Obesity causes changes in the architecture and cellular composition of lymph nodes.

<p><b>A.</b> Representative florescent micrograph (2.5× magnification) of inguinal lymph nodes harvested from control and obese mice and stained for B cells (B220; purple) and T cells (CD3; green). Note loss of follicular pattern and disorganization in obese mice. <b>B.</b> Representative florescent micrographs (2.5x) of inguinal lymph nodes harvested from control (left panels) and obese (right panels) wild-type mice stained for CCL21 (red) and DAPI (blue). CCL21 expression is shown on top panels with DAPI overlay on the bottom. Dotted circled represent follicular regions. Note loss of CCL21 expression gradients in obese animals. <b>C.</b> Representative whole mount immunofluorescent staining (Green = LYVE-1; Red = CCL21; Blue = DAPI) of ear sections from control (top) and obese (bottom). Sections are shown at 63× magnification. LYVE-1 staining is shown on the left; CCL21 is the middle panel; overlay is shown on the right panels. Dashed lines in the middle panel is the region of LYVE-1 vessel. <b>D.</b> Mean area of LYVE-1/CCL21 co-localization (presented as a percentage of LYVE-1 area overall) in control and obese mice. <b>E., F. G., H.</b> Flow cytometry analysis of T-helper cells (CD45+/CD3+/CD4+; <b>E</b>), cytotoxic T cells (CD45⁺/CD3⁺/CD8⁺; <b>F</b>); B cells (CD45⁺/B220⁺/CD19⁺; <b>G</b>), and macrophages (CD45^+//B220⁺/CD11b⁺; <b>H</b>). Mean percentage of cells from 4–5 animals per group is presented.