Phase variation of the opacity outer membrane protein controls invasion by Neisseria gonorrhoeae into human epithelial cells.

Abstract

Neisseria gonorrhoeae is a facultative intracellular bacterium capable of penetrating into certain human epithelial cell types. In order to identify gonococcal factors essential for invading Chang human conjunctiva cells, a gentamicin selection assay for the quantification of viable intracellular bacteria was used in conjunction with microscopy. The results demonstrate a correlation between the invasive behaviour of gonococci and the expression of Opa proteins, a family of variable outer membrane proteins present in all pathogenic Neisseria species. However, only particular Opa proteins supported invasion into Chang cells as indicated by the use of two unrelated gonococcal strains. Invasion was sensitive to cytochalasin D, and strong adherence mediated by the Opa proteins appeared to be essential for the internalization of gonococci. In contrast pili, which also conferred binding to Chang conjunctiva cells, did not support cellular invasion but rather were inhibitory.

Virulent strain associated outer membrane proteins of Borrelia burgdorferi.

“…The second category, lipoproteins, have a lipid moiety anchored to the inner leaflet of the OM and a periplasmic protein moiety. It is the outer membrane spanning proteins of many pathogenic bacteria, which are known to mediate essential steps in pathogenesis, such as adhesion (46,47), invasion (48)(49)(50)(51)(52), and serum resistance (53)(54)(55)(56). In contrast, most studies on pathogenesis and immunity in Lyme disease have focused on B. burgdorferi lipoproteins, such as OspA (5)(6)(7)(8)(9)(10)14), whose principle cellular location appears to be subsurface (12).…”

Ceramide and sphingosine in pulmonary infections

“…Neisseria gonorrhoeae interact with human mucosal epithelial cells by binding their opacity-associated (Opa) proteins to heparan sulfate proteoglycan (HSPG) receptors on epithelial cells, resulting in uptake of the pathogen (Makino et al, 1991). The infection of epithelial cells activates acid sphingomyelinase and increases the total cellular ceramide concentration.…”

Cholera toxin and extracellular Ca2+ induce adherence of non-piliated Neisseria: evidence for an important role of G-proteins and Rho in the bacteria-cell interaction

“…Thus, the binding observed was not mediated by Opa, an outer membrane protein known to mediate tight adherence and invasion of host cells (Makino et al, 1991). The contact between a bacterial pathogen and its host cell triggers a series of signal transduction events leading to a sophisticated cross-talk between the two actors.…”