Interactions of gonococci with HeLa cells: attachment, detachment, replication, penetration, and the role of protein II

Abstract

Colony variants of Neisseria gonorrhoeae differ in their interactions with eucaryotic cells. When gonococci were cultivated with HeLa cell monolayers, the opacity phenotype (Op) became increasingly dominant in the subpopulation of organisms which adhered to the HeLa cells. Once bound, Op organisms displayed very low levels of detachment. Adherent Op gonococci exhibited generation times up to threefold greater than cultures containing gonococci in the absence of HeLa cells. In addition, the progeny of adherent Op organisms remained bound to the HeLa cell monolayer. Both piliated (P+) and transparent (Tr) colony types attached to HeLa cells, but their progeny were retained less efficiently. Gonococci bound to HeLa cells were subjected to the bactericidal action of fresh rat serum and approximately 0.5 to 2.5% survived, irrespective of their opacity or piliation phenotype. Incubation with gentamicin resulted in a 10- to 50-fold further reduction in viability. Pretreatment of HeLa cell monolayers with the microfilament-disrupting agent cytochalasin b diminished gonococcal survival in either serum or gentamicin by up to eightfold. In contrast, cytochalasin b treatment did not decrease survival of the commensal organism N. sicca. The data suggest that very few gonococci are completely interiorized and a small proportion of adherent gonococci are partially protected from the soluble-phase environment by HeLa cells.

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

“…The under the conditions used, the inoculated gonococci multiplied -10-fold during the first 6 h of incubation (data not shown). In accordance with previous reports (Bessen and Gotschlich, 1986) the internalization of MS 11 gonococci by Chang epithelial cells was abrogated in the presence of 2.5 ,ug/ml cytochalasin D, suggesting an active involvement of the epithelial target cells in the invasion process ( Figure iB). Although the recovery of bacteria from the Gm assay does not formally prove the intracellular location of the bacteria, this notion is confirmed by microscopy studies presented below.…”

“…The binding of bacteria to integrins, which connect the surface of a eukaryotic cell with its (actin) microfilament network, is likely to trigger microfilament-dependent engulfment of the bound bacteria directly. As shown here and by others (Bessen and 1313 Gotschlich, 1986), gonococcal invasion also depends on actin polymerization. To examine how Opa proteins stimulate the engulfiment of gonococci by epithelial cells will be a future research goal.…”

“…Previous investigations were concerned with the adherence functions of Opa proteins which play a role in the interaction with both human epithelial and phagocytic cells (Lambden et al, 1979;Virji and Everson, 1981;Sugasawara et al, 1983;Bessen and Gotschlich, 1986;Elkins and Rest, 1990). Several studies with human leukocytes indicated a substantial degree of specificity in the adherence of certain Opa proteins to these cells.…”

Enhanced invasion by enteroinvasive Escherichia coli of multinucleated HeLa cells

“…E. coli strain HB101 lacked the plasmid. HeLa cell monolayers were grown as described previously [7] in Dulbecco's modified Eagle's medium containing 10% (v/v) zeta D serum (zeta-DME). One day prior to attaining confluence, HeLa cell monolayers were washed in phosphate-buffered saline (PBS) and incubated with prewarmed 40% (v/v) PEG 1000 (T.J. Baker, Phillipsburg, N J) in PBS for 1 min at 37 o C. The PEG was removed by aspiration, cells were washed extensively, and incubated in zeta-DME for 18 h before use in the invasion assay.…”

CEACAM is not necessary for Neisseria gonorrhoeae to adhere to and invade female genital epithelial cells

“…Gonococcal invasion of eukaryotic epithelial cells results from complex interactions between pili, Opa and paraglobosyl lipooligosaccharides (LOS) in the bacterial membrane and their corresponding receptors in the eukaryotic membrane (Punsalang and Sawyer, 1973;Bessen and Gotschlich, 1986;Wang et al, 1996;Song et al 2000). The Opa:CEACAM interaction is only one of several mechanisms for invasion of epithelial cells by gonococci that have been identified.…”