Acid sphingomyelinase is involved in CEACAM receptor‐mediated phagocytosis of Neisseria gonorrhoeae

FEBS Letters

Bock, J.²  Ferlinz, K.²  Gulbins, E.²  Hauck, C.R.¹  Meyer, T.F.¹  Grassmé, H.²  Jendrossek, V.² 

[1] Max-Planck-Institut für Biologie, Abteilung Infektionsbiologie, Spemannstrasse 34, 72076 Tübingen, Germany;Department of Physiology, University of Tübingen, Gmelinstrasse 5, 72076 Tübingen, Germany

关键词: Gonococcus;    Uptake;    Sphingolipid;    Src family kinase;    Signalling;   

DOI  :  10.1016/S0014-5793(00)01851-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 Opa₅₂-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 Opa₅₂-expressing N. gonorrhoeae into human neutrophils.

【 授权许可】

Unknown