B cell deficiency of SPPL2a−/− mice was recovered to a significant degree in SPPL2a−/− CD74−/− mice
| Cell type | Wild-type | SPPL2a−/− | CD74−/− | SPPL2a−/− CD74−/− | P-value | |||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | SPPL2a−/−/do-ko | ||
| BM (% of viable cells) | ||||||||||
| B cells | B220+ | 24.0 | 7.7 | 22.8 | 5.9 | 17.4 | 3.5 | 16.7 | 6.3 | ≥0.05 |
| Pro– /pre–B cells | B220+ IgM− | 13.8 | 4.4 | 16.6 | 3.1 | 12.2 | 1.7 | 10.8 | 3.7 | <0.05* |
| Immature B cells | B220+ IgM+ | 3.7 | 1.1 | 3.8 | 2.1 | 3.2 | 1.3 | 2.9 | 1.3 | ≥0.05 |
| Recirculating B cells | B220high | 4.7 | 3.3 | 0.8 | 0.8 | 0.8 | 0.6 | 1.6 | 1.1 | ≥0.05 |
| Spleen (% of viable cells) | ||||||||||
| B cells | B220+ | 53.4 | 6.4 | 25.0 | 6.6 | 39.3 | 7.8 | 35.3 | 10.1 | <0.05* |
| T1 transitional | B220+ CD21low CD24high | 9.0 | 2.2 | 14.3 | 3.9 | 11.1 | 3.3 | 9.5 | 4.4 | <0.05* |
| T2 transitional | B220+ CD21high CD24high | 7.2 | 1.9 | 0.3 | 0.5 | 10.8 | 4.3 | 9.5 | 3.6 | <0.001*** |
| Mature B cells | B220+ CD21low CD24low | 32.0 | 4.0 | 4.1 | 2.0 | 11.3 | 2.0 | 10.4 | 3.0 | <0.001*** |
| Spleen (x106 splenocytes) | ||||||||||
| B cells | B220+ | 39.7 | 7.4 | 6.8 | 3.1 | 12.3 | 4.0 | 9.2 | 5.1 | ≥0.05 |
| T1 transitional | B220+ CD21low CD24high | 6.8 | 1.7 | 3.8 | 1.8 | 3.4 | 1.5 | 2.3 | 1.5 | ≥0.05 |
| T2 transitional | B220+ CD21high CD24high | 5.5 | 1.9 | 0.03 | 0.03 | 3.7 | 1.1 | 2.6 | 1.3 | <0.05* |
| Mature B cells | B220+ CD21low CD24low | 23.6 | 4.4 | 1.2 | 0.7 | 3.2 | 1.3 | 2.8 | 1.7 | ≥0.05 |
| LNs (% of viable cells) | ||||||||||
| B cells | B220+ | 28.1 | 4.8 | 3.1 | 1.3 | 12.6 | 3.0 | 12.4 | 2.7 | <0.001*** |
| Peritoneal cells (% of viable cells) | ||||||||||
| B cells | B220+ | 40.1 | 12.8 | 8.5 | 5.6 | 34.5 | 7.0 | 38.0 | 9.4 | <0.001*** |
| B1 | B220neg/low CD19high | 24.5 | 8.7 | 7.7 | 5.5 | 27.2 | 8.8 | 31.8 | 9.1 | <0.001*** |
| B2 | B220high CD19+/low | 15.1 | 5.0 | 0.8 | 0.4 | 7.3 | 2.4 | 7.4 | 2.6 | <0.01** |
| Cell type | Wild-type | SPPL2a−/− | CD74−/− | SPPL2a−/− CD74−/− | P-value | |||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | SPPL2a−/−/do-ko | ||
| BM (% of viable cells) | ||||||||||
| B cells | B220+ | 24.0 | 7.7 | 22.8 | 5.9 | 17.4 | 3.5 | 16.7 | 6.3 | ≥0.05 |
| Pro– /pre–B cells | B220+ IgM− | 13.8 | 4.4 | 16.6 | 3.1 | 12.2 | 1.7 | 10.8 | 3.7 | <0.05* |
| Immature B cells | B220+ IgM+ | 3.7 | 1.1 | 3.8 | 2.1 | 3.2 | 1.3 | 2.9 | 1.3 | ≥0.05 |
| Recirculating B cells | B220high | 4.7 | 3.3 | 0.8 | 0.8 | 0.8 | 0.6 | 1.6 | 1.1 | ≥0.05 |
| Spleen (% of viable cells) | ||||||||||
| B cells | B220+ | 53.4 | 6.4 | 25.0 | 6.6 | 39.3 | 7.8 | 35.3 | 10.1 | <0.05* |
| T1 transitional | B220+ CD21low CD24high | 9.0 | 2.2 | 14.3 | 3.9 | 11.1 | 3.3 | 9.5 | 4.4 | <0.05* |
| T2 transitional | B220+ CD21high CD24high | 7.2 | 1.9 | 0.3 | 0.5 | 10.8 | 4.3 | 9.5 | 3.6 | <0.001*** |
| Mature B cells | B220+ CD21low CD24low | 32.0 | 4.0 | 4.1 | 2.0 | 11.3 | 2.0 | 10.4 | 3.0 | <0.001*** |
| Spleen (x106 splenocytes) | ||||||||||
| B cells | B220+ | 39.7 | 7.4 | 6.8 | 3.1 | 12.3 | 4.0 | 9.2 | 5.1 | ≥0.05 |
| T1 transitional | B220+ CD21low CD24high | 6.8 | 1.7 | 3.8 | 1.8 | 3.4 | 1.5 | 2.3 | 1.5 | ≥0.05 |
| T2 transitional | B220+ CD21high CD24high | 5.5 | 1.9 | 0.03 | 0.03 | 3.7 | 1.1 | 2.6 | 1.3 | <0.05* |
| Mature B cells | B220+ CD21low CD24low | 23.6 | 4.4 | 1.2 | 0.7 | 3.2 | 1.3 | 2.8 | 1.7 | ≥0.05 |
| LNs (% of viable cells) | ||||||||||
| B cells | B220+ | 28.1 | 4.8 | 3.1 | 1.3 | 12.6 | 3.0 | 12.4 | 2.7 | <0.001*** |
| Peritoneal cells (% of viable cells) | ||||||||||
| B cells | B220+ | 40.1 | 12.8 | 8.5 | 5.6 | 34.5 | 7.0 | 38.0 | 9.4 | <0.001*** |
| B1 | B220neg/low CD19high | 24.5 | 8.7 | 7.7 | 5.5 | 27.2 | 8.8 | 31.8 | 9.1 | <0.001*** |
| B2 | B220high CD19+/low | 15.1 | 5.0 | 0.8 | 0.4 | 7.3 | 2.4 | 7.4 | 2.6 | <0.01** |
B cell subsets were analyzed by flow cytometry in BM, spleen, LNs, and peritoneal lavage of wild-type, SPPL2a−/−, CD74−/−, and SPPL2a−/− CD74−/− (do-ko) mice. Proportions of cell populations are shown as percentage of viable cells (PI−) or absolute cell numbers, respectively. Results represent mean ± SD from n = 6 mice per genotype (BM, absolute number of splenocytes, LNs, and peritoneal cells) or n = 12 mice (spleen, % of viable cells), respectively. Data were analyzed by one-way ANOVA with Bonferroni post-hoc testing. ***, P < 0.001; **, P < 0.01; *, P < 0.05.