Bacterial invasion and transcytosis in transfected human brain microvascular endothelial cells

Most cases of neonatal bacterial meningitis develop as a result of a hemato genous spread, but it is not clear how circulating bacteria cross the blood -brain barrier. Attempts to answer these questions have been hampered by th e lack of a reliable model of the human blood-brain barrier. Human brain mi crovascular endothelial cells (HBMEC) were isolated and transfected with a pBR322 based plasmid containing simian virus 40 large T antigen (SV40-LT). The transfected HBMEC exhibited similar brain endothelial cell characterist ics as the primary HBMEC, i.e. gamma glutamyl transpeptidase and a high tra nsendothelial electrical resistance. Escherischia coli and Citrobacter spp, two important Gram-negative bacilli causing neonatal meningitis, were foun d to transcytose across primary and transfected HBMEC, without affecting th e integrity of the monolayer. In addition, E. coli and C. freundii invaded transfected HBMEC as shown previously with primary HBMEC. We conclude that E. coli and C. freundii are able to invade and transcytose HBMEC and these bacterial-HBMEC interactions are similar between primary and transfected HB MEC. Therefore, our transfected HBMEC should be useful for studying pathoge nesis of CNS infections. (C) 2001 Academic Press.