Peritoneal anti-Sm B-1 cells in 2-12H Tg, 2-12H MRL, 2-12H/Fas^lpr, and 2-12H MRL/Fas^lpr mice. (A) Phenotypic analysis of peritoneal B cells from 2-12H Tg, 2-12H MRL, 2-12H/Fas^lpr, and 2-12H MRL/Fas^lpr mice. Peritoneal cells from 1-month-old and 3-month-old mice were stained with CD19, IgM, CD11b, and Sm. Anti-Sm B-1 cells are boxed. All histograms are gated on CD19⁺ B cells. (B) Analysis of total B-1–cell numbers ± SEM (top and bottom graphs) and anti-Sm B-cell numbers ± SEM (middle) for mice between 1 and 6 months of age is shown.