Binding of IL-1 beta to IL-1R type II at single cell level.
To gain information on the possible biologic role of IL-1R type II (IL-1RII), expression of the 68-kDa IL-1 binding protein on human lymphoblastoid B cells was investigated at single cell level. Binding of iodinated IL-1 beta was evaluated by autoradiography on cytosmears of IL-1RII positive B cell lines RAJI, the RAJI clone 1H7, and STS 25. Results obtained suggest an heterogeneity of IL-1RII expression within the B cell population, with only 5 to 16% of the cells able to bind IL-1 beta. Up-regulation of IL-1RII expression by dexamethasone, evident in conventional binding assays, was achieved through both increase in the number of IL-1 binding cells (14-30%) and augmentation of receptor density on positive cells, By combining autoradiography with immunocytochemical staining, it could be shown that about 80% of IL-1RII + cells were negative for Ki67, a nuclear antigen expressed from late G1 to M phase. Cell cycle dependent expression of IL-1RII was confirmed on cells enriched in different phases of the cell cycle by counterflow centrifugal elutriation. It is thus proposed that IL-1RII is associated to the cell cycle.
Stoppacciaro
A
A
Department of Human Biopathology, University La Sapienza, Roma, Italy.
Bossu
P
P
Ghiara
P
P
Ruco
L P
LP
Censini
S
S
Scapigliati
G
G
Nuti
S
S
Tagliabue
A
A
Baroni
C D
CD
Boraschi
D
D
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001345:Autoradiography; D002453:Cell Cycle; D002460:Cell Line; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism*; D037181:Lectins, C-Type; D011971:Receptors, Immunologic / Q000032:analysis / Q000378:metabolism*; D017472:Receptors, Interleukin-1; D015375:Receptors, Interleukin-2 / Q000032:analysis; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D007375:Interleukin-1; D037181:Lectins, C-Type; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D015375:Receptors, Interleukin-2; D000099192:CD69 Antigens