Figure 3

Suppression of autoantibody formation. (A , B) At day 56 post first type II collagen (CII) immunization, serum samples were collected from C57BL/6 mice (n = 22) and RORγt Tg mice (n = 21) for measurement of CII-specific total IgG levels (A), and CII-specific IgG1, IgG2a, IgG2b, and IgG3 (B) by ELISA. Horizontal lines represent the mean values. (C , D) At day 10 post first CII immunization, the expression of CXCR5 (C) and the expression of inducible T-cell co-stimulator (ICOS) and programmed cell death-1 (PD-1) (D) in draining lymph nodes (LNs) were analyzed by fluorescence-activated cell sorting (FACS). Data represent gated CD4⁺ (C) and CXCR5⁺CD4⁺ cells (D). Bar graphs show percentages of CXCR5⁺ cells (C) and ICOS⁺PD-1⁺ cells (D). (E) cDNA was obtained from sorted CXCR5⁺CD4⁺ T cells isolated from draining LNs on day 10 post first CII immunization, and expression levels of Bcl-6 and IL-21 were analyzed by real-time PCR. Data are representative of two independent experiments with similar results, and represent the mean ± standard error of the mean. *P < 0.05, versus C57BL/6 mice, Student’s t-test.