J. Goverman - Academia.edu (original) (raw)

Papers by J. Goverman

Research paper thumbnail of 2-D Diagonal Gel Electrophoresis

2-D Proteome Analysis Protocols

Research paper thumbnail of Protein Administration of Myelin Basic TCR-Transgenic Mice After Oral Antigen-Specific T Cells in Rapid Depletion of Peripheral

Research paper thumbnail of Model genomes: The benefits of analysing homologous human and mouse sequences

Trends in Biotechnology, 1992

Research paper thumbnail of T cell regulation within the CNS

Journal of Neuroimmunology, 1998

Objective: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous syste... more Objective: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) postulated to be a Thl-type T-cell mediated autoimmune disease. IFN~7, a cytokine that is the hallmark of Th 1 type immune responses, appears to play an important role in disease pathogenesis as increased production of IFN-yprecedes clinical attacks and treatment of MS patients with recombinant IFN-7 induced exacerbations of the disease. Chemokines zce essential for inflammatory responses. Recent data suggest that there is a bias in expression of selected chemokine receptors by Thl cells (CXCR3 and CCR5 positive) compared to Th2 cloned cells (CCR3 and CCR4 positive).

Research paper thumbnail of A Pathogenic Role for Myelin-Specific Cd8+ T Cells in a Model for Multiple Sclerosis

The Journal of Experimental Medicine, 2001

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) characteri... more Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) characterized by plaques of infiltrating CD4+ and CD8+ T cells. Studies of MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS, focus on the contribution of CD4+ myelin-specific T cells. The role of CD8+ myelin-specific T cells in mediating EAE or MS has not been described previously. Here, we demonstrate that myelin-specific CD8+ T cells induce severe CNS autoimmunity in mice. The pathology and clinical symptoms in CD8+ T cell–mediated CNS autoimmunity demonstrate similarities to MS not seen in myelin-specific CD4+ T cell–mediated EAE. These data suggest that myelin-specific CD8+ T cells could function as effector cells in the pathogenesis of MS.

Research paper thumbnail of A Molecular Map of T Cell Development

Immunity, 1998

; Fehling and von Boehmer, 1997). Early * Section of Immunology stages of thymocyte development a... more ; Fehling and von Boehmer, 1997). Early * Section of Immunology stages of thymocyte development are clearly defined Yale University School of Medicine by several molecular events that include expression of Howard Hughes Medical Institute the RAG-1 and RAG-2 gene products (Lin and Desiderio, New Haven, Connecticut 06520-8011 1993; Ferguson et al., 1994; Hoffman et al., 1996), so-† Laboratory of Immunology matic rearrangement of the T cell receptor ␤ chain locus, National Institute of Allergy and Infectious Diseases expression of the coreceptor molecules CD4 and CD8, National Institutes of Health and, finally, recombination of the TCR ␣ locus (Dudley Bethesda, Maryland 20892 et al., 1994; Petrie et al., 1995). Productive rearrange-‡ Department of Molecular Biotechnology ment of both TCR chains allows surface expression of University of Washington School of Medicine the TCR and ensures life up to this point. Further devel-Seattle, Washington 98195-7650 opment, however, relies in part (Tourigny et al., 1997) upon signals generated by TCR interaction with MHC: self peptide complexes (von Boehmer, 1994). Most thy-Summary mocytes fail this rigorous criterion for selection and die of neglect (Janeway, 1994). Using a sensitive molecular marker for positive selec-While the early events in development can be clearly tion, the appearance of a particular functional TCR ␣ defined by molecular events, later stages of developchain sequence in cells from mice bearing a transgenic ment are typically defined by variations in the expression levels of cell surface proteins such as CD4, CD8, and ␤ chain, we address several aspects of intrathymic T the TCR. These molecules allow for several different cell development. First, by examining specific TCR intrathymic subpopulations to be distinguished. The deprior to and after maturation, we demonstrate how a velopmental status of such populations has been, in restricted TCR repertoire is positively selected from most cases, assessed by other means including intraa highly diverse immature TCR repertoire. Second, thymic injections of genetically marked cells and reconsince this molecular marker is enriched in cells prostitution of thymocytes in irradiated mice. gressing toward the CD4 lineage and depleted in cells In this report, we identify a sensitive molecular marker progressing toward the CD8 lineage, a map of the for positive selection. This marker, which is the appeardevelopmental pathway of ␣␤ thymocytes can be inance or loss of a specific TCR ␣ chain sequence, is used ferred. Third, the first cells that show clear signs of to address three issues concerning the development of positive intrathymic selection are identified. TCR␣␤ bearing thymocytes. First, we demonstrate that the restriction of TCR usage that was apparent in the mature repertoire in "single-peptide" mice bearing a Peptide-Specific Responses of Nonimmunized TCR ␤ Chain Transgenic Thymocytes § To whom correspondence should be addressed (e-mail: derek.

Research paper thumbnail of Separately expressed T cell receptor α and β chain transgenes exert opposite effects on T cell differentiation and neoplastic transformation

European Journal of Immunology, 1997

Two aspects of T cell differentiation in T cell receptor (TCR)‐transgenic mice, the generation of... more Two aspects of T cell differentiation in T cell receptor (TCR)‐transgenic mice, the generation of an unusual population of CD4−CD8−TCR+ thymocytes and the absence of γδ cells, have been the focus of extensive investigation. To examine the basis for these phenomena, we investigated the effects of separate expression of a transgenic TCR α chain and a transgenic TCR β chain on thymocyte differentiation. Our data indicate that expression of a transgenic TCR α chain causes thymocytes to differentiate into a CD4−CD8−TCR+ lineage at an early developmental stage, depleting the number of thymocytes that differentiate into the αβ lineage. Surprisingly, expression of the TCR α chain transgene is also associated with the development of T cell lymphosarcoma. In contrast, expression of the transgenic TCR β chain causes immature T cells to accelerate differentiation into the αβ lineage and thus inhibits the generation of γδ cells. Our observations provide a model for understanding T cell different...

Research paper thumbnail of Chimeric immunoglobulin-T cell receptor proteins form functional receptors: Implications for T cell receptor complex formation and activation

Cell, 1990

We constructed chimeric receptor chains in which an immunoglobulin heavy chain variable region (V... more We constructed chimeric receptor chains in which an immunoglobulin heavy chain variable region (V,) from a phosphorylcholine-specific antibody is substituted for T cell receptor (Tcr) a and 3 V regions. We demonstrate that the VH region joined to either the C, or the CB region can form stable chime& proteins in EL4 T cells. Both chimeric receptor chains associate with CD3 polypeptides in functional receptor complexes and respond to phosphorylcholine coupled to Sepharose beads. The V&Z, chimeric chain associates with the EL4 f3 chain, while the Vu-C, chimeric protein appears to form either a homodimer or a heterodimer with the native EL4 p chain. Thus, functional receptor complexes can be formed using two C, regions, and the C, region may not be required for CD3 association and surface expression of Tcr complexes.

Research paper thumbnail of A speculative view of the multicomponent nature of T cell antigen recognition

Cell, 1986

Recent data on the molecular biology of T cells have given us a detailed view of the genes and pr... more Recent data on the molecular biology of T cells have given us a detailed view of the genes and proteins involved in antigen recognition by T cells. T and B cells are responsible for specific antigen recognition in the vertebrate immune response. B cells recognize free antigen through cell surface-bound immunoglobulin (lg) with no other requirement except antigen/receptor complementarity. T cells recognize antigen only when it is presented on the cell surface in the context of class I or class II molecules

Research paper thumbnail of Implications of the Diversity of the Immunoglobulin Gene Superfamily

Cold Spring Harbor Symposia on Quantitative Biology, 1989

Research paper thumbnail of TCR signaling regulates thymic organization: lessons from TCR-transgenic mice

Research paper thumbnail of T cell deletion in high antigen dose therapy of autoimmune encephalomyelitis

Science, 1994

Encounters with antigen can stimulate T cells to become activated and proliferate, become nonresp... more Encounters with antigen can stimulate T cells to become activated and proliferate, become nonresponsive to antigen, or to die. T cell death was shown to be a physiological response to interleukin-2-stimulated cell cycling and T cell receptor reengagement at high antigen doses. This feedback regulatory mechanism attenuates the immune response by deleting a portion of newly dividing, antigen-reactive T cells. This mechanism deleted autoreactive T cells and abrogated the clinical and pathological signs of autoimmune encephalomyelitis in mice after repetitive administration of myelin basic protein.

Research paper thumbnail of An immunoglobulin promoter region is unaltered by DNA rearrangement and somatic mutation during B-cell development

Nucleic Acids Research, 1982

The V1 gene encodes the heavy chain variable region of antibodies that bind to phosphorylcholine ... more The V1 gene encodes the heavy chain variable region of antibodies that bind to phosphorylcholine in the Balb/c mouse. V1 genes have been cloned from mouse sperm DNA, an IgM-producing tumor HPCM2 and an IgA-producing tumor M167. The transcription start site of the V1 gene has been mapped 63 +/- 1 base pairs from the coding sequence for both alpha and mu transcripts. Comparison of flanking DNA sequence 574 base pairs 5' to the V1 transcription start site in sperm, HPCM2 and M167 DNA reveals that sperm and HPCM2 sequences are completely identical in this region and the M167 sequence differs from them by a single base change. Although the coding region of the V1 gene has undergone a high (4%) rate of somatic mutation in M167 we demonstrate that the somatic mutation mechanism stops near the transcription start site. These results demonstrate that initiation of V1 gene transcription remains unchanged with respect to location and 5' sequences throughout B-cell development.

Research paper thumbnail of Separation of disulfide-bonded polypeptides using two-dimensional diagonal gel electrophoresis

Research paper thumbnail of Regulatory T Cells Maintain Long-Term Tolerance to Myelin Basic Protein by Inducing a Novel, Dynamic State of T Cell Tolerance

The Journal of Immunology, 2007

Research paper thumbnail of Age-Dependent T Cell Tolerance and Autoimmunity to Myelin Basic Protein

Immunity, 2001

Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, is induc... more Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, is induced by activating a subset of myelin basic protein (MBP)-specific T cells that have escaped tolerance induction. Here, we define the tolerance mechanisms that eliminate the majority of MBP-specific T cells from the periphery. We show that MBP-specific T cells undergo central tolerance mediated by bone marrow-derived antigen-presenting cells presenting exogenously derived MBP epitopes. The efficiency of tolerance is age dependent, reflecting the developmentally regulated expression of MBP. Dependence of tolerance on the amount of MBP expressed in vivo results in an age window of susceptibility to EAE in mice that peaks during puberty. These results suggest that factors regulating expression of self-antigens in vivo can influence susceptibility to autoimmunity.

Research paper thumbnail of Thymic stromal organization is regulated by the specificity of T cell receptor/major histocompatibility complex interactions

European Journal of Immunology, 1997

The thymic architecture is normally compartmentalized into a central medulla surrounded by a peri... more The thymic architecture is normally compartmentalized into a central medulla surrounded by a peripheral cortical region. We investigated how compartmentalization of the thymic stroma is regulated using T cell receptor (TCR)-transgenic mouse models. Our studies show that the signals generated by TCR/peptide/major histocompatibility complex interactions regulate thymic stromal cell compartmentalization. In TCR-transgenic mice, normal stromal cell compartmentalization occurs when the transgenic TCR is expressed on a background that does not result in skewing toward either positive or negative selection. In models representing strong positive selection, the thymic stromal elements do not fully organize into a central medulla. Instead, small medullary foci are dispersed throughout the thymus with some regions residing directly under the capsule. The highest degree of disorganization in medullary epithelial regions is observed in TCR-transgenic mice that exhibit negative selection. Although the medullary foci lack central organization, the expression in these regions of CD80, CD86 and CD40, as well as the clustering of dendritic cells, is similar to that observed in medullae of wild-type mice. Thus, the organization of the medulla appears to occur in two stages: (1) small medullary epithelial regions that are dispersed in fetal thymi expand and associate with antigen-presenting cells, and (2) the expanded medullary foci organize into a central medullary compartment. Our data suggest a model in which this second stage of stromal cell organization is increasingly inhibited as the normal balance of TCR-mediated signals is skewed by higher-avidity interactions between thymocytes and antigen-presenting cells.

Research paper thumbnail of Experimental Autoimmune Encephalomyelitis Mediated by CD8+ T Cells

Annals of the New York Academy of Sciences, 2007

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is b... more Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is believed to have an autoimmune origin. CD4 + T cells have been well studied for their involvement in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). CD8 + T cells, however, have been overlooked until recently, when more attention has focused on their potential role in pathogenic mechanisms in MS. Here we summarize our work in generating a CD8 + T cell-mediated EAE model. We discuss immune tolerance mechanisms that regulate CD8 + T cells specific for myelin basic protein (MBP), and describe initial results regarding triggers of CD8 + T cellmediated disease. The availability of CD8 + T cell-mediated EAE models will help to elucidate the pathogenic roles of CD8 + T cells in MS, and provide tools for development of novel therapies for MS.

Research paper thumbnail of Oral Tolerance in Myelin Basic Protein TCR Transgenic Micea

Annals of the New York Academy of Sciences, 1996

The oral administration of myelin basic protein (MBP) in Lewis rats and some strains of mice resu... more The oral administration of myelin basic protein (MBP) in Lewis rats and some strains of mice results in suppression of clinical signs and histopathologic changes of experimental autoimmune encephalomyelitis (Em).'" Goverman et aL4 reported the development of TCR double-transgenic mice that expressed the Va2 and Vp8.2 ap TCR that recognizes the immunodominant NAcl-11 epitope of MBP. Cells from these mice, upon transfer into naive recipients, have been reported to undergo a deletion event following the administration of high doses of MBP intravenously? In this study, we examined the effect of oral administration of MBP on the fate and function of MBP-reactive double-transgenic T cells.

Research paper thumbnail of Highly Cross-Reactive T Cell Responses to Myelin Basic Protein Epitopes Reveal a Nonpredictable Form of TCR Degeneracy 1

The Journal of Immunology

We identified two nonoverlapping epitopes in myelin basic protein presented by I-A u that are res... more We identified two nonoverlapping epitopes in myelin basic protein presented by I-A u that are responsible for mediating tolerance induction to this self-Ag. A large number of T cells expressing diverse TCRs are strongly cross-reactive to both epitopes. Surprisingly, the TCR contact residues in each peptide are highly dissimilar. Furthermore, functional TCR contacts cannot be interchanged between the two epitopes, indicating that the TCR contacts in each peptide can only be recognized within the context of the other amino acids present in that peptide's sequence. This observation indicates that both buried and exposed residues of each peptide contribute to the sculpting of completely distinct antigenic surfaces. We propose that the cross-reactive TCRs adopt mutually exclusive conformations to recognize these dissimilar epitopes, adding a new dimension to TCR degeneracy. This unpredictable TCR plasticity indicates that using just the TCR contacts on a single epitope to define other cross-reactive peptides will identify only a subset of the complete repertoire of cross-reactive epitopes.

Research paper thumbnail of 2-D Diagonal Gel Electrophoresis

2-D Proteome Analysis Protocols

Research paper thumbnail of Protein Administration of Myelin Basic TCR-Transgenic Mice After Oral Antigen-Specific T Cells in Rapid Depletion of Peripheral

Research paper thumbnail of Model genomes: The benefits of analysing homologous human and mouse sequences

Trends in Biotechnology, 1992

Research paper thumbnail of T cell regulation within the CNS

Journal of Neuroimmunology, 1998

Objective: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous syste... more Objective: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) postulated to be a Thl-type T-cell mediated autoimmune disease. IFN~7, a cytokine that is the hallmark of Th 1 type immune responses, appears to play an important role in disease pathogenesis as increased production of IFN-yprecedes clinical attacks and treatment of MS patients with recombinant IFN-7 induced exacerbations of the disease. Chemokines zce essential for inflammatory responses. Recent data suggest that there is a bias in expression of selected chemokine receptors by Thl cells (CXCR3 and CCR5 positive) compared to Th2 cloned cells (CCR3 and CCR4 positive).

Research paper thumbnail of A Pathogenic Role for Myelin-Specific Cd8+ T Cells in a Model for Multiple Sclerosis

The Journal of Experimental Medicine, 2001

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) characteri... more Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) characterized by plaques of infiltrating CD4+ and CD8+ T cells. Studies of MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS, focus on the contribution of CD4+ myelin-specific T cells. The role of CD8+ myelin-specific T cells in mediating EAE or MS has not been described previously. Here, we demonstrate that myelin-specific CD8+ T cells induce severe CNS autoimmunity in mice. The pathology and clinical symptoms in CD8+ T cell–mediated CNS autoimmunity demonstrate similarities to MS not seen in myelin-specific CD4+ T cell–mediated EAE. These data suggest that myelin-specific CD8+ T cells could function as effector cells in the pathogenesis of MS.

Research paper thumbnail of A Molecular Map of T Cell Development

Immunity, 1998

; Fehling and von Boehmer, 1997). Early * Section of Immunology stages of thymocyte development a... more ; Fehling and von Boehmer, 1997). Early * Section of Immunology stages of thymocyte development are clearly defined Yale University School of Medicine by several molecular events that include expression of Howard Hughes Medical Institute the RAG-1 and RAG-2 gene products (Lin and Desiderio, New Haven, Connecticut 06520-8011 1993; Ferguson et al., 1994; Hoffman et al., 1996), so-† Laboratory of Immunology matic rearrangement of the T cell receptor ␤ chain locus, National Institute of Allergy and Infectious Diseases expression of the coreceptor molecules CD4 and CD8, National Institutes of Health and, finally, recombination of the TCR ␣ locus (Dudley Bethesda, Maryland 20892 et al., 1994; Petrie et al., 1995). Productive rearrange-‡ Department of Molecular Biotechnology ment of both TCR chains allows surface expression of University of Washington School of Medicine the TCR and ensures life up to this point. Further devel-Seattle, Washington 98195-7650 opment, however, relies in part (Tourigny et al., 1997) upon signals generated by TCR interaction with MHC: self peptide complexes (von Boehmer, 1994). Most thy-Summary mocytes fail this rigorous criterion for selection and die of neglect (Janeway, 1994). Using a sensitive molecular marker for positive selec-While the early events in development can be clearly tion, the appearance of a particular functional TCR ␣ defined by molecular events, later stages of developchain sequence in cells from mice bearing a transgenic ment are typically defined by variations in the expression levels of cell surface proteins such as CD4, CD8, and ␤ chain, we address several aspects of intrathymic T the TCR. These molecules allow for several different cell development. First, by examining specific TCR intrathymic subpopulations to be distinguished. The deprior to and after maturation, we demonstrate how a velopmental status of such populations has been, in restricted TCR repertoire is positively selected from most cases, assessed by other means including intraa highly diverse immature TCR repertoire. Second, thymic injections of genetically marked cells and reconsince this molecular marker is enriched in cells prostitution of thymocytes in irradiated mice. gressing toward the CD4 lineage and depleted in cells In this report, we identify a sensitive molecular marker progressing toward the CD8 lineage, a map of the for positive selection. This marker, which is the appeardevelopmental pathway of ␣␤ thymocytes can be inance or loss of a specific TCR ␣ chain sequence, is used ferred. Third, the first cells that show clear signs of to address three issues concerning the development of positive intrathymic selection are identified. TCR␣␤ bearing thymocytes. First, we demonstrate that the restriction of TCR usage that was apparent in the mature repertoire in "single-peptide" mice bearing a Peptide-Specific Responses of Nonimmunized TCR ␤ Chain Transgenic Thymocytes § To whom correspondence should be addressed (e-mail: derek.

Research paper thumbnail of Separately expressed T cell receptor α and β chain transgenes exert opposite effects on T cell differentiation and neoplastic transformation

European Journal of Immunology, 1997

Two aspects of T cell differentiation in T cell receptor (TCR)‐transgenic mice, the generation of... more Two aspects of T cell differentiation in T cell receptor (TCR)‐transgenic mice, the generation of an unusual population of CD4−CD8−TCR+ thymocytes and the absence of γδ cells, have been the focus of extensive investigation. To examine the basis for these phenomena, we investigated the effects of separate expression of a transgenic TCR α chain and a transgenic TCR β chain on thymocyte differentiation. Our data indicate that expression of a transgenic TCR α chain causes thymocytes to differentiate into a CD4−CD8−TCR+ lineage at an early developmental stage, depleting the number of thymocytes that differentiate into the αβ lineage. Surprisingly, expression of the TCR α chain transgene is also associated with the development of T cell lymphosarcoma. In contrast, expression of the transgenic TCR β chain causes immature T cells to accelerate differentiation into the αβ lineage and thus inhibits the generation of γδ cells. Our observations provide a model for understanding T cell different...

Research paper thumbnail of Chimeric immunoglobulin-T cell receptor proteins form functional receptors: Implications for T cell receptor complex formation and activation

Cell, 1990

We constructed chimeric receptor chains in which an immunoglobulin heavy chain variable region (V... more We constructed chimeric receptor chains in which an immunoglobulin heavy chain variable region (V,) from a phosphorylcholine-specific antibody is substituted for T cell receptor (Tcr) a and 3 V regions. We demonstrate that the VH region joined to either the C, or the CB region can form stable chime& proteins in EL4 T cells. Both chimeric receptor chains associate with CD3 polypeptides in functional receptor complexes and respond to phosphorylcholine coupled to Sepharose beads. The V&Z, chimeric chain associates with the EL4 f3 chain, while the Vu-C, chimeric protein appears to form either a homodimer or a heterodimer with the native EL4 p chain. Thus, functional receptor complexes can be formed using two C, regions, and the C, region may not be required for CD3 association and surface expression of Tcr complexes.

Research paper thumbnail of A speculative view of the multicomponent nature of T cell antigen recognition

Cell, 1986

Recent data on the molecular biology of T cells have given us a detailed view of the genes and pr... more Recent data on the molecular biology of T cells have given us a detailed view of the genes and proteins involved in antigen recognition by T cells. T and B cells are responsible for specific antigen recognition in the vertebrate immune response. B cells recognize free antigen through cell surface-bound immunoglobulin (lg) with no other requirement except antigen/receptor complementarity. T cells recognize antigen only when it is presented on the cell surface in the context of class I or class II molecules

Research paper thumbnail of Implications of the Diversity of the Immunoglobulin Gene Superfamily

Cold Spring Harbor Symposia on Quantitative Biology, 1989

Research paper thumbnail of TCR signaling regulates thymic organization: lessons from TCR-transgenic mice

Research paper thumbnail of T cell deletion in high antigen dose therapy of autoimmune encephalomyelitis

Science, 1994

Encounters with antigen can stimulate T cells to become activated and proliferate, become nonresp... more Encounters with antigen can stimulate T cells to become activated and proliferate, become nonresponsive to antigen, or to die. T cell death was shown to be a physiological response to interleukin-2-stimulated cell cycling and T cell receptor reengagement at high antigen doses. This feedback regulatory mechanism attenuates the immune response by deleting a portion of newly dividing, antigen-reactive T cells. This mechanism deleted autoreactive T cells and abrogated the clinical and pathological signs of autoimmune encephalomyelitis in mice after repetitive administration of myelin basic protein.

Research paper thumbnail of An immunoglobulin promoter region is unaltered by DNA rearrangement and somatic mutation during B-cell development

Nucleic Acids Research, 1982

The V1 gene encodes the heavy chain variable region of antibodies that bind to phosphorylcholine ... more The V1 gene encodes the heavy chain variable region of antibodies that bind to phosphorylcholine in the Balb/c mouse. V1 genes have been cloned from mouse sperm DNA, an IgM-producing tumor HPCM2 and an IgA-producing tumor M167. The transcription start site of the V1 gene has been mapped 63 +/- 1 base pairs from the coding sequence for both alpha and mu transcripts. Comparison of flanking DNA sequence 574 base pairs 5' to the V1 transcription start site in sperm, HPCM2 and M167 DNA reveals that sperm and HPCM2 sequences are completely identical in this region and the M167 sequence differs from them by a single base change. Although the coding region of the V1 gene has undergone a high (4%) rate of somatic mutation in M167 we demonstrate that the somatic mutation mechanism stops near the transcription start site. These results demonstrate that initiation of V1 gene transcription remains unchanged with respect to location and 5' sequences throughout B-cell development.

Research paper thumbnail of Separation of disulfide-bonded polypeptides using two-dimensional diagonal gel electrophoresis

Research paper thumbnail of Regulatory T Cells Maintain Long-Term Tolerance to Myelin Basic Protein by Inducing a Novel, Dynamic State of T Cell Tolerance

The Journal of Immunology, 2007

Research paper thumbnail of Age-Dependent T Cell Tolerance and Autoimmunity to Myelin Basic Protein

Immunity, 2001

Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, is induc... more Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, is induced by activating a subset of myelin basic protein (MBP)-specific T cells that have escaped tolerance induction. Here, we define the tolerance mechanisms that eliminate the majority of MBP-specific T cells from the periphery. We show that MBP-specific T cells undergo central tolerance mediated by bone marrow-derived antigen-presenting cells presenting exogenously derived MBP epitopes. The efficiency of tolerance is age dependent, reflecting the developmentally regulated expression of MBP. Dependence of tolerance on the amount of MBP expressed in vivo results in an age window of susceptibility to EAE in mice that peaks during puberty. These results suggest that factors regulating expression of self-antigens in vivo can influence susceptibility to autoimmunity.

Research paper thumbnail of Thymic stromal organization is regulated by the specificity of T cell receptor/major histocompatibility complex interactions

European Journal of Immunology, 1997

The thymic architecture is normally compartmentalized into a central medulla surrounded by a peri... more The thymic architecture is normally compartmentalized into a central medulla surrounded by a peripheral cortical region. We investigated how compartmentalization of the thymic stroma is regulated using T cell receptor (TCR)-transgenic mouse models. Our studies show that the signals generated by TCR/peptide/major histocompatibility complex interactions regulate thymic stromal cell compartmentalization. In TCR-transgenic mice, normal stromal cell compartmentalization occurs when the transgenic TCR is expressed on a background that does not result in skewing toward either positive or negative selection. In models representing strong positive selection, the thymic stromal elements do not fully organize into a central medulla. Instead, small medullary foci are dispersed throughout the thymus with some regions residing directly under the capsule. The highest degree of disorganization in medullary epithelial regions is observed in TCR-transgenic mice that exhibit negative selection. Although the medullary foci lack central organization, the expression in these regions of CD80, CD86 and CD40, as well as the clustering of dendritic cells, is similar to that observed in medullae of wild-type mice. Thus, the organization of the medulla appears to occur in two stages: (1) small medullary epithelial regions that are dispersed in fetal thymi expand and associate with antigen-presenting cells, and (2) the expanded medullary foci organize into a central medullary compartment. Our data suggest a model in which this second stage of stromal cell organization is increasingly inhibited as the normal balance of TCR-mediated signals is skewed by higher-avidity interactions between thymocytes and antigen-presenting cells.

Research paper thumbnail of Experimental Autoimmune Encephalomyelitis Mediated by CD8+ T Cells

Annals of the New York Academy of Sciences, 2007

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is b... more Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is believed to have an autoimmune origin. CD4 + T cells have been well studied for their involvement in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). CD8 + T cells, however, have been overlooked until recently, when more attention has focused on their potential role in pathogenic mechanisms in MS. Here we summarize our work in generating a CD8 + T cell-mediated EAE model. We discuss immune tolerance mechanisms that regulate CD8 + T cells specific for myelin basic protein (MBP), and describe initial results regarding triggers of CD8 + T cellmediated disease. The availability of CD8 + T cell-mediated EAE models will help to elucidate the pathogenic roles of CD8 + T cells in MS, and provide tools for development of novel therapies for MS.

Research paper thumbnail of Oral Tolerance in Myelin Basic Protein TCR Transgenic Micea

Annals of the New York Academy of Sciences, 1996

The oral administration of myelin basic protein (MBP) in Lewis rats and some strains of mice resu... more The oral administration of myelin basic protein (MBP) in Lewis rats and some strains of mice results in suppression of clinical signs and histopathologic changes of experimental autoimmune encephalomyelitis (Em).'" Goverman et aL4 reported the development of TCR double-transgenic mice that expressed the Va2 and Vp8.2 ap TCR that recognizes the immunodominant NAcl-11 epitope of MBP. Cells from these mice, upon transfer into naive recipients, have been reported to undergo a deletion event following the administration of high doses of MBP intravenously? In this study, we examined the effect of oral administration of MBP on the fate and function of MBP-reactive double-transgenic T cells.

Research paper thumbnail of Highly Cross-Reactive T Cell Responses to Myelin Basic Protein Epitopes Reveal a Nonpredictable Form of TCR Degeneracy 1

The Journal of Immunology

We identified two nonoverlapping epitopes in myelin basic protein presented by I-A u that are res... more We identified two nonoverlapping epitopes in myelin basic protein presented by I-A u that are responsible for mediating tolerance induction to this self-Ag. A large number of T cells expressing diverse TCRs are strongly cross-reactive to both epitopes. Surprisingly, the TCR contact residues in each peptide are highly dissimilar. Furthermore, functional TCR contacts cannot be interchanged between the two epitopes, indicating that the TCR contacts in each peptide can only be recognized within the context of the other amino acids present in that peptide's sequence. This observation indicates that both buried and exposed residues of each peptide contribute to the sculpting of completely distinct antigenic surfaces. We propose that the cross-reactive TCRs adopt mutually exclusive conformations to recognize these dissimilar epitopes, adding a new dimension to TCR degeneracy. This unpredictable TCR plasticity indicates that using just the TCR contacts on a single epitope to define other cross-reactive peptides will identify only a subset of the complete repertoire of cross-reactive epitopes.