How interleukin-2 can affect human fibroblasts behaviour.
The alpha and beta chains of the Interleukin 2 receptor (IL2R alpha and IL2R beta) were detected at the surface of cultured fibroblastic cells by flow cytometry, using monoclonal antibodies (mAbs) directed against the IL2R alpha and the IL2R beta. 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 alpha and beta chains. Internalisation studies show that the fibroblastic IL2R/IL2 complex is internalized at 37 degrees C. By Northern Blot analysis we detected the presence of specific transcripts for the IL2R alpha and IL2R beta 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 IL2R beta 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.(ABSTRACT TRUNCATED AT 250 WORDS)
Plaisance
S
S
INSERM UNITE-268, Hôpital Paul-Brousse, Villejuif, France.
Alileche
A
A
Han
D
D
Rubinstein
E
E
Sahraoui
Y
Y
Jasmin
C
C
Azzarone
B
B
D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000187:drug effects* / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006680:HLA Antigens / Q000096:biosynthesis / Q000187:drug effects; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis / Q000187:drug effects; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000096:biosynthesis / Q000187:drug effects; D011233:Precipitin Tests; D015375:Receptors, Interleukin-2 / Q000378:metabolism
D006680:HLA Antigens; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D015375:Receptors, Interleukin-2; D018799:Intercellular Adhesion Molecule-1