title: Native, but not genetically inactivated, pertussis toxin protects mice against experimental allergic encephalomyelitis.
abstract: Treatment of SJL mice with 400 ng Bordetella pertussis toxin (PT) either in saline or emulsified in incomplete Freund's adjuvant protected the mice against experimental autoimmune encephalomyelitis (EAE) induced 28 days later by a synthetic peptide of myelin proteolipid protein (PLP139-151) in complete Freund's adjuvant. However, treatment with a genetically inactivated pertussis toxin in which the catalytic and NAD-binding sites of the ADP-ribosyltransferase subunit were modified by site-directed mutagenesis was without effect. In vitro, lymphocyte proliferation was considerably enhanced by both the native and the inactivated toxin, at concentrations of 0.1-1 microgram/ml. However, strong inhibition of proliferation was also observed with the native toxin only, at concentrations that were two to three orders of magnitude lower than that required for the mitogenic effect (0.1-1 ng/ml). The inhibition of proliferation was detectable in the case of high-background proliferation, after stimulation with antigen (PLP139-151) or purified protein derivative of Mycobacterium tuberculosis), or with anti-CD3 monoclonal antibody, but not after stimulation with concanavalin A or phorbol esters and Ca2+ ionophore. These results suggest that the inhibitory effect of PT operates by interfering selectively with a T cell receptor-dependent signaling pathway. The biological significance of the in vitro inhibitory effect of PT was demonstrated by a considerable decrease and/or delay in the ability of lymphocytes grown with PLP139-151 and low concentrations of PT to transfer EAE to naive recipients.
authors.affiliation: Department of Microbiology and Immunology, The John P. Robarts Research Institute, University of Western Ontario, London, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Robbinson
authors.forename: S
authors.initials: S
authors.lastname: Cockle
authors.forename: B
authors.initials: B
authors.lastname: Singh
authors.forename: G H
authors.initials: GH
authors.lastname: Strejan
mesh_terms: D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D001665:Binding Sites; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D005620:Freund's Adjuvant; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000627:therapeutic use*; D016219:Immunotherapy, Adoptive; D007476:Ionophores / Q000494:pharmacology; D008198:Lymph Nodes; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D008934:Mitogens / Q000494:pharmacology; D008969:Molecular Sequence Data; D016853:Muromonab-CD3 / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D009185:Myelin Proteins / Q000633:toxicity; D018991:Myelin Proteolipid Protein; D009243:NAD / Q000378:metabolism; D010446:Peptide Fragments / Q000633:toxicity; D037342:Pertussis Toxin; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014373:Tuberculin / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000737:chemistry / Q000235:genetics / Q000627:therapeutic use*
chemical_list: D007166:Immunosuppressive Agents; D007476:Ionophores; D008934:Mitogens; D016853:Muromonab-CD3; D009185:Myelin Proteins; D018991:Myelin Proteolipid Protein; D010446:Peptide Fragments; D014373:Tuberculin; D010566:Virulence Factors, Bordetella; C435023:myelin proteolipid protein (139-151); D009243:NAD; D005620:Freund's Adjuvant; D011065:Poly(ADP-ribose) Polymerases; D037342:Pertussis Toxin