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Biomedical subjects

L Steinman

Publications and source records attributed to L Steinman.

At least 91 records · Page 5Linked to original sources
PubMed1996

CD45 isoforms on human CD4+ T-cell subsets.

We have examined the level of surface expression and functional properties of leukocyte function associated antigen-1, very late antigen-4, and CD45 isoforms on a panel of human CD4+ T-cell clones representative of TH0, TH1, and TH2 cells. There were no qualitative differences in the expression of these antigens among the three types of CD4+ T-cell clones. However, CD45RB was the only CD45 isoform that provided a costimulatory signal in a solid-phase antibody-induced cellular proliferation assay. Additionally, the antigen-induced proliferative response of T-cell clones was inhibited by soluble anti-CD45RO and anti-CD45RB antibodies. Our results suggest that CD45 isoforms differentially provide costimulatory signals to T cells. However, the ability of each CD45 isoform to provide a costimulatory signal does not differ among the TH0, TH1, or TH2 T-cell populations.

CD4-Positive T-Lymphocytes↗
PubMed1996

Regulation of disease susceptibility: decreased prevalence of IgE-mediated allergic disease in patients with multiple sclerosis.

The development of restricted cytokine profiles by subsets of CD4+ T cells is a pivotal point in the regulation of immune responses. T cells producing Th1 cytokines (IL-2 and interferon-gamma) induce cell-mediated immunity, whereas T cells producing Th2 cytokines (IL-4, IL-5, and IL-10) play a prominent role in the induction of humoral immunity. We examined a group of patients with multiple sclerosis, a disease caused by excess production of Th1 cytokines in myelin-reactive T cells, and control patients with noninflammatory neuroconvulsive disorders, for the presence of allergic disease, which is caused by excess production of Th2 cytokines in allergen-specific T cells. The patients with multiple sclerosis had significantly fewer allergic symptoms, a lower number of positive allergen-specific IgE test results, and lower composite allergy indexes than control subjects. These results demonstrate that the prevalence of IgE-mediated allergic disease is decreased in a group of patients with multiple sclerosis and support the hypothesis that genetic factors that promote susceptibility to Th1-mediated inflammatory disease in human beings protect against the development of Th2-mediated disease.

Adult↗
PubMed1996

Suppressive vaccination with DNA encoding a variable region gene of the T-cell receptor prevents autoimmune encephalomyelitis and activates Th2 immunity.

A variable region gene of the T-cell receptor, V beta 8.2, is rearranged, and its product is expressed on pathogenic T cells that induce experimental autoimmune encephalomyelitis (EAE) in H-2u mice after immunization with myelin basic protein (MBP). Vaccination of these mice with naked DNA encoding V beta 8.2 protected mice from EAE. Analysis of T cells reacting to the pathogenic portion of the MBP molecule indicated that in the vaccinated mice there was a reduction in the Th1 cytokines interleukin-2 (IL-2) and interferon-gama. In parallel, there was an elevation in the production of IL-4, a Th2 cytokine associated with suppression of disease. A novel feature of DNA immunization for autoimmune disease, reversal of the autoimmune response from Th1 to Th2, may make this approach attractive for treatment of Th1-mediated diseases like multiple sclerosis, juvenile diabetes and rheumatoid arthritis.

Amino Acid Sequence↗
PubMed1995

Fine specificity of the antibody response to myelin basic protein in the central nervous system in multiple sclerosis: the minimal B-cell epitope and a model of its features.

T cells, B cells, and antibody are found in the white matter of the central nervous system in multiple sclerosis. The epitope center for the antibody response to human myelin basic protein (MBP) fits precisely the minimal epitope Pro85-Val-Val-His-Phe-Phe-Lys-Asn-Ile-Val-Thr-Pro96 for that reported for HLA DR2b (DRB1*1501)-restricted T cells that recognize MBP [Wucherpfenning, K.W., Sette, A., Southwood, S., Oseroff, C., Matsui, M., Strominger, J. & Hafler, D. (1994) J. Exp. Med. 179, 279-290], and overlaps with the reported DR2a-restricted epitope for T cells reactive to MBP [Martin, R., Howell, M. D., Jaraquemada, D., Furlage, M., Richert, J., Brostoff, S., Long, E. O., McFarlin, D. E. & McFarland, H. F. (1991) J. Exp. Med. 173, 19-24]. We describe a molecular model of this epitope.

Amino Acid Sequence↗
PubMed1995

Unique T-cell receptor junctional sequences found in multiple sclerosis and T-cells mediating experimental allergic encephalomyelitis.

We have used two approaches to isolate TCR sequences that are unique to patients with multiple sclerosis. One strategy was to sequence TCR gene rearrangements directly from MS lesions. The second strategy utilized T-cell clones with a selectable mutation that are found only in MS patients. The selection of T-cell clones with mutations in the hypoxanthine guanine phosphoribosyltransferase (hprt) gene was used to isolate T-cells reactive to myelin basic protein (MBP) in patients with multiple sclerosis (MS). These T-cell clones are activated in vivo, and are not found in healthy individuals. The third complementarity determining regions (CDR3) of the T-cell receptor (TCR) alpha and beta chains are the putative contact sites for peptide fragments of MBP bound in the groove of the HLA molecule. The TCR V gene usage and CDR3s of these MBP-reactive hprt- T-cell clones are homologous to TCRs from other T-cells relevant to MS, including T-cells causing experimental allergic encephalomyelitis (EAE) and T-cells found in brain lesions and in the cerebrospinal fluid (CSF) of MS patients. In vivo activated MBP-reactive T-cells in MS patients may be critical in the pathogenesis of MS.

Amino Acid Sequence↗
PubMed1995

Reinduction of experimental autoimmune encephalomyelitis in mice.

Experimental autoimmune encephalomyelitis (EAE) in Lewis rats and some strains of mice is typically a monophasic disease, and recovered animals are resistant to reinduction of disease. We demonstrate that SJL mice remain susceptible to disease after recovery, and suffer a second episode of disease when reinjected with spinal cord homogenate in complete Freund's adjuvant. Reinduced disease occurs earlier after injection than the initial disease (mean onset 7.3 days compared with 14.5 days), and has comparable severity and incidence. The susceptibility to reinduced disease is present for at least 20 weeks after the initial injection. If the initial episode of EAE is elicited using a synthetic peptide of proteolipid protein, then reinjection of the same peptide causes reinduced disease. PL/J mice and PL/J x SJL F1 mice are also susceptible to reinduced disease which occurs with an accelerated onset and higher incidence than the initial disease. We conclude that SJL and PL/J mice have a defect in immunoregulation which causes them to be susceptible to recurrent episodes of autoimmune disease.

Amino Acid Sequence↗
PubMed1995

Pathogen antigen- and superantigen-reactive synovial fluid T cells in reactive arthritis.

Analysis of pathogen-reactive T cell clones (CD3+4+8-TCR alpha beta +), isolated from the synovial fluid of 2 HLA-B27-positive patients with Yersinia enterocolitica-triggered reactive arthritis, has provided important information about the cellular immune response to this disease-inciting pathogen. This study demonstrates that the proteins secreted by Y. enterocolitica, including a protein with tyrosine phosphatase activity (YopH), are potent immunogens stimulating CD4+ cells within the inflamed joint. The pathogen-reactive T cell clones preferentially utilized a limited set of T cell receptor variable region gene segments. A purified Yersinia superantigen triggered a proliferative response in most of the antigen-reactive T cell clones tested. These results suggest that the activity of this pathogen's superantigen influences the cellular immune response to its antigens.

Adult↗
PubMed1995

Characterization of acute bone marrow graft rejection in T cell-depleted, partially mismatched related donor bone marrow transplantation.

The purpose of this study was to characterize the phenotype and clonality of the T cell population in patients who experience acute rejection (AR) following bone marrow transplantation (BMT) from a partially mismatched related donor (PMRD). Phenotypic analysis was performed using flow cytometry, assignment of donor/host lineage by cytogenetics or HLA-specific flow cytometry, and analysis of the T cell receptor (TCR) by reverse-transcriptase polymerase chain reaction (RT-PCR). We have previously reported the initial appearance in the blood of AR patients of host CD8+brightCD3low T cells that progressively express increasing amounts of CD3+ cells. We now report that this cell population can differentiate into either a cytotoxic T cell phenotype (CD3+CD8+HLA-DR+CD57-) usually associated with AR of grafts from matched unrelated donors or a suppressor T cell phenotype (CD3+CD8+CD57+HLA-DR-) usually associated with AR of grafts from matched sibling donors. Analysis of the TCR V beta subsets from two patients revealed sorted host CD3+CD8+ cells (purity 90-95%) from the first patient to express V beta 18 almost exclusively. In a second patient with late rejection (55 days post-BMT), the CD3+CD8+ cells were predominantly restricted to V beta 1, 5.1, 7, 9, and 18. Although CD3+CD8+ T cells are known to be associated with AR, cytotoxic and suppressor lineages in AR from the same type of BMT and clonal distribution of T cells in AR have not been reported. Preliminary results suggest that V beta expression in AR of PMRD grafts is restricted and host T cell phenotype may vary. Further studies will investigate whether specific mismatches correlate with specific V beta usage and/or host T cell phenotype.

Base Sequence↗
PubMed1995

Administration of neutralizing antibodies to interleukin-6 (IL-6) reduces experimental autoimmune encephalomyelitis and is associated with elevated levels of IL-6 bioactivity in central nervous system and circulation.

BACKGROUND: We previously demonstrated the local production of the pleiotropic cytokine interleukin-6 (IL-6) in the central nervous system (CNS) in experimental autoimmune encephalomyelitis (EAE), an animal model for the human disease multiple sclerosis. MATERIALS AND METHODS: To assess the role of IL-6 in autoimmune CNS inflammation, we administered neutralizing antibodies to IL-6 in the EAE model. Their effect was examined at the clinical and histopathological level. Levels of administered antibody and IL-6 bioactivity were followed in serum and cerebrospinal fluid (CSF). RESULTS: Systemically administered antibodies penetrated into the fluid CSF in animals in which EAE was induced. Administration of anti-IL-6 reduced the development of actively induced as well as adoptively transferred EAE and was associated with increased levels of IL-6 activity in the CSF and to a lesser extent in the serum. Anti-IL-6 was still effective when given 1 day before the onset of disease signs in adoptively transferred EAE. The disease-reducing effect of anti-IL-6 was also reflected at the pathological level by the absence of inflammatory infiltrates in the CNS. CONCLUSIONS: Our study indicates that IL-6 plays an important role in autoimmune CNS inflammation. However, due to the complex nature of the in vivo interactions of administered antibodies, the disease-reducing effect of the anti-IL-6 antibodies could be caused by neutralization of IL-6 activity or by enhancement of IL-6 activity via induction of higher IL-6 levels in the CNS.

Amino Acid Sequence↗
PubMed1994

A predominant role of integrin alpha 4 in the spontaneous development of autoimmune diabetes in nonobese diabetic mice.

To elucidate the role of cell adhesion molecules in the pathogenesis of insulin-dependent diabetes mellitus and to determine the predominant lymphocytic homing pathway(s) involved in the selective lymphocytic infiltration of pancreatic islets (insulitis), nonobese diabetic mice were treated with monoclonal antibodies specific for the L-selectin and integrin alpha 4 lymphocyte adhesion molecules. Treatment of neonatal mice with either anti-L-selectin or anti-integrin alpha 4 monoclonal antibodies for the first 4 weeks of life led to a significant and long-term protection against spontaneous occurrence of insulitis and diabetes. The same treatment failed to inhibit lymphocytic infiltration of the salivary glands (sialadenitis). This tissue-specific inhibition of inflammation may be attributed to differences between the pancreas and salivary gland in their expression of endothelial ligands for L-selectin (peripheral vascular addressin) and for integrin alpha 4 (mucosal addressin cell adhesion molecule 1 and vascular cell adhesion molecule 1). Mucosal addressin cell adhesion molecule 1 is highly expressed by vessels within the inflamed islets but was not detected in the salivary glands. In contrast, peripheral vascular addressin- and vascular cell adhesion molecule 1-expressing vessels can be found in almost every area of inflammation within the salivary glands but are seen in only 40-50% of inflamed islets. Anti-L-selectin and anti-integrin alpha 4 treatment had no demonstrable effect on anti-beta-cell autoimmunity or on the immune responses to foreign antigens. Therapeutic treatment with anti-L-selectin after the onset of insulitis from 10 to 14 weeks of age delayed the onset but failed to prevent spontaneous insulin-dependent diabetes mellitus, whereas anti-integrin alpha 4 treatment resulted in a significant and long-lasting suppression of the disease. These data strongly suggest that integrin alpha 4 plays a prominent role in the spontaneous development of insulitis and diabetes in nonobese diabetic mice.

Animals↗
PubMed1994

Reversal of experimental autoimmune encephalomyelitis by a soluble peptide variant of a myelin basic protein epitope: T cell receptor antagonism and reduction of interferon gamma and tumor necrosis factor alpha production.

An immunodominant epitope of myelin basic protein (MBP), VHFFKNIVTPRTP (p87-99), is a major target of T cells in lesions of multiple sclerosis (MS) and in experimental allergic encephalomyelitis (EAE). T cells found in EAE lesions bear the same amino acids in the third complementary determining region of the T cell receptor (TCR) as those found in MS lesions. We analyzed the trimolecular interactions between MBP p87-99, class II major histocompatibility complex (MHC), and TCR, and designed soluble inhibitors for therapy. F, N, I, and V at positions 90, 92, 93, and 94 interact with MHC, whereas K, T, and P at positions 91, 95, and 96 interact with TCR. The peptides, p87-99[95T > A] and p87-99[96P > A] could compete more effectively with p87-99 for binding to MHC and could antagonize the in vitro response to T cells to p87-99 more effectively than p87-99[91K > A]. However, only p87-99[91K > A] prevented and reversed EAE, indicating that the extent of MHC or TCR competition does not predict success in treating EAE. To elucidate the mechanism of inhibition of EAE, draining lymph node cells from rats immunized with the native peptide alone or together with each of the three TCR antagonists were challenged in vitro with p87-99. Administration of p87-99[91K > A], but not p87-99 [95T > A] or p87-99[96P > A], reduced the production of tumor necrosis factor (TNF)- alpha and interferon (IFN) gamma. IFN-gamma and TNF-alpha are two cytokines that are critical in the pathogenesis of EAE and MS.

Amino Acid Sequence↗
PubMed1994

Specific T cell receptor gene rearrangements at the site of muscle degeneration in Duchenne muscular dystrophy.

Mononuclear cells infiltrate degenerating muscles of Duchenne muscular dystrophy (DMD) patients. Using a quantitative PCR, we first characterized the T cells infiltrating muscle biopsies from six DMD patients. High levels of TCR V beta 2 transcripts were observed in DMD muscle tissue. TCR V beta 2 transcripts from seven DMD patients and five controls were sequenced, and the VDJ junctional region analyzed in 166 clones. One specific amino acid motif, RVSG, was found in the third complementary determining region (CDR3) of TCR V beta 2 chains in samples from five DMD patients, but not in controls. A specific immune reaction at the site of tissue degeneration may play an important role in the pathogenesis of DMD.

Amino Acid Sequence↗
PubMed1994

A hippocampal protein associated with paraneoplastic neurologic syndrome and small cell lung carcinoma.

A hippocampal 38 kd autoantigen recognized by an autoantibody from the serum of a patient with paraneoplastic limbic encephalitis (PLE) and small cell lung carcinoma (SCLC) was isolated by screening a human hippocampal cDNA library. The 1,991-nucleotide ple21 clone was obtained and the deduced 350-residue protein encoded by the ple21 cDNA clone was found to be highly homologous to the neuron-specific RNA recognition motifs (RRMs)-containing proteins. The homologies were confined to the RRMs and the RRM connecting region. The presence of RRM in the antigenic protein may be important in the pathogenesis of SCLC-associated paraneoplastic neurologic syndrome.

Amino Acid Sequence↗