Figure 4.

TCRβ+CD138+ cells are unable to promote lupus diseases development in young MRL/Lpr mice. (A–C) Sorted splenic TCRβ+CD138+ and TCRβ+CD138- cells from 10 to 12 weeks old MRL/Lpr mice were co-cultured with purified splenic B cells from 6 weeks old mice in the presence of anti-CD3/CD28 antibodies for 5 days. After gating-out TCRβ+ T cells, the proliferation of B cells (A) and the frequency of plasma cells (CD19^intCD138+) (B) were measured by flow cytometry. Mean ± SD of 10 mice (A) or six mice (B) from three independent experiments are plotted. (C) Culture supernatants from the above co-culture experiment were analyzed for total IgM and IgG concentrations by ELISA. Mean ± SD of 10 mice from three independent experiments are plotted. (D,E) Splenic TCRβ+CD138+ and TCRβ+CD138- cells were sorted from 10 to 12 weeks old MRL/Lpr mice and then adoptively transferred into 7 to 8 weeks old MRL/Lpr mice without disease symptoms. (D) Autoreactive IgG antibody (dsDNA) and proteinuria levels were measured on indicated days. Mean ± SEM of 15 mice from three independent experiments are plotted. (E) Kidneys were collected 2 weeks after the transfer of cells and histopathological evaluations were performed on H&E and Masson stained specimens. Average pathology scores of 10 mice from two separate experiments are plotted. (F) Splenic TCRβ+CD138+ and TCRβ+CD138- cells were sorted from 10 to 12 weeks old MRL/Lpr mice and then adoptively transferred into 11 to 12 weeks old MRL/Lpr mice with existing disease symptoms. Autoreactive IgG antibody (dsDNA) and proteinuria levels were measured on indicated days. Mean ± SEM of 10 mice from two independent experiments are plotted. Two tailed Mann-Whitney rank sum test was used to calculate statistical significance.