Identification of IL-1 receptors on human monocytes.
The expression and functional analysis of IL-1 beta R on human monocytes were investigated. Binding of 125I-IL-1 to human monocytes was found to be specific and saturable. Scatchard plot analysis revealed a single class of receptors with a binding constant of 600 pM and a receptor density of approximately 100 binding sites per cell. At 37 degrees C 54% of the labeled ligand was internalized over 2 h of incubation. Addition of 0.2% sodium azide to the cells reduced ligand internalization to 9% of total bound. Cross-linking studies revealed that the IL-1R in human monocytes had a Mr of 80 kDa. The addition of IL-1 to monocytes caused changes in membrane Ag expression as assessed by flow cytometric analysis. The results of this study identify IL-1 receptors on monocytes and suggest that IL-1 may act as an effector molecule for monocytes by enhancing expression of Ag correlated with cell differentiation and immune function.
Uhl
J
J
E. I. du Pont de Nemours and Co., Medical Products Department, Glenolden, PA 19036.
Newton
R C
RC
Giri
J G
JG
Sandlin
G
G
Horuk
R
R
D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001667:Binding, Competitive; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism* / Q000502:physiology; D007700:Kinetics; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000302:isolation & purification*; D017472:Receptors, Interleukin-1
D000944:Antigens, Differentiation, B-Lymphocyte; D015214:Antigens, Differentiation, Myelomonocytic; D000945:Antigens, Differentiation, T-Lymphocyte; D007375:Interleukin-1; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1