Monocytes are required for mitogenic effects of SAA on Treg. (A) Expression of TLR2, TLR4, FPRL-1, CD36, and RAGE by immune cell subsets (n = 6). (B) Suppression assays with SJIA plasma and HC plasma in the presence or absence of monocytes (n = 5). (C left) Frequency of Treg in peritoneal fluid collected 16 hours after intraperitoneal injection with recombinant human SAA (rhSAA) in monocyte-depleted mice (n = 8). 400 μL of liposome solution (clodronate vs empty) was injected intraperitoneally 24 hours before SAA injection. (Right) Representative FACS plots of Treg frequency in peritoneal fluid. (D left) Percentage of proliferating Treg in peritoneal fluid after SAA injection in monocyte-depleted mice. (Right) Representative FACS plots of percentages of proliferating Teff and Treg in peritoneal fluid. Paired ANOVA (A), paired 2-tailed t tests (B), and unpaired 2-tailed t tests (C-D) were used for statistical analyses. Horizontal bars represented median values; bar graphs represented means and SEs where indicated throughout the figure.
