title: Tumor necrosis factor-alpha facilitates induction of CD80 (B7-1) and CD54 on human B cells by activated T cells: complex regulation by IL-4, IL-10, and CD40L.
abstract: Expression of immune accessory molecules, such as CD80 (B7-1), on antigen-presenting cells governs whether such cells can activate antigen-specific T cells. As such, the factors that regulate the expression of these accessory molecules may determine whether presentation of antigen leads to immune activation or anergy. We previously reported that anti-CD3-activated T cells (Ta) can induce expression of CD80 and CD54 (ICAM-1) on human B cells through a contact-dependent signal delivered to the CD40 molecule via the CD40 ligand. Here, we demonstrate that another molecule in the CD40-ligand family, namely tumor necrosis factor-alpha (TNF-alpha), also plays a role in the Ta-mediated induction of CD80 or CD54 on human B cells. Neutralizing mAbs specific for TNF-alpha can inhibit B cell expression of CD80 or CD54 that is induced when B cells are cultured with Ta cells or in Ta-cell conditioned media. Moreover, soluble, recombinant TNF-alpha or TNF-beta can induce significant increases in B cell expression of CD80 and CD54. The phenotypic changes effected by TNF-alpha can be recapitulated by crosslinking CD120b (p75 TNF-receptor), but not CD120a (p55 TNF-receptor), with mAbs presented on Fc gamma RII (CD32)-expressing L cells. IL-4 augments the expression of CD80 induced by crosslinking either CD40 or CD120b. However, although IL-10 augments CD40-induced expression of CD80, this cytokine inhibits the expression of CD80 that is induced by crosslinking CD120b. Further regulation of TNF-mediated CD80 expression may occur at the level of CD120b expression itself. We find that stimulation with exogenous IL-4 or CD40-cross-linking induces B cell expression of CD120b, but not CD120a. This study identifies an ancillary, TNF-mediated pathway, whereby activated T cells can induce B cells to express enhanced levels of the important costimulatory molecules, CD80 and CD54.
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla 92093-0663.
authors.forename: E A
authors.initials: EA
authors.lastname: Ranheim
authors.forename: T J
authors.initials: TJ
authors.lastname: Kipps
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D015703:Antigens, CD / Q000494:pharmacology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000096:biosynthesis*; D019013:CD40 Antigens; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D018122:B7-1 Antigen; D019013:CD40 Antigens; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D016753:Interleukin-10; D015847:Interleukin-4