Cell culture Bone marrow–derived macrophages (BMDM) from WT and Apoe mice were prepared as adherent cultures using recombinant mouse M-CSF (30 ng/ml, Peprotech). For ectopic expression of apoE in Apoe BMDMs and Ly-6C monocytes, the cells were cultured in Opti-

Mice All mice were housed and bred in specific pathogen–free conditions in the Animal Research Facility at the San Francisco Veterans Affairs Medical Center. All animal experiments were approved by the Institutional Animal Care and Use Committee at the VA Medical Center. WT C57BL/6, Ldlr (B6.129S7-Ldlr/J) and Apoe (B6.129P2-Apoe/J) mice (3-4 weeks old) were purchased from The Jackson Laboratory and fed with a rodent chow diet containing 4.0% fat (Harlan Teklad, 2916), or high fat diet (21% fat, 1.5% cholesterol, Research Diets, D12079B). ApoeLdlr and ApoeLdlr mice, established as previously described, were fed a rodent chow diet of equal nutritional value containing 4.0% fat (Harlan Teklad, 2916) and 9.0% fat (Harlan Teklad, 2919) respectively.