Protein a from Staphylococcus aureus-a mitogen for human T lymphocytes and B lymphocytes but not L lymphocytes
Sakane, T.; Green, I.
Journal of Immunology 120(1): 302-311
1978
ISSN/ISBN: 0022-1767 PMID: 304871 Document Number: 134433
Protein A from S. aureus (SpA) is known to bind specifically the Fc portion of Ig(immunoglobulin)G from several species. SpA was demonstrated to be a potent mitogen for T (thymus-derived) and non-T lymphocyte populations from human adult peripheral blood and cord blood. SpA was equivalent in mitogenic activity for T lymphocytes as compared to phytohemagglutinin (PHA), and was a much stronger mitogen than concanavalin A. Experiments separating non-T lymphocytes into B (bone marrow derived) lymphocytes (Fc-) and L (high affinity Fc receptor containing lymphocyte) lymphocytes (Fc+) by rosetting with IgG-coated sheep erythrocytes demonstrated that SpA can stimulate the proliferation of B lymphocytes but not L lymphocytes. The addition of mitomycin (M)-treated T lymphocytes to the culture of non-T lymphocytes greatly enhanced the non-T lymphocyte response to SpA, and vice versa. Enhanced response with either M-treated monocyte and T lymphocyte combinations or M-treated monocyte and non-T lymphocyte combinations was not observed. T and non-T lymphocyte synergism maybe needed for the maximal response to SpA. Discontinuous bovine serum albumin density gradient fractionation of T lymphocytes demonstrated a population of low density T lymphocytes which responded to SpA better than to PHA, and a population of high density T lymphocytes which responded to PHA better than to SpA. Some SpA-responsive T lymphocytes in human peripheral blood appear to be distinct from a population of T lymphocytes responding to PHA.