CD66-MEDIATED PHAGOCYTOSIS OF OPA(52) NEISSERIA-GONORRHOEAE REQUIRES A SRC-LIKE TYROSINE KINASE-DEPENDENT AND RAC1-DEPENDENT SIGNALING PATHWAY

The interaction of Neisseria gonorrhoeae with human phagocytes is a ha llmark of gonococcal infections, Recently, CD66 molecules have been ch aracterized as receptors for Opa(52)-expressing gonococci on human neu trophils, Here we show that Opa(52)-expressing gonococci or Escherichi a coli or F(ab) fragments directed against CD66, respectively, activat e a signalling cascade from CD66 via Src-like protein tyrosine kinases , Rac1 and PAK to Jun-N-terminal kinase, The induced signal is distinc t from Fc gamma-receptor-mediated signalling and is specific for Opa(5 2), since piliated Opa(-) gonococci, commensal Neisseria cinerea or E, coli do not stimulate this signalling pathway, Inhibition of Src-like kinases or Rad prevents the uptake of Opa(52) bacteria, demonstrating the crucial role of this signalling cascade for the opsonin-independen t, Opa(52)/CD66-mediated phagocytosis of pathogenic Neisseria.