Reduced alveolar macrophages in CD11c.Cre^pos -LPL^fl/fl and CD11.Cre⁺ -LPL^fl/+ mice. (A) Vector design for generation of conditional allele of LPL, encoded by gene Lcp1. A conditional allele was generated by flanking exon 2 of the gene encoding LPL, Lcp1, with loxP sequences. Exon 2 includes the ATG start site and was targeted in the generation of the LPL^−/− mice, in which expression of LPL is deleted in all cells.¹⁵  (B) Confirmation of deletion of LPL from CD11c⁺ alveolar macrophages sorted from adult CD11c.Cre^pos-LPL^fl/fl mice, with alveolar macrophages derived from CD11c.Cre^neg-LPL^fl/fl mice shown as control. (C) Representative flow cytometry of CD45⁺ singlets from the BAL fluid from mice of indicated genotypes. Alveolar macrophages identified as CD11c⁺SiglecF⁺ cells, confirmed as macrophages by the expression of the pan-macrophage markers CD64 and MerTK. Percentage of alveolar macrophages shown in upper right corners of flow plots and event count of cells identified as alveolar macrophages given in last panels. (D) Quantification of number of alveolar macrophages in recovered BAL fluid. Data from 4 independent experiments; n given below graphs. *One outlier value of 89 070 not shown on graph but included in statistical analysis. Exclusion of this outlier does not alter the statistical significance of differences between indicated groups. (E) Representative flow cytometry of whole lung homogenates from mice of the indicated genotypes. (F) Percentage of CD45⁺ cells that were alveolar macrophages (AMs), dendritic cells (DCs), or eosinophils (eos) obtained from whole lung homogenates from mice of indicated genotypes.