title: CD27-CD70 interactions regulate B-cell activation by T cells.
abstract: CD27, a member of the tumor necrosis factor (TNF) receptor family, binds to its ligand CD70, a member of the TNF family, and subsequently induces T-cell costimulation and B-cell activation. CD27 is expressed on resting T and B cells, whereas CD70 is expressed on activated T and B cells. Utilizing transfected murine pre-B-cell lines expressing human CD27 or CD70, we have examined the effect of such transfectant cells on human B-cell IgG production and B-cell proliferation. We show that the addition of CD27-transfected cells to a T-cell-dependent, pokeweed mitogen-driven B-cell IgG synthesis system resulted in marked inhibition of IgG production, whereas the addition of CD70-transfected cells enhanced IgG production. The inhibition and enhancement of pokeweed mitogen-driven IgG production by CD27 and CD70 transfectants were abrogated by pretreatment with anti-CD27 and anti-CD70 monoclonal antibodies, respectively. In contrast, little or no inhibition of IgG production and B-cell proliferation was noted with CD27-transfected cells or either anti-CD27 or CD70 monoclonal antibody in a T-cell-independent Staphylococcus aureus/interleukin 2-driven B-cell activation system. In this same system CD70-transfected cells enhanced B-cell IgG production and B-cell proliferation, and this enhancement could be gradually abrogated by addition of increasing numbers of CD27-transfected cells. These results clearly demonstrate that interactions among subsets of T cells expressing CD27 and CD70 play a key role in regulating B-cell activation and immunoglobulin synthesis.
mesh_terms: D015703:Antigens, CD; D001402:B-Lymphocytes / Q000502:physiology*; D053282:CD27 Ligand; D002478:Cells, Cultured; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008565:Membrane Proteins / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D053282:CD27 Ligand; C505771:CD70 protein, human; D007074:Immunoglobulin G; D008565:Membrane Proteins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7