title: Immunologic tolerance: self-nonself discrimination versus costimulatory factors and second signals.
abstract: An attempt is made to assess the total number of the theoretically possible antigenic epitopes, the number of lymphocyte clones and the number of epitopes on cell surface antibody of a clone may be able to recognize. We suggest that the structures of recognizing antibody sites of a human are far from random and derived from a limited number of structures adapted to the recognition of pathogenic agents. The probability of recognition for a random epitope-like structure is likely to be very small. Discriminative power of BCR and TCR binding sites, together with T-helper control, should be sufficient for prevention of peripheral autoimmune response, but second-signal-type controls should not be neglected as supplementary mechanisms to prevent such response.
authors.affiliation: Department of Biophysics, University of Medicine and Pharmacy, Timisoara, Romania.
authors.forename: Z
authors.initials: Z
authors.lastname: Simon
authors.forename: C A
authors.initials: CA
authors.lastname: Tatu
mesh_terms: D000906:Antibodies / Q000276:immunology; D000937:Antigen-Antibody Reactions; D000941:Antigens / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance; D008214:Lymphocytes / Q000276:immunology*; D018448:Models, Immunological; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D000941:Antigens; D000939:Epitopes; D011947:Receptors, Antigen, B-Cell; D011948:Receptors, Antigen, T-Cell