CD4⁺ T Cells Promote IgG Production in MHC-Independent and ICAM-1-Dependent Manners in Pristane-Induced Lupus Mice

Figure 6

ICAM-1 attenuates IgG production in the coculture of in vitro activated CD4⁺ T cell and B cells. Wildtype CD4⁺ T cells and B cells were sorted from 6- to 8-week-old BALB/c mice by MACS, respectively. CD4⁺ T cells were stimulated by anti-CD3 and anti-CD28 antibodies for 72 hours. Then, activated CD4⁺ T cells were cultured with B cells. (a) Flow cytometric analysis of ICAM-1 expression on CD4⁺ T cells. (b) Increased expression levels of ICAM-1 on in vitro activated CD4⁺ T cells. (c–f) Total IgG (c), IgM (d), IgG1 (e), and IgG2a (f) levels in the supernatant with or without anti-ICAM-1 blocking antibodies were determined by ELISA. (g, h) Determination of differentiated B cells after the coculture. Each group had at least five mice for the analysis. ; .

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