Plasma cells are not affected by Hsp90 inhibitors in vivo. (A) Bar graph of flow cytometric analysis of the frequency of B220⁻CD138⁺ plasma cells in the spleen after 6 weeks of treatment with vehicle or 17-DMAG. Values are means ± SEM of ≥ 6 mice per group. P > .05. (B) Representative corresponding flow cytometric analysis, with numbers in the top panels representing the percentages of plasma cells with respect to total cell numbers. (C) Bar graph of flow cytometric analysis of the frequency of B220⁻CD138⁺ plasma cells in the bone marrow after 6 weeks of treatment with vehicle or 17-DMAG. Values are means ± SEM of ≥ 6 mice per group. P > .05. (D) Representative corresponding flow cytometric analysis, with numbers in the top panels representing the percentages of plasma cells with respect to total cell numbers. (E) Bar graph of flow cytometric analysis of the frequency of B220⁺PNA⁺ germinal center B cells in the spleen after 6 weeks of treatment with vehicle or 17-DMAG. Values are means ± SEM of ≥ 6 mice per group. P > .05. (F) Representative corresponding flow cytometric analysis, with numbers in the top panels representing percentages of plasma cells with respect to total cell numbers. (G) Bar graph of immunohistochemical analysis of the frequency of CD138⁺ mCVIIC-specific autoreactive plasma cells from draining lymph nodes after 6 weeks of treatment with vehicle or 17-DMAG. Values are means ± SEM of ≥ 6 mice per group. P > .05. (H) Representative immunohistochemical specimens obtained from draining lymph nodes of mice injected with vehicle or 17-DMAG illustrating comparable numbers of autoreactive plasma cells (double stained in blue and brown) by the end of the treatment period.