![Figure 3. TACI-Ig inhibits macrophage- and mono-DC—induced costimulation of B-cell proliferation. (A) Enhancement of BCR-induced B-cell proliferation by macrophages requires a TACI ligand. Macrophages, 7-day conditioned macrophage culture supernatant, or BAFF was preincubated for at least 1 hour at 37°C with PBS, TACI-Ig, or a control-Ig fusion protein prior to coculture with B cells in the presence of goat anti-human IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD from 1 of 3 independent experiments. (B) A TACI ligand is required for mono-DC—mediated increases in BCR-induced B-cell proliferation. Dendritic cells or BAFF were pretreated for 1 hour at 37°C with PBS, TACI-Ig, or a control immunoglobulin fusion protein prior to coculture with B cells in the presence of goat anti-human IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD from 1 of 2 experiments. (C) TACI-Ig partially reduces anti-IgM—induced B-cell proliferation. B cells in the presence or absence of BAFF were preincubated for 1 hour at 37°C with PBS, TACI-Ig, or control-Ig fusion protein prior to culture in the presence of goat antihuman IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD of triplicate incubations from 1 of 2 separate experiments.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/101/11/10.1182_blood-2002-10-3123/5/h81134391003.jpeg?Expires=1726825746&Signature=nAFoukjRdSv0RG-~34cJ~oxwIXZgmMUPNPYcHvEyL26UqLIR0prmd8OME1JFhdc9FF7uRVi9acWkqWXW71saZpcTsdK6jqpC97MeKyvTtaIe0ePQYcy28-gyMIJAmnTy7u3KpffeFbB4OtVv1HvOaAz~pAecK6r5muY5jRkfmgAsINfnZvbztSdHPvgk5C3Cb1RNCaKNnz-Wk~Ez4Sd7HBv35YPHooB3Tw0WEe3WByr4~BI2SSIZLFIOI~0zWXk8keg75U66Rc5zfysIO7XaRZ336s7DDXsUIw69GEPNNEotbiRHZdx~v5piPuB2qFJmu718W8Wk9cMqLn6WCoGKbw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
TACI-Ig inhibits macrophage- and mono-DC—induced costimulation of B-cell proliferation. (A) Enhancement of BCR-induced B-cell proliferation by macrophages requires a TACI ligand. Macrophages, 7-day conditioned macrophage culture supernatant, or BAFF was preincubated for at least 1 hour at 37°C with PBS, TACI-Ig, or a control-Ig fusion protein prior to coculture with B cells in the presence of goat anti-human IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD from 1 of 3 independent experiments. (B) A TACI ligand is required for mono-DC—mediated increases in BCR-induced B-cell proliferation. Dendritic cells or BAFF were pretreated for 1 hour at 37°C with PBS, TACI-Ig, or a control immunoglobulin fusion protein prior to coculture with B cells in the presence of goat anti-human IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD from 1 of 2 experiments. (C) TACI-Ig partially reduces anti-IgM—induced B-cell proliferation. B cells in the presence or absence of BAFF were preincubated for 1 hour at 37°C with PBS, TACI-Ig, or control-Ig fusion protein prior to culture in the presence of goat antihuman IgM F(ab′)2 fragments. [3H]-thymidine incorporation assays were performed as described in Figure 1. Incubations were performed in triplicate, and results are presented as the mean ± SD of triplicate incubations from 1 of 2 separate experiments.
