title: Identification of an anti-idiotypic antibody that defines a B-cell subset(s) producing xenoantibodies in primates.
abstract: Synthetic anti-idiotypic antibodies represent a potentially valuable tool for the isolation and characterization of B cells that produce xenoantibodies. An anti-idiotypic antibody that binds to a subset of B cells producing antibodies encoded by the variable-region heavy chain 3 (V(H)3) germline genes DP35 [immunoglobulin variable-region heavy chain 3-11 (IGHV3-11)], DP-53 and DP-54 plus a small number of V(H)4 gene-encoded antibodies in humans has recently been identified. These germline progenitors also encode xenoantibodies in humans. We tested whether the small, clearly defined group of B cells identified with this anti-idiotypic antibody produce xenoantibodies in non-human primates mounting active immune responses to porcine xenografts. Peripheral blood B cells were sorted by flow cytometry on the basis of phenotype, and cDNA libraries were prepared from each of these sorted groups of cells. Immunoglobulin V(H) gene libraries were prepared from the sorted cells, and the V(H) genes expressed in each of the sorted groups were identified by nucleic acid sequencing. Our results indicate that xenoantibody-producing peripheral blood B cells, defined on the basis of binding to fluorescein isothiocyanate (FITC)-conjugated galactose alpha(1,3) galactose-bovine serum albumin (Gal-BSA) and the anti-idiotypic antibody 2G10, used the IGHV3-11 germline gene to encode xenoantibodies and were phenotypically CD11b+ (Mac-1+) and CD5-. This novel reagent may be used in numerous applications including definition of xenoantibody-producing B-cell subsets in humans and non-human primates and immunosuppression by depletion of B cells producing anti-Gal xenoantibodies.
authors.affiliation: Department of Cardiothoracic Surgery, Saban Research Institute of the Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Fischer-Lougheed
authors.forename: Clare
authors.initials: C
authors.lastname: Gregory
authors.forename: Zena
authors.initials: Z
authors.lastname: White
authors.forename: Irina
authors.initials: I
authors.lastname: Shulkin
authors.forename: Mirja
authors.initials: M
authors.lastname: Gunthart
authors.forename: Mary
authors.initials: M
authors.lastname: Kearns-Jonker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000910:Antibodies, Heterophile / Q000096:biosynthesis*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001483:Base Sequence; D039481:CD11b Antigen / Q000032:analysis; D004187:Disaccharides / Q000276:immunology; D015723:Gene Library; D005803:Genes, Immunoglobulin; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D034421:Sus scrofa; D014183:Transplantation, Heterologous
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000910:Antibodies, Heterophile; D039481:CD11b Antigen; D004187:Disaccharides; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; C055075:galactosyl-(1-3)galactose