As expected, a similar phenomenon was observed in the lymph nodes; that is, compared with control MDSCs, lupus MDSCs significantly promoted the activation of macrophages (Fig. 1I), DCs (Fig. 1J), B cells (Supplementary Fig. 2A, B), and CD4+ T cells (Supplementary Fig. 2C, D) and increased the percentage of germinal center B cells (Supplementary Fig. 2E, F) and plasmacytes (Supplementary Fig. 2G, H) in mesenteric lymph nodes (mLNs). Here, CD4 is linked to systemic lupus erythematosus.