Myelin Basic Protein In Patients Research Articles

Citrullination of myelin basic protein induces a Th17-cell response in healthy individuals and enhances the presentation of MBP85-99 in patients with multiple sclerosis

The post-translational modification citrullination has been proposed to play a role in the pathogenesis of multiple sclerosis (MS). Myelin basic protein (MBP) is a candidate autoantigen which is citrullinated to a minor extent under physiological conditions and hypercitrullinated in MS. We examined immune cell responses elicited by hypercitrullinated MBP (citMBP) in cultures of mononuclear cells from 18 patients with MS and 42 healthy donors (HDs). The immunodominant peptide of MBP, MBP85-99, containing citrulline in position 99, outcompeted the binding of native MBP85-99 to HLA-DR15, which is strongly linked to MS. Moreover, using the monoclonal antibody MK16 as probe, we observed that B cells and monocytes from HLA-DR15+ patients with MS presented MBP85-99 more efficiently after challenge with citMBP than with native MBP. Both citMBP and native MBP induced proliferation of CD4+ T cells from patients with MS as well as TNF-α production by their B cells and CD4+ T cells, and citrullination of MBP tended to enhance TNF-α secretion by CD4+ T cells from HLA-DR15+ patients. Unlike native MBP, citMBP induced differentiation into Th17 cells in cultures from HDs, while neither form of MBP induced Th17-cell differentiation in cultures from patients with MS. These data suggest a role for citrullination in the breach of tolerance to MBP in healthy individuals and in maintenance of the autoimmune response to MBP in patients with MS.

Some structural features of the peptide profile of myelin basic protein-hydrolyzing antibodies in schizophrenic patients.

The antibodies of schizophrenic patients that hydrolyze myelin basic protein (MBP) have been actively studied recently, but the mechanism of the catalytic properties of immunoglobulin molecules remains unknown. Determination of specific immunoglobulin sequences associated with the high activity of MBP proteolysis will help to understand the mechanisms of abzyme catalysis. In the course of comparative mass spectrometric analysis of IgG peptides from the blood serum of patients with acute schizophrenia and healthy people, 12 sequences were identified, which were found only in antibodies that hydrolyze MBP. These sequences belong to IgG heavy chains and κ- and λ-type light chains, with eight of them belonging to variable domains. The content of peptides from the variable regions of the light chains does not correlate with the proteolytic activity of IgG to MBP in patients with schizophrenia, whereas for two sequences from the variable regions of the heavy chains (FQ(+0.98)GWVTMTR and *LYLQMN(+0.98)SLR), an increase in activity with increasing their concentration. The results suggest that these sequences may be involved in one way or another in MBP hydrolysis.

Autoreactivity against myelin basic protein in patients with chronic paraplegia

Previous studies have shown the existence of either cellular or humoral MBP-reactive elements up to 5 years after spinal cord injury (SCI), but not the presence of both after 10 years. Twelve SCI patients, with more than 10 years of evolution, and 18 healthy blood donors were studied. Lymphocyte proliferation (colorimetric-BrdU ELISA assay) and antibody titers against MBP (ELISA Human IgG MBP-specific assay) were assessed. SCI patients presented a significant T-cell proliferation against MBP (lymphocyte proliferation index: 3.7 ± 1.5, mean ± SD) compared to control individuals (0.7 ± 0.3; P < 0.001). Humoral response analysis yielded a significant difference (P < 0.0001) between the antibody titers of controls and SCI patients. A significant correlation between cellular and humoral responses was observed. Finally, patients with an ASIA B presented the highest immune responses. This work demonstrates, for the first time, the existence of both cellular and humoral responses against MBP in the chronic stages (>10 years) of injury.

The dynamic changes and its clinic values of serum S100B、 NSE、 MBP in patients with carbon monoxide poisoning

Objective To explore the clinical significance and the dynamic changes of serum S 100B, neuron specific Enolase（NSE）, myelin basic protein（MBP） in patients with carbon monoxide poisoning. Methods 185 carbon monoxide poisoning patients and 30 healthy volunteers were enrolled in this study. The serum S 100B, NSE, MBP at admission were measured in all cases, and in the following two days for the 60 moderate and severe patients.Rasulta The moderate and severe patients had higher S100B, NSE level at admission than the controls and the mild patients, but MBp level at admission were significantly different among the three groups.Compared with the survivor group,death group had higher S100B, NSE, MBP in all three days.In death group, both S100B and NSE increased remarkably in the second day and kept higher level in the third day, but MBP level were not significantly different in all three days for the death group. For the survivors group, no difference were found for these index among the three days.Conclusions The serum MBP level at admission was related with the severity of carbon monoxide poisoning.Dynamic analysis of serum NSE and S100B could effectively evaluate the progress and prognosis of the patients with carbon monoxide poisoning. Key words: Carbon monoxidepoisoning; S100B; NSE; MBP; Prognosis

T cell reactivity to P0, P2, PMP-22, and myelin basic protein in patients with Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy

Objectives: It has been suggested that autoimmunity to peripheral myelin proteins is involved in the pathogenesis of Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We aimed to compare...

Time course of T-cell responses to MOG and MBP in patients with clinically isolated syndromes

CD4 + T-cell lines (TCLs) from patients with clinically isolated syndromes (CIS) were selected with purified human myelin basic protein (MBP) and recombinant human myelin oligodendrocyte glycoprotein (rhMOG), at onset of neurological symptoms and when patients developed clinically definite multiple sclerosis (CDMS). The epitope specificity of each TCL was mapped with overlapping synthetic peptides. TCLs were assessed for their ability to secrete IFN-γ, IL-4, and IL-6. Diverse patterns of epitope recognition were observed: (a) recognition of a broad spectrum of MBP peptide epitopes with evidence of shifts over time; (b) an initial T-cell response focused to a restricted segment of the MBP molecule (83–102) that broadened over the course of disease; and (c) persistence of a focused anti-MOG T-cell response. CIS patients who failed to develop CDMS maintained a focused epitope response against two to six MBP epitopes. Most MBP peptide-specific TCLs secreted considerable amounts of IFN-γ and low amounts of IL-4 and IL-6, whereas anti rhMOG Igd peptide-specific TCLs secreted preferentially IL-4 and IL-6. These data raise important issues for the pathogenesis and treatment of multiple sclerosis (MS).

Glatiramer acetate induces a Th2-biased response and crossreactivity with myelin basic protein in patients with MS

Glatiramer acetate induces a Th2-biased response and crossreactivity with myelin basic protein in patients with MS

Detection of brain-specific autoantibodies to myelin oligodendrocyte glycoprotein, S100β and myelin basic protein in patients with Devic's neuromyelitis optica

Neuromyelitis optica (NMO) is a rare syndrome characterized by the combination of acute optic neuritis and transverse myelitis, usually not seen in Multiple Sclerosis (MS) and other demyelinating syndromes of the central nervous system (CNS). A high prevalence of various autoantibodies has been described in patients with NMO suggesting a polyclonal activation of the humoral immune system. We examined autoantibody responses to myelin (MBP, MOG with isotypes and epitopes) and astroglial (S100β) antigens in four patients with NMO by ELISA and Immunoblot. All patients showed a positive anti-MOG response, with one showing reaction to the MOG epitope corresponding to amino acid sequence 63–87. MBP-autoantibodies were only detected in two and S100β-autoantibodies in one patient. Despite the limited number of samples, these findings suggest a predominant anti-MOG rather than anti-MBP or anti-S100β autoantibody response in NMO, though no NMO-specific antibody pattern was found, which is in keeping with a widespread acute immune activation, including a strong B-cell response.

T cell responses to myelin basic protein in patients with spinal cord injury and multiple sclerosis

Autoimmune inflammation secondary to myelin destruction may play an inhibitory role in restoration of nerve functions in spinal cord injury (SCI). In this study, we demonstrated that T cells recognizing myelin basic protein (MBP) occurred at a high precursor frequency in patients with SCI, which was compatible to that in patients with multiple sclerosis (MS), a disease of presumed autoimmune pathology. The findings suggest of hyperactivity of MBP-reactive T cells in patients with SCI. MBP-reactive T cell lines derived from patients with SCI exhibited a preferential recognition pattern toward the 81–99 and the 151–169 regions of MBP. There were functional differences in the epitope recognition and cytokine profile between two panels of MBP-reactive T cell lines derived from patients with SCI and patients with MS. The study provides new evidence important for further investigation of the role of the inflammatory component in SCI.

T cell recognition motifs for an immunodominant peptide of myelin basic protein in patients with multiple sclerosis: Structural requirements and clinical implications

T cell recognition motifs for an immunodominant peptide of myelin basic protein in patients with multiple sclerosis: Structural requirements and clinical implications

Restricted TCR Valpha gene rearrangements in T cells recognizing an immunodominant peptide of myelin basic protein in DR2 patients with multiple sclerosis.

T cell responses to myelin basic protein (MBP) are thought to play an important role in the pathogenesis of multiple sclerosis (MS). The response to the 83-99 region of MBP represents a dominant response to MBP in patients with MS and is associated with HLA-DR2 that is linked with susceptibility to MS. Although T cell clones reactive to various regions of MBP have been found to exhibit heterogeneous TCR Vbeta gene usage in patients with MS, it is unclear whether T cell clones uniformly recognizing the 83-99 peptide of MBP in the context of the same DR molecule would have restricted TCR V gene rearrangements and recognition motifs. In this study, a panel of DR2- or DR4-restricted T cell clones specific for the MBP83-99 peptide were derived from 11 patients with MS and examined for TCR V gene usage by PCR and the recognition motifs using analog peptides. Our study revealed that despite a few T cell clone pairs having similar recognition motifs and shared sequence homology in the CDR3, the overall recognition motifs of MBP83-99-specific T cells were considerably diverse. Interestingly, the DR2-restricted T cell clones displayed a biased V gene usage for Valpha3 and Valpha8, while Vbeta gene rearrangements were highly heterogeneous. This study provided experimental evidence suggesting a limited heterogeneity in TCR Valpha gene rearrangements of MBP-reactive T cells in DR2 patients with MS.

T cell recognition motifs of an immunodominant peptide of myelin basic protein in patients with multiple sclerosis: structural requirements and clinical implications.

Myelin basic protein (MBP)-reactive T cells may play an important role in the pathogenesis of multiple sclerosis (MS). The T cell response to the 83-99 region of MBP represents a dominant autoreactive response to MBP in MS patients of DR2 haplotype. In this study, a large panel of DR2- and DR4-restricted T cell clones specific for the MBP83-99 peptide were examined for the recognition motifs and structural requirements for antigen recognition using alanine-substituted peptides. Our study revealed that although the recognition motifs of the T cell clones were diverse, the TCR contact residues within the 83-99 region of MBP were highly conserved. Two central residues (Phe90 and Lys91) served as the critical TCR contact points for both DR2- and DR4-restricted T cell clones. Single alanine substitution at residue 90 or residue 91 abolished the responses of 81-95 % of the T cell clones while a double alanine substitution rendered all T cell clones unresponsive. It was also demonstrated in this study that the substituted peptides altered the cytokine profile of some, but not all, T cell clones. Some MBP83-99-specific T cell clones were able to sustain alanine substitutions and were susceptible to activation by microbial antigens. The study has an important implication in designing a peptide-based therapy for MS.

T-cell response to myelin basic protein and lipid-bound myelin basic protein in patients with multiple sclerosis and healthy donors

An autoimmune T-cell response to myelin proteins is thought to be involved in the pathogenesis of multiple sclerosis (MS) and myelin basic protein (MBP) is the most widely studied potential target antigen. We investigated the T-cell response to MBP in MS patients and controls using two different molecular forms of the protein: the classical hydrophilic MBP (lipid-free MBP, LF-MBP) and a lipid-bound, native-like preparation of MBP isolated in a molecular form retaining the binding to all myelin lipids (lipid-bound-MBP, LB-MBP). Short term T-cell lines (TCL) were generated using either LF- or LB-MBP and tested for their reactivity to the in vitro stimulating antigen. No differences were detected between MS patients and healthy donors in the percentage of T-cell cultures responsive to the LF-MBP. In contrast, the number of LB-MBP reactive cultures was higher in MS patients than in controls. This difference was almost entirely due to the presence of high numbers of LB-MBP-specific TCL in MS patients which did not cross-react with LF-MBP and were not present in healthy subjects. LB-MBP may represent a novel antigen worth to be investigated in MS.

Cytokine profile of myelin basic protein-reactive T cells in multiple sclerosis and healthy individuals.

Myelin basic protein (MBP)-reactive T cells have been implicated in the autoimmune pathogenesis of multiple sclerosis (MS). In this study, we examined the cytokine profile of 531 primary MBP-reactive T-cell lines and 72 independently established clones from 32 patients with MS and 18 healthy controls (NS) by using highly sensitive enzyme-linked immunosorbent assays. An increased number of primary T-cell lines producing interferon-gamma (IFN gamma) and/or interleukin-4 (IL-4) in response to MBP were found in patients with MS compared with controls. No distinct Th1 or Th2 subtypes could be demonstrated among the MBP-reactive clones. IL-4 was more frequently observed among MS-derived clones. Clones derived from MS patients produced increased levels of IL-2, IL-4, tumor necrosis factor-alpha (TNF alpha), IFN gamma, and IL-10, but not IL-6. It is interesting that MBP-reactive T cells from MS patients expressing the disease-associated HLA-DRB1*15 allele produced increased quantities of TNF alpha, a cytokine suggested to play an important role in inflammation and demyelination. When challenged with either MBP or a bacterial superantigen, the clones expressed similar levels of the proinflammatory cytokine IFN gamma. Our study suggests a functional difference in T-cell responses to MBP in patients with MS compared with healthy individuals, and provides further insights into the role of MBP-reactive T cells and their cytokine profile in the inflammatory processes of MS.

Episodic changes in T‐cell frequencies to myelin basic protein in patients with multiple sclerosis

Episodic changes in T‐cell frequencies to myelin basic protein in patients with multiple sclerosis

The T‐lymphocyte response against myelin‐associated glycoprotein and myelin basic protein in patients with multiple sclerosis

In addition to myelin basic protein (MBP), other minor components of myelin, such as myelin-associated glycoprotein (MAG), may be important autoantigens in MS. To determine whether MAG might be involved in an autoimmune reaction in MS, we screened peripheral blood lymphocytes from MS patients and normal subjects for their sensitization to human MBP and MAG antigen using a [3H]thymidine incorporation assay. We recorded three patterns in MS patients: (1) patients who responded neither to MAG nor to MBP (4/11); (2) patients who responded to both MBP and MAG (5/11); and (3) patients who gave an exclusive response to MAG (2/11). The 10 healthy controls did not respond to either MAG or MBP. That some individuals with MS expressed a specific response against MAG and that more than 50% of MS patients expressed a sensitization to MAG suggest that MAG may have a role in the pathogenesis of MS.

Detection of cerebrospinal fluid antibodies against myelin basic protein in patients with AIDS dementia complex

We evaluated cerebrospinal fluid (CSF) antibody levels against a lipid-free, denatured form of myelin basic protein (LF-MBP) in 11 patients with AIDS dementia complex (ADC) by using an enzyme-linked immunosorbent assay (ELISA). In 9 out of 11 patients, anti-LF-MBP antibody levels were significantly higher than those observed both in 15 human immunodeficiency virus (HIV)-infected patients without neurological disorders and in 9 anti-HIV-negative subjects affected by other neurological diseases. Furthermore, we followed up anti-MBP levels in 5 out of the 11 ADC patients and detected a strict relationship with the encephalopathy progression. At the same time, with the aim to detect early demyelinating events we investigated CSF antibody levels against a lipid-bound, native-like form of MBP (LB-MBP). Results did not show any significant difference between LF-MBP and LB-MBP in terms of antibody reactivity. The detection of anti-MBP antibodies in CSF may provide the opportunity to assess a diagnostic tool for discovering demyelinating lesions in ADC patients.

T Cells Responsive to Myelin Basic Protein in Patients with Multiple Sclerosis

Gene mutation in vivo in human T lymphocytes appears to occur preferentially in dividing cells. Individuals with multiple sclerosis (MS) are assumed to have one or more populations of diving T cells that are being stimulated by autoantigens. Mutant T cell clones from MS patients were isolated and tested for reactivity to myelin basic protein, an antigen that is thought to participate in the induction of the disease. The hypoxanthine guanine phosphoribosyltransferase (hprt) clonal assay was used to determine mutant frequency values in MS patients with chronic progressive disease. Eleven of 258 thioguanine-resistant (hprt-) T cell clones from five of the six MS patients who were tested proliferated in response to human myelin basic protein without prior in vitro exposure to this antigen. No wild-type clones from these patients, nor any hprt- or wild-type clones from three healthy individuals responded to myelin basic protein. Thus, T cell clones that react with myelin basic protein can be isolated from the peripheral blood of MS patients.

Diagnostic value of cerebrospinal fluid anti–myelin basic protein in patients with multiple sclerosis

Prevalence and titer of total, free, and bound cerebrospinal fluid anti-myelin basic protein (MBP) antibodies as well as free/bound ratios were determined in four groups of patients with multiple sclerosis (MS) and three groups of controls. All patients with clinically active MS have elevated levels of total anti-MBP, which may be present in either free or bound form. Patients whose disease is in remission have undetectable anti-MBP levels, and some patients with clinically stable disease with residual disability may have detectable antibody titers. Chronically progressive MS is usually associated with high levels of antibody in the bound rather than the free form, resulting in a low or normal free/bound ratio. In contrast, MS exacerbations are characterized by relatively high levels of free anti-MBP in the cerebrospinal fluid, resulting in a high free/bound antibody ratio. Bound anti-MBP was also detected in elevated levels in 1 patient with subacute sclerosing panencephalitis and 2 of 8 patients with postinfectious encephalomyelitis. Although elevated levels of cerebrospinal fluid anti-MBP are not specific for MS, they are strongly associated with disease activity and may be involved in the pathogenesis of demyelination in patients with MS.

Myelin basic protein-responsive blood T lymphocytes in patients with multiple sclerosis.

Previous studies from our laboratory showed the development of circulating T lymphocytes sensitized to myelin basic protein (MBP) in guinea pigs challenged with MBP. Also, lymphocytes sensitized to MBP were found in patients with multiple sclerosis (MS). In this report, we describe the kinetics of MBP-sensitized lymphocytes in a longitudinal study (140-316 days) of seven MS patients using the MBP-stimulated active rosette-forming T cell assay (MBP-ARFC). Expressed as the ratio of MBP-ARFC over ARFC (early and 37 degrees C stable rosette-forming T lymphocytes without added antigen), the results show a considerable degree of variation in the levels of MBP-ARFC. Although the levels of ARFC during the study period were relatively unchanged for each patient, increases in the MBP-ARFC/ARFC ratios were associated with the development of neurological symptoms of disease. The results of this study demonstrate the development of T-cell-mediated immunity to MBP in patients with MS. Detection of MBP-sensitive cells was possible during the course of the disease. The level of sensitivity was influenced by the clinical status, degree of neurological deficit, and particular treatment course.