Expression of intimin gamma from enterohemorrhagic Escherichia coli in Citrobacter rodentium.
The carboxy-terminal 280 amino acids (Int280) of the bacterial adhesion molecule intimin include the receptor-binding domain. At least five different types of Int280, designated alpha, beta, gamma, delta, and epsilon, have been described based on sequence variation in this region. Importantly, the intimin types are associated with different evolutionary branches and contribute to distinct tissue tropism of intimin-positive bacterial pathogens. In this study we engineered a strain of Citrobacter rodentium, which normally displays intimin beta, to express intimin gamma from enterohemorrhagic Escherichia coli. We show that intimin gamma binds to the translocated intimin receptor (Tir) from C. rodentium and has the ability to produce attaching and effacing lesions on HEp-2 cells. However, C. rodentium expressing intimin gamma could not colonize orally infected mice or induce mouse colonic hyperplasia. These results suggest that intimin may contribute to host specificity, possibly through its interaction with a receptor on the host cell surface.
Hartland
E L
EL
Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom.
Huter
V
V
Higgins
L M
LM
Goncalves
N S
NS
Dougan
G
G
Phillips
A D
AD
MacDonald
T T
TT
Frankel
G
G
D018528:ATP-Binding Cassette Transporters; D018829:Adhesins, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D002648:Child; D002954:Citrobacter / Q000235:genetics / Q000472:pathogenicity*; D003106:Colon / Q000382:microbiology / Q000473:pathology; D004926:Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D029968:Escherichia coli Proteins; D005818:Genetic Engineering; D006801:Humans; D006965:Hyperplasia; D058619:Maltose-Binding Proteins; D051379:Mice; D008809:Mice, Inbred C3H; D009004:Monosaccharide Transport Proteins; D010581:Peyer's Patches / Q000382:microbiology; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013045:Species Specificity; D013601:T-Lymphocytes
D018528:ATP-Binding Cassette Transporters; D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D009004:Monosaccharide Transport Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C109287:Tir protein, E coli; C461599:maltose transport system, E coli; C073819:eaeA protein, E coli