Figure 2
From: CEACAM1 recognition by bacterial pathogens is species-specific
Opa CEA protein expressing Neisseria gonorrhoeae selectively binds to human CEACAM1. (A) Neisseria gonorrhoeae MS11 strains lacking Opa protein expression (Ngo Opa-) or expressing a CEACAM-binding Opa protein (Ngo OpaCEA) were lysed and the Opa protein expression was determined by Western blotting with a monoclonal anti-Opa antibody (clone 4B12/C11). (B) Expression of the soluble GFP-fusion proteins of CEACAM1 Igv-like domains was determined by Western blotting of culture supernatants with polyclonal anti-GFP antibody. Culture supernatants from cells transfected with a vector encoding cytoplasmically expressed GFP served as control. (C) Culture supernatants containing soluble GFP-tagged amino-terminal domains of the indicated mammalian CEACAMs or a control culture supernatant from GFP-transfected cells (neg. control) were incubated with OpaCEA protein-expressing N. gonorrhoeae (Ngo OpaCEA) or the non-opaque strain (Ngo Opa-). After washing, bacteria were analysed by flow cytometry and the bacteria-associated GFP-fluorescence was determined. Only human CEACAM1 (hCEA1) binds to Ngo OpaCEA.