APCs expressing a similar phenotype to the APCs in medullary cords were also detected in the paracortex of the human axillary lymph node. Anatomical definition was obtained by staining frozen lymph node sections with antibodies detecting CD3 and CD21 to identify the T lymphocyte–rich paracortex and follicles, respectively (A). Sequential sections were probed with a panel of antibodies to defining APC markers (B-G). In addition to the CD209⁺ APCs in the medullary cords, cells expressing low-level CD209 colonized the diffuse T-lymphocyte areas surrounding the medullary cords and follicles (B-G). The majority of CD209^lo APCs in the diffuse T-lymphocyte zones coexpressed CD68 (B), whereas CD14 (C) and CD206 (D) expression was variable. These CD209^lo APCs did not express CD1a (E), CD207 (F), CD208 (G), or BDCA-2 (H). BDCA-2⁺ APCs also lacked CD68 expression (I,J). Panels A to G were acquired from the same area on sequential sections. Blue represents DAPI staining of cell nuclei (A,H-J). Data are representative of 4 independent experiments. BDCA-2⁺ APC data are representative of 3 independent experiments.