title: Monoclonal antibodies directed against major histocompatibility complex antigens bind to the surface of Treponema pallidum isolated from infected rabbits or humans.
abstract: Evidence is presented for the association of class I major histocompatibility complex (MHC) antigens with the surface of Treponema pallidum during infection. A monoclonal antibody (IgG2a) directed against a murine H-2Kb epitope of public specificity reacted with the cell surface of T. pallidum, as assayed by the binding of protein A-colloidal gold in immunoelectron microscopy. Monoclonal antibodies directed against class I rabbit MHC antigens also reacted in immunofluorescence assays with material on the surface of rabbit-cultivated T. pallidum. In addition, impression smears of human syphilitic genital ulcers that were darkfield-positive for the presence of spirochetes were tested in immunofluorescence assays with monoclonal antibodies directed against human MHC antigens; antibody directed against HLA-ABC (class I) was reactive whereas antibody directed against HLA-DR (class II) was nonreactive. Results of the study suggest that the association of host-derived class I MHC antigens or molecular mimicry may play a role in T. pallidum evasion of host immune defenses.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D003429:Cross Reactions; D000939:Epitopes / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology*; D006801:Humans; D008297:Male; D051379:Mice; D011817:Rabbits; D013045:Species Specificity; D013587:Syphilis / Q000276:immunology; D014210:Treponema pallidum / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000939:Epitopes; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse