Figure 6. B cell development and function in HET mice.

A. Normal marginal zone B cell and follicular B cell populations in the spleen of HET mice. Marginal Zone B cell (B220⁺CD21^hiCD23^low/−) and follicular B cell (B220⁺CD21^int/hiCD23^hi) populations in WT and HET spleens were analyzed by 3-color flow cytometry. Percentages are indicated. B. B1 B cell and B2 B cell subpopulation in peritoneal exudates of HET mice. Peritoneal exudate B1a (B220⁺CD23⁻CD5⁺IgM^hi), B1b (B220⁺CD23⁻CD5⁻IgM^hi) and B2 (B220⁺CD23⁺IgM^int/hi) B cells of WT and HET mice were analyzed by by 4-color flow cytometery. Percentages are indicated. C. Proliferation of B cells from HET mice. WT and HET spleen B cells were stimulated with different stimuli as indicated (anti-IgM: 5 µg/ml; IL-4∶10 ng/ml; anti-CD40 mAb: 2 µg/ml; LPS: 2 µg/ml). The cells were pulsed with ³H-thymidine 6 h before harvesting. ³H-thymidine uptake by the cells was measured at 24 h and 48h after the initiation of the culture. Samples were in triplicate, and means ± SD of CPM are shown. D. B cell activation markers CD80 and CD86 expression on activated WT and HET B cells. WT and HET spleen B cells were stimulated as described in C. CD80 and CD86 expression on B220⁺ B cells was measured by 3-color flow cytometry 24 h after the initiation of the culture. E. Plasma cells in the draining lymph nodes of immunized WT and HET mice. WT and HET mice were immunized with chick type II collagen with adjuvants at the tail base and sacrificed 21 days after the immunization. Isotype-switched plasmablast/plasma cells (IgD⁻IgM⁻CD138⁺B220^lo/−) from the draining lymph nodes of WT and HET were analyzed by 4-color flow cytometry. F. Serum collagen-specific antibody production in WT and HET mice. Sera from mice (WT n = 7, HET n = 4) as described in E were collected on day 21 after the immunization. Chick collagen-specific IgG Abs were measured by ELISA. The data are expressed as arbitrary titres. The titres between WT and HET groups were not statiscially significant (p = 0.8724, Student’s t test). Experiments A-E were repeated at least 3 times and representative data are shown.