Species specificity of the Listeria monocytogenes InlB protein.
InlA and InlB mediate L. monocytogenes entry into eukaryotic cells. InlA is required for the crossing of the intestinal and placental barriers. InlA uses E-cadherin as receptor in a species-specific manner. The human E-cadherin but not the mouse E-cadherin is a receptor for InlA. In human cells, InlB uses Met and gC1qR as receptors. By studying the role of InlB in vivo, we found that activation of Met by InlB is species-specific. In mice, InlB is important for liver and spleen colonization, but not for the crossing of the intestinal epithelium. Strikingly, the virulence of a DeltainlB deletion mutant is not attenuated in guinea pigs and rabbits. Guinea pig and rabbit cell lines do not respond to InlB, although expressing Met and gC1qR, but support InlB-mediated responses upon human Met gene transfection, indicating that InlB does not recognize or stimulate guinea pig and rabbit Met. In guinea pig cells, the effect of human Met gene transfection on InlB-dependent entry is increased upon cotransfection with human gc1qr gene, showing the additive roles of gC1qR and Met. These results unravel a second L. monocytogenes species specificity critical for understanding human listeriosis and emphasize the need for developing new animal models for studying InlA and InlB functions in the same animal model.
Institut Pasteur, Unité des Interactions Bactéries-Cellules, 25-28 rue du Docteur Roux, Paris, F-75015 France.
Nadia
N
Khelef
Marc
M
Lecuit
Hélène
H
Bierne
Pascale
P
Cossart
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics; D002460:Cell Line; D005260:Female; D017353:Gene Deletion; D006168:Guinea Pigs; D006801:Humans; D008089:Listeria monocytogenes / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology / Q000503:physiopathology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019859:Proto-Oncogene Proteins c-met; D011817:Rabbits; D011951:Receptors, Complement / Q000235:genetics / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D014774:Virulence
D001426:Bacterial Proteins; D015820:Cadherins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D011951:Receptors, Complement; D017978:Receptors, Growth Factor; C032402:complement 1q receptor; C095768:inlB protein, Listeria monocytogenes; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met