Rat thymic epithelial cells in culture constitutively secrete IL-1 and IL-6.
To study the in vitro interactions between rat thymic non-lymphoid cells and thymocytes, we established a system for long-term cultivation of thymic epithelial cells (TEC). TEC were cultivated and successfully propagated for over 8 months in RPMI 1640 medium containing 15% FCS, dexamethasone, insulin, epidermal growth factor, and poly-L-lysin as an adhesive matrix. Their epithelial nature has been confirmed using monoclonal anti-cytokeratin (CK) antibodies. More than 95% of these cells were reactive with K 8.13 and CK 8 mAbs, which are pan-epithelial markers for rat TEC in situ. An epithelial cell clone (TE-R 2.5) established from a long-term TEC culture was 100% reactive with these anti-CK antibodies. Phenotypic analysis of TEC cultures was performed by a large panel of mAbs reactive with a subset of rat TEC or CK polypeptides as well as UIex europaeus agglutinin I using a streptavidin-biotin immunofluorescence assay. Although the results obtained demonstrated phenotypic heterogeneity among these cells, most cultures, including the TE-R 2.5 clone, were of subcapsular/medullary phenotype. Medium conditioned by TEC cultures exhibited IL-1 and IL-6 activities when tested on D10S and B9 sensitive cell lines, respectively. Cytokine activities were neutralized (IL-1) or significantly inhibited (IL-6) by specific polyclonal antibodies. In addition, both anti-IL-1 and anti-IL-6 antibodies reacted with TEC in culture and epithelial (CK-positive) cells on thymic cryostat sections, indicating that thymic epithelium provides an important intrathymic source for molecules contributing to T cell activation.
Colić
M
M
Institute of Medical Research, Military Medical Academy, Belgrade, Crnotravska, Yugoslavia.
Pejnović
N
N
Kataranovski
M
M
Stojanović
N
N
Terzić
T
T
Dujić
A
A
D000818:Animals; D002478:Cells, Cultured; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D005455:Fluorescent Antibody Technique; D007375:Interleukin-1 / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D010641:Phenotype; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology*
D007375:Interleukin-1; D015850:Interleukin-6