Figure 5. LNK regulates pro-B homeostasis and aging.

(A and B) Young and old Lnk^–/– mice show increased pro-B cells in the BM. Percentages of various lymphoid progenitors in young and old mice are shown. The following markers are used: LMPP, Lin^–Kit⁺Sca1⁺Flt3^hi; CLP, Lin^–IL-7R⁺Flt3⁺Sca1^loKit^lo; pre-pro B, Lin^–Ly6C^–NK1.1^–IgM^–AA4.1⁺CD19^–B220⁺; pro-B, B220⁺CD43⁺AA4.1⁺CD19⁺. *P < 0.05; **P < 0.01; ***P < 0.0001; ns, not significant, 2-tailed Student’s t test. n = 8–9 mice per group. (C) Young and old Lnk^–/– mice show increased numbers of pre-B cells and immature B cells in the BM. Representative flow plots are shown. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant, 2-tailed Student’s t test. n = 7–9 mice per group. (D) Young p53^–/–Lnk ^–/– mice show increased pro-B% in the BM. Pro-B cells were determined by a stringent panel of markers B220⁺IgM^–Nk1.1^–Ly6C^–CD43⁺AA4.1⁺CD19⁺, as shown by representative flow plots. n = 7–12 mice per group.