Impact of macrophages on Balamuthia mandrillaris virulence properties using human brain microvascular endothelial cells in vitro

Balamuthia amoebic encephalitis (BAE) is a serious human disease almost always leading to death. An important step in BAE is amoebae invasion of the bloodstream, followed by their haematogenous spread. Balamuthia mandrillaris entry into the central nervous system (CNS) most likely occurs at the blood–brain barrier (BBB) sites. Macrophages are thought to be the first line of defense in many infectious diseases and are present in high numbers during infections. The objective of the present study was to determine the impact of cytokines and macrophages on the virulence characteristics of B. mandrillaris in vitro.