Anti-alpha B-crystallin immunoreactivity in inflammatory nervous system diseases

Interactions Between Extracellular Vesicles and Autophagy in Neuroimmune Disorders

Neuroimmune disorders, such as multiple sclerosis, neuromyelitis optica spectrum disorder, myasthenia gravis, and Guillain-Barré syndrome, are characterized by the dysfunction of both the immune system and the nervous system. Increasing evidence suggests that extracellular vesicles and autophagy are closely associated with the pathogenesis of these disorders. In this review, we summarize the current understanding of the interactions between extracellular vesicles and autophagy in neuroimmune disorders and discuss their potential diagnostic and therapeutic applications. Here we highlight the need for further research to fully understand the mechanisms underlying these disorders, and to develop new diagnostic and therapeutic strategies.

Putative Roles and Therapeutic Potential of the Chaperone System in Amyotrophic Lateral Sclerosis and Multiple Sclerosis

The putative pathogenic roles and therapeutic potential of the chaperone system (CS) in amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are reviewed to provide a bibliographic and conceptual platform for launching research on the diagnostic and therapeutic applications of CS components. Various studies suggest that dysfunction of the CS contributes to the pathogenesis of ALS and MS, and here, we identify some of the implicated CS members. The physiology and pathophysiology of the CS members can be properly understood if they are studied or experimentally or clinically manipulated for diagnostic or therapeutic purposes, bearing in mind that they belong to a physiological system with multiple interacting and dynamic components, widespread throughout the body, intra- and extracellularly. Molecular chaperones, some called heat shock protein (Hsp), are the chief components of the CS, whose canonical functions are cytoprotective. However, abnormal chaperones can be etiopathogenic factors in a wide range of disorders, chaperonopathies, including ALS and MS, according to the data reviewed. Chaperones typically form teams, and these build functional networks to maintain protein homeostasis, the canonical role of the CS. However, members of the CS also display non-canonical functions unrelated to protein homeostasis. Therefore, chaperones and other members of the CS, if abnormal, may disturb not only protein synthesis, maturation, and migration but also other physiological processes. Thus, in elucidating the role of CS components in ALS and MS, one must look at protein homeostasis abnormalities and beyond, following the clues emerging from the works discussed here.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

Extracellular small heat shock proteins: exosomal biogenesis and function

Small heat shock proteins (sHsps) belong to the family of heat shock proteins (Hsps): some are induced in response to multiple stressful events to protect the cells while others are constitutively expressed. Until now, it was believed that Hsps, including sHsps, are present inside the cells and perform intracellular functions. Interestingly, several groups recently reported the extracellular presence of Hsps, and sHsps have also been detected in sera/cerebrospinal fluids in various pathological conditions. Secretion into the extracellular milieu during many pathological conditions suggests additional or novel functions of sHsps in addition to their intracellular properties. Extracellular sHsps are implicated in cell-cell communication, activation of immune cells, and promoting anti-inflammatory and anti-platelet responses. Interestingly, exogenous administration of sHsps showed therapeutic effects in multiple disease models implying that extracellular sHsps are beneficial in pathological conditions. sHsps do not possess signal sequence and, hence, are not exported through the classical Endoplasmic reticulum-Golgi complex (ER-Golgi) secretory pathway. Further, export of sHsps is not inhibited by ER-Golgi secretory pathway inhibitors implying the involvement of a nonclassical secretory pathway in sHsp export. In lieu, lysoendosomal and exosomal pathways have been proposed for the export of sHsps. Heat shock protein 27 (Hsp27), αB-crystallin (αBC), and Hsp20 are shown to be exported by exosomes. Exosomes packaged with sHsps have beneficial effects in in vivo disease models. However, secretion mechanisms and therapeutic use of sHsps have not been elucidated in detail. Therefore, this review aimed at highlighting the current understanding of sHsps (Hsp27, αBC, and Hsp20) in the extracellular medium.

Can innate and autoimmune reactivity forecast early and advance stages of age-related macular degeneration?

Age-related macular degeneration (AMD) is a major cause of central vision loss in persons over 55years of age in developed countries. AMD is a complex disease in which genetic, environmental and inflammatory factors influence its onset and progression. Elevation in serum anti-retinal autoantibodies, plasma and local activation of complement proteins of the alternative pathway, and increase in secretion of proinflammatory cytokines have been seen over the course of disease. Genetic studies of AMD patients confirmed that genetic variants affecting the alternative complement pathway have a major influence on AMD risk. Because the heterogeneity of this disease, there is no sufficient strategy to identify the disease onset and progression sole based eye examination, thus identification of reliable serological biomarkers for diagnosis, prognosis and response to treatment by sampling patient's blood is necessary. This review provides an outline of the current knowledge on possible serological (autoantibodies, complement factors, cytokines, chemokines) and related genetic biomarkers relevant to the pathology of AMD, and discusses their application for prediction of disease activity and prognosis in AMD.

Behcet’s disease: from heat shock proteins to infections

Background: Behcet’s disease (BD) is a chronic, inflammatory multisystemic condition of unknown etiology. Although the cause of BD is not clear, it is believed to be the result of an autoimmune process triggered by an infectious or environmental agent (possibly local to a geographic region) in a genetically predisposed individual.

Objective: To detail current knowledge of the role of microorganisms in the pathogenesis of BD and review the infectious etiology of this disease.

Methods: The review based on publication in SCOPUS, Science direct, and PubMed.

Results: A microbial infection has been implicated in the development of the disease to explain the strong inflammatory reactions observed, the activation of monocytes and macrophages, and the induction of proinflammatory cytokines and chemokines detected. Common factors linking some of the possible pathogenetic agents are extrinsically induced tissue stress or heat shock proteins, which react with host tissues and elicit significant T-helper type 1 cell responses.

Conclusion: Based on collected data, we conclude that the microorganisms discussed seem to participate and, at least in part, act as triggers during the course of BD. By clarifying the microbial associations of BD and finding its etiology, particularly the causative antigens leading to BD, it would be easier to suggest more effective treatment and preventive strategies for this disease.

Phosphorylation negatively regulates exosome mediated secretion of cryAB in glioma cells

Exosomes mediate secretion of crystallin alphaB (cryAB), a well characterized molecular chaperone with anti-apoptotic activity. However, the mechanisms governing its packaging and secretion remained unexplored. In glioma cells, notwithstanding extensive phosphorylation of cryAB at Ser59 followed by Ser45 (Ser19 is largely unphosphorylated), we discovered that the majority of secreted exosomal cryAB is nonphosphorylated. Transient ectopic expression of a yellow fluorescent protein (YFP) tagged triple phosphomimic (3-SD) cryAB construct in cryAB absent glioma cells led to the formation of large cytosolic inclusions. Our findings demonstrate that mimicking phosphorylation significantly reduces cryAB secretion via exosomes. Moreover, decreased colocalization of 3-SD YFP-cryAB with multivesicular endosome (MVE) and exosome marker, CD63 or Rab27, a small GTPase regulating exocytosis of MVEs, suggests that phosphorylation deters packaging of cryAB in vesicles bound for secretion as exosomes. Additionally, we found that preventing O-GlcNAcylation on cryAB also curtailed its colocalization with CD63 and Rab27 resulting in reduced exosomal secretion. Thus, our study points to O-GlcNAcylation and lack of phosphorylation as being the selective processes involved in the packaging and secretion of cryAB via exosomes.

Positive or negative involvement of heat shock proteins in multiple sclerosis pathogenesis: an overview

Multiple sclerosis (MS) is the most diffuse chronic inflammatory disease of the central nervous system. Both immune-mediated and neurodegenerative processes apparently play roles in the pathogenesis of this disease. Heat shock proteins (HSPs) are a family of highly evolutionarily conserved proteins; their expression in the nervous system is induced in a variety of pathologic states, including cerebral ischemia, neurodegenerative diseases, epilepsy, and trauma. To date, investigators have observed protective effects of HSPs in a variety of brain disease models (e.g. of Alzheimer disease and Parkinson disease). In contrast, unequivocal data have been obtained for their roles in MS that depend on the HSP family and particularly on their localization (i.e. intracellular or extracellular). This article reviews our current understanding of the involvement of the principal HSP families in MS.

Body fluid biomarkers in multiple sclerosis: how far we have come and how they could affect the clinic now and in the future

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system, which affects over 2.5 million people worldwide. Although MS has been extensively studied, many challenges still remain in regards to treatment, diagnosis and prognosis. Typically, prognosis and individual responses to treatment are evaluated by clinical tests such as the expanded disability status scale, MRI and presence of oligoclonal bands in the cerebrospinal fluid. However, none of these measures correlates strongly with treatment efficacy or disease progression across heterogeneous patient populations and subtypes of MS. Numerous studies over the past decades have attempted to identify sensitive and specific biomarkers for diagnosis, prognosis and treatment efficacy of MS. The objective of this article is to review and discuss the current literature on body fluid biomarkers in MS, including research on potential biomarker candidates in the areas of miRNA, mRNA, lipids and proteins.

The Presence of Autoantibodies Against Vascular and Nervous Tissue in Sera From Patients with Neuro-Behçet's Disease

INTRODUCTION

Behçet's disease is a chronic inflammatory disease of unknown aetiology that affects multiple organ systems. Since the diagnosis of this disease mainly relies on clinical criteria, a diagnostic laboratory test is required especially for neuro-Behçet's patients without systemic involvement.

METHOD

In this study, we searched for the presence of autoantibodies against brain tissue, by means of indirect immunofluorescent staining technique in sera obtained from patients with neuro-Behçet's disease, based on reports that humoral immune dysregulation may play a role in susceptibility to Behçet's disease. After pre-absorbtion of sera with guinea pig liver powder to reduce nonspecific staining, serum samples were applied to mouse brain sections and immunoreactivity was detected with fluorescein (FITC)-conjugated goat antibody against human IgG.

RESULTS

Ten sera from neuro-Behçet's patients and 10 age-matched control sera were screened for immunoreactivity. We detected specific immunoreactivity to both parenchymal and vascular brain structures in the patients' sera. Parenchymal vessel immunopositivity was detected in 8 of 10 patients, whereas only two of control sera showed no significant parenchymal vascular immunoreactivity (p=.025). In addition to vascular immunoreactivity, filamentous and reticular immunopositive structures were detected in brain sections of 5 out of 10 patients. No such immunoreactivity was detected in sections incubated with control sera (p=.016).

CONCLUSION

We detected a specific immunoreactivity against vascular and parenchymal filamentous structures in neuro-Behçet patients' sera. Humoral autoimmunity may play a role in the pathogenesis of neuro-Behçet's disease in addition to cellular immune response. Findings of this preliminary study will be evaluated with a large number of patients and controls, to determine whether it is the cause or the result and, further studies are underway to disclose the nature of epitope to which the immunoreactivity was directed against and to develop a diagnostic laboratory method for investigating central nervous system involvement in Behçet's patients.

The good and the bad of neuroinflammation in multiple sclerosis

Multiple sclerosis (MS) is the most common inflammatory, demyelinating, neurodegenerative disorder of the central nervous system (CNS). It is widely considered a T-cell mediated autoimmune disease that develops in genetically susceptible individuals, possibly under the influence of certain environmental trigger factors. The invasion of autoreactive CD4+ T-cells into the CNS is thought to be a central step that initiates the disease. Several other cell types, including CD8+ T-cells, B-cells and phagocytes appear to be involved in causing inflammation and eventually neurodegeneration. But inflammation is not entirely deleterious in MS. Evidence has accumulated in the recent years that show the importance of regulatory immune mechanisms which restrain tissue damage and initiate regeneration. More insight into the beneficial aspects of neuroinflammation might allow us to develop new treatment strategies for this enigmatic disease.

Innate and Adaptive Responses to Heat Shock Proteins in Behcet's Disease

Behcet's disease (BD) is a systemic, chronic inflammatory disorder with both innate and adaptive immune responses. Heat shock proteins (HSP) are highly conserved molecules in different species with scavenger activity and involved in correct folding of newly synthesized proteins. T and B cell responses against HSPs are observed in BD patients in both αβ and γδ T-cell populations. 60-kD HSP (HSP60) is also shown to be recognized by pattern recognition receptors such as toll-like receptors (TLR) and is suggested to be an endogenous "danger" signal to the immune system with rapid inflammatory cytokine releases and enhancement of adaptive Th1-type responses. Elucidating the exact role of HSPs in BD pathogenesis might pave the way to less toxic therapeutic approaches to BD, such as antibacterial therapies and immunomodulation.

Mitochondrial carrier homolog 1 (Mtch1) antibodies in neuro-Behçet's disease

Efforts for the identification of diagnostic autoantibodies for neuro-Behcet's disease (NBD) have failed. Screening of NBD patients' sera with protein macroarray identified mitochondrial carrier homolog 1 (Mtch1), an apoptosis-related protein, as a potential autoantigen. ELISA studies showed serum Mtch1 antibodies in 68 of 144 BD patients with or without neurological involvement and in 4 of 168 controls corresponding to a sensitivity of 47.2% and specificity of 97.6%. Mtch1 antibody positive NBD patients had more attacks, increased disability and lower serum nucleosome levels. Mtch1 antibody might be involved in pathogenic mechanisms of NBD rather than being a coincidental byproduct of autoinflammation.

Diagnostic yield of heat shock protein 70 (HSP-70) and anti-HSP-70 in Behcet-induced uveitis

Heat shock proteins (HSPs) are intracellular proteins with pro- and anti-inflammatory actions, playing an important role in the pathogenesis of Behcet's disease (BD). Diagnosis of BD uveitis in early stages is still problematic, thus this study was undertaken to determine diagnostic values of serum HSP- and anti-HSP-70 in BD uveitis. Serum levels of HSP- and anti-HSP-70 were measured in 53 patients with BD (26 with and 27 without uveitis). In control group, 25 age- and sex-matched idiopathic uveitis patients were enrolled consecutively. Both groups had no medical problems save uveitis at the time of sampling. Confounders like medications were analysed subsequently. HSP- and anti-HSP-70 values were measured by commercial ELISA kits. Data were analysed by spss 11.5 and medcalc 11.5.1 software. The Mean HSP-70 serum levels were different among aforementioned subgroups (P = 0.001, anova). They were elevated in BD uveitis compared with BD without uveitis (4.84 ± 4.21 versus 2.24 ± 2.08 ng/ml; P = 0.045). HSP-70 in sera of BD uveitis was also higher than that parameter in patients with idiopathic uveitis (4.84 ± 4.21 versus 2.37 ± 3.30 ng/ml; P = 0.001; cut-off point value 1.0 9 ng/ml, 95% CI 0.61-0.86, P = 0.0002, ß = 0.06). However, there was not any statistical difference among those groups in the serum anti-HSP-70 levels (P = 0.63, anova). Multiple regression analysis demonstrated that among different confounders, only prednisolone increases and BD uveitis decreases HSP-70 levels independently. This prospective cross-sectional study suggested that HSP-70 serum level is impressed over the course of BD uveitis, and it could be utilized to diagnose or predict developing it.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

Investigation of autoantibody profiles for cerebrospinal fluid biomarker discovery in patients with relapsing-remitting multiple sclerosis

Using the UNIarray® marker technology platform, cerebrospinal fluid immunoglobulin G reactivities of 15 controls and 17 RRMS patients against human recombinant proteins were investigated. Patient cerebrospinal fluids were oligoclonal band positive and reactivities were compared to that of sex- and age-matched controls. We hereby aimed at the characterization of autoreactivity in patients with RRMS. Differences in autoreactivities between control and RRMS samples were identified comprising autoantigens identified in this study only and previously reported autoantigens as well. A combination of the 10-15 most significant proteins may be investigated further as autoantigens for diagnostic purposes. Additional investigations may include minimizing the number of proteins used in such diagnostic tests.

The emerging link between autoimmune disorders and neuropsychiatric disease

Abnormal autoimmune activity has been implicated in a number of neuropsychiatric disorders. In this review, the authors discuss a newly recognized class of synaptic autoimmune encephalitides as well as behavioral and cognitive manifestations of systemic autoimmune diseases.

New insights into the pathogenesis of Behçet's disease

Behçet's disease (BD) is a recurrent systemic inflammatory disorder of unknown origin characterized by oral and genital mucous ulcer, uveitis, and skin lesions. Involvement of large vessels, central nervous system (CNS), gastrointestinal tract and thrombotic events are less frequent but can be life threatening. The aim of this review is to provide new insights into the pathogenesis of BD. Over the past year substantial advances have been done in the understanding of the genetic [1,2] and immunology [3] of BD. BD is at the crossroad between autoimmune and autoinflammatory syndromes. In common with autoimmune diseases BD shares class I MHC association. However, in contrast to autoimmune disorders, BD has clinical features that seem to be mostly autoinflammatory. The pathogenesis of BD is still unknown, but major determinants of the genetic and immune system abnormalities have been reported recently. Triggering infectious factors are supposed to participate in the outbreak of BD in genetically predisposed patients. Two recent large genome-wide association study (GWAS) conducted in Turkey and Japan reported association between single nucleotide polymorphism (SNP) of interleukin (IL)-10 and IL-23R/IL-12RB2 genes and BD. New insights into the perturbations of T cell homeostasis of BD recently emerged. We have recently demonstrated the promotion of Th17 responses and the suppression of regulatory T cells (Tregs) that were driven by interleukin (IL)-21 production and that correlates with BD activity. Inflammatory cells within BD inflammatory lesions included mostly neutrophils, Th1 and Th17 cells, and cytotoxic CD8+ and γδ T cells. Altogether, the recent progresses in the knowledge of BD pathogenesis pave the way for innovative therapy.

Anti-neuronal and stress-induced-phosphoprotein 1 antibodies in neuro-Behçet's disease

No disease-specific neuronal antibodies have so far been defined in neuro-Behçet's disease (NBD). Immunohistochemistry and immunocytochemistry studies showed antibodies to hippocampal and cerebellar molecular layers and the surface antigens of cultured hippocampal neurons in sera and/or cerebrospinal fluids (CSF) of 13 of 20 NBD and 6 of 20 BD patients but not in multiple sclerosis or headache controls. Screening with a protein macroarray led to identification of stress-induced-phosphoprotein-1 (STIP-1) as an antigenic target. High-titer STIP-1-antibodies were detected in 6 NBD patients' sera but not in controls. These results suggest that neuronal antibodies could be useful as diagnostic biomarkers in NBD.

Chaperone activity of α B-crystallin is responsible for its incorrect assignment as an autoantigen in multiple sclerosis

For 15 y, α B-crystallin (heat shock protein [Hsp] B5) has been labeled an autoantigen in multiple sclerosis (MS) based on humoral and cellular responses found in humans and animal models. However, there have been several scientific inconsistencies with this assignment, ranging from studies demonstrating small differences in anticrystallin responses between patients and healthy individuals to the inability of crystallin-specific T cells to induce symptoms of experimental allergic encephalomyelitis in animal models. Experiments in this article demonstrate that the putative anti-HspB5 Abs from 23 MS patients cross-react with 7 other members of the human small Hsp family and were equally present in normal plasma. Biolayer interferometry demonstrates that the binding was temperature dependent, and that the calculated K(a) increased as the concentration of the sHsp decreased. These two patterns are characteristic of multiple binding sites with varying affinities, the composition of which changes with temperature, supporting the hypothesis that HspB5 bound the Ab and not the reverse. HspB5 also precipitated Ig heavy and L chains from sera from patients with MS. These results establish that small Hsps bind Igs with high affinity and refute much of the serological data used to assign α B-crystallin as an autoantigen.

The emerging link between autoimmune disorders and neuropsychiatric disease

Abnormal autoimmune activity has been implicated in a number of neuropsychiatric disorders. In this review, the authors discuss a newly recognized class of synaptic autoimmune encephalitides as well as behavioral and cognitive manifestations of systemic autoimmune diseases.

Cross-reactivity of antibodies against leptospiral recurrent uveitis-associated proteins A and B (LruA and LruB) with eye proteins

Infection by Leptospira interrogans has been causally associated with human and equine uveitis. Studies in our laboratories have demonstrated that leptospiral lipoprotein LruA and LruB are expressed in the eyes of uveitic horses, and that antibodies directed against LruA and LruB react with equine lenticular and retinal extracts, respectively. These reactivities were investigated further by performing immunofluorescent assays on lenticular and retinal tissue sections. Incubation of lens tissue sections with LruA-antiserum and retinal sections with LruB-antiserum resulted in positive fluorescence. By employing two-dimensional gel analyses followed by immunoblotting and mass spectrometry, lens proteins cross-reacting with LruA antiserum were identified to be alpha-crystallin B and vimentin. Similarly, mass spectrometric analyses identified beta-crystallin B2 as the retinal protein cross-reacting with LruB-antiserum. Purified recombinant human alpha-crystallin B and vimentin were recognized by LruA-directed antiserum, but not by control pre-immune serum. Recombinant beta-crystallin B2 was likewise recognized by LruB-directed antiserum, but not by pre-immune serum. Moreover, uveitic eye fluids contained significantly higher levels of antiibodies that recognized alpha-crystallin B, beta-crystallin B2 and vimentin than did normal eye fluids. Our results indicate that LruA and LruB share immuno-relevant epitopes with eye proteins, suggesting that cross-reactive antibody interactions with eye antigens may contribute to immunopathogenesis of Leptospira-associated recurrent uveitis.

Disease biomarkers in multiple sclerosis: potential for use in therapeutic decision making

Multiple sclerosis (MS) is an autoimmune disorder of the brain and spinal cord that predominantly affects white matter. MS has a variable clinical presentation and has no 'diagnostic' laboratory test; this often results in delays to definite diagnosis. In confronting the disease, early diagnosis and appropriate, timely therapeutic intervention are critical factors in ensuring favorable long-term outcomes. The availability of reliable biomarkers could radically alter our management of MS at critical phases of the disease spectrum. Identification of markers that could predict the development of MS in high-risk populations would allow for intervention strategies that may prevent evolution to definite disease. Work with anti-myelin antibodies and the ongoing analysis of microarray gene expression have thus far not yielded biomarkers that predict future disease development. Similarly, extensive studies with serum and cerebrospinal fluid (CSF) have not yielded a disease-specific and sensitive diagnostic biomarker for MS. Establishment of disease diagnosis always leads to questions about long-term prognosis because in an individual patient the natural history of the disease is clinically unpredictable. Biomarkers that correlate with myelin loss, spinal cord disease, grey matter and subcortical demyelination need to be developed in order to accurately predict the disease course. The bulk of effort in biomarker development in MS has been concentrated in the area of monitoring disease activity. At present, a disease 'activation' panel of CSF biomarkers would include the following: interleukin-6 or its soluble receptor, nitric oxide and nitric oxide synthase, osteopontin, and fetuin-A. Although disease activity in MS is predominantly inflammatory, disease progression is likely to be the result of neurodegeneration. Therefore, the roles of proteins indicative of neuronal, axonal, and glial loss such as neurofilaments, tau, 14-3-3 proteins, and N-acetylaspartate are all under investigation, as are proteins affecting remyelination and regeneration, such as Nogo-A. With the increasing awareness of cognition dysfunction in MS, molecules such as apolipoprotein and proteins in the amyloid precursor protein pathway implicated in dementia are also being examined. Serum biomarkers that help monitor therapeutic efficacy such as the titer of antibody to beta-interferon, a first-line medication in MS, are established in clinical practice. Ongoing work with biomarkers that reflect drug bioavailability and factors that distinguish between medication responders and nonresponders are also under investigation. The discovery of new biomarkers relies on applying advances in proteomics along with microarray gene and antigen analysis and will hopefully result in the establishment of specific biomarkers for MS.

Intrathecal anti-alphaB-crystallin IgG antibody responses: potential inflammatory markers in Guillain-Barré syndrome

OBJECTIVE

alphaB-crystallin (alphaBC), a small stress protein with cytoprotective and anti-apoptotic functions, is a potent antigen in autoimmune demyelinating diseases. To address the role of alphaBC in Guillain-Barré syndrome (GBS) we analyzed humoral responses against alphaBC in relation to clinical, electrophysiological and CSF features in GBS.

METHODS

Anti-alphaBC-IgG antibodies were measured in serum and cerebrospinal fluid (CSF) of patients with GBS (n = 41), infectious inflammatory neurological diseases (n = 21), multiple sclerosis (n = 42), and other, non-inflammatory neurological disorders (n = 40) by ELISA using human recombinant alphaBC. Expression of alphaBC was immunohistochemically analyzed in postmortem peripheral nerve tissue of GBS and controls without neuropathy.

RESULTS

Serum alphaBC-IgG antibody levels did not differ between disease groups, whereas alphaBC-IgG antibodies in CSF were increased in GBS and infectious inflammatory neurological diseases. Calculation of an antigen specific alphaBC-IgG index (alphaBC-Ig-G(CSF) x total IgG(CSF))/(alphaBC-IgG(Serum) x total IgG(Serum)) revealed significantly elevated values in patients with GBS compared to other disease groups (p < 0.001). alphaBC-IgG indices exceeding a cut off value > 0.8 had an 85 % specificity and a 76 % sensitivity for GBS. alphaBC was overexpressed in dorsal root ganglia and spinal roots of autopsy cases with GBS.

CONCLUSIONS

We demonstrate increased alphaBC-IgG indices in a high proportion of our GBS patients, which reflect enhanced antigen-specific intrathecal antibody responses against abnormally expressed alphaBC in inflamed peripheral nerve tissue. Elevated alphaBC-IgG indices might therefore serve as markers of PNS inflammation and supplement currently used laboratory tests in the diagnosis of GBS.

Associations of seroreactivity against crystallin proteins with disease activity and cataract in patients with uveitis

PURPOSE

betaB1-crystallin is a putative target of an autoantibody observed in a subset of patients with uveitis. The purpose of this study was to determine whether seroreactivity against betaB1 or other specific purified crystallin proteins is observed in patients with uveitis and whether this reactivity is associated with either cataract or active intraocular inflammation.

METHODS

Sera from patients with uveitis were tested for IgG antibodies with reactivity against alphaA-, alphaB-, betaB1-, or betaB2-crystallin proteins using a modified slot-blot protocol. Ophthalmic evaluations included analysis of the degree of intraocular inflammation and assessment of lens opacity by the Lens Opacities Classification System (LOCS) III. Positive anti-crystallin reactivity was defined as greater than the mean + 2 SD of the reactivity of a commercially available control serum panel. Statistical analysis was performed with the Fisher exact test, Kruskal-Wallis test, and Student's t-test.

RESULTS

IgG antibodies against alphaA-, alphaB-, or betaB1-crystallin were identified in 70% of 39 subjects; in contrast, only 30% of the control sera exhibited reactivity against one or more of these crystallin proteins (P <or= 0.01). Seroreactivity against alphaA-, alphaB-, or betaB1-, but not betaB2-crystallin was related to active anterior segment inflammation. Seroreactivity against alphaB and betaB1 was significantly related to cortical cataract (P <or= 0.05).

CONCLUSIONS

Serum antibodies against specific crystallin proteins are present in most patients with uveitis. The relationship between the presence of specific anti-crystallin antibodies and active inflammation may indicate a role for these autoantibodies in uveitis pathogenesis.

Systems biology approaches for the study of multiple sclerosis

Multiple sclerosis (MS) is a progressive neurological disease caused by an autoimmune attack to the central nervous system (CNS). MS is thought to result from a complex interaction between genetic and environmental factors. In this review we analyze the contribution of genomics, trancriptomics and proteomics in delineating these factors, as well as their utility for the monitoring of disease progression, the identification of new targets for therapeutic intervention and the early detection of individuals at risk.

Immunopathogenesis of Behçet's disease with special emphasize on the possible role of antigen presenting cells

Behçet's disease (BD) is a systemic vasculitis with unclear etiology and pathogenesis. Although several viral and bacterial causes have been investigated in detail for several years, of late it is widely accepted that microorganisms may play a role as a trigger, or as a cross-reactive antigens that interfere with self-antigens, such as heat-shock proteins. Genes such as HLA-B51, MICA and TNF, considered to play a crucial role in the pathogenesis of BD, are located in the major histocompatibility complex (MHC). However, it has been accepted that, only HLA-B51 is directly related with pathogenesis of the disease, and others have strong linkage disequilibrium with HLA-B51. Some other genes such as IL1, Factor V and ICAM-1, KIR and eNOS assumed to take a part in the pathogenesis are settled out of the MHC region. In patients with BD, several abnormalities in innate and acquired immunity were detected. Mainly, the hypersensitivity of T lymphocytes to different types of antigens plays a critical role in the pathogenesis. However, it is not clear that whether defective signal transduction or antigen presenting cell (APC) dysfunction is responsible for T cell hypersensitivity. Cytokines and chemokines secreted from APCs and T cells are suggested to cause the neutrophil hyperactivation. Activated neutrophils secrete some cytokines, which prime themselves and also stimulate Th1 cells. These relationships among APCs, Th1 lymphocytes and neutrophils constitute the basis of immune responses in BD. In this review, we focus on the possible role of APC in the pathogenesis of BD with an attempt to take attention of researchers in this field to these cells at the crossroads of innate and adaptive immunity, and discuss other potential contributors including cells of the immune system and mediators.

Quantification of antineural antibodies in autoimmune neurological disorders

More than 50 different neurological pathologies have a confirmed or suspected autoimmune etiology affecting an estimated number of 75 million people worldwide. Autoantibodies are a useful diagnostic marker for most autoimmune diseases even though their pathological role is not evident, and several tests for their detection are commercially available. However, for autoimmune diseases involving the nervous system, lack of clear information on the identity of antineural antibody targets and the presence of many rare diseases have hampered the development of specific diagnostic assays. This review focuses on the actual knowledge on confirmed and suspected autoimmune diseases that target the CNS and the diagnostic relevance of corresponding antineural autoantibodies.

Multiple sclerosis: Disease biomarkers as indicated by pathophysiology

Multiple sclerosis (MS), the most important human inflammatory demyelinating disease of the central nervous system, is characterized by heterogenous genetic backgrounds and immunopathogenetic subtypes, various clinical disease courses, and inhomogeneous and unpredictable therapeutic effects. Because of this heterogeneity, subtyping of our MS patients by genetical, clinical, neuroradiological, and neuroimmunological parameters will be an urgent need in the near future. Therefore the importance of identifying biological markers for MS has evolved over the past years. Evidence for a possible role of antibodies as biological markers for MS comes from several studies indicating that intrathecal antibody production and the dominance of B-cells are associated with a more progressive disease course. This review summarizes the current status and potential applicability of antibodies as biological markers for the diagnosis, classification, disease activity and prediction of clinical courses in MS. Antibodies (and other molecules) serving as biomarkers will help to establish a differential therapeutic concept in MS, which should allow to treat individuals selectively according to their pathogenetic subtype and disease status.

Pro-inflammatory cellular immune response in Behçet's disease

Several proteins are investigated as candidate auto-antigens in the pathogenesis of Behçet's disease (BD). This study aimed to screen the cellular responses to auto-antigen (alphaB-crystallin, alphaBC), and microorganism (Streptococcus sangius KTH-1 BES-1 protein) derived peptides as well as to isopentenyl pyrophosphate (IPP). Peripheral blood mononuclear cells (PBMC) from 22 BD patients and 22 healthy controls (HC) were stimulated in vitro with alphaBC, BES-1 peptides, IPP and PPD and induced proliferation as well as the secreted interleukin (IL)-12 and interferon (IFN)-gamma production levels were measured. We did not observe any significant difference in cellular proliferation between BD patients and HC. Induction of IL-12 secretion with alphaBC was stronger in BD patients (P = 0.04) and in the disease subgroup with uveitis (P = 0.027) compared the HC. When responses to PPD were compared, proliferation of PMBC was lower (P = 0.03), whereas IL-12 secretion was higher in BD (P = 0.04) as well as in patients under colchicum treatment (P = 0.04) and with vascular involvement (P = 0.006) compared to HC. BES-1(373-385 )peptide induced also higher IL-12 productions by PBMC of BD patients (P = 0.017) and of patients with uveitis (P = 0.013). Finally, IPP stimulated higher IL-12 secretions from PBMC in BD patients (P = 0.035) and in patients with (P = 0.02) or without (P = 0.017) uveitis or arthritis (P = 0.04), under colchicum treatment (P = 0.01) or not receiving any immunosuppressive treatment (P = 0.007) compared to HC. These results suggest a more prominent pro-inflammatory cytokine secretion from PBMC in BD patients compared to HC in response to various antigens including alphaBC protein, BES-1(373-385), IPP and PPD.

Physiopathologie de la maladie de Behçet

SUBJECT

Pathophysiology of Behçet's disease (BD) is complex. Recent experimental data shed new light on the mechanisms leading to organ lesions.

MAIN ISSUES

Neutrophils and cytotoxic lymphocytes are now recognized as key effector cells in BD. Genetic susceptibility, environmental factors (virus and/or bacterial infections), inflammatory response abnormalities (heat shock proteins, dysregulated NO production) and abnormal immune response play also a major role in BD pathogeny.

PERSPECTIVES

Better understanding of the BD pathophysiology will allow the development of new therapies more specific of BD.

Antibodies as biological markers for pathophysiological processes in MS

Multiple sclerosis (MS), the most important human inflammatory demyelinating disease of the central nervous system, is characterized by various clinical disease courses, inhomogeneous and unpredictable therapeutic effects, heterogenous genetic backgrounds and immunopathogenetic subtypes as demonstrated by neuropathology. Because of this heterogeneity of MS, a subtyping of our patients by genetical, clinical, neuroradiological, and neuroimmunological parameters will be necessary in the future. Therefore the importance of identifying biological markers for MS has evolved over the past years. Evidence for a possible role of antibodies as biological markers for MS comes from several studies indicating that intrathecal antibody production and the dominance of B cells are associated with a more progressive disease course. In this review we will give an overview on the current status and potential applicability of antibodies as biological markers for the diagnosis, classification, disease activity and prediction of clinical courses in MS. We will therefore summarize the findings on autoantibodies to myelin and nonmyelin antigens and on viral antigens in MS. We believe that antibodies serving as biomarkers will help to establish a differential therapeutic concept in MS, which will allow to treat individuals selectively according to their pathogenetic subtype and disease status.

Autoantibodies against alpha B-crystallin, a candidate autoantigen in multiple sclerosis, are part of a normal human immune repertoire

Human T-cell responses to the stress protein alpha B-crystallin in multiple sclerosis (MS)-affected brain samples are dominant when compared to other myelin antigens. The establishment of the apparent autoimmune repertoire against this antigen has been suggested to involve cross-priming during viral infection. Yet, another possibility would be that determinant spreading during ocular inflammation could generate a response to alpha B-crystallin, since it is also a major component of the eye. In this study, we compared serum IgG, IgA and IgM repertoires against a range of eye lens-derived ocular antigens using sera from healthy control subjects and MS patients with or without uveitis. This comparison revealed that among ocular antigens, alpha B-crystallin is the dominant target antigen for serum autoantibodies in both MS patients and healthy controls. Uveitis generally did not affect the antibody reactivity profile. These data provide further support for the notion that a normal adult human immune system is selectively reactive to alpha B-crystallin and they indicate that this responsiveness is unlikely to result from determinant spreading following ocular inflammation.

αB-crystallin in cerebrospinal fluid of patients with multiple sclerosis

BACKGROUND

(alpha)B-crystallin is a chaperone protein and a potential myelin antigen to human T cells in Multiple Sclerosis (MS). In this study we investigate the existence of (alpha)B-crystallin in the cerebrospinal fluid (CSF) of patients with clinical symptoms of MS and control individuals without these symptoms, using a newly developed (alpha)B-crystallin specific chicken antibody.

METHODS

A chicken anti-(alpha)B-crystallin was raised against recombinant (alpha)B-crystallin, characterized and used in a semi-quantitative Western blot analysis of CSF from 16 MS patients and 16 neurological patients without MS.

RESULTS

Western blot analysis revealed the presence of high molecular weight (alpha)B-crystallin in CSF. Possibly posttranslationally modified aggregates of (alpha)B-crystallin were found in human astroglioma U373 cells. CSF (alpha)B-crystallin was seen in the CSF in 100% of MS patients and 88% of neurological controls without MS.

CONCLUSION

(alpha)B-crystallin is present in the CSF in patients with MS and other neurological controls. Furthermore, (alpha)B-crystallin in CSF and human astroglioma cell line U373 is found in aggregates.

Neutrophil and lymphocyte responses to oralStreptococcusin Adamantiades-Behçet's disease

Immune reactions against microorganisms play an important pathogenic role in Adamantiades-Behçet's disease. We had previously obtained Streptococcus sanguinis (strain BD113-20), isolated from the oral cavity of patients with Adamantiades-Behçet's syndrome. To investigate the pathogenesis of this isolate, we examined neutrophil reactions and levels of cytokine production by lymphocytes after stimulation with the strain. The reactions of neutrophils were examined by chemiluminescence assay using whole blood. The amounts of interferon gamma (IFN-gamma) and interleukin (IL)-4, IL-8, IL-10 and IL-12, produced by peripheral blood mononuclear cells, were measured by ELISA. Strain BD113-20 activated neutrophils from Adamantiades-Behçet's patients and healthy volunteers, and, in addition it increased the IFN-gamma production by lymphocytes. Lymphocytes from Adamantiades-Behçet's patients showed a dominant T helper-1 immune response. Results indicated that both bacterial stimulation and host hypersensitivity might be involved in the symptoms and pathogenesis of Adamantiades-Behçet's disease.

Heat shock proteins and neuromuscular disease

The heat shock proteins are families of proteins with known activities that include chaperoning nascent peptides within the cell and cytoprotection. Most work on the nervous system has related to the role of heat shock proteins in neuroprotection from either hypoxic-ischemic or traumatic injury. The role of these proteins during normal physiological activity and injury is still under investigation. Heat shock proteins in neuromuscular disease have been investigated to some extent but were largely neglected until recently. The goal of this review is to summarize the evidence linking heat shock proteins with neuromuscular disease and to provide some insight into the roles or functions of these proteins in disease states.

Prevalence of anti-heat shock protein antibodies in cerebrospinal fluids of patients with Guillain–Barré syndrome

We examined antibodies against 10 heat shock proteins (HSPs) in cerebrospinal fluids (CSF) and sera from patients with Guillain-Barré syndrome (GBS). Significantly higher IgG antibody titers against HSP27, HSP60, HSP70 and HSP90 family, including mycobacterial HSP65 and Escherichia coli GroEL, were found in CSF from GBS patients as compared with motor neuron disease. Serum IgG antibodies against each HSP showed no difference between GBS patients and normal controls. GBS seems to be induced by reactive autoimmune responses frequently triggered by infections. The CSF antibodies against HSPs may modify the immune responses and/or cell-protective functions of HSPs in the pathophysiology of GBS.

B cells in multiple sclerosis

The most common laboratory abnormality in multiple sclerosis (MS) is an increased amount of cerebrospinal fluid IgG and the presence of oligoclonal bands. Despite studies of the humoral response that suggest the involvement of an infectious agent or autoantigen in disease, the major targets of the oligoclonal response are still unknown. Identification of these targets will reveal valuable insights into the cause and pathogenesis of MS and is likely to lead to effective treatment.

Cytokines and chemokines in neuro-Behçet's disease compared to multiple sclerosis and other neurological diseases

Cytokines and chemokines in cerebrospinal fluid (CSF) can have implications on the pathogenesis of neuro-Behçet's disease (NB). CSF and serum samples from 33 patients with NB, 25 with multiple sclerosis (MS), 20 patients with infectious and/or inflammatory neurological diseases (IN) and 14 with other noninflammatory neurological diseases (NIN) were investigated by ELISA. In the CSF, CXCL10 levels were significantly higher in NB and IN than NIN and MS, whereas CXCL8 was increased in NB compared to NIN. CCL2 levels in MS CSF and sera were lower, whereas CXCL8 in MS sera was higher than the other groups. IL-12 was elevated in CSF of IN compared to NB and NIN and also in the CSF of MS compared to NIN. No difference was detected for IL-10 and IL-17. These results reflect that NB has a mediator pattern in resemblance with non-specific inflammations such as neuro-infections compared to autoimmune disorders such as multiple sclerosis, suggesting that a currently unknown infection might be the trigger of a vasculitic process in the central nervous system (CNS).

Neuropathology of multiple sclerosis-new concepts

Multiple sclerosis is a chronic inflammatory disease of the central nervous system with profound heterogeneity in clinical course, neuroradiological presentation and response to therapy. The pathological analysis of 235 actively demyelinating lesions coming from three centers revealed different structural and immunological features suggesting that different pathogenetic mechanisms are involved in lesion formation. On the basis of the presence or absence of immunoglobulin and complement deposition, myelin protein loss and the patterns of oligodendrocyte degeneration beside a T cell- and macrophage-dominated immune response, four distinct patterns of demyelination have been identified. In this short review, possible paraclinical markers for tissue destruction on the basis of the main features of myelin destruction are discussed. Furthermore, the importance of early axonal damage in multiple sclerosis is highlighted.

Phe71 is essential for chaperone-like function in alpha A-crystallin

Experiments with mini-alphaA-crystallin (KFVIFLDVKHFSPEDLTVK) showed that Phe(71) in alphaA-crystallin could be essential for the chaperone-like action of the protein (Sharma, K. K., Kumar, R. S., Kumar, G. S., and Quinn, P. T. (2000) J. Biol. Chem. 275, 3767-3771). In the present study we replaced Phe(71) in rat alphaA-crystallin with Gly by site-directed mutagenesis and then compared the structural and functional properties of the mutant protein with the wild-type protein. There were no differences in molecular size or intrinsic tryptophan fluorescence between the proteins. However, 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid interaction indicated a higher hydrophobicity for the mutant protein. Both wild-type and mutant proteins displayed similar secondary structure during far UV CD experiments. Near UV CD signal showed a slight difference in the tertiary structure around the 285-295 region for the two proteins. The mutant protein was totally inactive in suppressing the aggregation of reduced insulin, heat-denatured citrate synthase, and alcohol dehydrogenase. However, a marginal suppression of beta(L)-crystallin aggregation was observed when mutant alphaA-crystallin was included. These results suggest that Phe(71) contributes to the chaperone-like action of alphaA-crystallin. Therefore we conclude that the 70-88-region in alphaA-crystallin, identified by us earlier, is the functional chaperone site in alphaA-crystallin.