Engulfment of apoptotic cells by HMEC-1 cells is necessary for enhanced synthesis of IL-8 and MCP1 mRNA. (A) HMEC-1 cells were exposed to untreated or apoptotic cells for 3 hours and IL-8 and MCP1 expression was measured by real-time qPCR. Pretreatment with cytochalasin D (4 μM) reversed the enhanced synthesis of IL-8 and MCP1 to the level of the controls. (B) At temperatures where the internalization of bound cells is prevented, apoptotic cells failed to induce enhanced expression of IL-8 and MCP1 transcript. Data are given as mean ± SD of 3 independent experiments.