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Acid sphingomyelinase is involved in CEACAM receptor‐mediated phagocytosis of Neisseria gonorrhoeae
Author(s) -
Hauck C.R.,
Grassmé H.,
Bock J.,
Jendrossek V.,
Ferlinz K.,
Meyer T.F.,
Gulbins E.
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01851-2
Subject(s) - internalization , acid sphingomyelinase , neisseria gonorrhoeae , opsonin , sphingomyelin , phagocytosis , ceramide , biology , receptor , microbiology and biotechnology , kinase , signal transduction , biochemistry , apoptosis , membrane
The interaction with human phagocytes is a hallmark of symptomatic Neisseria gonorrhoeae infections. Gonococcal outer membrane proteins of the Opa family induce the opsonin‐independent uptake of the bacteria that relies on CEACAM receptors and an active signaling machinery of the phagocyte. Here, we show that CEACAM receptor‐mediated phagocytosis of Opa 52 ‐expressing N. gonorrhoeae into human cells results in a rapid activation of the acid sphingomyelinase. Inhibition of this enzyme by imipramine or SR33557 abolishes opsonin‐independent internalization without affecting bacterial adherence. Reconstitution of ceramide, the product of acid sphingomyelinase activity, in imipramine‐ or SR33557‐treated cells restores internalization of the bacteria. Furthermore, we demonstrate that CEACAM receptor‐initiated stimulation of other signalling molecules, in particular Src‐like tyrosine kinases and Jun N‐terminal kinases, requires acid sphingomyelinase. These studies provide evidence for a crucial role of the acid sphingomyelinase for CEACAM receptor‐initiated signalling events and internalization of Opa 52 ‐expressing N. gonorrhoeae into human neutrophils.