FIG 4.

Distribution of lymphoid cre expression in CD11c-cre and lysM-cre mice. (a) Naive CD11c-cre × flox-Tom and lysM-cre × flox-Tom mice were analyzed for tdTomato (Tom) expression in tissue sections. In lungs, CD11c-cre expression gave Tom⁺ AM (CD68⁺) but not AEC1 (PDP⁺) or AEC2 (SPC⁺). lysM-cre expression gave Tom⁺ AEC2 and AM. In LN, the expression of both CD11c-cre and lysM-cre gave Tom⁺ SSM (CD169⁺) and other Tom⁺ myeloid cells (CD68⁺). CD11c-cre labeled most DC (CD11c^hi). LysM-cre labeled <10% of DC. In spleens, both CD11c-cre and lysM-cre labeled myeloid cells in the MZ. CD11c-cre labeled most (although not all) CD11c⁺ cells, while lysM-cre labeled <5% of CD11c⁺ cells. (b) Example Tom⁺ fluorescence in B220⁺ cells of CD11c-cre⁺ and lysM-cre⁺ LN. (c) Summary of Tom expression in LN and spleens of lysM-cre⁺ and CD11c-cre⁺ mice. Bars show the mean percentages of Tom⁺ cells ± standard errors of the means for each cell type marker. Cells counts are for at least 3 sections per organ. (d) The olfactory epithelium of lysM-cre × flox-Tom mice contains occasional Tom⁺ cells, but they are OMP⁻ and thus are not olfactory neurons. They also lack the characteristic epithelium-spanning morphology of sustentacular cells and thus seem likely to be intraepithelial myeloid cells.