Figure 4.

Most macrophages around alveoli have a stellar shape and correspond to so-called ductal macrophages. (A–D) Three-dimensional maximum intensity projections (MIPs) of confocal microscopy images representative of optically cleared C57BL/6J lactating mammary glands. (A) Predominance of stellar-shaped F4/80 ^pos alveolar cells closely associated with SMA^pos myoepithelial cells among mammary gland CD45^pos leukocytes. (B–D) F4/80 ^pos alveolar cells (white arrows) are CD11c ^pos, CD11b^neg, and MHCII ^pos. (E) Four sequential optical slices (1.3 µm thick), in which the depth (z value) is relative to the first image in the sequence, showing the intercalary position of CD45^pos CD11c^pos cells (white arrows) between the luminal and basal epithelial cells in two distinct alveoli. Scale bars = (A) 100 µm, (B–E) 50 µm.