Common pathways for receptor-mediated ingestion of Escherichia coli and LDL cholesterol by Entamoeba histolytica regulated in part by transmembrane kinase 39

[Display omitted] ► Entamoeba histolytica ingests low density lipoprotein (LDL) particles in a saturable manner. ► LDL particles are a competitive ligand for the ingestion of Escherichia coli bacteria. ► The adherence and ingestion of E. coli bacteria is regulated by transmembrane kinase 39. The single-celled parasite, Entamoeba histolytica, is an enteric pathogen that ingests bacteria and host cells. Inhibition of phagocytosis renders the parasite avirulent. The ligand/receptor interactions that allow E. histolytica to phagocytose are not well understood. We hypothesised that E. histolytica trophozoites might accomplish ingestion through the utilisation of a scavenger receptor for cholesterol. Here we show that acetylated low density lipoprotein cholesterol was phagocytosed by amoebae via receptor-mediated mechanisms. Acetylated low density lipoprotein cholesterol competitively inhibited by 31±1.3% (P