![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=1735851131&Signature=YBVAagEU26Se-R44tONylmqMmgtzdLYEG5qWQS8CZg5z-38KOhST6EpajDfwiZOrWrxKEvmKVjZZPpWW6a6Se9VC3-JQHz6vttCSGyXSA6CLpTFiHQL-mt3RXsQK3n4PZYvH4K2LG5BZDJ6oxCsnyx7oKFQmnf2SUldixvf2z2f6FU5toL8jFAu6R45CWj0a-URMBxdIkM4kH2~fCl8SBkzEWd7EvM~5pDPCr3BB8kUSynAg8-JLDQxwoN84qroJ~j5zv65wLV9ge3n3EyrhTOoih6UdGPKjMI7EOiCmY0eh2IP72Aj6DiJBx8NYvM5V~QIP21cx2V3UmZGwbW7XjQ__&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.
