Oligodendrocyte-specific protein peptides induce experimental autoimmune encephalomyelitis in SJL/J mice.

Oligodendrocyte-specific protein (OSP) is a recently isolated and cloned, 207-aa, hydrophobic, four-transmembrane protein found in CNS myelin. It represents approximately 7% of total myelin protein. The OSP cDNA sequence has no significant homology with previously reported genes, but the predicted protein structure suggests that OSP is a CNS homologue of peripheral myelin protein-22. We previously reported the presence of anti-OSP Abs in the cerebrospinal fluid of relapsing-remitting multiple sclerosis (MS) patients, but not control patient groups. In this study, we tested the ability of a panel of 20-mer peptides with 10-aa overlaps, representing the sequence of murine OSP, to induce experimental autoimmune encephalomyelitis (EAE), an animal model for MS. SJL mice challenged with murine OSP peptides 52-71, 82-101, 102-121, 142-161, 182-201, and 192-207 exhibited clinical EAE. OSP:52-71 elicited severe relapsing-remitting EAE in some individuals. All other encephalitogenic peptides elicited, at most, a loss of tail tonicity from which the mice most often completely recovered. Mononuclear cell infiltrates and focal demyelination characteristic of EAE were evident. T cell proliferative responses were seen with all encephalitogenic peptides except 142-161 and 182-201. OSP peptides 72-91 and 132-151 did not cause clinical EAE, but did elicit robust proliferative responses. B10.PL and PL/J mice challenged with the same OSP peptide doses as SJL mice did not exhibit clinical EAE. These results in the SJL EAE model, together with the results from MS patient clinical samples, make OSP a promising candidate for autoantigenic involvement in MS.     

Administration of dehydroepiandrosterone suppresses experimental allergic encephalomyelitis in SJL/J mice.

Experimental allergic encephalomyelitis (EAE) is a Th1-mediated inflammatory demyelinating disease in the CNS, an animal model of multiple sclerosis. We have examined the effect of dehydroepiandrosterone (DHEA) on the development of EAE in mice. The addition of DHEA to cultures of myelin basic protein-primed splenocytes resulted in a significant decrease in T cell proliferation and secretion of (pro)inflammatory cytokines (IFN-gamma, IL-12 p40, and TNF-alpha) and NO in response to myelin basic protein. These effects were associated with a decrease in activation and translocation of NF-kappaB. In vivo administration of DHEA significantly reduced the severity and incidence of acute EAE, along with a decrease in demyelination/inflammation and expressions of (pro)inflammatory cytokines in the CNS. These studies suggest that DHEA has potent anti-inflammatory properties, which at least are in part mediated by its inhibition of NF-kappaB activation.     

Lymphocytes from SJL/J mice immunized with spinal cord respond selectively to a peptide of proteolipid protein and transfer relapsing demyelinating experimental autoimmune encephalomyelitis.

Relapsing experimental autoimmune encephalomyelitis (R-EAE) can be induced in SJL/J mice by immunization with spinal cord homogenate and adjuvant. The specific Ag(s) responsible for acute disease and subsequent relapses in this model is unknown. Myelin basic protein (BP), an encephalitogenic peptide of BP (BP 87-99), and proteolipid protein (PLP) can each induce R-EAE in SJL/J mice, and a peptide of PLP (PLP 139-151) has been reported to induce acute EAE. To determine the encephalitogens in cord-immunized mice with R-EAE, the in vitro proliferative responses of lymph node cells (LNC) and central nervous system mononuclear cells to BP, BP peptides, and PLP peptides were examined during acute EAE and during relapses. LNC responded only to PLP peptides 139-151 and 141-151 and did not respond to BP or its peptides during acute or chronic disease. Central nervous system mononuclear cells also preferentially responded to PLP 139-151 and 141-151 during acute and relapsing disease. A PLP 139-151 peptide-specific Th cell line was selected from LNC of cord-immunized donors. Five million peptide-specific line cells transferred severe relapsing demyelinating EAE to naive recipients. We conclude that PLP peptide 139-151 is the major encephalitogen for R-EAE in cord-immunized SJL/J mice. We demonstrate for the first time that Th cells specific for this peptide are sufficient to transfer relapsing demyelinating EAE. The predominance of a PLP immune response rather than a BP response in SJL/J mice suggests that genetic background may determine the predominant myelin Ag response in human demyelinating diseases such as multiple sclerosis.     

Zinc aspartate suppresses T cell activation in vitro and relapsing experimental autoimmune encephalomyelitis in SJL/J mice

Zinc is an essential trace element with a critical role in normal growth and development and in immune homeostasis. Zinc deficiency impairs both the innate and the adaptive immune system and can be normalized by zinc supplementation. On the other end of the spectrum, high dosages of zinc diminish immune cell functions similar to zinc deficiency. Here, we investigated the influence of zinc aspartate on proliferation and cytokine production of stimulated human T cells and mouse splenocytes in vitro. Furthermore, the effect of zinc aspartate was examined in mice with experimental autoimmune encephalomyelitis (EAE), an animal model of Multiple Sclerosis (MS) with a Th1/Th17 T cell-mediated immunopathogenesis. Zinc aspartate suppressed proliferation as well as IL-2, IL-10 and IL-17 production in stimulated human T cells and mouse splenocytes. Importantly, administration of a medium range dose of 30 μg/day zinc aspartate [1.5 mg/kg body weight (BW)] in a therapeutic manner led to a significant reduction of the clinical severity of the EAE during the first relapse of the disease. A lower zinc aspartate dose (6 μg/day, 0.3 mg/kg BW) had no significant therapeutic effect on the severity of the EAE, while administration of higher zinc aspartate amounts (120 μg/day, 6 mg/kg BW) led to more severe disease. Taken together, our data suggest that zinc aspartate can modulate activation, proliferation and cytokine production of effector T cells in vitro and in vivo and that activated autoreactive T cells may be potential therapeutic targets of tightly controlled zinc supplementation in autoimmune diseases like MS.     

Basic protein-specific T-cell lines that induce experimental autoimmune encephalomyelitis in SJL/J mice: comparison with Lewis rat lines

Myelin basic protein (BP)-specific T-cell lines were selected from SJL/J mice using techniques to select similar lines from Lewis rats. SJL/J BP-specific T-cell lines were composed of T cells with the helper/inducer phenotype (Lyt 1.2+, 2.2- and L3T4+) and proliferated in response to both the 1-37 and the 89-169 fragments of guinea pig BP. BP-specific T-cell lines transferred delayed-type hypersensitivity (DTH) responses to BP that persisted for over 60 days. Most recipient animals (32/41) developed acute experimental autoimmune encephalomyelitis (EAE), and most survivors (19/24) developed chronic relapsing EAE. Spinal cords of animals during both the acute and the chronic phases of illness contained plaques of demyelination and infiltrates of lymphocytes and macrophages. These findings differed from those of Lewis rat BP-specific lines which respond to a different region of BP, transfer DTH responses that last less than 12 days, and induce acute EAE in which demyelination does not occur.     

Inhibition of CX3CL1 (fractalkine) improves experimental autoimmune myositis in SJL/J mice

Idiopathic inflammatory myopathy is a chronic inflammatory muscle disease characterized by mononuclear cell infiltration in the skeletal muscle. The infiltrated inflammatory cells express various cytokines and cytotoxic molecules. Chemokines are thought to contribute to the inflammatory cell migration into the muscle. We induced experimental autoimmune myositis (EAM) in SJL/J mice by immunization with rabbit myosin and CFA. In the affected muscles of EAM mice, CX3CL1 (fractalkine) was expressed on the infiltrated mononuclear cells and endothelial cells, and its corresponding receptor, CX3CR1, was expressed on the infiltrated CD4 and CD8 T cells and macrophages. Treatment of EAM mice with anti-CX3CL1 mAb significantly reduced the histopathological myositis score, the number of necrotic muscle fibers, and infiltration of CD4 and CD8 T cells and macrophages. Furthermore, treatment with anti-CX3CL1 mAb down-regulated the mRNA expression of TNF-alpha, IFN-gamma, and perforin in the muscles. Our results suggest that CX3CL1-CX3CR1 interaction plays an important role in inflammatory cell migration into the muscle tissue of EAM mice. The results also point to the potential therapeutic usefulness of CX3CL1 inhibition and/or blockade of CX3CL1-CX3CR1 interaction in idiopathic inflammatory myopathy.     

Inhibition of experimental autoimmune encephalomyelitis by a nonimmunogenic non-self peptide that binds to I-Au.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory neurologic disease initiated by myelin basic protein-reactive CD4+ T cells, which are restricted by a particular MHC class II molecule. Recent studies have utilized inhibitor peptides that bind to restricting MHC class II molecules in order to inhibit EAE, presumably by means of competing with encephalitogenic epitopes. However, these studies leave open the possibility of alternative explanations, such as Ag-specific nonresponsiveness and immunodominance. In order to demonstrate that competition for MHC binding alone can inhibit EAE, the inhibitor peptide should ideally be structurally unrelated and nonimmunogenic yet physically associate with the MHC class II molecule. In this study, we show that the OVA-323-339 peptide, which is unrelated to the disease-inducing peptide, binds to A alpha uA beta u. However, although OVA-323-339 is extremely immunogenic in A alpha dA beta d-expressing BALB/c mice, it is nonimmunogenic in (PL/J x SJL)F1 and PL/J mice expressing A alpha uA beta u. When administered as a coimmunogen with Ac1-11, OVA-323-339 inhibited induction of EAE in (PL/J x SJL)F1 mice. Myelin basic protein-89-101, which does not bind A alpha uA beta u, had no effect on the disease process. This study provides evidence that MHC class II binding alone can modulate the induction of EAE. The use of a nonimmunogenic non-self peptide to modulate an autoimmune disease minimizes the potential complications of immunodominance or alternative regulatory mechanisms associated with immunogenic peptide therapies and further confirms the MHC-blocking model of immunosuppression.     

Monomeric recombinant TCR ligand reduces relapse rate and severity of experimental autoimmune encephalomyelitis in SJL/J mice through cytokine switch

Our previous studies demonstrated that oligomeric recombinant TCR ligands (RTL) can treat clinical signs of experimental autoimmune encephalomyelitis (EAE) and induce long-term T cell tolerance against encephalitogenic peptides. In the current study, we produced a monomeric I-A(s)/PLP 139-151 peptide construct (RTL401) suitable for use in SJL/J mice that develop relapsing disease after injection of PLP 139-151 peptide in CFA. RTL401 given i.v. or s.c. but not empty RTL400 or free PLP 139-151 peptide prevented relapses and significantly reduced clinical severity of EAE induced by PLP 139-151 peptide in SJL/J or (C57BL/6 x SJL)F(1) mice, but did not inhibit EAE induced by PLP 178-191 or MBP 84-104 peptides in SJL/J mice, or MOG 35-55 peptide in (C57BL/6 x SJL/J)F(1) mice. RTL treatment of EAE caused stable or enhanced T cell proliferation and secretion of IL-10 in the periphery, but reduced secretion of inflammatory cytokines and chemokines. In CNS, there was a modest reduction of inflammatory cells, reduced expression of very late activation Ag-4, lymphocyte function-associated Ag-1, and inflammatory cytokines, chemokines, and chemokine receptors, but enhanced expression of Th2-related factors, IL-10, TGF-beta3, and CCR3. These results suggest that monomeric RTL therapy induces a cytokine switch that curbs the encephalitogenic potential of PLP 139-151-specific T cells without fully preventing their entry into CNS, wherein they reduce the severity of inflammation. This mechanism differs from that observed using oligomeric RTL therapy in other EAE models. These results strongly support the clinical application of this novel class of peptide/MHC class II constructs in patients with multiple sclerosis who have focused T cell responses to known encephalitogenic myelin peptides.     

Epitope specificity of autoreactive T and B cells associated with experimental autoimmune encephalomyelitis and optic neuritis induced by oligodendrocyte-specific protein in SJL/J mice

The encephalitogenic potential of oligodendrocyte-specific protein (OSP) in mice, its specific localization in the intralamellar tight junctions in CNS myelin, and the detection of autoreactivity against OSP in multiple sclerosis (MS) strongly suggest the relevance of autoreactivity against OSP in the pathogenesis of MS. In this study, we have characterized the autoimmune T and B cells that are associated with clinicopathological manifestations of OSP-induced MS-like disease in mice by using recombinant soluble mouse OSP (smOSP) and synthetic overlapping peptides spanning smOSP. SJL/J mice immunized with smOSP developed chronic relapsing clinical experimental autoimmune encephalomyelitis accompanied with intense perivascular and parenchymal inflammatory infiltrates, widespread demyelination, axonal loss, and remarkable optic neuritis. The smOSP-primed lymph node cells reacted predominantly against OSP55-80 and to a lesser extent also to OSP22-46 and OSP179-207. Unexpectedly, in vitro selection with smOSP resulted in pathogenic smOSP-specific CD4+ T cells that reacted equally well against OSP55-80, OSP22-46, OSP45-66, and OSP179-207. Fine analysis of the anti-OSP autoimmunity revealed that the disease is primarily associated with CD4+ T cells directed against the major (OSP55-80) and the minor (OSP179-207) encephalitogenic regions that were further delineated, both in vitro and in vivo, to OSP55-66 and OSP194-207, respectively. In contrast, the OSP-induced Abs were predominantly directed against OSP22-46; these Abs were mostly of IgG1 isotype, but high levels of IgG2a and IgG2b and significant levels of IgE were also observed. The reactivity of pathogenic T cells to two encephalitogenic regions, OSP55-80 and OSP179-207, and their diverse TCRVbeta gene repertoire may impose difficulties for epitope-directed or TCR-targeting approaches to immune-specific modulation of OSP-related pathogenesis.     

Adoptively transferred experimental autoimmune encephalomyelitis in SJL/J, PL/J, and (SJL/J x PL/J)F1 mice. Influence of I-A haplotype on encephalitogenic epitope of myelin basic protein

Guinea pig basic protein (GPBP)-immune lymph node cells (LNC) from SJL, PL, and SJL x PL (F1) mice proliferated to whole GPBP and GPBP fragments 1-37, 43-88, and 89-169. All three strains of mice developed experimental allergic encephalomyelitis (EAE) by active immunization with whole GPBP or by passive transfer of LNC cultured with whole GPBP. SJL (H-2s) and PL (H-2u) mice developed EAE by active immunization with fragments 89-169 or 1-37, respectively, or by passive transfer of LNC cultured with the same Ag. F1 mice developed EAE by active immunization only with fragment 1-37 or by passive transfer of LNC cultured with either of the above fragments. Removal of macrophages (MO) from immune-F1 LNC resulted in the loss of a proliferative response and the ability to transfer EAE. Reconstitution of MO-depleted immune F1 T cells with either F1-, SJL-, or PL-MO restored the proliferative responses to whole GPBP and the three fragments. Cultures of immune F1 T cells reconstituted with any of the three MO populations and incubated with whole GPBP passively transferred EAE into naive F1 mice. Immune F1 T cells cultured with F1 MO in the presence of either fragment 1-37 or 89-169 transferred EAE. F1 T cells cultured with SJL MO were able to transfer EAE only if the Ag was fragment 89-169, whereas F1 T cells cultured with PL MO were able to transfer disease only if incubated in the presence of fragment 1-37. F1 mice are passively susceptible to EAE induced by adoptive transfer of cells reactive to either the N-terminal or C-terminal fragment and that the encephalitogenic determinant of GPBP is related to the genome of MO present in vitro.     

Analysis of protein induction in the CNS of SJL mice with experimental allergic encephalomyelitis by proteomic screening and immunohistochemistry.

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease characterized by demyelination and inflammatory infiltrates in the CNS, and it is an animal model of multiple sclerosis. Piperonyl butoxide (PBO) suppresses disease in EAE mice, and it exhibits a dual effect on cytochrome P450s that manifests in a transient inhibitory phase followed by induction. In order to identify the expression of proteins associated with EAE, a proteomic screening was performed on hindbrain microsomes from control + vehicle, control + PBO, EAE + vehicle, and EAE + PBO female mice. Glucose regulated protein 94 (Grp94) and coagulation factor VIII were among the proteins identified in EAE + vehicle and EAE + PBO mice. Immunohistochemical staining of Grp94 was present in some neurons and oligodendrocytes in hindbrain sections from control animals, and in some cells within inflammatory infiltrates in EAE animals. Since Grp94 (also known as Gp96) can partake in antigen presentation and induction of proinflammatory cytokine expression, its presence in these cells suggests that it may play a role in the pathogenesis of EAE. Coagulation factor VIII is carried and protected by von Willebrand factor. Immunohistochemical staining of von Willebrand factor revealed its presence in some vessels within hindbrain sections from control animals. In EAE animals, the number of labeled vessels was significantly increased, and extracellular granular deposits were observed around labeled vessels indicating that the breakdown of the blood-brain barrier that occurs in EAE permitted its extravasation into the CNS. Additional proteins were identified in the different groups of mice by proteomic screening, but confirmation of their expression profile awaits investigations by independent measures.     

Sodium phenylacetate inhibits adoptive transfer of experimental allergic encephalomyelitis in SJL/J mice at multiple steps

Experimental allergic encephalomyelitis (EAE) is the animal model for multiple sclerosis. The present study underlines the importance of sodium phenylacetate (NaPA), a drug approved for urea cycle disorders, in inhibiting the disease process of adoptively transferred EAE in female SJL/J mice at multiple steps. Myelin basic protein (MBP)-primed T cells alone induced the expression of NO synthase (iNOS) and the activation of NF-kappaB in mouse microglial cells through cell-cell contact. However, pretreatment of MBP-primed T cells with NaPA markedly inhibited its ability to induce microglial expression of iNOS and activation of NF-kappaB. Consistently, adoptive transfer of MBP-primed T cells, but not that of NaPA-pretreated MBP-primed T cells, induced the clinical symptoms of EAE in female SJL/J mice. Furthermore, MBP-primed T cells isolated from NaPA-treated donor mice were also less efficient than MBP-primed T cells isolated from normal donor mice in inducing iNOS in microglial cells and transferring EAE to recipient mice. Interestingly, clinical symptoms of EAE were much less in mice receiving NaPA through drinking water than those without NaPA. Similar to NaPA, sodium phenylbutyrate, a chemically synthesized precursor of NaPA, also inhibited the disease process of EAE. Histological and immunocytochemical analysis showed that NaPA inhibited EAE-induced spinal cord mononuclear cell invasion and normalized iNOS, nitrotyrosine, and p65 (the RelA subunit of NF-kappaB) expression within the spinal cord. Taken together, our results raise the possibility that NaPA or sodium phenylbutyrate taken through drinking water or milk may reduce the observed neuroinflammation and disease process in multiple sclerosis patients.     

T- and B-cell nonresponsiveness to self-alphaB-crystallin in SJL mice prevents the induction of experimental allergic encephalomyelitis

The myelin-associated stress protein alphaB-crystallin triggers strong proliferative responses and IFN-gamma production by human T cells and it is considered a candidate autoantigen in multiple sclerosis. In this study we examined the capacity of alphaB-crystallin or peptides derived thereof to induce experimental autoimmune encephalomyelitis (EAE) in SJL mice. Despite extensive efforts to induce EAE using active immunization with whole alphaB-crystallin, using adoptive transfer of lymphocytes or using peptide immunizations, no clinical or histological signs of EAE could be induced. SJL mice were unable to mount proliferative T-cell responses in vitro or delayed-type hypersensitivity responses in vivo to self-alphaB-crystallin. Also, immunization with self-alphaB-crystallin did not lead to any antibody response in SJL mice while bovine alphaB-crystallin triggered clear antibody responses within 1 week. Immunizations with alphaB-crystallin-derived peptides led to the activation of IL-4-producing Th2 cells and only a few IFN-gamma-producing Th1 cells. Peptide-specific T cells showed no cross-reactivity against whole alphaB-crystallin. The inability of SJL mice to mount proinflammatory T-cell responses against self-alphaB-crystallin readily explains the lack of EAE induction by immunization with whole protein or peptides derived from it. T- and B-cell nonresponsiveness is associated with constitutive expression of full-length alphaB-crystallin in both primary and secondary lymphoid organs in SJL mice, which is seen in other mammals as well, but not in humans.     

Suppression of experimental autoimmune encephalomyelitis using peptide mimics of CD28

The B7:CD28/CTLA-4 costimulatory pathway plays a critical role in regulating the immune response and thus provides an ideal target for therapeutic manipulation of autoimmune disease. Previous studies have shown that blockade of CD28 signaling by mAbs can both prevent and exacerbate experimental autoimmune encephalomyelitis (EAE). In this study, we have designed two CD28 peptide mimics that selectively block B7:CD28 interactions. By surface plasmon resonance, both the end group-blocked CD28 peptide (EL-CD28) and its retro-inverso isomer (RI-CD28) compete effectively with the extracellular domain of CD28 for binding to B7-1. Both the CD28 peptide mimics inhibited expansion of encephalitogenic T cells in vitro. A single administration of EL-CD28 or RI-CD28 peptide significantly reduced disease severity in EAE. Importantly, we show that either CD28 peptide mimic administered during acute disease dramatically improved clinical signs of EAE, suppressing ongoing disease. The ratio of CD80:CD86 expression was significantly lower on CD4(+) and F4/80(+) spleen cells in CD28 peptide-treated mice. Peripheral deletion of Ag-specific CD4(+) T cells occurs following in vivo blockade of CD28 with synthetic CD28 peptides.     

Treatment of passive experimental autoimmune encephalomyelitis in SJL mice with a recombinant TCR ligand induces IL-13 and prevents axonal injury

The major goal of this study was to evaluate the efficacy and mechanism of a rTCR ligand (RTL) construct (I-A(s)/proteolipid protein (PLP)-139-151 peptide = RTL401) for treatment of SJL/J mice developing passive experimental autoimmune encephalomyelitis (EAE) that did not involve coimmunization with the highly inflammatory CFA. Our results demonstrated clearly that RTL401 was highly effective in treating passive EAE, with kinetics of recovery from disease very similar to treatment of actively induced EAE. The potent RTL401 treatment effect was reflected by a partial reduction of infiltrating mononuclear cells into CNS, minimal inflammatory lesions in spinal cord, and preservation of axons injured in vehicle-treated mice during the progression of EAE. Interestingly, in the absence of CFA, RTL401 treatment strongly enhanced production of the Th2 cytokine, IL-13, in spleen, blood, and spinal cord tissue, with variable effects on other Th1 and Th2 cytokines, and no significant effect on the Th3 cytokine, TGF-beta1, or on FoxP3 that is expressed by regulatory T cells. Moreover, pretreatment of PLP-139-151-specific T cells with RTL401 in vitro induced high levels of secreted IL-13, with lesser induction of other pro- and anti-inflammatory cytokines. Given the importance of IL-13 for protection against EAE, these data strongly implicate IL-13 as a dominant regulatory cytokine induced by RTL therapy. Pronounced IL-13 levels coupled with marked reduction in IL-6 levels secreted by PLP-specific T cells from blood after treatment of mice with RTL401 indicate that IL-13 and IL-6 may be useful markers for following effects of RTL therapy in future clinical trials in multiple sclerosis.     

E- and P-selectin are not required for the development of experimental autoimmune encephalomyelitis in C57BL/6 and SJL mice

In multiple sclerosis and in its animal model experimental autoimmune encephalomyelitis (EAE), inflammatory cells migrate across the endothelial blood-brain barrier (BBB) and gain access to the CNS. It is well-established that alpha4 integrins are actively involved in leukocyte recruitment across the BBB during EAE. In contrast, the role of endothelial E- and P-selectin in this process has been a controversial issue. In this study, we demonstrate that P-selectin protein can be detected in meningeal blood vessel endothelial cells in healthy SJL and C57BL/6 mice and on rare parenchymal CNS blood vessels in C57BL/6, but not SJL, mice. During EAE, expression of P-selectin but not E-selectin was found up-regulated on inflamed CNS microvessels surrounded by inflammatory infiltrates irrespective of their meningeal or parenchymal localization with a more prominent immunostaining detected in C57BL/6 as compared with SJL mice. P-selectin immunostaining could be localized to CNS endothelial cells and to CD41-positive platelets adhering to the vessel wall. Despite the presence of P-selectin in wild-type mice, E/P-selectin-deficient SJL and C57BL/6 mice developed clinical EAE indistinguishable from wild-type mice. Absence of E- and P-selectin did neither influence the activation of myelin-specific T cells nor the composition of the cellular infiltrates in the CNS during EAE. Finally, endothelial-specific tetracycline-inducible expression of E-selectin at the BBB in transgenic C57BL/6 mice did not alter the development of EAE. Thus, E- and P-selectin are not required for leukocyte recruitment across the BBB and the development of EAE in C57BL/6 and in SJL mice.     

实验性自身免疫性脑脊髓炎小鼠的视神经损害

目的:探讨实验性自身免疫性脑脊髓炎(EAE)的视神经损害以及将其作为视神经炎模型的可能性.方法:取MOG35-55多肽和完全弗氏佐剂制备成抗原乳剂免疫C57BL/6小鼠,并在腹腔内注射2次百日咳杆菌,建立EAE模型.在EAE疾病高峰时,观察小鼠视神经炎的发生率及病理学改变.结果:模型组12只小鼠中有10只从免疫后第12天开始陆续起病,约在第17～19天达到疾病高峰,发病率为83.3%;而对照组未出现任何神经功能受损的症状.HE染色结果显示模型组的视神经组织中有大量的炎症细胞浸润,动物视神经炎的发生率为83.3%,其炎症评分为2.1±0.8分,与对照组相比均有统计学意义.LFB染色可见模型组的视神经有明显的脱髓鞘改变,病灶内可见炎症细胞浸润;而对照组小鼠的视神经未见明显异常改变.结论:借助EAE建立视神经炎模型是可行的,这为深入探讨视神经炎的发病机制提供了理想的动物平台.     

PETIR-001, a dual inhibitor of dipeptidyl peptidase IV (DP IV) and aminopeptidase N (APN), ameliorates experimental autoimmune encephalomyelitis in SJL/J mice

Cellular dipeptidyl peptidase IV (DP IV, CD26) and amino-peptidase N (APN, CD13) play regulatory roles in T cell activation and represent potential targets for treatment of inflammatory disorders. We have developed a novel therapeutic strategy, 'peptidase-targeted Immunoregulation' (PETIR?), which simultaneously targets both cellular DP IV and APN via selective binding sites different from the active sites with a single inhibitor. To prove the therapeutic concept of PETIR? in autoimmunity of the central nervous system (CNS), we evaluated the effect of a single substance, PETIR-001, in an animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE) in SJL/J mice. Administration of PETIR-001 significantly delayed and decreased clinical signs of active EAE, when given in a therapeutic manner intraperitoneally from day 15 to day 24 after induction of EAE. Both the acute phase and the first relapse of EAE were markedly inhibited. Importantly, a similar therapeutic benefit was obtained after oral administration of PETIR-001 from day 12 to day 21 after disease induction. Our results demonstrate that PETIR-001 exhibits a therapeutic effect on EAE in SJL/J mice. Thus, PETIR? represents a novel and efficient therapeutic approach for immunotherapy of CNS inflammation.     

P-selectin glycoprotein ligand 1 is not required for the development of experimental autoimmune encephalomyelitis in SJL and C57BL/6 mice

In multiple sclerosis and in its animal model experimental autoimmune encephalomyelitis (EAE), inflammatory cells migrate across the endothelial blood-brain barrier and gain access to the CNS. The involvement of P-selectin glycoprotein ligand 1 (PSGL-1) and of its major endothelial ligand P-selectin in this process have been controversial. In this study we demonstrate that although encephalitogenic T cells express functional PSGL-1, which can bind to soluble and immobilize P-selectin if presented in high concentrations, PSGL-1 is not involved T cell interaction with P-selectin expressing brain endothelial cells in vitro. Furthermore, neither anti-PSGL-1 Abs nor the lack of PSGL-1 in PSGL-1-deficient mice inhibits the recruitment of inflammatory cells across the blood-brain barrier or the development of clinical EAE. Taken together, our findings demonstrate that PSGL-1 is not required for the pathogenesis of EAE.     

Antibodies specific for VB8 receptor peptide suppress experimental autoimmune encephalomyelitis.

Recent studies from our laboratory have shown, for the first time, that a synthetic peptide from that TCR VB chain used preferentially by encephalitogenic T cells induced the formation of protective, MHC class I-restricted T cells and prevented the development of EAE in Lewis rats. In this report we 1) demonstrate that immunization with the TCR-VB8-39-59 peptide generated peptide-specific antibodies that protect against experimental autoimmune encephalomyelitis induced by either of the two distinct encephalitogenic epitopes of basic protein, and 2) characterize the production and biologic functions of rat and rabbit antibody responses to the TCR peptide. The antibodies in both species increased in titer over time, were highly specific for the immunogen by direct reaction and inhibition assays, stained only VB8+ T cells, and suppressed clinical signs and to lesser extent the number of histologic lesions of experimental autoimmune encephalomyelitis mediated by VB8+ T cells. Coupled with our previous work, these results indicate that both humoral and cellular responses to the TCR-VB8-39-59 peptide can contribute independent immunoregulatory effects on encephalitogenic T lymphocytes that use common V region genes in response to epitopes of myelin basic protein.