The thymic microenvironment. Characterization of in vitro differentiation of the IT26R21 rat thymic epithelial cell line.

Published

Journal Article

We have previously postulated an in vivo pathway of thymic epithelial (TE) cell maturation in pre- and postnatal thymus, whereby endocrine medullary TE cells terminally differentiate to form Hassall's bodies. Epithelial-cell differentiation has been well documented in vitro using epidermal keratinocytes. Therefore, to characterize TE-cell differentiation in vitro, we observed clones of the rat TE cell line, IT26R21, after 4 and 14 days in culture. We found alterations in cell morphology, the cessation of cell proliferation, and the acquisition of a differentiation antigen defined by monoclonal antibody TE-19 (a marker of terminally differentiated epithelial cells). At light and electron microscopy, we detected progressive TE-cell stratification and squamous-cell formation between 4 and 14 days of culture. Autoradiography on day 14 showed that squamous TE cells in stratified layers did not incorporate tritiated thymidine, while surrounding smaller cells adhering to the substratum continued to synthesize DNA. At indirect immunofluorescence, only 3% of cells reacted with monoclonal antibody TE-19 at day 4, while on day 14, 22% of the TE cells were TE-19 positive (P less than 0.02). Antibody-TE-19 reactivity was limited to stratified, squamous TE cells. Additionally, we isolated a clone of the IT26R21 cell line that did not undergo these changes characteristic of TE cell differentiation. We conclude that IT26R21 TE cells are capable of undergoing programs of both terminal differentiation and cell renewal in vitro.

Full Text

Duke Authors

Cited Authors

  • Lobach, DF; Itoh, T; Singer, KH; Haynes, BF

Published Date

  • January 1987

Published In

Volume / Issue

  • 34 / 1

Start / End Page

  • 50 - 59

PubMed ID

  • 2440749

Pubmed Central ID

  • 2440749

Electronic International Standard Serial Number (EISSN)

  • 1432-0436

International Standard Serial Number (ISSN)

  • 0301-4681

Digital Object Identifier (DOI)

  • 10.1111/j.1432-0436.1987.tb00050.x

Language

  • eng