Accumulation of GC B cells, increased serum IgG levels, and spontaneous GC formation in miR-146a TG mice at early ages. (A) The immunoglobulin levels were measured by the Milliplex assay in the sera from TG (n = 7 - 9) and WT (n = 5) mice at age 8 and 52 weeks. (B) The B-cell frequency and numbers in dLNs from 6- to 8-week-old WT and TG mice. (C) Detection of GCs by the immunohistochemistry analysis on dLN sections from WT and TG mice (PNA, brown; hematoxylin, blue). (D) The percentage of B220⁺PNA⁺CD38^lowGC B cells was determined by FACS in peripheral LNs from 8-, 26-, and 52-week-old mice, as well as in mLNs and PPs from 8-week-old mice (n = 4). All data are expressed in terms of mean ± standard deviation values. Comparison of means was performed with an unpaired Student 2-tailed t test. All data are representative of at least 3 independent experiments (*P < .05, **P < .01).