Figure 2: Both Ly-6B⁺ and Ly-6B⁻ inflammatory macrophages (MØ) are derived from the bone marrow.

Partial BM chimeras were generated as previously described²⁶, after shielding the peritoneal cavity, and then were left to recover for 6 weeks. (a) Analysis of blood myeloid cell chimerism 1 day before induction of peritonitis shows a stable chimerism in all experimental animals. Each line links the data from an individual mouse. (b) Gating strategy for the identification of Res and inflammatory (Inf) MØ (both Ly-6B⁺ and Ly-6B⁻) 72 h after the induction of peritonitis by i.p. administration of 2 × 10⁶ zymosan particles. The plot has been pre-gated on CD11b^highF4/80^low-high cells as previously reported¹⁸. (c) Representative flow-cytometric analysis of the indicated MØ subsets to determine the level of chimerism between CD45.1 recipient cells and CD45.2 donor cells. (d) Graphical representation of the chimerism in all of the experimental animals correlating the chimerism of the three peritoneal MØ subsets with that of Ly-6C^high blood monocytes within the same animal. Data were analysed by linear regression, and r² values are indicated alongside significance testing for a non-zero slope. Each symbol represents an individual irradiation chimera.