title: Potential role of 4-1BB in T cell activation. Comparison with the costimulatory molecule CD28.
abstract: The expression of the murine T cell Ag 4-1BB, a member of the TNF-R family, is induced by T cell activation. Previously, we and others had shown that signaling through 4-1BB enhanced proliferative T cell responses. To investigate a potential role for the interaction of 4-1BB with its ligand (4-1BBL) in T cell activation, we studied the ability of a soluble chimera of 4-1BB (4-1BBFc) to interfere with proliferative responses and cytokine production in models of activation dependent in intercellular interactions. The potential blocking effect of 4-1BBFc was compared with that of the chimeric molecule CTLA-4Ig, a reagent known to interfere with the interaction of CD28 (and/or CTLA-4) with B7 costimulatory receptors. In this study, we report that 4-1BBFc partially blocked both the activation of unfractionated splenocytes triggered by soluble anti-CD3 (anti-CD3s), and the more physiologically relevant responses to alloantigen. In addition, we show that both chimeric molecules partially blocked proliferative responses and IL-2 secretion by highly purified resting T cells activated with anti-CD3s in the presence of fixed accessory cells that express B7 receptors and 4-1BBL. Furthermore, in this model system, the blocking capacity of 4-1BBFc and CTLA-4Ig appears to correlate with the relative expression of their respective cognate receptors (4-1BBL and B7) on the accessory cell. Simultaneous addition of both blocking reagents produced an additive effect in the model systems studied.
authors.affiliation: Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Hurtado
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: K E
authors.initials: KE
authors.lastname: Pollok
authors.forename: Z H
authors.initials: ZH
authors.lastname: Lee
authors.forename: B S
authors.initials: BS
authors.lastname: Kwon
mesh_terms: D000818:Animals; D015703:Antigens, CD; D018106:CD28 Antigens / Q000276:immunology* / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology; D002455:Cell Division; D002478:Cells, Cultured; D005260:Female; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D017475:Receptors, Nerve Growth Factor / Q000276:immunology* / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000276:immunology* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9
chemical_list: D015703:Antigens, CD; D018106:CD28 Antigens; D017252:CD3 Complex; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C505715:Tnfrsf9 protein, mouse; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9