Optic neuritis and multiple sclerosis: the T cell repertoires to myelin proteins and MBP peptides change with time

Autoreactive T cells recognizing myelin basic protein (MBP), proteolipid protein (PLP) and MBP peptides have been described in multiple sclerosis (MS) and optic neuritis (ON), but their role in disease pathogenesis, if any, is unknown. A consistency of the T cell repertoire over the course of MS and ON should facilitate the development of specific immunotherapies. We have examined the T cell responses to autoantigens in two consecutive blood specimens taken from patients with ON and MS, and in two consecutive CSF specimens obtained from ON patients. As read-out numbers of T cells responding to antigen stimulation by the secretion of interferon-γ were estimated. Pronounced differences in occurrence and numbers of T cells recognizing MBP, MBP peptides with the amino acid sequences 63–88, 110–128 and 148–165, and PLP were noticed in individual ON and MS patients over the course of disease. The MBP peptide among those three included, that was predominantly recognized by T cells in the individual patient, also varied over the course. The quantitative and qualitative changes of the myelin antigen-specific T cell response in MS and in ON, the latter to a certain extent reflecting the situation in early MS, do not favor the future useful development of specific immunotherapies in these diseases.     

Clues to the immunopathogenesis of multiple sclerosis by investigating untreated patients during the very early stage of disease

Plethora of abnormalities of the immune system has been described in multiple sclerosis (MS). They include a number of myelin antigens (e. g. MBP, MOG, PLP, MAG), the presence of reactive T cells in blood and, further enriched, in the cerebrospinal fluid (CSF), large numbers of B cells in the CSF secreting antibodies of multiple but unknown specificities, an increase of mononuclear cells (MNC) expressing and secreting both pro- and anti-inflammatory cytokines, including Th1 cytokines interferon-gamma (IFN-γ) and interleukin (IL)-6, the Th2 related IL-4 and IL-10, and the Th3-driven TGF-β, elevated numbers of MNC in both blood and CSF expressing a spectrum of metalloproteinases and their inhibitors, as well as many other aberrations. However, no consistent patterns have emerged that relate any of these findings to clinical variables such as exacerbations, during of disease, disability, or lesions in the central nervous system (CNS) detected at magnetic resonance imaging. In order to elucidate the relevance of these immunological abnormalities in the pathogenesis of MS, my colleagues and I studied patients with acute monosymptomatic optic neuritis (ON) and compared them with patients with clinically definite MS (CDMS). The patients have not been treated and have not received corticosteroids or interferon-β. When comparing these two groups, we were unable to identify any differences in any of the variables mentioned. Thus, very early MS, as represented by ON, shows the same full-blown pattern of immunological abnormalities seen in CDMS. Furthermore, a complete epitope spread affecting MBP, MOG, PLP, MAG and other myelin components is already present in ON. Whether any of these alterations play a pathogenetic role is still unsettled.     

Frequency of T cells specific for myelin basic protein and myelin proteolipid protein in blood and cerebrospinal fluid in multiple sclerosis

T cell sensitization to two myelin components, myelin basic protein (MBP) and myelin proteolipid protein (PLP), may be important to the pathogenesis of multiple sclerosis (MS). Using the limiting dilution assay, we demonstrated that the blood of MS patients had an increased frequency of MBP-reactive T cells compared with normal subjects and patients with other neurological diseases (OND) and rheumatoid arthritis. There was no difference in T cell frequency to a synthetic peptide, PLP139-151, or Herpes simplex virus. Within cerebrospinal fluid (CSF), 37% of IL-2/IL-4-reactive T cell isolates from MS patients responded either to MBP or PLP139-151 while only 5% of similar isolates from OND patients responded to these myelin antigens. The mean relative frequency of MBP-reactive T cells within CSF from MS patients was significantly higher than that of OND patients (22 x 10(-5) cells versus 1 x 10(-5) cells) and was similar to that of MBP reactive T cells within the central nervous system of rats with experimental autoimmune encephalomyelitis. These results lend new support to the hypothesis that myelin-reactive T cells mediate disease in MS.     

Virus-reactive and autoreactive T cells are accumulated in cerebrospinal fluid in multiple sclerosis

Elevated numbers of B cells--plasma cells secreting antibodies to measles and mumps virus, and to myelin associated glycoprotein (MAG), one of several putative myelin autoantigens--have previously been reported in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS), while it is unknown if corresponding T cell reactivities occur. We have defined the T cell reactivities to measles and mumps virus and to MAG in an immunospot assay which is based on the detection of secretion of interferon-gamma (IFN-gamma) by single cells upon stimulation with specific antigen in short term cultures. Patients with MS had higher numbers of MAG-reactive T cells in blood compared to controls, while no differences were observed for measles or mumps virus-reactive T cells. In CSF, elevated numbers of MAG-reactive T cells and also of measles- and mumps-reactive T cells were found in patients with MS compared to other neurological diseases. A strong accumulation of antigen-reactive T cells was observed in the MS patients' CSF compared to blood. The magnitude of these T cell reactivities did not correlate with clinical MS variables. The T cell repertoire in MS thus includes, besides myelin basic protein, proteolipid protein and myelin oligodendrocyte glycoprotein, also MAG and, in addition, measles and mumps virus. It is not clear whether these T cell reactivities accumulated in the CSF have importance for the pathogenesis of MS or reflect phenomena secondary to myelin damage, or result from both these alternatives.     

多发性硬化症髓鞘素组分特异性抗体分泌细胞

本文用酶联免疫斑点法（Ｅｌｉｓｐｏｔ）检测了２３例临床确诊多发性硬化症（ＭＳ）和１２例无菌性脑膜炎（ＡＭ）患者外周血（ＰＢ）和脑脊液（ＣＳＦ）中髓鞘素碱性蛋白（ＭＢＰ）、髓鞘素结合糖蛋白（ＭＡＧ）和含脂质蛋白（ＰＬＰ）特异性ＩｇＧ抗体分泌细胞。两组患者ＣＳＦ中该３种抗体分泌细胞均呈明显增多趋势，ＭＳ组尤著，但两组ＰＢ中该类细胞数均很少。指示对髓鞘素组分的Ｂ细胞免疫应答主要局限于与中枢神经系统（ＣＮ     

Cytokine phenotype of human autoreactive T cell clones specific for the immunodominant myelin basic protein peptide (83–99)

Experimental allergic encephalomyelitis (EAE), an animal model resembling multiple sclerosis (MS), is mediated by myelin antigen-specific CD4+ T cells secreting cytokines such as interferon-γ (IFN-γ), tumor necrosis factor-β (TNF-β), and the proinflammatory cytokine TNF-α—all associated with the T-helper-1 (Th1) T cell subset. Based on numerous similarities between MS and EAE, it has been postulated that Th1-like T cells are involved in the pathogenesis of MS. Production of proinflammatory cytokines such as IFN-γ and, in particular, TNF-α/β by autoreactive T cells is considered crucial for the initiation and amplification of inflammatory brain lesions and possibly also for direct myelin damage. In contrast, regulatory cytokines such as interleukin-4 (IL-4), IL-10, and IL-13, which are associated with the Th2-like phenotype, may play a role in the resolution of relapses. Although the human T cell response to myelin basic protein (MBP) is well characterized in terms of antigen specificity, HLA restriction, and T cell-receptor (TCR) usage, little is known about the cytokine pattern of these autoreactive T cells. To gain such information, conditions for studying cytokine secretion by human autoreactive T cell clones (TCC) were established. The cytokine secretion profile of human autoreactive CD4+ TCC, specific for myelin basic protein peptide (83–89) [MBP(83–99)], a candidate autoantigen in MS, was investigated. Our results show that TCC cytokine production in long-term culture was stable. In addition, the correlation of various cytokines within specific TCC revealed differences compared to murine T cells. The comparison of 30 human MBP(83–99)-specific TCC demonstrated heterogeneity in cytokine secretion, with a continuum between Th1- and Th2-like cells rather than distinct Th1 or Th2 subsets. These data are important for further investigation of the potential role of cytokines in the inflammatory process of MS, and provide a powerful tool to investigate therapeutic interventions with respect to their influence on cytokine secretion of autoreactive T cells. © 1996 Wiley-Liss, Inc.     

Cell-mediated immunity to myelin-associated glycoprotein, proteolipid protein, and myelin basic protein in multiple sclerosis

Peripheral blood lymphocytes (PBL) from active and stable multiple sclerosis (MS) patients, patients with other neurologic diseases (OND), and control subjects were tested for sensitization to two myelin antigens not previously examined in multiple sclerosis, using a [3H]thymidine incorporation assay. The antigens investigated were myelin-associated glycoprotein (MAG) and proteolipid protein (PLP). In addition, sensitization to myelin basic protein (MBP) was also tested. Lymphocyte stimulation indices in active MS patients that were greater than 2 standard deviations above controls were as follows: 9/30 for MAG, 0/17 for PLP, and 8/81 for MBP. No control subjects responded to MAG or PLP, and only 1/29 control subjects responded to MBP. Three of the patients that responded to MAG also responded to MBP. Although the mean proliferative response to MAG and to MBP was greater in the population of active MS patients than in stable MS, ONDs, or controls, the difference was not statistically significant. The OND group was the only population which proliferated to PLP (6/16). The only statistically significant differences among the groups for all myelin antigens tested were the proportion of individuals with active MS vs. controls that responded to MAG (P less than 0.05), and OND vs. controls and active MS that responded to PLP (P less than 0.025). The greatest individual responses to the three antigens tested were to MBP in active MS patients. Elimination of the T8 (cytotoxic/suppressor) subset amplified the responses to myelin antigens in some patients and ONDs studied. These studies have demonstrated reactivity to MAG but not PLP in some patients with active MS, and reactivity to PLP in some patients with other neurologic diseases.     

Multiple MAG peptides are recognized by circulating T and B lymphocytes in polyneuropathy and multiple sclerosis

Abnormal immune responses to myelin associated glycoprotein (MAG), a component of myelin of the central and peripheral nervous system, have been suggested to play a role in the pathogenesis of multiple sclerosis (MS) and certain types of inflammatory polyneuropathy. To identify possible immunodominant MAG peptides in neuroinflammation, we examined T and B cell responses to five selected synthetic MAG peptides and myelin proteins in 21 patients with non-inflammatory polyneuropathy, 26 patients with MS, 10 optic neuritis patients and 17 healthy subjects. Enzyme-linked immunosorbent spot-forming cell assays were adopted, allowing the detection and enumeration of individual antigen responsive T and B cells in body fluids. Patients with polyneuropathy as well as those with MS had elevated levels of T and B cells recognizing MAG and its peptides. Any of the five MAG peptides under study functioned as immunodominant T and/or B cell epitope in individual subjects. None of the MAG peptides elicited a specific disease-associated T or B cell response. The enhanced T and B cell response to myelin components like MAG may play some role in initiation and/or progression of these diseases, but they could also represent secondary responses associated with myelin damage and indicate tolerization rather than autoaggressive immunity.     

Multiple sclerosis: occurrence of myelin basic protein peptide-reactive T cells in healthy family members

Genetic factors influence the susceptibility to multiple sclerosis (MS). This disease is accompanied by augmented T cell responses to CNS myelin components such as myelin basic protein. To evaluate the familial occurrence of such T cell autoreactivity, we have studied 12 MS families including 37 healthy first-degree relatives for occurrence of numbers of interferon-gamma (IFN-γ) secreting cells among blood mononuclear after culture in presence of myelin basic protein (MBP), eight synthetic MBP peptides and the control antigen acetylcholine receptor (AChR). There were no differences between MS patients and healthy family members regarding frequencies of autoreactive T cells recognizing MBP, the eight different MBP peptides or AChR. None of the MBP peptides predominated as T cell antigen among the MS patients or their unaffected family members. In some families the highest number of MBP peptide reactive T cells were found among unaffected family members. No correlation was observed between numbers of MBP or MBP peptide reactive T cells in various subjects and their HLA-DR-DQ phenotypes. In conclusion, this study has revealed the presence of MBP and MBP peptide reactive T cells of similar frequencies in MS patients and their healthy family members.     

亚低温治疗对实验性脑出血大鼠死亡率及脑组织钙含量的影响

目的本研究观察３２℃亚低温对实验性脑出血大鼠２４ｈ内死亡率和脑组织钙含量的影响。方法１３４只大鼠分成两部分：（１）６８只大鼠用于死亡率观察;（２）６６只大鼠用于脑组织钙含量测定。每一部分分成假手术对照组、常温脑出血组及亚低温脑出血组。结果常温组２４ｈ内死亡率为３６．６７％,亚低温组为４．５５％;脑组织钙含量常温组较对照组和亚低温组为高。结论亚低温治疗能显著减少实验性脑出血大鼠２４ｈ内死亡率,减少脑出血后脑组织钙含量。     

Myelin-associated glycoprotein in multiple sclerosis lesions: a quantitative and qualitative analysis

Myelin-associated glycoprotein (MAG), myelin basic protein (MBP), and proteolipid protein (PLP) were quantitated by immunoassays in nine plaque, inner periplaque, outer periplaque, and normal-appearing white matter regions from brains of five multiple sclerosis patients and compared with the levels found in white matter samples of control subjects matched for age, postmortem time, and brain region. In plaque and inner periplaque regions, all three proteins were substantially reduced due to extensive myelin loss. In outer periplaque regions, MBP and PLP were close to control levels, but MAG was significantly reduced to a mean of 57% of control. All three proteins were close to control levels in the normal-appearing white matter samples. MAG in the various regions was qualitatively examined on Western blots by binding of lectins and by immunostaining with polyclonal and monoclonal antibodies against carbohydrate and protein epitopes of MAG. Densitometric scanning of these blots did not reveal any qualitative differences in the oligosaccharide or polypeptide moieties of MAG between samples from control subjects and those from multiple sclerosis patients. However, a high proportion of the MAG in the multiple sclerosis samples was often in the form of dMAG, a proteolytic derivative of MAG that is formed by a myelin-associated, Ca2+-activated, neutral protease. The preferential loss of MAG at the periphery of multiple sclerosis plaques may be initiated by its proteolytic conversion to dMAG.     

Autoreactivity to myelin antigens: myelin/oligodendrocyte glycoprotein is a prevalent autoantigen.

Autoreactive T cells specific for myelin antigens are thought to play a role in the pathogenesis of multiple sclerosis (MS). We compared T cell proliferative responses in peripheral blood following challenge in vitro with myelin/oligodendrocyte glycoprotein (recombinant protein, rMOG), myelin basic protein (MBP) and proteolipid apoprotein (PLP) in 50 patients with MS and 40 healthy controls. T cell reactivity against rMOG (defined by a specific stimulation index of 2.5 or greater) was present in 13 (26%) MS patients and 12 (30%) healthy controls and was MHC-restricted, as anti-MHC class II antibodies abolished all proliferative responses. By contrast, reactivity against PLP was present in only one (2%) MS patient and six (15%) controls, and no reactivity against MBP was found in any subject. Thus, by the criteria of the present study, an increased reactivity of circulating T cells to MOG is present to a similar degree in healthy individuals and in patients with MS. This finding raises the possibility that additional factors contribute to the pathogenicity of these autoreactive T cell populations in demyelinating disorders of the central nervous system.     

Preferential survival of an MBP-specific T cell clone in an HLA-DR2 multiple sclerosis patient

Anti-myelin basic protein (MBP) autoreactive T cells play a key role in the pathogenesis of multiple sclerosis. Thus, we applied the Immunoscope strategy to cerebrospinal fluid (CSF) and peripheral blood lymphocytes (PBLs) of an HLA-DR2 patient. Both compartments showed major expansion for the V(beta)13S5 chain, which was associated in peripheral blood with significant proliferation of PBLs in response to MBP and the 84-102 HLA-DR2-restricted peptide. Sequencing revealed a unique nucleotide sequence in the CSF that gives rise to the amino acid sequence V(beta)13S5-RPGQGDQETQ-J(beta)2.5 if translated. This CDR3 sequence had already been reported to be reactive against the 84-102 peptide. This specific sequence was not detected in PBLs on day 0, whereas it was readily detectable on day 6 culture samples. Thus, cell culture may lead to enrichment in a T cell clone identified as autoreactive.     

Autoreactive T lymphocytes in multiple sclerosis: pathogenic role and therapeutic targeting

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), leading to demyelination. Accumulating evidence suggests that MS is an autoimmune disease, mediated by autoreactive T cells with specificity for myelin antigens. The identity of the brain antigens, which are the primary targets of the autoimmune process remains unknown, but myelin basic protein (MBP) is a likely candidate. We will overview some of the experimental evidence, suggesting that MBP reactive T cells hold a central position in the pathogenesis of MS, and discuss how these autoreactive T cells can be therapeutically targeted by T cell vaccination.     

Myelin basic protein in the CSF of patients with multiple sclerosis, optic neuritis and various neurological diseases

We tested 104 patients for myelin basic protein (MBP) content in the CSF. Of these subjects 14 were selected as control group, 36 were affected by multiple sclerosis (MS), 14 by optic neuritis (ON) and 42 presented other not primarily demyelinating neurological diseases (ND ND). CSF MBP level was significantly higher in the MS group than in the other groups of patients, while no statistical difference was found between the MS patients with acute exacerbation and those in remission.     

多发性硬化T淋巴细胞系增殖反应性的研究

目的 比较多发性硬化(MS)患者和正常人T淋巴细胞对碱性髓鞘蛋白(MBP)和蛋白脂质蛋白(PLP)及其合成多肽的增殖反应性。方法 选HLA-DRl5亚型MS患者和正常人外周血单个核细胞。以人神经髓鞘为致敏原，采用二次致敏诱导法。经短期体外培养产生外周血T淋巴细胞系(TCL)，用MBP、PLP及其合成多肽等11种抗原检测TCL的增殖反应。结果 MS和对照组对神经髓鞘成分反应均显示多态性。MS组对7种。对照组对5种抗原有反应；比较两组总的平均阳性孔无差别(P=0．177)；两组间对MBP、P30-49、P95-117、P178-191的增殖反应差异有统计学意义。结论 作为神经髓鞘主要成分的MBP和PLP免疫反应性高，可能在体内触发自身免疫反应过程发挥作用，而M87-106、P40-60、P95-117和P185-206等位点值得进一步研究。     

Lack of restriction of T cell receptor β variable gene usage in cerebrospinal fluid lymphocytes in acute optic neuritis

OBJECTIVES: There have been many studies reporting restricted patterns of T cell receptor usage in established multiple sclerosis and these have led to clinical trials of immunomodulation directed at deleting clonal T cell populations. The present study aims to test the hypothesis that highly restricted T cell populations are also present in the CSF in the earliest clinical stages of acute demyelinating disease of the CNS. METHODS: T cell receptor Vbeta (TCRBV) gene expression was studied in CSF and blood in nine patients with acute optic neuritis within 7 days of onset of symptoms, six patients with an acute relapse of multiple sclerosis, and 13 control subjects. RNA was extracted and cDNA synthesised from unstimulated CSF and blood lymphocytes, and TCRBV gene segments were amplified from the cDNA by polymerase chain reaction (PCR) using 21 family specific primers. PCR products were separated by polyacrylamide gel electrophoresis and detected via a labelled oligonucleotide probe. A semiquantitative analysis of band intensity was performed by laser densitometry. RESULTS: TCRBV mRNA was detected in the CSF of eight of nine patients with optic neuritis, six of six patients with multiple sclerosis, and five of 13 controls, and was closely correlated with the presence of oligoclonal IgG. Usage of a single TCRBV family was demonstrated in two of nine patients with optic neuritis and two of six patients with multiple sclerosis. The number of TCRBV families expressed in the other patients ranged between 5 and 15 (optic neuritis) and 4 and 17 (multiple sclerosis). CONCLUSIONS: There is a relative lack of restriction of TCRBV usage by CSF lymphocytes in the very earliest stages (<7 days) of acute optic neuritis. This may imply either that multiple sclerosis is not a monoclonal disease even at onset, or that the autoimmune response has widened before the disease becomes clinically evident. This may have important consequences for the design of immune therapies in multiple sclerosis. Further studies are required to determine whether the CSF T cell repertoire at presentation has prognostic importance. Longitudinal studies are required to follow the CSF T cell repertoire from the time of presentation and to determine whether it may have prognostic significance.     

Cytokines in neuroinflammatory disease: role of myelin autoreactive T cell production of interferon-gamma

Many cytokines must be considered as effector and immunoregulatory molecules in neuroinflammatory diseases such as multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE). We have studied the potential role of interferon-gamma (IFN-γ) in the pathogenesis of these diseases, since this cytokine has a number of important effects such as macrophage activation, induction of MHC class I and class I antigens, and T cell homing. An immunospot assay that allows enumeration of single cells secreting IFN-γ after short-term culture in vitro of mononuclear cell suspensions has been used. In EAE, increased numbers of IFN-γ-secreting cells (IFN-γ-sc) appear in the central nervous system shortly before onset of clinical signs. Such cells also increased during pharmacologically induced relapse of EAE. In later stages of EAE, memory T cells that produced IFN-γ in response to presented antigen, recognized multiple regions of the myelin basic protein (MBP), showing that (i) myelin autoreactive T cells have the functional ability to produce this cytokine, (ii) the concept of immunodominance as to autoantigen peptide reactivity is non-absolute and time-dependent. In multiple sclerosis (MS) there are increased numbers of IFN-γ-sc among the CSF cells. Also, there are increased numbers of memory T cells, strongly enriched to the cerebrospinal fluid, which upon recognition of several myelin antigens and several MBP peptide stretches, produce IFN-γ. Taken together, the data are consistent with a role for IFN-γ as a key mediator in inflammatory demyelinating diseases.     

B and T lymphocytes in cerebrospinal fluid and blood in multiple sclerosis, optic neuritis and mumps meningitis

B and T cells were defined in cerebrospinal fluid (CSF) and blood of 18 multiple sclerosis (MS), five optic neuritis, and 17 mumps meningitis patients by counting immunoglobulin-bearing lymphocytes for B cells, and the capacity of rosette formation with sheep erythrocytes for T-cell determination. Patients with MS and mumps meningitis had significantly higher T-cell values in CSF compared to blood, while the B cell value was significantly lower in CSF in mumps meningitis only. MS patients also displayed significantly lower B-cell values in blood compared to mumps meningitis patients and blood donors. No significant differences were observed between MS patients in exacerbation and in remission.     

Myelin reactive T cells after T cell vaccination in multiple sclerosis: cytokine profile and depletion by additional immunizations

Pathogenic autoreactive T cells can be targeted by T cell vaccination (TCV), a procedure in which patients are immunized with autologous attenuated pathogenic T cells. We reported previously that TCV with myelin basic protein (MBP) reactive T cell clones in multiple sclerosis (MS) patients induced T cell immune responses, resulting in a clonal depletion of MBP reactive T cells in all patients. Five years after TCV, MBP reactive T cells were observed in five out of nine MS patients. These clones had a different clonal origin from those isolated before vaccination. We have studied the cytokine profile, cytotoxicity and epitope specificity of these reappearing clones. Our data indicate that the clones express similar effector functions as those isolated before TCV, suggesting that they also could play a pathogenic role in the disease. We demonstrated that these clones can be depleted by an additional sequence of immunizations. These findings may be relevant to other T cell targeted immunotherapies for MS and other autoimmune diseases.