Activation of human monocytes for enhanced production of interleukin 8 during transendothelial migration in vitro.
Interleukin-8 (IL-8) is a chemokine for polymorphonuclear leukocytes (PMNs) and lymphocytes, which promotes the extravasation of these inflammatory cells. In this study, we investigated IL-8 synthesis induced by the adhesive interaction between monocytes and endothelial cells during transmigration and the capacity of transmigrated monocytes to produce IL-8. Cocultured human monocytes and human umbilical vein endothelial cell (HUVEC) monolayers induced the synergistic production of IL-8, compared with cultures of either monocytes or HUVEC monolayers alone. Coculture-induced IL-8 production almost doubled after HUVECs were stimulated with IL-1 beta. The induced IL-8 mRNA expression was consistent with the protein data, indicating the de novo synthesis of IL-8 by the coculture. Monoclonal antibodies (mAbs) against IL-8 inhibited the transendothelial chemotactic activity of the supernatants for PMNs by 55%. Immunohistochemistry revealed that both adherent and transmigrated monocytes and unstimulated HUVECs expressed IL-8 protein, whereas nonadherent monocytes did little. Transmigrated monocytes spontaneously secreted a 3.8-fold greater amount of IL-8 than the initial monocytes. Coculture-induced IL-8 production was inhibited about 30% by polyclonal Abs against IL-alpha, IL-1 beta, or tumor necrosis factor alpha, while it was not affected by mAbs against intercellular adhesion molecule 1 or vascular cell adhesion molecule 1. The results suggested that adhesive interaction during the transmigration of monocytes through HUVEC monolayers activates both cell types to produce IL-8 and that transmigrated monocytes are capable of producing ample IL-8.
Takahashi
M
M
Department of Cardiology, Kyoritsu College of Pharmacy, Tokyo, Japan.
Ikeda
U
U
Kasahara
T
T
Kitagawa
S
S
Takahashi
Y
Y
Shimada
K
K
Kano
S
S
Morimoto
C
C
Masuyama
J
J
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015815:Cell Adhesion Molecules / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000276:immunology; D004730:Endothelium, Vascular / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D008262:Macrophage Activation; D009000:Monocytes / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D012995:Solubility; D013194:Staining and Labeling
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D016207:Cytokines; D016209:Interleukin-8; D012333:RNA, Messenger