title: Lymphocyte stimulation by protein A of Staphylococcus aureus.
abstract: Protein A from Staphylococcus aureus (SpA) is known to bind to the Fc region of most mammalian IgG classes. In the present article data are presented showing that SpA is a highly efficient mitogen for human peripheral B lymphocytes, with no detectable activity for T lymphocytes. In order to achieve optimal stimulating conditions SpA should be presented to the lymphocytes on an insoluble matrix, such as the SpA-positive bacteria themselves or SpA covalently attached to Sephadex or Sepharose beads. Using such conditions SpA is equivalent with regard to stimulatory capacity for B lymphocytes as phytohemagglutinin is for the human T lymphocytes. Specificity controls proved beyond doubt that SpA and not any other contaminating product is the B cell mitogen. It is concluded that SpA as an inducer of human B lymphocyte division might serve as a highly useful assay in the clinical assessment of B lymphocyte function. It should also be a suitable tool in the fine analysis of B lymphocyte activation via the specific interactions with surface IgG molecules.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology* / Q000378:metabolism; D001665:Binding Sites; D002473:Cell Wall / Q000276:immunology; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D008213:Lymphocyte Activation; D009088:Mucoproteins / Q000276:immunology; D009154:Mutation; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D012995:Solubility; D013211:Staphylococcus aureus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D013682:Teichoic Acids / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D007140:Immunoglobulin Fab Fragments; D009088:Mucoproteins; D011947:Receptors, Antigen, B-Cell; D013682:Teichoic Acids