PMC

Ultrastructure analysis for thymic epithelial cells for autophagy. Electron micrograph (×2,500) of thymus tissues from a 2-, b 12-, and c 24-month-old C57BL/6J ♀ mice. Seventy-nanometer ultrathin sections were stained with uranyl acetate and lead stain solution. They were observed under the transmission electron microscope and photographed at ×2,500. Arrow marks indicate the autophagic structure in thymic epithelial cells. d The number of autophagic structure in thymic epithelial cells were enumerated under the electron microscope and presented as the number of thymic epithelial cells and autophagic structure per 100 squares in the copper grid. This figure shows the representative results from three independent experiments. e The number of autophagic structure in subcapsullar thymic epithelial cell (Sc TEC), pale thymic epithelial cell (P TEC), intermediate thymic epithelial cell (Im TEC), dark thymic epithelial cell (D TEC), large medullary thymic epithelial cell (LM TEC), and in epithelial cell extension was enumerated under the electron microscope and presented as the number of thymic epithelial cells and autophagic vacuole (AV) per 100 squares in the copper grid. This figure shows the representative results from three independent experiments

Schematic representation of thymic epithelial cell (TEC) subsets, defined by their specific cell markers in the different thymic compartments (cortex, cortico-medullary junction (CMJ) and medulla). PDPN: podoplanin; TNC: thymic nurse complexes.

The known inborn errors of thymic stromal cells and their relative effects on 3rd pharyngeal pouch patterning, thymic organogenesis, thymic epithelial cell development and function. PP = pharyngeal pouch; PTH = parathyroids; RA = retinoic acid; TEC = thymic epithelial cell

Lipopolysaccharide-induced acute thymic atrophy and the cells subsets of thymus after a 24 h lipopolysaccharide treatment. (a) Representative flow cytometry plots of thymocyte subsets (CD4, CD8 double-negative [DN], double-positive [DP], or single-positive [SP]) were determined. (b) Proportion of thymocytes subsets. Percentage of thymocytes subsets were calculated based on the fluorescence-activated cell sorting profiles in the control and lipopolysaccharide treatment groups. (c) Representative flow cytometry plots of medullary thymic epithelial cells and cortical thymic epithelial cells. Cell subsets were determined based on the fluorescence-activated cell sorting profiles gated from CD45⁻EpCAM1⁺MHCII⁺cells, cortical thymic epithelial cells (CD45⁻EpCAM1⁺MHCII⁺UEA⁻) and medullary thymic epithelial cells (CD45−EpCAM1⁺MHCII⁺UEA⁺). (d) Frequency of thymic epithelial cells subsets were quantified by the fluorescence-activated cell sorting after a 24 h lipopolysaccharide challenge. (e) Immunohistochemical staining showed the thymic epithelial cell subsets, K5⁻K8⁺ cells (green-stained) represents cortical thymic epithelial cells, K5⁺K8⁻ cells (red-stained) represents medullary thymic epithelial cells, and K5⁺K8⁺ cells (yellow-stained) represents thymic epithelial progenitors. Scar bar is 50 μm. (f) Total number of medullary thymic epithelial cells and cortical thymic epithelial cells determined by the fluorescence-activated cell sorting. Values are mean ± standard error (n = 5). *P < 0.05 with respect to the control mice. EpCAM: Epithelial cellular adhesion molecule; MHC: Major histocompatibility complex; UEA: Ulex europeus lectin; K: Keratin. LPS: Lipopolysaccharide; TECs: thymic epithelial cells; cTECs: cortical thymic epithelial cells; mTECs: medullary thymic epithelial cells.