Biochemical and immunogenetic analysis of an immunodominant peptide (B6dom1) encoded by the classical H7 minor histocompatibility locus

Of the many minor histocompatibility (H) Ags that have been detected in mice, the ability to induce graft vs host disease (GVHD) after bone marrow transplantation is restricted to a limited number of immunodominant Ags. One such murine Ag, B6dom1, is presented by the H2-Db MHC class I molecule. We present biochemical evidence that the natural B6dom1 peptide is indistinguishable from AAPDNRETF, and we show that this peptide can be isolated from a wide array of tissues, with highest levels from the lymphoid organs and lung. Moreover, we employ a novel, somatic cell selection technique involving CTL-mediated immunoselection coupled with classical genetics, to show that B6dom1 is encoded by the H7 minor H locus originally discovered approximately 40 years ago. These studies provide a molecular genetic framework for understanding B6dom1, and exemplify the fact that mouse minor H loci that encode immunodominant CTL epitopes can correspond to classical H loci originally identified by their ability to confer strong resistance to tumor transplantation. Additionally, these studies demonstrate the utility of somatic cell selection approaches toward resolving H Ag immunogenetics.     

Identification of candidate susceptibility and resistance genes of mice infected with Streptococcus suis type 2

Streptococcus suis type 2 (SS2) is an important swine pathogen and zoonosis agent. A/J mice are significantly more susceptible than C57BL/6 (B6) mice to SS2 infection, but the genetic basis is largely unknown. Here, alterations in gene expression in SS2 (strain HA9801)-infected mice were identified using Illumina mouse BeadChips. Microarray analysis revealed 3,692 genes differentially expressed in peritoneal macrophages between A/J and B6 mice due to SS2 infection. Between SS2-infected A/J and control A/J mice, 2646 genes were differentially expressed (1469 upregulated; 1177 downregulated). Between SS2-infected B6 and control B6 mice, 1449 genes were differentially expressed (778 upregulated; 671 downregulated). These genes were analyzed for significant Gene Ontology (GO) categories and signaling pathways using the Kyoto Encylopedia of Genes and Genomes (KEGG) database to generate a signaling network. Upregulated genes in A/J and B6 mice were related to response to bacteria, immune response, positive regulation of B cell receptor signaling pathway, type I interferon biosynthesis, defense and inflammatory responses. Additionally, upregulated genes in SS2-infected B6 mice were involved in antigen processing and presentation of exogenous peptides, peptide antigen stabilization, lymphocyte differentiation regulation, positive regulation of monocyte differentiation, antigen receptor-mediated signaling pathway and positive regulation of phagocytosis. Downregulated genes in SS2-infected B6 mice played roles in glycolysis, carbohydrate metabolic process, amino acid metabolism, behavior and muscle regulation. Microarray results were verified by quantitative real-time PCR (qRT-PCR) of 14 representative deregulated genes. Four genes differentially expressed between SS2-infected A/J and B6 mice, toll-like receptor 2 (Tlr2), tumor necrosis factor (Tnf), matrix metalloproteinase 9 (Mmp9) and pentraxin 3 (Ptx3), were previously implicated in the response to S. suis infection. This study identified candidate genes that may influence susceptibility or resistance to SS2 infection in A/J and B6 mice, providing further validation of these models and contributing to understanding of S. suis pathogenic mechanisms.     

Adoptive transfer of minor histocompatibility antigen-specific T lymphocytes eradicates leukemia cells without causing graft-versus-host disease.

Adoptive transfer of T cells reactive to minor histocompatibility antigens has the unmatched ability to eradicate malignant hematopoietic cells. Unfortunately, its use is hampered by the associated graft-versus-host disease. The critical issue of a possible dissociation of the antileukemic effect and graft-versus-host disease by targeting specific minor histocompatibility antigens remains unresolved because of the unknown nature and number of minor histocompatibility antigens necessary or sufficient to elicit anti-leukemic activity and graft-versus-host disease. We found that injection of T lymphocytes primed against a single major histocompatibility complex class I-restricted immunodominant minor histocompatibility antigen (B6dom1) caused no graft-versus-host disease but produced a curative anti-leukemic response. Avoidance of graft-versus-host disease required that no other host-reactive T cells be co-injected with T cells primed with B6dom1. Here we show that effective and non-toxic immunotherapy of hematologic malignancies can be achieved by targeting a single immunodominant minor histocompatibility antigen.     

Immunization of mice with vaccinia virus-M2 recombinant induces epitope-specific and cross-reactive Kd-restricted CD8+ cytotoxic T cells.

The M2 protein of respiratory syncytial virus (RSV) is a protective antigen in H-2d, but not H-2b or H-2k mice. None of the other RSV proteins, excluding the surface glycoproteins that induce neutralizing antibodies, is protective in mice bearing these haplotypes. Thus, the M2 protein stands alone as a nonglycoprotein-protective antigen of RSV. The M2 protein is a target for murine Kd-restricted cytotoxic T lymphocytes (CTLs), and the resistance induced by infection with a vaccinia virus-RSV M2 (vac-M2) recombinant is mediated by CD8+ CTLs. Since the nonameric consensus sequence for H-2 Kd-restricted T-cell epitopes and the amino acid sequence of the M2 protein of subgroup A and B strains of RSV are known, the present study sought to identify the specific epitope(s) on the M2 protein recognized by CD8+ CTLs. This was done by examining the ability of four predicted Kd-specific motif peptides present in the M2 amino acid sequence of an RSV subgroup A strain to sensitize target cells for lysis by pulmonary or splenic CTLs obtained from mice infected with RSV or vac-M2. The following observations were made. First, two of the four peptides sensitized target cells for lysis by pulmonary or splenic CTLs induced by infection with either vac-M2 or RSV. Second, one of the two peptides, namely the 82-90 (M2) peptide, sensitized targets at a very low peptide concentration (10(-10) to 10(-12) M). Third, cold-target competition experiments revealed that the predominant CTL population induced by infection with vac-M2 or RSV recognized the 82-90 (M2) peptide, and this CTL population appeared to recognize the 71-79 (M2) peptide in a cross-reactive manner. Fourth, CTL recognition of targets sensitized with either the 71-79 (M2) or the 82-90 (M2) peptide was Kd restricted. Fifth, CTLs induced by infection with RSV subgroup A or B strains recognized the two M2 peptides. The findings suggest that the M2 protein of RSV contains an immunodominant Kd-restricted CTL epitope consisting of amino acid residues 82 to 90 (SYIGSINNI), which are shared by subgroup A and B RSVs.     

Maternally transmitted histocompatibility antigen of mice: a hydrophobic peptide of a mitochondrially encoded protein

MTF, a murine minor histocompatibility antigen, is maternally inherited and thought to be encoded by a mitochondrial gene. We sequenced the entire mitochondrial genomes from three strains that differ in MTF Mtf beta, Mtf gamma, and Mtf delta) and compared the sequences with the known, Mtf alpha, mitochondrial DNA sequence. We found only one site where all four genomes differed, affecting amino acid residue 6 of ND1, a subunit of NADH dehydrogenase. Incubation of non-Mtf alpha target cells with synthetic peptide ND1 alpha 1-17 (the first 17 amino acid of the ND1 protein of Mtf alpha mice) rendered them susceptible to lysis by MTF alpha-specific cytotoxic T cells (CTLs). Similarly, non-Mtf beta target cells were lysed by MTF beta-specific CTLs after incubation with the allelic form ND1 beta 1-17. Thus, Mtf is attributable to allelic variation at a single residue of the ND1 protein. Cells can therefore display peptides derived from mitochondrially encoded proteins, and such peptides can be histocompatibility antigens.     

Polyhistidine-tagged hepatitis B core particles as carriers of HIV-1/gp120 epitopes of different HIV-1 subtypes

The hepatitis B core antigen is a widely accepted carrier particle to enhance the immunogenicity of foreign epitopes. From electron cryomicroscopy, the immunodominant region between amino acid positions 79 to 81 is known to protrude from the surface of the shells. It can be replaced by heterologous sequences without interfering with the particle-forming capacity in many cases. Here we have introduced various V3 sequences of the envelope protein of different subtypes (A, B, O) of HIV-1/gp120 in order to enhance their immunogenicity and broaden the immune response against the virus. To improve purification efficiency and solubility of the E. coli-expressed hybrids, six histidine residues were fused to amino acid 156. An adjustable purification scheme was utilised including denaturation, Ni(2+)-NTA affinity chromatography and particle renaturation under high salt conditions, resulting in highly pure antigen preparations. The hybrids reacted specifically with sera of HIV-1-infected patients. They further induced an autologous, subtype-specific anti-HIV-1 antibody response superior to that of Keyhole limpet-haemocyanine-coupled peptides.     

Genetic attachment of undecane peptides to ovomucoid third domain can suppress the production of specific IgG and IgE antibodies

An undecane peptide (Gly-Ser-Pro-Gly-Ile-Pro-Gly-Ser-Thr-Gly-Met) was genetically attached to the N-terminus of ovomucoid third domain (DIII) to investigate structural characteristics of linear IgE and IgG (B cell) epitopes in DIII with respect to modulation of the immune response towards antigenicity and allergenicity. Balb/c mice were sensitized with native DIII, wild type recombinant DIII, and recombinant modified DIII containing the extra amino acid stretch. The immune responses to the antigens were compared using enzyme-linked immunosorbent assay. Interestingly, specific IgE and IgG levels were suppressed when the modified DIII was used as antigen. This was further confirmed by synthesizing immunodominant IgE and IgG epitopes of DIII on cellulose acetate membrane (SPOTs) and probing them with antibodies raised against DIII antigens. Anti-recombinant wild type DIII anti-serum showed strong binding activities to immunodominant IgE and IgG epitopes, while anti-modified DIII serum did not show any significant binding to the IgE and IgG epitopes. Thus, it is clearly demonstrated that the amino acid stretch in DIII is masking the immune reactive epitope. Genetical attachment of peptides into DIII was found to be effective in reducing the production of specific IgE and IgG antibodies in mice.     

Diversity in fine specificity and T cell receptor usage of the human CD4+ cytotoxic T cell response specific for the immunodominant myelin basic protein peptide 87-106.

Multiple sclerosis (MS), a human demyelinating disease, is thought to be caused by an autoimmunologic process, and myelin basic protein (MBP) is considered a likely autoantigen. Studies of T cell lines (TCL) responding to different parts of the MBP molecule have indicated that amino acids 87 through 106 contain an immunodominant epitope of MBP. We have demonstrated previously that amino acids 89 through 99 represent the core of this 87-106 peptide epitope. Importantly, this epitope is not only encephalitogenic in SJL/J mice and Lewis rats but also has been shown to be recognized by human cytotoxic TCL in the context of four HLA-DR molecules that are associated with MS in different geographic areas. If the immune response to MBP peptide 87-106 was homogeneous with respect to epitope specificity and TCR usage, specific immunotherapies targeting the interaction of peptide, MHC, and TCR might be possible. In this study, the fine specificity of 29 CD4+ cytotoxic, long term, and limiting dilution TCL that had been generated against whole MBP and were derived from four MS patients and two healthy relatives was dissected using truncated and alanine-substituted peptides for the 87-106 peptide. In addition, the TCR alpha and beta chain usage of 15 CD4+ TCL was determined. Using truncated peptides, the presence of several nested immunogenic epitopes within amino acids 87 to 106 was demonstrated. TCL with identical restriction elements and similar responses to truncated peptides could be differentiated further using alanine-substituted peptides. Finally, heterogeneity of TCR usage was shown not only for those lines that differed in their peptide specificity but also for some that showed identical responses and were restricted by the same HLA-DR antigen. In conclusion, the CD4+ cytotoxic T cell response to the immunodominant MBP peptide 87-106 demonstrates a high degree of heterogeneity at the level of fine specificity and TCR usage. These findings indicate that specific immunotherapies aimed at TCR in MS will probably be more complicated than previously anticipated.     

Retro-inverso peptide analogues of Trypanosoma cruzi B13 protein epitopes fail to be recognized by human sera and peripheral blood mononuclear cells

Retro inverso (RI) analogues of antigenic synthetic peptides, which are made of D-amino acids with a reversed sequence, may mimic the side chain conformation of natural all-L peptides. RI analogues were cross-reactively recognized by antibodies and CD4+ T cells reactive against natural all-L synthetic peptides or native proteins in animal models. Since peptides containing D-amino acids are highly resistant to proteolytic digestion, cross-reactive RI analogues may be ideal for in vivo administration to humans as synthetic peptide vaccines or immunomodulators. B13 is an immunodominant tandemly repetitive protein from Trypanosoma cruzi, a protozoan parasite that is the causative antigen of Chagas' disease. In order to test whether RI peptides can be recognized by human antibody and T cells, we synthesized two all-L peptides containing the immunodominant B (S12) and T (S15.7) cell epitopes of B13 protein from T. cruzi and their retro (R, made of all-L amino acids with reversed sequence), inverso (I, made of all-D amino acids) and RI analogues. Recognition of peptides S12, S12-R, S12-I and S12-RI by anti-B13 antibodies in sera from T. cruzi-infected patients was tested in competitive ELISA assay with recombinant B13 protein as the solid phase antigen. Peptides S15.7 and its topological analogues were tested at the 10-50 microM range in proliferation assays on peripheral blood mononuclear cells (PBMC) from S15.7-responder individuals. The median percentage inhibition of B13 ELISA for peptide S12 was 94%, while those of the RI analogue or the other topological analogues were below 12%. While peptide S15.7 was recognized by PBMC from all subjects tested, none recognized the RI analogue of the S15.7 T cell epitope. Our results indicate that cross-reactivity with natural epitopes is not an universal property of RI analogues. This may limit the general applicability of the use of cross-reactive RI analogues as human vaccines and immunotherapeutic agents.     

Neutrophil elastase cleaves the murine hemidesmosomal protein BP180/type XVII collagen and generates degradation products that modulate experimental bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease associated with autoantibodies against the hemidesmosomal proteins BP180 and BP230. In the IgG passive transfer model of BP, blister formation is triggered by anti-BP180 IgG and depends on complement activation, mast cell degranulation, and neutrophil recruitment. Mice lacking neutrophil elastase (NE) do not develop experimental BP. Here, we demonstrated that NE degrades recombinant mouse BP180 within the immunodominant extracellular domain at amino acid positions 506 and 561, generating peptide p561 and peptide p506. Peptide p561 is chemotactic for neutrophils both in vitro and in vivo. Local injection of NE into B6 mice recruits neutrophils to the skin, and neutrophil infiltration is completely blocked by co-injection with the NE inhibitor α1-proteinase inhibitor. More importantly, NE directly cleaves BP180 in mouse and human skin, as well as the native human BP180 trimer molecule. These results demonstrate that (i) NE directly damages the extracellular matrix and (ii) NE degradation of mouse BP180 generates neutrophil chemotactic peptides that amplify disease severity at the early stage of the disease.     

Linear epitopes of the replication-activator protein of Epstein-Barr virus recognised by specific serum IgG in nasopharyngeal carcinoma

The linear antigenic epitopes of the Epstein-Barr virus replication activator protein (ZEBRA), recognised by specific serum IgG in nasopharyngeal carcinoma (NPC), were determined. This was achieved by synthesizing the entire amino acid sequence of ZEBRA as a set of 29, 22-residue peptides with an overlap of 14 amino acids. The ZEBRA peptides were tested in enzyme-linked immunosorbent assay (ELISA) for IgG binding in sera from 37 selected NPC patients who had IgG antibodies to the native ZEBRA protein. The most immunogenic epitope was peptide 1 at the amino-terminal end with 36 of the sera reactive against it. Further analysis of peptide 1, using the multipin peptide-scanning technique, defined a 10-amino-acid sequence FTPDPYQVPF, which was strongly bound by IgG. Two other regions of ZEBRA were also identified as immunodominant IgG epitopes, namely peptide 11 (amino acids 82–103) and peptide 19/20 (amino acids 146–175) with 8–13 of the NPC sera reactive against the peptides. The number of peptides reactive with individual NPC serum varies from 1 to 6 or more and there is some correlation between a greater number of peptide (at least 4) bound and a higher (at least 1:40) titre of serum IgA to viral capsid antigen. The immunodominant ZEBRA peptide 1 could be utilised in IgG ELISA for the detection of NPC.     

Mass spectrometrical characterisation of mouse and rat synapsin isoforms 2a and 2b

Synapsin 2 proteins are key elements of the synaptic machinery and still hold the centre stage in neuroscience research. Although fully sequenced at the nucleic acid level in mouse and rat, structural information on amino acid sequences and post-translational modifications (PTMs) is limited. Knowledge on protein sequences and PTMs, however, is mandatory for several purposes including conformational studies and the generation of antibodies. Hippocampal proteins from rat and mouse were extracted, run on two-dimensional gel electrophoresis and multi-enzyme digestion was carried out to generate peptides for mass spectrometrical analysis [nano-LC-ESI-(CID/ETD)-MS/MS]. As much as 12 synapsin 2 proteins (6 alpha and 6 beta isoforms) in the mouse and 13 synapsin 2 proteins (6 alpha and 7 beta isoforms) were observed in the rat. Protein sequences were highly identical to nucleic acid sequences, and only few amino acid exchanges probably representing polymorphisms or sequence conflicts were detected. Mouse and rat synapsins 2a differed in three amino acids, while rat and mouse synapsins 2b differed in two amino acids. As much as 13 phosphorylation sites were determined by MS/MS data in rat and mouse hippocampus and 5 were verified by phosphatase treatment. These findings are important for interpretation of previous results and design of future studies on synapsins.     

Mapping of B cell epitopes in an immunodominant antigen of Trypanosoma cruzi using fusions to the Escherichia coli LamB protein

The JL8 protein antigen from Trypanosoma cruzi, a dominant immunogen in man, has been characterized as containing tandem amino acid repeats. Here, we describe the use of the LamB protein of Escherichia coli as a carrier of JL8 derived sequences in order to map the immunodominant B cell epitopes in this antigen. Five different sequences of JL8 were inserted in the LamB protein and the JL8-LamB fusion proteins were tested by ELISA with human chronic chagasic sera. The fusion carrying the sequence AEKQKAAEATKVAE was recognized by most sera. This protein was also capable of inhibiting the binding of human chagasic antibodies to GST-JL8 in competitive ELISA suggesting that it contains an immunodominant B cell epitope of JL8.     

丙型肝炎病毒核壳蛋白抗原的化学合成及其在血清学诊断中的应用

选取丙型肝炎病毒(HCV)核壳蛋白区两个可能含有优势抗原表位的19和16氨基酸的肽殴(C-19肽和C-16肽),利用固相多肽合成技术进行了化学合成。经用反相高压液相层析(HPLC)及脉冲液相多肽测序技术检定合成肽产品的纯度及序列后,以C-19和C-16肽作为包被抗原组装成检测HCV血清抗体的ELISA诊断试剂。用所组装的合成肽试剂检测中国药品生物制品检定所提供的HCV标准参比血清,并比较利用该试剂和美国Abbott实验室生产的HCV第二代EIA诊断试剂平行检测109份献血员血清的结果,表明C-19肽能够特异、重复、灵敏地检出HCV血清抗体,可以作为我国第一代HCV诊断试剂的合成肽抗原。     

Silencing of immunodominant epitopes by contiguous sequences in complex synthetic peptides.

We have previously shown that the T cell response to the synthetic peptide cI12-26:NP365-380 (covalently linked epitopes of lambda repressor (cI) and influenza A nucleoprotein (NP) polypeptides) requires amino acid sequences located in the junctional region between the cI12-26 and NP365-380 epitopes in the H-2d and H-2k haplotypes. In this study, we show that the dominant epitope of cI12-26:NP365-380 in H-2b mice is also located within the junctional region of the peptide, indicating that the same amino acid sequence is immunodominant in three different H-2 haplotypes. Based on results using fixed APC, there was no qualitative difference in epitope recognition due to antigen processing. In addition, antigen presentation by APC expressing mutant I-A molecules constructed by hemiexon shuffling of regions of the molecule containing primarily beta sheet or alpha helix showed that many different substitutions were permissive for at least one of the T hybridomas. More importantly, however, when the junctional sequences are covalently linked in composite synthetic peptides containing additional previously defined T cell epitopes, antigenicity of the immunodominant junctional region was silenced and a new epitope assumed immunodominance. Thus, immunodominance does not correlate with the primary amino acid sequence of the potential epitope. Instead, the immunodominant epitope is determined by complex interactions among the epitopes, which most likely depend on the structural conformation of the composite peptide.     

Immunodominance in the T cell response to multiple non-H-2 histocompatibility antigens. IV. Partial tissue distribution and mapping of immunodominant antigens

The immunization of C57BL/6 responder mice with spleen cells from H-2-matched BALB.B donors, which differ by multiple non-H-2 histocompatibility (H) antigens, results in the generation of cytotoxic T lymphocytes (CTL) that are specific for only a limited number of immunodominant antigens. Previous analysis of the genes encoding these dominant antigens has not mapped these genes to any of the non-H-2 H loci defined by congenic strains. It would have been expected that the histogenetic techniques employed for congenic strain selection would have preferentially identified the "strongest" H antigens. Therefore, we have investigated the possibility that immunodominant antigens do not belong to the class of non-H-2 H antigens encoded by genes mapping to H loci defined and mapped by congenic strains. The first experiments were aimed at identifying antigens that were expressed by independently derived inbred strains and were cross-reactive with the immunodominant cytotoxic T cell target (CTT-1) antigen of BALB.B. Strong cross-reaction with the C3H.SW (H-2b) strain was observed; the C3H gene encoding this antigen was mapped with BXH recombinant inbred strains. Contrary to the mapping of the CTT-1 gene to chromosome 1 in BALB.B, the C3H gene was shown to map to either chromosome 4 or chromosome 7. This result indicates that identical, or at least extensively cross-reactive, non-H-2 antigens may be encoded by genes mapping to independently segregating loci in different inbred strains. The tissue distribution of immunodominant antigens was approached by determining the reactivity of CTL specific for these antigens with either lymphoid-derived or fibroblast-derived targets. These CTL effectively lysed lymphoblast and lymphoid tumor targets but did not lyse an SV40-transformed fibroblast line that was shown to be efficiently lysed by CTL specific for non-H-2 H antigens defined by congenic strains. Therefore, it was concluded that immunodominant antigens detected by B6 anti-BALB.B CTL have a restricted tissue distribution in comparison to non-H-2 H antigens defined by congenic strains. The implications of these results for our understanding of the origin and heterogeneity of non-H-2 cell-surface antigen recognized by effector T cells are discussed.     

N-terminal amino acid sequence of the Borrelia burgdorferi flagellin

Abstract The 41 kDa flagellar protein of Borrelia burgdorferi appears to be an immunodominant antigen producing an early and strong response in most, if not all, individuals during infection in humans. It would represent a very good antigen for serodiagnosis of Lyme disease, if its crossreactivity with flagella of other bacteria was low. To gain information on this point we isolated the B. burgdorferi flagellin by preparative two-dimensional electrophoresis for N-terminal amino acid analysis. By comparing the N-terminal amino acid sequences of flagellar proteins from other eubacteria we found that the first six out of twenty nine amino acids were identical to the Treponema pallidum and Treponema phagedenis 'class B' flagellins. All 29 N-terminal residues exhibited a moderate inter-genus homology (44–55%), in contrast to the high degree (67–95%) of inter-species conservation of the treponemal 'class B' flagellar N-terminal sequences. There was little similarity to other flagellins except the B. subtilis flagellar protein.     

CD8 T cell responses to myelin oligodendrocyte glycoprotein-derived peptides in humanized HLA-A*0201-transgenic mice

Multiple sclerosis (MS) is a demyelinating inflammatory disease of the CNS. Though originally believed to be CD4-mediated, additional immune effector mechanisms, including myelin-specific CD8(+) T cells, are now proposed to participate in the pathophysiology of MS. To study the immunologic and encephalitogenic behavior of HLA-A*0201-binding myelin-derived epitopes in vivo, we used a humanized HLA-A*0201-transgenic mouse model. Eight HLA-A*0201-binding peptides derived from myelin oligodendrocyte glycoprotein (MOG), an immunodominant myelin self-Ag, were identified in silico. After establishing their relative affinity for HLA-A*0201 and their capacity to form stable complexes with HLA-A*0201 in vitro, their immunological characteristics were studied in HLA-A*0201-transgenic mice. Five MOG peptides, which bound stably to HLA-A*0201 exhibited strong immunogenicity by inducing a sizeable MOG-specific HLA-A*0201-restricted CD8(+) T cell response in vivo. Of these five candidate epitopes, four were processed by MOG-transfected RMA target cells and two peptides proved immunodominant in vivo in response to a plasmid-encoding native full-length MOG. One of the immunodominant MOG peptides (MOG(181)) generated a cytotoxic CD8(+) T cell response able to aggravate CD4(+)-mediated EAE. Therefore, this detailed in vivo characterization provides a hierarchy of candidate epitopes for MOG-specific CD8(+) T cell responses in HLA-A*0201 MS patients identifying the encephalitogenic MOG(181) epitope as a primary candidate.