title: Stimulation of human lymphocyte subpopulations by protein A from Staphylococcus aureus.
abstract: Protein A from Staphylococcus aureus is known to stimulate human lymphocytes. Using 3H-thymidine incorporation, virus plaque assay and induction of cytotoxic T lymphocytes (CTL), this study showed that soluble or insoluble protein A stimulated different lymphocyte subpopulations. Soluble protein A is highly mitogenic to T lymphocytes. In both 3H-thymidine incorporation and virus plaque assay, its maximum stimulation was as high as the stimulation by the nonspecific mitogens phytohemagglutinin and concanavalin A, and a higher CTL response than that induced by phytohemagglutinin or concanavalin A was induced. Mitogenic activity to B lymphocytes was negligible. S. aureus (Cowan I strain) is itself considered to be an insoluble form of protein A and is 3--4 times more mitogenic to B lymphocytes than pokeweed mitogen without any increase in virus plaque-forming cells. No mitogenicity was noted to T lymphocytes. Sepharose CL-4B-protein A, also known as insoluble protein A, stimulated both T and B lymphocytes effectively, but its mitogenicity to T lymphocytes was considered to be due to the soluble protein A released from the Sepharose CL-4B beads.
mesh_terms: D001402:B-Lymphocytes / Q000166:cytology; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000145:classification / Q000166:cytology*; D008934:Mitogens / Q000494:pharmacology; D012397:Rosette Formation; D012995:Solubility; D013205:Staphylococcal Protein A / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000166:cytology; D013997:Time Factors; D010948:Viral Plaque Assay
chemical_list: D007140:Immunoglobulin Fab Fragments; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D008934:Mitogens; D013205:Staphylococcal Protein A