Open AccessFimH‐mediated Escherichia coli K1 invasion of human brain microvascular endothelial cells
Author(s) -
Khan Naveed Ahmed,
Kim Yuri,
Shin Sooan,
Kim Kwang Sik
Publication year - 2007
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/j.1462-5822.2006.00779.x
Subject(s) - biology , fimbria , bacterial adhesin , escherichia coli , microbiology and biotechnology , receptor , biochemistry , gene
Summary Adhesion to brain microvascular endothelial cells, which constitute the blood–brain barrier is considered important in Escherichia coli K1 bacterial penetration into the central nervous system. Type 1 fimbriae are known to mediate bacterial interactions with human brain microvascular endothelial cells (HBMEC). Here, we demonstrate that type 1 fimbriae, specifically FimH adhesin is not only an adhesive organelle that provides bacteria with a foothold on brain endothelial cells but also triggers signalling events that promote E. coli K1 invasion in HBMEC. This is shown by our demonstrations that exogenous FimH increases cytosolic‐free‐calcium levels as well as activates RhoA. Using purified recombinant mannose‐recognition domain of FimH, we identified a glycosylphosphatidylinositol‐anchored receptor, CD48, as a putative HBMEC receptor for FimH. Furthermore, E. coli K1 binding to and invasion of HBMEC were blocked by CD48 antibody. Taken together, these findings indicate that FimH induces host cell signalling cascades that are involved in E. coli K1 invasion of HBMEC and CD48 is a putative HBMEC receptor for FimH.