Figure 1. Cd11c drives Cre-mediated recombination in lung DCs and AMs while Sftpc drives Cre-mediated recombination in ECs.

(a) Fluorescent microscopic images of a PCLS prepared from progeny of Cd11c-cre x LoxP-Stop-LoxP-tdTomato cross. Top images show Tomato⁺ cells (red), CD103⁺ (green), Tomato⁺CD103⁺ DCs (yellow) and E-cadherin⁺ ECs (blue). Bottom images show Tomato⁺ cells (red), SIRP-1α⁺ (green), Tomato⁺SIRP-1α⁺ DCs (yellow) and E-cadherin⁺ ECs (blue). Low power images (left) include white squares marking an area also shown in higher power (right). (b) Real time PCR analysis of Myd88 exon 3 in cDCs and AMs sorted from Myd88^fx/fx (Cre⁻), Myd88^fx/fx Cd11c-cre (Cd11c-cre⁺), Myd88^fx/fx Sftpc-cre (Sftpc-cre⁺), and Myd88^−/− mice at 6h post-sensitization with OVA/FLA. Lung cDCs were gated on single cells that are CD11c^hi, nonautofluorescent, I-A^b+, Ly6C⁻, and CD88⁻. Data are representative of three to six separate cDC or AM sorts per genotype and are normalized to the Eef1g housekeeping gene. (c) Fluorescent microscopic images of a frozen lung section from progeny of Sftpc-cre x LoxP-Stop-LoxP-tdTomato cross. Shown are a low power image of the whole lung, including the bifurcation of the trachea (top), and a high power image of a representative small airway, showing fluorescent ECs in the airway and alveoli (bottom). tdTomato cells (red), DAPI (blue), and Differential Interference Contrast (DIC)/ brightfield (gray). (d) Real time PCR for the ‘floxed’ exon 3 region of the Myd88 gene in ECs sorted from Myd88^fx/fx (Cre⁻), Myd88^fx/fx Cd11c-cre (Cd11c-cre⁺), Myd88^fx/fx Sftpc-cre (Sftpc-cre⁺), and Myd88^−/− mice at 2h post-sensitization with OVA/FLA. Data is representative of three different EC sorts per genotype. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001