis (MS) is incompletely understood, and evidence suggests there may be more than one underlying cause in this disorder. Furthermore, this complex and heterogeneous autoimmune disease shows a high degree of clinical variability between patients. Therefore, in the absence of a single therapeutic target for MS, it is difficult to apply conventional drug design strategies in the search for new treatments. We review the potential mechanisms of action of several effective therapies for MS that are currently available or in development. The effects of each treatment are described in terms of their actions on key processes in a five-step model of MS pathogenesis. Conventional immunosuppressants targeting intracellular ligands (e.g. mitoxantrone) have broad cytotoxic effects on B cells, T cells, and macrophages. This suppresses the pathogenic immune response in MS with high efficacy but is also associated with high toxicity, limiting the long-term use of these agents. Monoclonal antibodies (e.g. natalizumab and alemtuzumab) are a new generation of immunosuppressants that act on immune-cell surface ligands. These agents have narrower immunosuppressive actions and different safety profiles compared with conventional immunosuppressants. Immunomodulators (interferon-beta and glatiramer acetate), which shift the immune balance toward an anti-inflammatory response, are at the frontline of treatments for MS. Immunomodulators have targeted actions on the immune system, but affect a greater number of immunopathogenic processes than monoclonal antibodies. Given the inherent heterogeneity of MS, such treatments, which act at many levels of the disease, may achieve the best clinical results. Using our understanding of the interplay between mechanism of action and clinical effects in MS therapies may help us to better design and select new treatments for the future.

Interferons in relapsing-remitting multiple sclerosis: are there benefits from long-term use?

Multiple sclerosis (MS) is one of the most common chronic neurological diseases in young adults in western countries. An important aspect of treatment of this disease is the use of interferons (IFNs). These are molecules with antiviral, immunomodulatory, antiproliferative and hormonal activities. IFNbeta, a class I IFN, has been used extensively in the therapy of MS, particularly in its relapsing-remitting (RRMS) phase, the most frequent clinical form of the disease. Although the available evidence from published clinical trials is difficult to evaluate because of methodological differences, an unbiased review of the data reveals sufficient evidence to conclude that treatment with IFNbeta in RRMS is both efficacious and safe, at least over the periods so far investigated (up to 4-6 years). While there is no reason to suspect that IFNbeta should not continue to be efficacious and safe over the longer term, studies investigating these questions over longer periods and including greater numbers of patients are needed.

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.

What do we know about the mechanism of action of disease-modifying treatments in MS?

Multiple sclerosis (MS), a chronic inflammatory disorder of the central nervous system (CNS), 2 results in damage to axons and their surrounding myelin sheath. The exact cause of inflammation remains unclear, but an autoimmune response directed against CNS antigens is suspected. MS can affect the brain, optic nerve and spinal cord, thus causing many neurological symptoms. These can include limb numbness or weakness, sensory or motor changes, ataxia, blurry vision, painful eye movements, bladder and bowel dysfunction, decreased memory, fatigue and effective disorders. This article will include a concise overview of the pathogenesis of MS in order to set the stage for subsequent discussion of the mechanisms of action of disease-modifying treatments, and whether these should influence our treatment choices. Although the exact pathogenesis of MS is not fully understood, current knowledge has already led to the development of effective treatments, namely interferon (IFN) 3 and glatiramer acetate, both of which have been shown to reduce relapse rates, while IFN 3- 1 a also reduces confirmed disability progression. Further increases in our understanding of the pathogenesis of MS are likely to assist in the identification of new targets for disease-modifying therapies and in the optimisation of current treatments..

High-dose, frequently administered interferon beta therapy for relapsing–remitting multiple sclerosis must be maintained over the long term: the interferon beta dose-reduction study

Long-term trials have demonstrated the continued efficacy of interferon (IFN) beta treatment in patients with relapsing-remitting (RR) multiple sclerosis (MS) during prolonged administration. The objective of the work was to evaluate the effects of reducing IFN beta administration frequency and total weekly dose in patients with RR MS who have achieved clinical and MRI disease activity stabilization during long-term IFN beta-1b treatment. Prospective 1-year follow-up of 27 RR MS patients on long-term 250 microg every other day (standard dose) IFN beta-1b treatment were randomized either to gradually reduce dose to 30 microg once-a-week IFN beta-1a (13 patients), or to continue on IFN beta-1b standard dose (14 patients). We found significant differences in the two group of patients. In the group of patients continuously treated with IFN beta-1b standard dose, 79% remained relapse free compared to 23% in the group receiving once-weekly IFN beta-1a (p=0.006). The number of patients without new PD/T2 lesions was higher in the group of patients continuously treated with IFN beta-1b standard dose (77%) compared to the once-weekly IFN beta-1a group (23%) (p=0.04). IFN beta is a long-term treatment for MS. The reduction of IFN beta-1b administration frequency and dose is not advisable even in patients free from clinical and MRI disease activity for many years.

Blood-brain barrier permeability and monocyte infiltration in experimental allergic encephalomyelitis: a quantitative MRI study

Enhanced cerebrovascular permeability and cellular infiltration mark the onset of early multiple sclerosis lesions. So far, the precise sequence of these events and their role in lesion formation and disease progression remain unknown. Here we provide quantitative evidence that blood-brain barrier leakage is an early event and precedes massive cellular infiltration in the development of acute experimental allergic encephalomyelitis (EAE), the animal correlate of multiple sclerosis. Cerebrovascular leakage and monocytes infiltrates were separately monitored by quantitative in vivo MRI during the course of the disease. Magnetic resonance enhancement of the contrast agent gadolinium diethylenetriaminepentaacetate (Gd-DTPA), reflecting vascular leakage, occurred concomitantly with the onset of neurological signs and was already at a maximal level at this stage of the disease. Immunohistochemical analysis also confirmed the presence of the serum-derived proteins such as fibrinogen around the brain vessels early in the disease, whereas no cellular infiltrates could be detected. MRI further demonstrated that Gd-DTPA leakage clearly preceded monocyte infiltration as imaged by the contrast agent based on ultra small particles of iron oxide (USPIO), which was maximal only during full-blown EAE. Ultrastructural and immunohistochemical investigation revealed that USPIOs were present in newly infiltrated macrophages within the inflammatory lesions. To validate the use of USPIOs as a non-invasive tool to evaluate therapeutic strategies, EAE animals were treated with the immunomodulator 3-hydroxy-3-methylglutaryl Coenzyme A reductase inhibitor, lovastatin, which ameliorated clinical scores. MRI showed that the USPIO load in the brain was significantly diminished in lovastatin-treated animals. Data indicate that cerebrovascular leakage and monocytic trafficking into the brain are two distinct processes in the development of inflammatory lesions during multiple sclerosis, which can be monitored on-line with MRI using USPIOs and Gd-DTPA as contrast agents. These studies also implicate that USPIOs are a valuable tool to visualize monocyte infiltration in vivo and quantitatively assess the efficacy of new therapeutics like lovastatin.

Interferon-β in the treatment of relapsing–remitting multiple sclerosis

The role of interferon-beta as a disease-modifying drug (DMD) for the treatment of relapsing-remitting multiple sclerosis (RRMS) is now well established, and its efficacy has been demonstrated unequivocally in large-scale clinical trials. However, current evidence suggests that in order to increase the benefit of therapy, use of an effective drug and dosing regimen should be commenced early in the course of the disease, a finding that places new emphasis on the need for early diagnosis. Indeed, it is now known that MS lesions often develop at a subclinical level and that axonal damage occurs even in the very early stages of the disease. Moreover, such damage may be irreversible, and there is strong evidence to suggest that efficacy lost as a consequence of delay in the onset of treatment or the use of a suboptimal drug regimen cannot be regained. At present, the choice of interferon-beta is complicated by the availability of 3 different products, each with a different dosing regimen. Although the optimal interferon-beta dosing regimen for RRMS has been the focus of much discussion, the issues of dose, and particularly dosing frequency, have not been satisfactorily addressed in clinical trials until recently. Over the last 2 years, however, 3 comparative studies of interferon-beta products have been conducted. The results obtained from these recent trials underline the importance of both dose and dosing frequency and indicate that for improved efficacy in RRMS, interferon-beta therapy should be administered frequently at the highest tolerable, and thus most effective, dose.

The immunomodulatory properties of in vitro immunoglobulins are dose-dependent

OBJECTIVES

The mechanism by which intravenous immunoglobulins (immunoglobulin G, IgG) exert their beneficial effect on multiple sclerosis (MS) is unknown. Furthermore, there is uncertainty about the optimal dosage of IgG. Therefore, we investigated the influence of different IgG dosages on cytokine production in MS.

MATERIALS AND METHODS

Twenty-five MS patients and 15 healthy controls were enrolled. We measured the production of interferon gamma (IFN-gamma), tumour necrosis factor alpha (TNF) and interleukin 10 (IL-10) in peripheral blood lymphocytes by flowcytometry after stimulation without and with IgG in different doses (1, 5 and 10 mg/ml).

RESULTS

IFN-gamma and TNF were decreased significantly (P = 0.001) in the untreated and interferon beta (IFN-beta) treated patients after stimulation with IgG. In contrast, IL-10 production was significantly enhanced (P = 0.001) at least in the untreated patient group. The reduction of the pro-inflammatory cytokines IFN-gamma and TNF after stimulation with different IgG doses was clearly dose-dependent in all groups.

CONCLUSION

Besides a suppression of the pro-inflammatory cytokines IFN-gamma and TNF, IgG enhances the anti-inflammatory cytokine IL-10. This effect is dose-dependent, speaking in favour of higher IgG doses in the treatment of MS.

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.

Modulation of monocytes matrix metalloproteinase-2, MT1-MMP and TIMP-2 by interferon-gamma and -beta: implications to multiple sclerosis

Recent findings have implicated the activity of matrix metalloproteinases (MMPs) in the pathogenesis of multiple sclerosis (MS), while in vivo interferon (IFN)-beta treatment was demonstrated to suppress MMPs. In the present study, the effects mediated by IFN-gamma and IFN-beta on the mRNA and protein expression of MMP-2, its physiological activator, MT1-MMP and its endogenous inhibitor, TIMP-2, by monocytes were evaluated in vitro. The results point to the significance of IFNs in modulating MMPs/tissue inhibitors of MMPs (TIMPs) expression, and support the possibility that the therapeutic effects of IFN-beta may be, in part, due to induction of a shift from "pro-" to "anti-proteolytic" pattern of MMPs and TIMPs expression.

Differential regulation of membrane bound and soluble ICAM 1 in human endothelium and blood mononuclear cells: effects of interferon beta-1a

The membrane-associated Intercellular Adhesion Molecule 1 (mICAM 1) is fundamental for adhesion of leukocytes to endothelial cells. A soluble form of ICAM 1 (sICAM 1) exists in the human serum, and is seen as marker of disease activity in patients suffering from Multiple Sclerosis (MS). High levels of sICAM 1 have been detected in MS patients benefiting from interferon beta (IFNbeta) treatment, but little is known on the molecular origins of sICAM 1. This study investigated the interrelationship and the mechanisms of production of sICAM 1 and mICAM 1 in human endothelium (Human Umbilical Vein Endothelial Cells, HUVECs) and mononuclear leukocytes (MNL) upon stimulation with IFNbeta-1a and other inducers. We found that the expression of mICAM 1 and the release of sICAM 1 are differentially regulated in both these cytotypes. HUVECs and MNL express specific mRNA for both mICAM 1 and sICAM 1, and modification of the content of each of these transcripts results in regulation of both the ICAM 1 isoforms. We show that IFNbeta-1a is strong regulator of the ICAM 1 RNA splicing machinery. Effect of IFNbeta-1a over expression of the ICAM 1 isoforms might have a relevant immunomoregulatory role in Multiple Sclerosis.

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.

Interferon-beta therapy in multiple sclerosis: evidence for a clinically relevant dose response

There have been considerable advances made recently in the treatment of multiple sclerosis (MS). In particular, interferon (IFN)beta has been demonstrated in several independent, multicentre clinical trials to lower unequivocally the biological activity of this illness. The results of these trials have been remarkably consistent, demonstrating a reduction in both disease activity and cumulative disability, using a combination of clinical and magnetic resonance imaging outcome measures. Nevertheless, the importance of the total weekly IFNbeta dose in the clinical management of individual patients has been controversial. However, there is considerable information available regarding the effect of IFNbeta dose on the various biochemical and clinical markers that are affected by IFNbeta, which is derived both from pre-clinical studies and multicentre clinical trials. On balance, convincing evidence is provided to support the notion that there is a clinically relevant dose-response in the use of IFNbeta to treat patients with relapsing/remitting MS. However, many of the clinical trials of IFNbeta in MS have confounded the potential effects of dose with the possible effects of frequency of IFNbeta administration. As a result, it is possible that the apparent dose-response observed in these clinical trials may be due, in part, to the more frequent dose administration schedule rather than the total weekly dose.

Use of interferon beta in multiple sclerosis: rationale for early treatment and evidence for dose- and frequency-dependent effects on clinical response

The current approach to the use of interferon (IFN) beta in the treatment of multiple sclerosis (MS) is, in general, conservative. However, recent findings about early events in MS and data on dose-response relationships with IFN beta indicate that such an approach may be suboptimal. Four lines of evidence suggest that delays in the initiation of therapy with IFN beta may be detrimental: 1) axonal damage secondary to inflammation starts very early in the course of MS; 2) pathological events occurring early in MS are predictive of the future course of the disease; 3) inflammatory activity in relapsing MS is not confined to episodes of clinical impairment, but often starts before the first such episode and generally continues during remissions; and 4) the immune-mediated activity that underlies MS may become more difficult to control as the disease progresses. An early treatment strategy is also supported by data from two recently published clinical studies. In addition, preclinical and clinical results suggest that the beneficial effects of IFN may be dose- and frequency-dependent. Taken together, these findings indicate that treatment with IFN beta should be started as early as possible in the course of MS, and suggest that, in order to maximize patent benefit, the highest possible dose of IFN beta should be chosen.

Ovine IFN-tau modulates the expression of MHC antigens on murine cerebrovascular endothelial cells and inhibits replication of Theiler's virus

Interferon-beta (IFN-beta) has been used successfully to treat patients with relapsing-remitting multiple sclerosis (MS). IFN-tau is a new class of type I IFN that is secreted by the trophoblast and is the signal for maternal recognition of pregnancy in sheep. IFN-tau has potent immunosuppressive and antiviral activities similar to other type I IFN but is less cytotoxic than IFN-alpha/beta. The current investigation concerns the effect of recombinant ovine IFN-tau (rOvIFN-tau) on the modulation of MHC class I and II expression on cloned mouse cerebrovascular endothelial (CVE) cells. IFN-tau induced tyrosine phosphorylation of Stat1 and upregulated the expression of MHC class I on CVE. One proposed action by which type I IFN reduce the relapse rate in MS is via interference with IFN-gamma-induced MHC class II expression. IFN-tau was shown to downregulate IFN-gamma-induced MHC class II expression on CVE and, hence, may be of potential therapeutic value in downregulating inflammation in the central nervous system (CNS). IFN-tau did not upregulate the expression of MHC class II on CVE. IFN-tau also inhibited the replication of Theiler's virus in CVE. These in vitro results suggest that IFN-tau may be of therapeutic value in the treatment of virus-induced demyelinating disease.

Immunomodulatory effects of interferon-beta-1b in patients with multiple sclerosis

The mechanisms by which IFN beta-1b acts in the treatment of patients with multiple sclerosis (MS) are not completely known. Immunomodulatory effects of IFN beta-1b were investigated in patients with relapsing-remitting (RR) MS in vivo and in vitro. Compared to baseline and controls, defined as patients with RR-MS without immunomodulatory therapy, the expression of TGF beta-1-mRNA by peripheral blood mononuclear cells (PBMC) was persistently increased at week 6, month 3 and month 6 (p < or = 0.05), that of the TGF beta-1 receptor type II from day 5 up to month 6 (p < 0.01). The expression of TNF alpha-mRNA decreased from day 1 to month 3 compared to day 0 and the controls (p < 0.01). The in vitro investigations performed on isolated peripheral blood lymphocytes demonstrated that these effects were dose-dependent. The mRNA and protein expression of TNF alpha-R-I (55 kD-receptor) was only temporarily elevated at the beginning of the therapy in vivo. The expression of TNF alpha-R-I-mRNA increased dose-dependently after stimulation with IFN beta-1b for 24 h in vitro. Serum levels of soluble vascular cell adhesion molecule (sVCAM) were increased during the whole time of in vivo treatment (p < 0.01). The CD8CD38 lymphocyte subpopulation was continuously elevated from day 5 up to month 6 (p < 0.01) in the MS patients treated with IFN beta-1b in vivo. No persistent, significant changes were demonstrable concerning the percentage of total CD4, CD8, CD19 nor in CD4 subpopulations (CD4CD29, CD4CD45RA). The present data suggest that IFN beta-1b induces the mRNA expression of TGF beta-1 and TGF beta-R-II by PBMC, decreases that of TNF alpha and increases levels of sVCAM-1 and of circulating activated CD8 cells (CD8CD38) in blood. These might be other mechanisms by which IFN beta-1b mediates its positive effects in the treatment of MS patients.

In vitro modulation of adhesion molecules, adhesion phenomena, and fluid phase endocytosis on human umbilical vein endothelial cells and brain-derived microvascular endothelium by IFN-beta 1a

Administration of interferon-beta (IFN-beta) in multiple sclerosis (MS) patients provides clinical benefits, although its mechanism(s) of action are not completely understood. We addressed the issue of whether concentrations of IFN-beta1a close to those reached in the serum of treated MS patients could modulate either adhesion molecules or adhesion of peripheral blood mononuclear cells (PBMC) as well as fluid phase endocytosis (FPE) in human umbilical vein endothelial cells (HUVEC) and in brain-derived microvascular endothelial cells (HBMEC). Adhesion was assessed by flow cytometry, and FPE was evaluated by peroxidase uptake. In our study, 200 U/ml IFN-beta1a induced a reduction in adhesion of PBMC to HUVEC. The information reported herein may contribute to further elucidating some of the mechanisms of action of IFN-beta on vascular endothelium.

LFA-1 expression on CD4(+)CD45RO(+) peripheral blood T-lymphocytes in RR MS: effects induced by rIFNbeta-1a

We investigate the in vivo and in vitro effects of short-term treatment with recombinant Interferon beta-1a (rIFNbeta-1a) on CD4(+)CD45RO(+) activated/memory peripheral blood T-lymphocytes (PBTLs) expressing Leukocyte Function Antigen-1 (LFA-1; CD11a/CD18) in relapsing-remitting (RR) Multiple Sclerosis (MS) patients. Blood samples were obtained from 10 RR MS patients before and after 2, 4 and 6 months of rIFNbeta-1a (Avonex) treatment. For each sample, the percentage of CD4(+)CD45RO(+)CD11a(+) (CD11a(dim) and CD11a(bright)) T-cells was evaluated in in vivo PBTLs and in untreated or rIFNbeta-1a (1000 U/ml) or recombinant soluble Intercellular Adhesion Molecule-1 (ICAM-1, the ligand for LFA-1) (400 ng/ml) treated cultured PBTLs by triple fluorescence flow-cytometry (FACS analysis). Soluble ICAM-1 (sICAM-1) serum levels were evaluated by ELISA. In vivo, the percentage of CD4(+)CD45RO(+), CD4(+)CD45RO(+)CD11a(+), CD4(+)CD45RO(+)CD11a(dim) PBTLs increased after 4 and 6 months of rIFNbeta-1a treatment compared to pretreatment and 2 months of treatment (p<0.05). The CD11a expression per se did not change during the time course. Soluble ICAM-1 (sICAM-1) serum levels also increased (p<0.05) after 4 and 6 months of treatment. When T-cells, obtained from the blood of the same patients before and during in vivo treatment, were cultured either untreated or treated with rIFNbeta-1a, they showed an increase in the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a(bright) (p<0.05). The addition of recombinant sICAM-1 to untreated cultures decreased the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a. This last finding seems to support an indirect effect in vivo of rIFNbeta-1a via sICAM-1 on this T-cell subset, since the ICAM-1 soluble form, induced in vivo in serum by rIFNbeta-1a but lacking in in vitro conditions, keeps the percentage of CD11a(+) unchanged within CD4(+)CD45RO(+) T-cells and induces their expression of CD11a(dim), probably preventing T-cells from transmigrating.

Recombinant human interferon beta in relapsing-remitting multiple sclerosis: a review of the major clinical trials

The beneficial effects of interferon beta (IFN-beta) on disease activity in relapsing-remitting multiple sclerosis (RRMS) have been confirmed in several clinical trials. Three IFN-beta products are currently available and licensed for use in RRMS at different dosages and with different routes of administration. For the prescribing physician, therefore, questions remain about the effect these differences may have on the success of therapy. This paper reviews the four large placebo-controlled clinical trials that have been conducted with IFN-beta in patients with RRMS. The evidence available indicates that optimal results are likely to be achieved with the highest tolerable dosage of IFN-beta. Furthermore, as inflammatory brain lesions in MS have been shown to exhibit more extensive and early axonal damage than previously suspected, early treatment may be advisable in order to delay disease progression in RRMS.

Transcription-coupled translation control of AML1/RUNX1 is mediated by cap- and internal ribosome entry site-dependent mechanisms

AML1/RUNX1 belongs to the runt domain transcription factors that are important regulators of hematopoiesis and osteogenesis. Expression of AML1 is regulated at the level of transcription by two promoters, distal (D) and proximal (P), that give rise to mRNAs bearing two distinct 5' untranslated regions (5'UTRs) (D-UTR and P-UTR). Here we show that these 5'UTRs act as translation regulators in vivo. AML1 mRNAs bearing the uncommonly long (1,631-bp) P-UTR are poorly translated, whereas those with the shorter (452-bp) D-UTR are readily translated. The low translational efficiency of the P-UTR is attributed to its length and the cis-acting elements along it. Transfections and in vitro assays with bicistronic constructs demonstrate that the D-UTR mediates cap-dependent translation whereas the P-UTR mediates cap-independent translation and contains a functional internal ribosome entry site (IRES). The IRES-containing bicistronic constructs are more active in hematopoietic cell lines that normally express the P-UTR-containing mRNAs. Furthermore, we show that the IRES-dependent translation increases during megakaryocytic differentiation but not during erythroid differentiation, of K562 cells. These results strongly suggest that the function of the P-UTR IRES-dependent translation in vivo is to tightly regulate the translation of AML1 mRNAs. The data show that AML1 expression is regulated through usage of alternative promoters coupled with IRES-mediated translation control. This IRES-mediated translation regulation adds an important new dimension to the fine-tuned control of AML1 expression.

Exacerbation of glomerulonephritis in subjects with chronic hepatitis C virus infection after interferon therapy

We previously reported the glomerular deposition of hepatitis C virus (HCV) core antigen (Ag) in HCV-related nephropathy. In this study, we analyzed 23 HCV-positive subjects with exacerbation of proteinuria and/or hematuria during interferon (IFN) therapy and measured urinary protein selectivity. We also examined the involvement of HCV-related Ag using anti-HCV core (capside) Ag murine monoclonal antibody (Ab) and anti-core2 rabbit polyclonal Abs in nine subjects. Of 17 subjects, 13 (78%) showed low selective proteinuria. We found mesangial proliferative glomerulonephritis in 9 subjects, membranoproliferative glomerulonephritis in 1 subject, and nephrosclerosis in 1 subject. Immunofluorescence study showed the glomerular deposition of immunoglobulin G (IgG) or IgA and complements in all 9 subjects examined. Trace amounts only of HCV core Ag were detected along the glomerular capillary wall in 3 of 9 subjects (33%). Electron microscopy showed subendothelial or mesangial electron-dense deposits and also foot process effacement (20% to 72.5% of glomerular capillary walls) in all subjects and endothelial swelling in 4 subjects. In conclusion, IFN therapy for HCV may exacerbate the underlying glomerulopathies, unrelated to HCV Ags, through direct or indirect effects on glomerular endothelial and epithelial cells. Physicians should carefully distinguish HCV-related nephropathy from other glomerular diseases when they administer IFN therapy to HCV-positive subjects.

Vascular Endothelial Genes That Are Responsive to Tumor Necrosis Factor- In Vitro Are Expressed in Atherosclerotic Lesions, Including Inhibitor of Apoptosis Protein-1, Stannin, and Two Novel Genes

Activation and dysfunction of endothelial cells play a prominent role in patho-physiological processes such as atherosclerosis. We describe the identification by differential display of 106 cytokine-responsive gene fragments from endothelial cells, activated by monocyte conditioned medium or tumor necrosis factor-. A minority of the fragments (22/106) represent known genes involved in various processes, including leukocyte trafficking, vesicular transport, cell cycle control, apoptosis, and cellular protection against oxidative stress. Full-length cDNA clones were obtained for five novel transcripts that were induced or repressed more than 10-fold in vitro. These novel human cDNAs CA2_1, CG12_1, GG10_2, AG8_1, and GG2_1 encode inhibitor of apoptosis protein-1 (hIAP-1), homologues of apolipoprotein-L, mouse rabkinesin-6, rat stannin, and a novel 188 amino acid protein, respectively. Expression of 4 novel transcripts is shown by in situ hybridization on healthy and atherosclerotic vascular tissue, using monocyte chemotactic protein-1 as a marker for inflammation. CA2_1 (hIAP-1) and AG8_1 are expressed by endothelial cells and macrophage foam cells of the inflamed vascular wall. CG12_1 (apolipoprotein-L like) was specifically expressed in endothelial cells lining the normal and atherosclerotic iliac artery and aorta. These results substantiate the complex change in the gene expression pattern of vascular endothelial cells, which accompanies the inflammatory reaction of atherosclerotic lesions.

Recent developments in drug therapy for multiple sclerosis

Symptomatic treatment of multiple sclerosis (MS) includes a diverse range of drugs intended to relieve the specific symptoms with which a patient may present at a particular point in the progression of the disease. These drugs, not specifically designed for the treatment of MS, may include antispastic agents (e.g. baclofen), drugs to reduce tremor (e.g. clonazepam), anticholinergics (e.g. oxybutynin) which relieve urinary symptoms, anti-epileptics (e.g. carbamazepine) to control neuralgia, stimulants to reduce fatigue (e.g. amantadine), and antidepressants (e.g. fluoxetine) to treat depression. The treatment of acute relapses or exacerbations is dominated by corticosteroids such as methylprednisolone. The most active area of current investigation is the development of drugs which will inhibit the progression of the disease process itself, and in this category the beta- and alpha-interferons are the most effective drugs currently available, although many new treatments are currently in trials, including immunoglobulin, copolymer-1. bovine myelin, T-cell receptor (TCR) peptide vaccines, platelet activating factor (PAF) antagonists, matrix metallo-proteinase inhibitors, campath-1, and insulin-like growth factor (IGF).

Occurrence of thyroid autoimmunity and dysfunction throughout a nine-month follow-up in patients undergoing interferon-beta therapy for multiple sclerosis

Thyroid autoimmunity and dysfunction are a well known side effect of IFN alpha therapy for viral hepatitis and tumors, while the IFN beta effects on the thyroid gland in neurological patients have not been studied. The aim of this longitudinal study was to look for the appearance of thyroid autoimmunity as well as for the occurrence of overt thyroid disease in the patients affected by multiple sclerosis (MS) treated with IFN beta 1b. Eight patients (4 males, 4 females) undergoing r-IFN beta 1b treatment (8 M.U. every other day for 9 months) for relapsing remitting multiple sclerosis entered the study. We have analyzed thyroid function parameters and auto antibody levels before and after 1, 2, 3, 6 and 9 months of therapy. None of them referred to familiar thyroid pathology or presented clinically overt thyroid disease except for one patient (case 4) who showed TPO-Ab pretreatment positivity and another (case 8) who was in therapy with Levothyroxine 100 microg/die for multinodular goiter. The number of patients with appearance of thyroid antibodies has slowly increased, until the third month of therapy with 3 patients out of 7 positive for TPO-Ab. The only case of overt thyroid dysfunction reported by us appeared after nine months of therapy and consisted of a hypothyroidism. Our data suggest that short-term interferon beta treatment is able to induce thyroid autoimmunity (42.8%) and dysfunction (12.5%).

Alzheimer's beta-amyloid peptides induce inflammatory cascade in human vascular cells: the roles of cytokines and CD40

Accumulating evidence suggests that beta-amyloid (Abeta)-induced inflammatory reactions may partially drive the pathogenesis of Alzheimer's disease (AD). Recent data also implicate similar inflammatory processes in cerebral amyloid angiopathy (CAA). To evaluate the roles of Abeta in the inflammatory processes in vascular tissues, we have tested the ability of Abeta to trigger inflammatory responses in cultured human vascular cells. We found that stimulation with Abeta dose-dependently increased the expression of CD40, and secretion of interferon-gamma (IFN-gamma) and interleukin-1beta (IL-1beta) in endothelial cells. Abeta also induced expression of IFN-gamma receptor (IFN-gammaR) both in endothelial and smooth muscle cells. Characterization of the Abeta-induced inflammatory responses in the vascular cells showed that the ligation of CD40 further increased cytokine production and/or the expression of IFN-gammaR. Moreover, IL-1beta and IFN-gamma synergistically increased the Abeta-induced expression of CD40 and IFN-gammaR. We have recently found that Abeta induces expression of adhesion molecules, and that cytokine production and interaction of CD40-CD40 ligand (CD40L) further increase the Abeta-induced expression of adhesion molecules in these same cells. These results suggest that Abeta can function as an inflammatory stimulator to activate vascular cells and induces an auto-amplified inflammatory molecular cascade, through interactions among adhesion molecules, CD40-CD40L and cytokines. Additionally, Abeta1-42, the more pathologic form of Abeta, induces much stronger effects in endothelial cells than in smooth muscle cells, while the reverse is true for Abeta1-40. Collectively, these findings support the hypothesis that the Abeta-induced inflammatory responses in vascular cells may play a significant role in the pathogenesis of CAA and AD.

ICAM 1 expression and fluid phase endocytosis of cultured brain microvascular endothelial cells following exposure to interferon beta-1a and TNFalpha

We have studied the effect of interferon (IF) beta-1a on the basal and TNFalpha-induced intercellular adhesion molecule 1 (ICAM 1) expression and fluid phase endocytosis (FPE) of horseradish peroxidase in cultured rat brain microvascular endothelial cells. Neither basal ICAM 1 expression nor basal FPE were significantly affected by 24-72 h exposure to 1000 U/ml IFbeta-1a. ICAM 1 induction and FPE enhancement caused by 100 U/ml TNFalpha for 24 h was not influenced by simultaneous administration of 1000 U/ml IFbeta-1a. Treatment of cultures with IFbeta-1a for 48 h followed by 24-h coincubation with TNFalpha (100 U/ml) and IFbeta-1a (1000 U/ml) resulted in significant downregulation of TNFalpha-induced ICAM 1 expression and FPE. Downregulation of TNFalpha-induced ICAM 1 expression was not observed when combined treatment with TNFalpha (100 U/ml) and IFbeta-1a (1000 U/ml) for 24 h was followed by 48 h exposure to IFbeta-1a. We concluded that the blood-brain barrier endothelium may be a target of IFbeta-1a. Further, these in vitro findings may correlate with the results of recent clinical trials indicating that chronic treatment of relapsing remitting multiple sclerosis with IFbeta-1a prevents both clinical exacerbations and the appearance on Magnetic Resonance Imaging of new lesions enhanced by gadolinium which is taken up by increased transendothelial fluid phase vesicular transport.

Cytokine-directed therapies in multiple sclerosis and experimental autoimmune encephalomyelitis

Secreted and cell surface molecules that control the nature of immune responses or directly mediate tissue damage are important targets for therapeutic intervention of autoimmune inflammatory disorders. The precise aetiology of multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system is unknown and therapeutic interventions for this disease are limited. However, as it is believed that MS is autoimmune in nature, it seems likely that targeting of the immune system, either to deviate it down a more benign pathway or to directly block tissue damaging effector mechanisms, may enable this disease to be controlled. In this overview we examine three alternative approaches to therapy of MS: cytokine-directed immune deviation, immunoregulation by type I interferons and blockade of TNF. Underlying rationales for the application of these approaches to the treatment of MS are based largely on studies in the disease model experimental autoimmune encephalomyelitis. These studies are reviewed.

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.

Interferon-beta and -gamma, but not tumor necrosis factor-alpha, demonstrate immunoregulatory effects on carcinoma cell lines infected with human papillomavirus

BACKGROUND

Mechanisms whereby cells infected with human papillomavirus (HPV) escape immune surveillance, ultimately leading to invasive cervical carcinoma, may involve changes in local cytokine production, loss of responsiveness to cytokines, and alterations in the expression of immune-regulatory molecules such as histocompatibility-related leukocyte antigen (HLA) Class 1 and 2 and ICAM-I. This study examined the separate and combined effects of immune-activating cytokines, interferon (IFN)-gamma, IFN-beta, and tumor necrosis factor (TNF)-alpha, on the expression of these molecules.

METHODS

Membrane protein expression and cellular mRNA levels were analyzed in cervical carcinoma-derived cell lines, SiHa and CaSki (with low and high HPV16 copy number, respectively), after exposure to cytokines.

RESULTS

Both cell lines demonstrated constitutive expression of HLA Class 1 but not HLA Class 2 membrane antigens. IFN-gamma and -beta induced changes in Class 1 mRNA levels but not in membrane molecule expression. IFN-gamma induced dose-dependent expression of Class 2 membrane and mRNA molecules in both cell lines (more pronounced in SiHa than in CaSki cells), which was antagonized by IFN-beta. Constitutive ICAM-I membrane expression was observed only on CaSki cells, although ICAM-I mRNA was expressed in both cell lines. IFN-gamma up-regulated the membrane expression of this molecule, whereas IFN-beta led to its suppression. Differential modulation of ICAM-I mRNA was observed in both cell lines. A lack of response to TNF-alpha was observed throughout the experiments.

CONCLUSIONS

The findings of this study point to possible mechanisms leading to suppression of local immune response in the pathogenesis of HPV-associated neoplasia. They also emphasize the complexity of developing an efficient cytokine therapy for patients with premalignant cervical disease.

Beta-interferon and multiple sclerosis

Interferon-beta (IFN-beta) is the first therapeutic intervention shown to alter the natural history of multiple sclerosis (MS), a relapsing then progressive inflammatory degenerative disease of the CNS. Since publication of the first randomized placebo-controlled trial of IFN-beta, and subsequent acquisition of US and European product licences for use in relapsing-remitting MS, the hopes and expectations of patients have been elevated greatly only to be dampened as more critical analysis of the trial results, in conjunction with the cost of treatment, led to marked limitations on prescription in several countries. IFN-beta is not a cure. Here we review what is known about the mechanisms of action of IFN-beta in demyelinating disease, and propose a possible model of action of IFN-beta in the treatment of MS.

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

Interferon beta-1b (IFN beta-1b) (Betaseron) has been recently approved for treatment of multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS). The mechanism of action of IFN beta-1b is not understood, but its effect in reducing gadolinium enhanced MRI lesions suggest an effect at the blood brain barrier (BBB). Thus the objective of this study is to examine the effect of IFN beta-1b treatment of endothelial cells (EC) on lymphocyte-EC adhesion, and on the expression of the adhesion molecules (AM) ICAM-1, VCAM and E-selectin induced by IFN-gamma, TNF-alpha, or IL-1 beta. Primary cultures of human umbilical vein EC (HUVEC) were used which under basal conditions expressed low levels of ICAM-1 but not VCAM or E-selectin. IFN beta-1b (1-1000 IU/ml) had minimal effect on basal expression of AM on HUVEC, but AM could be substantially upregulated by IFN-gamma, IL-1 beta or TNF-alpha which was associated with a parallel increase in lymphocyte-EC adhesion. The effect of IFN beta-1b on AM expression induced by IFN-gamma, IL-1 beta or TNF-alpha was slightly additive, and was associated with a modest increase in lymphocyte-EC adhesion. In contrast TGF-beta, shown previously to downregulate lymphocyte-EC adhesion, inhibited this adhesion in our experiments. It is concluded that IFN-beta does not downregulate the inducible expression of ICAM-1, VCAM or E-selectin on HUVEC and does not inhibit the adhesion of lymphocytes to HUVEC. These findings have implications on the mechanism of action of IFN beta-1b in MS.