Figure 5.

Absence of B cells inhibits the development of spontaneous autoimmune polyneuropathy (SAP). (a) Examples of scatterplots confirming the lack of B cells [CD19⁺immunoglobulin (Ig)M⁺] in B cell‐deficient (muMT)/B7‐2^–/– non‐obese diabetic (NOD) mice. (b) Modest increase in the frequency of T_regs in muMT/B7‐2^–/– mice compared to that from B7‐2^–/– NOD mice. *P < 0·001 (n = 3). (c) T_regs from B7‐2^–/– and muMT/B7‐2^–/– mice suppressed T cell proliferation with similar efficacy in vitro (n = 3). Experimental conditions were as described in Fig. 2a. (d) T_regs from muMT/B7‐2^–/– mice decreased the percentage of CD4⁺interferon (IFN)‐γ T cells, and led to a greater increase in the percentage of CD4⁺interleukin (IL)−10⁺ T cells in co‐cultures when compared to T_regs from B7‐2^–/– mice. *P < 0·02 and **P < 0·002 (n = 3). Experimental conditions were as described in Fig. 2c. (e) Clinical severity.*P < 0·00001 for B7‐2^–/– versus muMT/B7‐2^–/–. (f). Sciatic nerve electrophysiology. *P < 0·003 for all parameters comparing B7‐2 KO versus muMT (n = 5–6).