CD11b⁺ myeloid cells localize in close proximity with gp38⁺ stromal cells in neonatal LNs, which contain abundant CD11b⁺F4/80⁺MHCII^low cells. (A) Expression of CD11b and gp38 in neonatal LNs. Cryosections of day 3-old C57BL/6 mice were stained with antibodies as indicated. Shown are sections representative for 5 animals analyzed. (B) Flow cytometric analysis of CD45⁺CD11b⁺ myeloid cells compartment in neonatal peripheral LNs. DAPI⁻CD45⁺ cells were grouped into CD11b⁺F4/80⁺ (top box) and CD11b⁺F4/80⁻ (bottom box) subpopulations. The CD11b⁺F4/80⁺ subpopulation was further subdivided into CD11c^low (blue box) and CD11c^high (red box). Solid lines, mAbs as indicated; dotted lines, isotype. Data are representative of 3 independent experiments.