The α and β chains of the Interleukin 2 receptor (IL2Rα and IL2Rβ) were detected at the surface of cultured fibroblastic cells by flow cytometry, using monoclonal antibodies (mAbs) directed against the IL2Rα and the IL2Rβ. These cells bound (FITC)-IL2 and this binding was inhibited by an excess of cold ligand and by mAbs recognizing the IL2 binding sites of the α and β chains. Internalisation studies show that the fibroblastic IL2R/IL2 complex is internalized at 37°C. By Northern Blot analysis we detected the presence of specific transcripts for the IL2Rα and IL2Rβ genes. Finally, the addition of exogenous IL2 specifically modified the surface expression of different antigens involved in the process of immunosurveillance. Indeed, IL2 at concentrations affecting the high affinity IL2R caused the down regulation of ICAM-1 protein. IL2 also decreased the surface expression of the class I and class II HLA. By contrast, the use of IL2 concentrations which saturate the intermediate affinity IL2Rβ caused the up regulation of the surface expression of the ICAM-1 protein. ICAM-1 is the natural ligand for the LFA-1 integrin expressed at the surface of lymphoid cells. ICAM-1/LFA-1 interactions favour homotypic and heterotypic cell-cell adhesion. Since human fibroblasts express an LFA-1 like molecule, we propose that in these cells IL2 can modify homotypic and heterotypic interactions acting on the surface expression of ICAM-1 protein. The presence of the IL2R on human fibroblasts as well as the IL2 dependent modulation of ICAM-1, class I and class II HLA may influence the immune response inside reactive tissues and tumors.
|Number of pages||8|
|Journal||Pathology Research and Practice|
|Publication status||Published - 1994|
- Flow cytometry
- Interleukin-2, -R
ASJC Scopus subject areas
- Pathology and Forensic Medicine