Influence of membrane cholesterol on monocyte chemotaxis

Cholesterol content influences several important physiological functions due to its effect on membrane receptors. In this work, we tested the hypothesis that cellular cholesterol alters chemotactic response of monocytes to Monocyte Chemoattractant Protein-1(MCP-1) due to their effect on the receptor, CCR2. We used Methyl-beta-cyclodextrin (M beta CD) to alter the baseline cholesterol in human monocytic cell line THP-1, and evaluated their chemotactic response to MCP-1. Compared to untreated cells, cholesterol enrichment increased the number of monocytes transmigrated in response to MCP-1 while depletion had opposite effect. Using imaging flow cytomerry, we established that these differences were due to alterations in expression levels, but not the surface distribution, of CCR2.