title: Molecular mimicry and clonal deletion: A fresh look.
abstract: In this article, I trace the historic background of clonal deletion and molecular mimicry, two major pillars underlying our present understanding of autoimmunity and autoimmune disease. Clonal deletion originated as a critical element of the clonal selection theory of antibody formation in order to explain tolerance of self. If we did have complete clonal deletion, there would be major voids, the infamous "black holes", in our immune repertoire. For comprehensive, protective adaptive immunity, full deletion is necessarily a rare event. Molecular mimicry, the sharing of epitopes among self and non-self antigens, is extraordinary common and provides the evidence that complete deletion of self-reactive clones is rare. If molecular mimicry were not common, protective adaptive immunity could not be all-encompassing. By taking a fresh look at these two processes together we can envision their evolutionary basis and understand the need for regulatory devices to prevent molecular mimicry from progressing to autoimmune disease.
authors.affiliation: Departments of Pathology and of Molecular Microbiology and Immunology, The Johns Hopkins Schools of Medicine and Public Health, Johns Hopkins Center for Autoimmune Disease Research, Johns Hopkins University, 615 N. Wolfe St., MMI E5009, Baltimore, MD 21205, USA. Electronic address: nrrose@jhmi.edu.
authors.forename: Noel R
authors.initials: NR
authors.lastname: Rose
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D017637:Clonal Deletion; D000939:Epitopes / Q000276:immunology; D006706:Homeostasis; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology; D008954:Models, Biological; D018716:Molecular Mimicry
chemical_list: D001324:Autoantigens; D000939:Epitopes
keywords: Adaptive immunity; Autoimmunity; Clonal deletion; Immunoregulation; Molecular mimicry