Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model, experimental autoimmune encephalomyelitis (EAE). This study investigates the role of high mobility group box 1 (HMGB1) in oligodendrocyte precursor cells (OPCs) in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier (BBB) by using OPC-specific HMGB1 knockout (KO) mice. We found that HMGB1 released from OPCs promotes BBB disruption, subsequently allowing increased immune cell infiltration. The migration of CD4+ T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes (OLs). OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS, leading to less damage to the myelin sheath and mitigated EAE progression. CD4+ T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs. Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; HMGB1 Protein/deficiency* ; Mice, Knockout ; Oligodendrocyte Precursor Cells/immunology* ; Mice, Inbred C57BL ; CD4-Positive T-Lymphocytes/immunology* ; Cell Movement ; Blood-Brain Barrier/immunology* ; Mice ; Myelin Sheath/pathology* ; Disease Models, Animal ; Coculture Techniques ; Oligodendroglia/metabolism* ; Female ; Cells, Cultured

In the present study, the use of dogs with experimental autoimmune encephalomyelitis (EAE) as a disease model for necrotizing encephalitis (NE) was assessed. Twelve healthy dogs were included in this study. Canine forebrain tissues (8 g), including white and grey matter, were homogenized with 4 mL of phosphate-buffered saline for 5 min in an ice bath. The suspension was emulsified with the same volume of Freund's complete adjuvant containing 1 mg/mL of killed Mycobacterium tuberculosis H37Ra. Under sedation, each dog was injected subcutaneously with canine brain homogenate at four sites: two in the inguinal and two in the axillary regions. A second injection (booster) was administered to all the dogs using the same procedure 7 days after the first injection. Clinical assessment, magnetic resonance imaging, cerebrospinal fluid analyses, necropsies, and histopathological and immunohistochemical examinations were performed for the dogs with EAE. Out of the 12 animals, seven (58%) developed clinically manifest EAE at various times after immunization. Characteristics of canine EAE models were very similar to canine NE, suggesting that canine EAE can be a disease model for NE in dogs.
Animals ; Brain/*pathology ; Disease Models, Animal ; Dog Diseases/*immunology ; Dogs ; Encephalitis/immunology/*veterinary ; Encephalomyelitis, Autoimmune, Experimental/immunology/*veterinary ; Female ; Fluorescent Antibody Technique/veterinary ; Immunization/veterinary ; Immunohistochemistry/veterinary ; Magnetic Resonance Imaging/veterinary ; Male ; Necrosis/immunology/*veterinary

Experimental autoimmune encephalomyelitis (EAE) is an autoimmune disease of the central nervous system (CNS); it serves as a model for the human multiple sclerosis (MS). In mice, EAE is mediated by T cells specific for various myelin basic proteins which migrate from the periphery to the CNS. In search of a way to prevent the induction and progression of EAE, we observed the effects of recombinant immunotoxin IP10-DT390 on blocking or eliminating the active T cells in the EAE model. In this paper is presented an experimental gene therapy-based model in which the mice were made resistant to EAE induction by plasmid DNA encoding recombinant immunotoxin that was injected into the leg muscles of mice. The new immuno-biological construct could selectively impair autoreactive T-cell homing while the duration of clinical signs is shorter, and the new construct would not affect other components of the immune response. These data demonstrated the effectiveness of the constructs in the treatment of EAE and suggested its usefulness in the treatment of other autoimmune diseases.
Animals ; Chemokine CXCL10 ; biosynthesis ; genetics ; therapeutic use ; Diphtheria Toxin ; biosynthesis ; genetics ; therapeutic use ; Encephalomyelitis, Autoimmune, Experimental ; immunology ; pathology ; therapy ; Female ; Genetic Therapy ; Immunoglobulin Fragments ; biosynthesis ; genetics ; therapeutic use ; Immunotoxins ; genetics ; metabolism ; therapeutic use ; Mice ; Mice, Inbred C57BL ; Receptors, CXCR3 ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; therapeutic use ; Recombinant Proteins ; biosynthesis ; genetics ; therapeutic use ; T-Lymphocytes ; immunology ; Transfection

OBJECTIVETo detect the function of proteolipid protein (PLP) peptide (residues 56 - 70)-specific CD(4)(+) T cells in experimental allergic encephalomyelitis (EAE) in Biozzi AB/H mice (H-2A(g7)).

METHODSBiozzi AB/H mice were immunized by synthetic PLP(56 - 70) peptide (DYEYLINVIHAFQYV) which was emulsified by sonication with complete Freund's adjuvant, a EAE model proven histologically and clinically. Murine splenocytes and spinal cord infiltrated (SCI) T cells were stimulated by PLP(56 - 70), then the CD(4)(+) T cells were isolated by Dynabeads, and confirmed by staining with anti-CD(4) antibody. Finally, the IL2 bioassay and IFN-gamma/IL4 ELISA were done to detect T cell proliferation and cytokine secretion after PLP(56 - 70) stimulation.

RESULTSThe histology of murine spinal cord showed a great number of lymphocytes infiltrated the spinal cord; the clinical signs showed high scores (4.3) on the peak, as well as a good EAE model. After being isolated by Dynabeads, CD(4)(+) T cells showed high purification (> 99%) by staining with anti-CD(4) antibody. IL2 bioassay showed that those T cells were PLP(56 - 70)-specific T cells. ELISA showed that those T cells had high IFN-gamma/IL4 ratio, indicating that they are T helper 1 (Th1) cells.

CONCLUSIONSPLP(56 - 70)-specific splenocytes and SCI CD(4)(+) T cells in EAE from Biozzi AB/H mice were detected and showed that both of them were PLP(56 - 70)-specific Th1 cells. It is beneficial to understand what kind of role these T cells play in the development of EAE.

Amino Acid Sequence ; Animals ; CD4-Positive T-Lymphocytes ; drug effects ; immunology ; metabolism ; Cell Line ; Encephalomyelitis, Autoimmune, Experimental ; immunology ; pathology ; Interferon-gamma ; metabolism ; Interleukin-2 ; metabolism ; Interleukin-4 ; metabolism ; Mice ; Mice, Inbred Strains ; Molecular Sequence Data ; Myelin Proteolipid Protein ; chemistry ; immunology ; Peptide Fragments ; administration & dosage ; immunology ; Spleen ; cytology ; immunology ; metabolism ; Th1 Cells ; drug effects ; immunology ; metabolism

Melatonin (N-acetyl-5-methoxytryptamine), a pineal neurohormone, is a hydroxyl radical scavenger and antioxidant, and plays an important role in the immune system. We studied the effect of exogenous melatonin on the pathogenesis of experimental autoimmune encephalomyelitis (EAE). EAE was induced in Lewis rats by immunization with rat spinal cord homogenates. Subsequent oral administration of melatonin at 5 mg/kg significantly reduced the clinical severity of EAE paralysis compared with administration of the vehicle alone (p<0.01). Infiltration of ED1 macrophages and CD4 T cells into spinal cords occurred both in the absence and presence of melatonin treatment, but melatonin-treated rats had less spinal cord infiltration of inflammatory cells than did the control group. ICAM-1 immunoreactivity in the blood vessels of EAE lesions was decreased in melatonin-treated rats compared to vehicle-treated rats. These findings suggest that exogenous melatonin ameliorates EAE via a mechanism involving reduced expression of ICAM-1 and lymphocyte function associated antigen-1a in autoimmune target organs.
Animals ; Encephalomyelitis, Autoimmune, Experimental/*immunology/prevention & control ; Female ; Immunohistochemistry ; Intercellular Adhesion Molecule-1/analysis/*immunology ; Male ; Melatonin/administration & dosage/*physiology ; Rats ; Rats, Inbred Lew ; Spinal Cord/chemistry/pathology

Experimental autoimmune encephalomyelitis was induced in macaques. T cell clones infiltrated into the brain lesion area were compared with those in blood. Intradermal immunization of macaques with brain white matter derived from healthy macaque in combination with pertussis toxin, induced neurological symptoms in two macaques. One died on day 25 after immunization, whereas the other survived. Gross examination of the brain from the dead macaque, showed clear hemorrhagic lesions in the white matter. Hematological analysis showed that drastic T cell response was induced in macaques immunized with white matter, but not in control macaques. Flow cytometric analysis of blood cells from the affected macaques demonstrated an increase of CD4 and CD8 T cell populations expressing the CD69 early activation marker. Single strand conformation polymorphism (SSCP) analysis of T cell receptor beta chain showed T cell clones infiltrated into the brain lesion, which were different from those found in the peripheral blood of the same monkey. The present paper shows that SSCP analysis of TCR is useful in studying clonality of T cells infiltrating into the brain tissue of macaque with EAE.
Animals ; Antigens, CD3/analysis ; Disease Models, Animal ; Encephalomyelitis, Autoimmune, Experimental/immunology/*pathology ; Flow Cytometry/veterinary ; Leukocyte Count/veterinary ; *Macaca fascicularis ; Male ; Polymorphism, Single-Stranded Conformational ; Receptors, Antigen, T-Cell, alpha-beta/genetics ; T-Lymphocytes/cytology/immunology

An experimental allergic encephalomyelitis was induced by bovine myelin basic protein (MBP) and bovine galactocerebroside (GC) on male guinea pigs. Animals were divided into five experimental and one control groups. Among the five experimental groups, three were inoculated with 75 micrograms, 150 micrograms and 300 micrograms of MBP, respectively, to see the dose dependency of demyelination. The fourth group was inoculated with mixture of 75 micrograms of MBP and 180 micrograms of GC and the fifth group with 180 micrograms GC. All inocula was injected intradermally in emulsion state mixed with equal amount of complete Freund adjuvant. Control group was injected with adjuvant only. Clinical symptoms began to appear from 15th day after inoculation and animals were sacrificed on maximum neurologic deficit or 4 to 5 days after the onset of symptoms. Demyelination was observed in 6 out of 8 animals inoculated with MBP/GC mixture, while only 3 out of 24 animals inoculated with various dosage of MBP showed demyelination. The difference was statistically significant. Serum antibodies to MBP and GC were measured by ELISA method. All of the eight animals inoculated with MBP/GC mixture and two animals inoculated with GC had low titer of anti-GC antibodies, while all animals inoculated with MBP, MBP alone or MBP/GC mixture, had high titer of anti-MBP antibodies. Therefor it is concluded that the demyelination is augmented by GC and is not significantly dose-dependent on MBP.
Animals ; Autoantibodies/*immunology ; Central Nervous System/*immunology/pathology ; Cerebrosides/*immunology ; Dose-Response Relationship, Drug ; Encephalomyelitis, Autoimmune, Experimental/*metabolism/pathology ; Galactosylceramides/*immunology ; Guinea Pigs ; Male ; Myelin Basic Protein/*immunology

An experimental allergic encephalomyelitis was induced by bovine myelin basic protein (MBP) and bovine galactocerebroside (GC) on male guinea pigs. Animals were divided into five experimental and one control groups. Among the five experimental groups, three were inoculated with 75 micrograms, 150 micrograms and 300 micrograms of MBP, respectively, to see the dose dependency of demyelination. The fourth group was inoculated with mixture of 75 micrograms of MBP and 180 micrograms of GC and the fifth group with 180 micrograms GC. All inocula was injected intradermally in emulsion state mixed with equal amount of complete Freund adjuvant. Control group was injected with adjuvant only. Clinical symptoms began to appear from 15th day after inoculation and animals were sacrificed on maximum neurologic deficit or 4 to 5 days after the onset of symptoms. Demyelination was observed in 6 out of 8 animals inoculated with MBP/GC mixture, while only 3 out of 24 animals inoculated with various dosage of MBP showed demyelination. The difference was statistically significant. Serum antibodies to MBP and GC were measured by ELISA method. All of the eight animals inoculated with MBP/GC mixture and two animals inoculated with GC had low titer of anti-GC antibodies, while all animals inoculated with MBP, MBP alone or MBP/GC mixture, had high titer of anti-MBP antibodies. Therefor it is concluded that the demyelination is augmented by GC and is not significantly dose-dependent on MBP.
Animals ; Autoantibodies/*immunology ; Central Nervous System/*immunology/pathology ; Cerebrosides/*immunology ; Dose-Response Relationship, Drug ; Encephalomyelitis, Autoimmune, Experimental/*metabolism/pathology ; Galactosylceramides/*immunology ; Guinea Pigs ; Male ; Myelin Basic Protein/*immunology