title: GM-CSF-neuroantigen fusion proteins reverse experimental autoimmune encephalomyelitis and mediate tolerogenic activity in adjuvant-primed environments: association with inflammation-dependent, inhibitory antigen presentation.
abstract: Single-chain fusion proteins comprised of GM-CSF and neuroantigen (NAg) are potent, NAg-specific inhibitors of experimental autoimmune encephalomyelitis (EAE). An important question was whether GMCSF-NAg tolerogenic vaccines retained inhibitory activity within inflammatory environments or were contingent upon steady-state conditions. GM-CSF fused to the myelin oligodendrocyte glycoprotein MOG35-55 peptide (GMCSF-MOG) reversed established paralytic disease in both passive and active models of EAE in C57BL/6 mice. The fusion protein also reversed EAE in CD4-deficient and B cell-deficient mice. Notably, GMCSF-MOG inhibited EAE when coinjected adjacent to the MOG35-55/CFA emulsion. GMCSF-MOG also retained dominant inhibitory activity when directly emulsified with MOG35-55 in the CFA emulsion in both C57BL/6 or B cell-deficient models of EAE. Likewise, when combined with proteolipid protein 139-151 in CFA, GM-CSF fused to proteolipid protein 139-151 peptide inhibited EAE in SJL mice. When deliberately emulsified in CFA with the NAg, GMCSF-NAg inhibited EAE even though NAg was present at >30-fold molar excess. In vitro studies revealed that the GM-CSF domain of GMCSF-MOG stimulated growth and differentiation of inflammatory dendritic cells (DC) and simultaneously targeted the MOG35-55 domain for enhanced presentation by these DC. These inflammatory DC presented MOG35-55 to MOG-specific T cells by an inhibitory mechanism that was mediated in part by IFN-γ signaling and NO production. In conclusion, GMCSF-NAg was tolerogenic in CFA-primed proinflammatory environments by a mechanism associated with targeted Ag presentation by inflammatory DC and an inhibitory IFN-γ/NO pathway. The inhibitory activity of GMCSF-NAg in CFA-primed lymphatics distinguishes GMCSF-NAg fusion proteins as a unique class of inflammation-dependent tolerogens that are mechanistically distinct from naked peptide or protein-based tolerogens.
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834.
authors: S M Touhidul
authors: SM
authors: Islam
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834.
authors: Alan D
authors: AD
authors: Curtis
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834.
authors: Najla
authors: N
authors: Taslim
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834.
authors: Daniel S
authors: DS
authors: Wilkinson
authors: Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834 manniem@ecu.edu.
authors: Mark D
authors: MD
authors: Mannie
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects* / Q000235:genetics; D001324:Autoantigens / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000494:pharmacology*; D007108:Immune Tolerance / Q000187:drug effects* / Q000235:genetics; D007249:Inflammation / Q000188:drug therapy / Q000235:genetics / Q000276:immunology / Q000473:pathology; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology; D051379:Mice; D063308:Myelin-Oligodendrocyte Glycoprotein / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D009569:Nitric Oxide / Q000235:genetics / Q000276:immunology; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology
chemical_list: D001324:Autoantigens; D063308:Myelin-Oligodendrocyte Glycoprotein; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C445081:myelin oligodendrocyte glycoprotein (35-55); D009569:Nitric Oxide; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor