Open AccessLipopolysaccharide O antigen chains mask IcsA (VirG) in Shigella flexneri
Author(s) -
Morona Renato,
Bosch Luisa
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00210-6
Subject(s) - shigella flexneri , lipopolysaccharide , immunofluorescence , chemistry , microbiology and biotechnology , cell , antigen , serotype , shigella , escherichia coli , antibody , biology , biochemistry , gene , immunology
Shigella flexneri 2a strain 2457T lipopolysaccharide (LPS) has O antigen (Oag) chains with two modal lengths (S‐type and VL‐type), and has IcsA apparently located at one pole on its cell surface. Treatment of Y serotype derivatives of 2457T and RMA696 (2457T wzz SF ) with Sf6 tailspike protein (TSP) resulted in hydrolysis of Oag chains, and an increase in detection of IcsA by indirect immunofluorescence staining on both the lateral and polar regions of the cell surface. Newly synthesised IcsA expressed from a pBAD promoter in a S. flexneri Y strain was also detected on both the lateral and polar regions of the cell when incubated with TSP prior to immunofluorescence staining. We conclude that IcsA is actually located on both lateral and polar regions of the S. flexneri cell surface, and that LPS Oag chains mask the presence of IcsA by hindering its detection with antibodies. These results have implications for the mechanism of IcsA export. They suggest that while IcsA export is predominantly targeted to the old cell pole, it can also occur on the lateral regions of the cell surface.