title: MHC/Peptide-Specific Interaction of the Humoral Immune System: A New Category of Antibodies.
abstract: Abs bind to unprocessed Ags, whereas cytotoxic CD8(+) T cells recognize peptides derived from endogenously processed Ags presented in the context of class I MHC complexes. We screened, by ELISA, human sera for Abs reacting specifically with the influenza matrix protein (IMP)-derived peptide(58-66) displayed by HLA-A*0201 complexes. Among 653 healthy volunteers, blood donors, and women on delivery, high-titered HLA-A*0201/IMP(58-66) complex-specific IgG Abs were detected in 11 females with a history of pregnancies and in 1 male, all HLA-A*0201(-). These Abs had the same specificity as HLA-A*0201/IMP(58-66)-specific cytotoxic T cells and bound neither to HLA-A*0201 nor the peptide alone. No such Abs were detected in HLA-A*0201(+) volunteers. These Abs were not cross-reactive to other self-MHC class I alleles displaying IMP(58-66), but bound to MHC class I complexes of an HLA nonidentical offspring. HLA-A*0201/IMP(58-66) Abs were also detected in the cord blood of newborns, indicating that HLA-A*0201/IMP(58-66) Abs are produced in HLA-A*0201(-) mothers and enter the fetal blood system. That Abs can bind to peptides derived from endogenous Ags presented by MHC complexes opens new perspectives on interactions between the cellular and humoral immune system.
authors.affiliation: Department of Internal Medicine I, Saarland University Medical School, 66421 Homburg/Saar, Germany;
authors.forename: Gerhard
authors.initials: G
authors.lastname: Held
authors.affiliation: Ludwig Center for Cancer Research, Lausanne Branch, University of Lausanne, CH-1066 Epalinges, Switzerland;
authors.forename: Immanuel F
authors.initials: IF
authors.lastname: Luescher
authors.affiliation: Department of Internal Medicine I, Saarland University Medical School, 66421 Homburg/Saar, Germany;
authors.forename: Frank
authors.initials: F
authors.lastname: Neumann
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Medicine, Saarland University Medical School, 66421 Homburg/Saar, Germany;
authors.forename: Chrysostomos
authors.initials: C
authors.lastname: Papaioannou
authors.affiliation: Institute of Biochemistry and Biotechnology, University of Braunschweig, 38106 Braunschweig, Germany;
authors.forename: Thomas
authors.initials: T
authors.lastname: Schirrmann
authors.affiliation: Department of Transplant and Infection Immunology, Saarland University Medical School, 66421 Homburg/Saar, Germany; and.
authors.forename: Martina
authors.initials: M
authors.lastname: Sester
authors.affiliation: Institute of Virology, Saarland University Medical School, 66421 Homburg/Saar, Germany.
authors.forename: Sigrun
authors.initials: S
authors.lastname: Smola
authors.affiliation: Department of Internal Medicine I, Saarland University Medical School, 66421 Homburg/Saar, Germany; michael.pfreundschuh@uks.eu.
authors.forename: Michael
authors.initials: M
authors.lastname: Pfreundschuh
mesh_terms: D000918:Antibody Specificity; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D056724:Immunity, Humoral; D007518:Isoantibodies / Q000276:immunology*; D061986:MCF-7 Cells; D008297:Male; D010446:Peptide Fragments / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology*
chemical_list: C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D007518:Isoantibodies; D010446:Peptide Fragments; D014763:Viral Matrix Proteins; C448634:influenza matrix peptide (58-66)