Email updates

Keep up to date with the latest news and content from BMC Microbiology and BioMed Central.

Open Access Research article

CEACAM1 recognition by bacterial pathogens is species-specific

Maike Voges12, Verena Bachmann1, Robert Kammerer3, Uri Gophna4 and Christof R Hauck12*

Author Affiliations

1 Lehrstuhl für Zellbiologie, Universität Konstanz, Mailbox X908, 78457 Konstanz, Germany

2 Konstanz Research School Chemical Biology, Universität Konstanz, 78457 Konstanz, Germany

3 Institute of Immunology, Friedrich-Löffler-Institut, Tübingen, Germany

4 Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel

For all author emails, please log on.

BMC Microbiology 2010, 10:117  doi:10.1186/1471-2180-10-117

Published: 20 April 2010

Abstract

Background

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), an immunoglobulin (Ig)-related glycoprotein, serves as cellular receptor for a variety of Gram-negative bacterial pathogens associated with the human mucosa. In particular, Neisseria gonorrhoeae, N. meningitidis, Moraxella catarrhalis, and Haemophilus influenzae possess well-characterized CEACAM1-binding adhesins. CEACAM1 is typically involved in cell-cell attachment, epithelial differentiation, neovascularisation and regulation of T-cell proliferation, and is one of the few CEACAM family members with homologues in different mammalian lineages. However, it is unknown whether bacterial adhesins of human pathogens can recognize CEACAM1 orthologues from other mammals.

Results

Sequence comparisons of the amino-terminal Ig-variable-like domain of CEACAM1 reveal that the highest sequence divergence between human, murine, canine and bovine orthologues is found in the β-strands comprising the bacteria-binding CC'FG-face of the Ig-fold. Using GFP-tagged, soluble amino-terminal domains of CEACAM1, we demonstrate that bacterial pathogens selectively associate with human, but not other mammalian CEACAM1 orthologues. Whereas full-length human CEACAM1 can mediate internalization of Neisseria gonorrhoeae in transfected cells, murine CEACAM1 fails to support bacterial internalization, demonstrating that the sequence divergence of CEACAM1 orthologues has functional consequences with regard to bacterial recognition and cellular invasion.

Conclusions

Our results establish the selective interaction of several human-restricted bacterial pathogens with human CEACAM1 and suggest that co-evolution of microbial adhesins with their corresponding receptors on mammalian cells contributes to the limited host range of these highly adapted infectious agents.