Figure 2.
Increased number of B1a cells in IgH-hEBI2 mice. (A). Gating scheme used to define CD19+IgM+B220lowCD5+ B1a and CD19+IgM+B220+CD5− B2 cell populations in spleen and blood. (B) B1a and B2 B-cell subsets in blood samples from 6- to 9-month-old WT and IgH-hEBI2 mice were analyzed by FACS as shown in panel A. Cells were gated on lymphocytes. The number of cells in the B-cell subsets is given as percentage of total leukocytes. The results are mean ± SEM of data from 3 mice. *P < .05 by Student t test. (C-D) Subsets of splenic B1a and B2 B cells of young (12-15 weeks) (C) and old (16-18 months) (D) WT and IgH-hEBI2 mice were analyzed by FACS as shown in panel A. Cells were gated on lymphocytes. The numbers of cells in the B1a and B2 B-cell subsets are given as percentage of total lymphocytes. Data are mean ± SEM of data from 3 to 9 mice. **P < .01 and ***P < .001 by Student t test. (E). Subsets of B1 and B2 B cells in the peritoneum of young (13 weeks) WT and IgH-hEBI2 mice were analyzed by FACS as shown in panel A. Cells were gated on lymphocytes. The numbers of cells in the B1a and B2 B-cell subsets are given as percentage of total lymphocytes. Data are mean ± SEM of data from 5 mice. ***P < .001 and ****P < .0001 by Student t test. (F-H) The concentration of serum IgM (F), IgG (G), and anti-dsDNA IgM (H) in IgH-hEBI2 and WT mice was determined by ELISA. The results are mean ± SEM of data from 13 IgH-hEBI2 and 12 WT mice. **P < .01 and ***P < .001 by Student t test. (I) Gating scheme used to define splenic B220+IgM+CD21+CD23− MZ and B220+IgM+CD21−CD23+ follicular B-cell subsets. (J-K) Subsets of splenic follicular (Fo.) and MZ B cells of young (12-15 weeks) (J) and old (16-18 months) (K) WT and IgH-hEBI2 mice were analyzed by FACS as shown in panel I. Cells were gated on lymphocytes. The numbers of cells in the follicular and MZ B-cell subsets are given as percentage of total lymphocytes. Data are mean ± SEM of data from 3 to 9 mice. ***P < .001 by Student t test. (L) Correlation of the numbers of CD19+/B220low/− B cells as determined by FACS and hEBI2 expression as determined by qPCR in 7 IgH-hEBI2 founder mice. Pearson correlation coefficient is 0.96 with P = .0005.