LPS stimulates TNF-α secretion by freshly extracted human leukocytes
Three in vitro cell-interaction models (Figure 2) were employed to study the effects of LPS on TNF-α secretion by WBCs alone, or in combination with HUVECs or HUVECs and erythrocytes. In the presence of WBCs, erythrocytes and HUVECs, LPS promoted TNF-α secretion in a dose-dependent manner when it was added incrementally in the range 0.0-0.5 ng ml-1.