Model for the coexistence of host- and donor-derived AMs. (A) Strategy: First, lungs of mice were protected with lead prior to irradiation. Postirradiation, congenic BM cells were transferred intravenously. Set 1: irradiated CD45.1 mice received CD45.2 BM. Set 2: irradiated CD45.2 mice received CD45.1 BM. Eight weeks later, mice were treated with CLL via intranasal (IN) delivery to deplete AMs. By day 35, post-CLL treatment, mice contained ∼50% host- or donor-derived AMs. (B) Time course analysis of the reconstitution of host- and donor-derived AMs post-CLL treatment. Frequency of contribution of CD45.1⁺ donor-derived CD11c⁺CD64⁺ AMs was analyzed (illustrated by set 2). Data represents 3 independent experiments. (C) Time course analysis of the total numbers of AM post-CLL treatment. Data represents 3 independent experiments. (D) Morphologic analysis of BM reconstituted mice at day 35 post-CLL. Cytospin of sorted host- and donor-derived AM. MACs, macrophages.