title: A protective human monoclonal IgA antibody produced in vitro: anti-pneumococcal antibody engendered by Epstein-Barr virus-immortalized cell line.
abstract: Human lymphocytes that produce anti-pneumococcal antibodies were separated and immortalized by Epstein-Barr virus and then cloned. One clone (NAD-Sel) produces an IgA, kappa antibody which is specific for the polysaccharides of type 8 pneumococcus, while not reactive with any of the polysaccharides derived from 24 other pneumococcal strains. The antibody, which is present in the cell supernatant as monomer and polymer, binds to protein A and does not fix complement. When incubated in vitro with type 8 pneumococci, it induces direct killing and increases the opsonization of these bacteria by mouse macrophages.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000276:immunology; D002460:Cell Line; D002472:Cell Transformation, Viral; D003168:Complement Fixation Tests; D004797:Enzyme-Linked Immunosorbent Assay; D004854:Herpesvirus 4, Human; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis* / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D010587:Phagocytosis; D011008:Pneumococcal Infections / Q000517:prevention & control; D011817:Rabbits; D013205:Staphylococcal Protein A / Q000378:metabolism; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D007070:Immunoglobulin A; D013205:Staphylococcal Protein A