Characterization of the murine model of HCDD. (A) Splenocytes from 6-month-old WT, CH1⁺, or CH1⁻ (top) and DH, DH-CH1⁺, or DH-CH1⁻ (bottom) mice were stained with the indicated antibodies and analyzed by flow cytometry. Representative results from 3 independent experiments with ≥2 mice of each strain are shown. Numbers indicate percentages of plasma cells on biparametric graphs and human γHC-positive plasma cells on histograms. (B) Serum human γHC production from 8- to 12-week-old mice. Each dot represents an individual mouse. Results are expressed in log scale as mean ± SEM (µg/mL; n = 9-14 per group in ≥3 independent experiments; ns, not significant; ***P < .001). (C) Human γHC production in supernatants of 6-hour cultures of nonstimulated spleen cells (left) and 3-day LPS stimulated B cells (right). Plated cell counts were normalized on the number of secreting CD138⁺ cells. Means ± SEM (ng/mL) are shown (n = 4 per strain in 2 independent experiments; *P < .05; ***P < .001).