title: CEACAM3: an innate immune receptor directed against human-restricted bacterial pathogens.
abstract: Carcinoembryonic antigen-related cell adhesion molecule 3 (CEACAM3) is an immunoglobulin-related glycoprotein exclusively expressed on granulocytes. In contrast to other members of the CEACAM family, CEACAM3 does not support cell-cell adhesion, but rather mediates the opsonin-independent recognition and elimination of a restricted set of human-specific Gram-negative bacterial pathogens including Neisseria gonorrhoeae, Haemophilus influenzae, and Moraxella catarrhalis. Within the last 4 years, molecular determinants of CEACAM3 function and CEACAM3-initiated signaling pathways have been elucidated. Sequence comparison between CEACAM3 and other CEACAM family members points to a chimeric origin of this receptor with the bacteria-binding extracellular domain and the function-promoting intracellular domain derived from different genes. This review summarizes the current knowledge about the structure-function relationship of CEACAM3 and tries to combine these molecular aspects with a plausible scenario concerning the evolutionary origin of this phagocyte receptor in the light of host-pathogen adaptation.
authors.affiliation: Lehrstuhl Zellbiologie, Fachbereich Biologie X908, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Pils
authors.forename: Dave T
authors.initials: DT
authors.lastname: Gerrard
authors.forename: Axel
authors.initials: A
authors.lastname: Meyer
authors.forename: Christof R
authors.initials: CR
authors.lastname: Hauck
mesh_terms: D002272:Carcinoembryonic Antigen / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D019143:Evolution, Molecular; D006090:Gram-Negative Bacteria / Q000276:immunology*; D006801:Humans; D015398:Signal Transduction
chemical_list: C075729:CEACAM3 protein, human; D002272:Carcinoembryonic Antigen