Interleukin-4 receptors on human blood mononuclear cells.
We have studied regulation of the expression of the interleukin-4 receptor (IL-4R) on human blood mononuclear cells (PBMC) using both 125I-IL-4 binding assay and flow cytometric analysis of biotinylated IL-4 (B-IL-4) binding. PBMC express approximately 300 high-affinity IL-4R per cell (Kd = 25-100 pM). Activation of PBMC for 60-80 hr by phytohemagglutinin (PHA) or concanavalin A (Con A) results in a 2- to 4.5-fold increase of IL-4R number without alteration of IL-4R affinity for IL-4. Binding of B-IL-4 showed that IL-4R expression is upregulated on virtually all PHA-stimulated PBMC, whereas it mostly concerns larger cells among Con A-activated PBMC. Reculture of PHA-blasts with 1 nM IL-4 further upregulates IL-4R expression to a level approximately 10-fold higher than observed on freshly isolated PBMC. Interestingly, IL-4 is able to reinduce high IL-4R levels on cells that have been deprived of IL-4 for 20 hr and IL-2 is almost as efficient. Finally, SDS-PAGE analysis of IL-4-binding molecules on unstimulated, PHA- and PHA/IL-4-activated PBMC revealed the same three peptides of MW 140-130, 80-75, and 70-65 kDa, as shown on human cell lines.
Zuber
C E
CE
Schering-Plough (UNICET), Laboratory for Immunological Research, Dardilly, France.
Galizzi
J P
JP
Harada
N
N
Durand
I
I
Banchereau
J
J
D001710:Biotin; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000502:physiology; D015847:Interleukin-4 / Q000097:blood* / Q000502:physiology; D007457:Iodine Radioisotopes; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D010835:Phytohemagglutinins / Q000494:pharmacology; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000097:blood*
D003432:Cross-Linking Reagents; D007376:Interleukin-2; D007457:Iodine Radioisotopes; D010835:Phytohemagglutinins; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D015847:Interleukin-4; D001710:Biotin