title: Involvement of Fcα/μ Receptor in IgM Anti-Platelet, but Not Anti-Red Blood Cell Autoantibody Pathogenicity in Mice.
abstract: IgM anti-mouse platelet autoantibodies cause thrombocytopenia by mediating uptake of opsonized thrombocytes, whereas IgM anti-erythrocyte autoantibodies induce anemia through a phagocytosis-independent cell destruction. In this article, we show that infection with lactate dehydrogenase-elevating virus, a benign mouse arterivirus, exacerbates the pathogenicity of IgM anti-platelet, but not anti-erythrocyte autoantibodies. To define the role of Fcα/μ receptor (Fcα/μR) in IgM-mediated thrombocytopenia and anemia, we generated mice deficient for this receptor. These animals were resistant to IgM autoantibody-mediated thrombocytopenia, but not anemia. However, the lactate dehydrogenase-elevating virus-induced exacerbation of thrombocytopenia was not associated with enhanced Fcα/μR expression on macrophages. These results indicate that Fcα/μR is required for the pathogenicity of IgM anti-platelet autoantibodies but is not sufficient to explain the full extent of the disease in virally infected animals.
authors.affiliation: Unité de Médecine Experimentale, Institut de Pathologie Cellulaire, Université Catholique de Louvain, 1200 Bruxelles, Belgium;
authors.forename: Sarah
authors.initials: S
authors.lastname: Legrain
authors.affiliation: Unité de Médecine Experimentale, Institut de Pathologie Cellulaire, Université Catholique de Louvain, 1200 Bruxelles, Belgium;
authors.forename: Dan
authors.initials: D
authors.lastname: Su
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, 2333 Leiden, the Netherlands; and.
authors.forename: Cor
authors.initials: C
authors.lastname: Breukel
authors.affiliation: Unité de Médecine Experimentale, Institut de Pathologie Cellulaire, Université Catholique de Louvain, 1200 Bruxelles, Belgium;
authors.forename: Laurent
authors.initials: L
authors.lastname: Detalle
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, 2333 Leiden, the Netherlands; and.
authors.forename: Jill W
authors.initials: JW
authors.lastname: Claassens
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, 2333 Leiden, the Netherlands; and.
authors.forename: Jos
authors.initials: J
authors.lastname: van der Kaa
authors.affiliation: Department of Pathology and Immunology, University Medical Center, University of Geneva, 1211 Geneva 4, Switzerland.
authors.forename: Shozo
authors.initials: S
authors.lastname: Izui
authors.affiliation: Department of Human Genetics, Leiden University Medical Center, 2333 Leiden, the Netherlands; and.
authors.forename: J Sjef
authors.initials: JS
authors.lastname: Verbeek
authors.affiliation: Unité de Médecine Experimentale, Institut de Pathologie Cellulaire, Université Catholique de Louvain, 1200 Bruxelles, Belgium; jean-paul.coutelier@uclouvain.be.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Coutelier
mesh_terms: D000818:Animals; D018174:Arterivirus Infections / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D001792:Blood Platelets / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D007772:Lactate dehydrogenase-elevating virus; D051379:Mice; D008810:Mice, Inbred C57BL; D011961:Receptors, Fc / Q000502:physiology*; D013921:Thrombocytopenia / Q000209:etiology
chemical_list: D001323:Autoantibodies; C526791:Fcalpha-mu protein, mouse; D007075:Immunoglobulin M; D011961:Receptors, Fc