Transforming growth factor-beta 1 serves as an autocrine inhibitor of human endothelial cell/lymphocyte adhesion.
Other investigators have shown that exogenously administered transforming growth factor-beta (TGF-beta) inhibits lymphocyte adherence to vascular endothelial cells (VEC). We examined the role of TGF-beta 1 as an autocrine mediator of lymphocyte adhesion to adult human VECs. VECs were harvested from eight saphenous or cadaveric iliac veins using 0.2% collagenase. Low-passage VECs in MCDB + 0.1% BSA were pretreated for 24 hr with monoclonal anti-TGF-beta 1 antibody (5 micrograms/ml), LPS (5 micrograms/ml), or IL-1 (10 U/ml). Adherence of fluorescently labeled lymphocytes to pretreated VECs was quantitated and results were expressed as relative adhesion compared to untreated control. Total mRNA from LPS- or IL-1-treated VECs was subjected to Northern analysis to determine relative TGF-beta 1 expression. Total TGF-beta 1 protein concentration in supernatants from LPS- or IL-1-treated VECs was determined by ELISA. Data (means +/- SEM) were analyzed by ANOVA with a Newman-Keuls posttest. Neutralizing endogenous TGF-beta 1 with anti-TGF-beta 1 antibody significantly increased adhesion of lymphocytes to VEC monolayers compared to control (125 +/- 3 vs 101 +/- 2%, P < 0.01, n = 8). The level of adhesion was equivalent to that seen with IL-1 stimulation (131 +/- 6%). Spearman correlation of lymphocyte adherence to IL-1- or LPS-treated VECs vs TGF-beta 1 mRNA expression or vs relative TGF-beta 1 protein concentration showed significant inverse relationships (r = -0.82, P < 0.001, and r = -0.87, P < 0.001, respectively). Endogenous TGF-beta 1's inhibitory effect on lymphocyte adhesion was blocked by a specific neutralizing antibody. VEC TGF-beta 1 mRNA expression and TGF-beta 1 production were inversely proportional to lymphocyte adhesion, suggesting down-regulation of TGF-beta 1 in response to proinflammatory cytokines. Together, these observations support the hypothesis that TGF-beta 1 has an autocrine inhibitory role in regulation of lymphocyte adhesion to VECs.
Department of Surgery, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey 17033, USA.
J M
JM
Rhodes
E
E
Engelmyer
A F
AF
Tilberg
R R
RR
Gifford
D000328:Adult; D015152:Blotting, Northern; D002448:Cell Adhesion; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008214:Lymphocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D004247:DNA