Characterization and histological localization of multipotent mesenchymal stromal cells in the human postnatal thymus
Résumé
The aim of this work was to characterize multipotent mesenchymal stromal cells (MSCs) in the postnatal human thymus and to localize these MSCs in the organ. Adherent cells isolated from thymus samples were characterized by cell-surface antigen expression. This showed that adherent cells have a MSC profile as assessed by the expression of CD73 and CD105 markers and the lack of CD45 expression. These cells are able to differentiate in vitro into adipocytes, osteoblasts, and chondrocytes and to inhibit mixed lymphocyte reaction. This indicates that isolated cells have all of the characteristics of MSC. The fibroblast colony-forming unit (CFU-F) assay was used to determine their frequency in the postnatal thymus. This frequency was 60.9 ± 14.8 CFU-F per 1 × 105 freshly isolated mononuclear cells. Moreover, taking advantage of CD34 and CD105 expression, immunohistological staining allowed us to localize MSC within interlobular trabeculae in close contact with the outer cortex. Polymerase chain reaction experiments indicated that thymic MSC expressed interleukin-7 and stromal cell-derived factor-1 messenger RNA. Overall, these results confirm previous findings of the presence in the adult human thymus of multipotent MSCs with a phenotype similar to adipose-derived adult stem cells. These results also show for the first time a histological localization of MSC in an organ. This suggests a possible role of thymic MSC in intrathymic differentiation. © Mary Ann Liebert, Inc. 2008.
Mots clés
5' nucleotidase
CD34 antigen
CD45 antigen
chondroitin sulfate proteoglycan 2
collagen type 3
cytokeratin
cytokeratin 19
cytokeratin 5
cytokeratin 6
endoglin
gene product
glyceraldehyde 3 phosphate dehydrogenase
interleukin 7
lipoprotein lipase
membrane antigen
messenger RNA
osteoclast stimulating factor 1
stromal cell derived factor 1
unclassified drug
vimentin
adipocyte
adipose tissue
antigen expression
article
cartilage cell
cell differentiation
cell isolation
controlled study
fibroblast
histology
human
human cell
human tissue
immunohistology
mesenchymal stromal cell
mesenchyme cell
mixed lymphocyte reaction
mononuclear cell
osteoblast
perinatal period
phenotype
polymerase chain reaction
priority journal
thymus
5'-Nucleotidase
Adipocytes
Adult Stem Cells
Antigens
CD
CD34
CD45
Cell Differentiation
Chondrocytes
Colony-Forming Units Assay
Female
Gene Expression Regulation
Humans
Infant
Newborn
Interleukin-7
Lymphokines
Male
Multipotent Stem Cells
Osteoblasts
Platelet-Derived Growth Factor
Receptors
Cell Surface
Reverse Transcriptase Polymerase Chain Reaction
RNA
Messenger
Stromal Cells
Thymus Gland