Differential expression and release of CD54 induced by cytokines.
Intercellular adhesion molecule-1 (ICAM-1, CD54) is upregulated in many cell types stimulated by cytokines. A human hepatoblastoma cell line (C3A, a subclone of HepG2/C3 that is currently being used as a surrogate liver) and human lung adenocarcinoma cells (A549) were stimulated with interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN gamma), or IL-6 to determine any differences in cell type responsiveness to individual cytokines for ICAM-1 upregulation. Time courses were performed with each cytokine evaluating ICAM-1 mRNA, surface expression, and cICAM-1 in the cell culture media. Between 3 and 6 hours, IL-1 beta (30 U/mL) stimulated the greatest increase in hepatocyte ICAM-1 mRNA, followed by IFN gamma (100 U/ mL), and IL-6 (100 U/mL) in order of potency. Except for IL-6, cytokine-induced hepatocyte surface levels of ICAM-1 (immunofluorescence flow cytometry, mAb R6.5) were dose dependent, with inhibition at higher concentration. Highest levels followed stimulation with INF gamma (P < .05). Significantly less was found after both IL-1 beta and TNF alpha; none was detected after IL-6 (P < .05). In contrast, IL-1 beta stimulated significantly more cICAM-1 release from hepatocytes than the other cytokines (P < .001), and IL-6 stimulated modest cICAM-1. Between 3 and 6 hours in the A549 cells, IL-1 beta stimulated the greatest increase in ICAM-1 mRNA, followed by TNF alpha. Both responses were greater than that observed in the hepatocytes. IFN gamma- and IL-6-induced ICAM-1 mRNA synthesis was not different from unstimulated A549 cells. Cytokine-induced A549 surface levels of ICAM-1 (immunofluorescence flow cytometry, mAb R6.5) was highest for IL-1 beta (peak levels similar to hepatocyte response), modest with TNF alpha (peak levels less than hepatocytes), detectable with IFN gamma (much less than hepatocytes), and nondetectable after IL-6. No ICAM-1 release from A549 cells was induced under any condition. In hepatocytes the amount of ICAM-1 mRNA was best accounted for by considering both cell surface levels of ICAM-1 and cICAM-1 levels. In human lung adenocarcinoma cells, the cytokine induction of ICAM-1 mRNA could potentially be accounted for by observing cell surface levels of ICAM-1 because no cICAM-1 was produced. These results suggest that surface ICAM-1 and cICAM-1 may be differentially controlled by each cytokine and by each parenchymal cell type.
Mickelson
J K
JK
Section of Cardiology, Methodist Hospital, Houston TX, USA.
Kukielka
G
G
Bravenec
J S
JS
Mainolfi
E
E
Rothlein
R
R
Hawkins
H K
HK
Kelly
J H
JH
Smith
C W
CW
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D003470:Culture Media / Q000378:metabolism; D016207:Cytokines / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018197:Hepatoblastoma / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured
D003470:Culture Media; D016207:Cytokines; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1