Figure 2.

Role of SCA-1 Re-expression, Cell-Cycle Activation, and Cell Survival in LSK Expansion following LPS

(A and B) Lys-GFP reporter mice were challenged with LPS or PBS and their BM analyzed by FACS at 24 hr. (A) Representative density plots for Lys-GFP and FCγR expression on GMP, CMP, LSK, LT-HSC, and MPP subsets in the BM. (B) Absolute number per femur of total (red), FCγR⁺ (purple), and Lys-GFP⁺ (green) cells in LSK (left), LT-HSC (middle), and MPP (right) subsets (n = 3–4).

(C–E) Analysis of the BM after 24 hr of LPS or PBS challenge in WT, TRIF^−/−, and MYD88^−/− mice. (C) Representative contour plots (left) showing S phase (as bromodeoxyuridine incorporation) and G₀/G₁ phase for the LSK population. Bar graph (right) indicates the mean LSK distribution in S phase and G₀ phase (n = 16–20). (D) Bar graphs show the percentage of cells in S phase in LT-HSC, MPP1, and MMP2 (n = 7–10). (E) Bar graphs show the percentage of annexin V⁺ cells in LSK, LT-HSC, MPP1, and MMP2 (n = 3–5).

Data represent mean ± SEM. LPS versus PBS: ^∗p < 0.05, ^∗∗p < 0.01; WT versus MYD88^−/− or TRIF^−/−: ˆˆp < 0.01.