Model for invasion of human tissue culture cells by Neisseria gonorrhoeae

Abstract

A tissue culture model has been developed for studying the ability of Neisseria gonorrhoeae to invade eucaryotic cells. The cell line HecIB, a human adenocarcinoma endometrial cell line, was found to support gonococcal invasion. The bactericidal antibiotic gentamicin was used to kill those bacteria that had not entered the HecIB cells, allowing us to quantitate internalized bacteria. Kinetic studies showed an increase in the titer of gentamicin-protected gonococci at 4 h postinfection followed by a decrease; a second increase occurred after 6 h. The state of piliation did not affect the degree of invasion when the bacteria were spun down onto the monolayer. Gonococcal invasion was inhibited when the HecIB cells were preincubated with cytochalasin D before bacterial infection. N. lactamica was used as a negative control. No internalized N. lactamica cells were observed by electron microscopy. Electron microscopy documented the intracellular location of the gonococci in HecIB cells and the eventual destruction of the invaded HecIB cells. After 24 h, clusters of gonococci encased in a matrix of cell debris were observed.

Enhancement of the invasive ability of Neisseria gonorrhoeae by contact with HeclB, an adeno‐carcinoma endometrial cell line

“…Invasion was defined as the number of gonococci resistant to 90 mm of treatment with 20tAg gantamicin ml '. by Shaw and Faikow (1988), We found identical kinetics of invasion, with approximately a six-hour iag before efficient invasion occurred, and a dependence on the presence of IsoVitaleX in the invasion assay {Fig, 1). We investigated the requirement for IsoVitaleX for optimal invasion by adding each component of this preparation individually to the invasion assay.…”

PilT is required for PI(3,4,5)P3-mediated crosstalk between Neisseria gonorrhoeae and epithelial cells

“…A431 cells were infected with wt MS11 for 6 h in the presence or absence of PI-3 kinase inhibitors wortmannin or LY294002. The bacterial invasion index was determined using the Gentamicin protection assay (Shaw and Falkow, 1988;Makino et al ., 1991;Gomez-Duarte et al ., 1997). This assay allows quantification of intracellular, or Gentamicin-protected, bacteria on a large scale.…”

“…Gentamicin protection assays (Shaw and Falkow, 1988) were performed as described previously (Waldbeser et al, 1994). A431 cells were grown to 80% confluency in 12 well Plate 24 h prior to infection.…”

Internalization and intracellular survival of Mycoplasma pneumoniae by non-phagocytic cells

“…On the host cell surface it seems that M. pneumoniae interact with several types of receptors such as sialoglycoconjugates, a sialic acid-free glycoprotein and sulphated glycolipids containing terminal Gal(3SO 4 )b1-residues [14,15]. Some bacterial pathogens are capable of entering eukaryotic host cells where the host cytoplasm serves as a permissive environment for intracellular bacterial persistence and growth [16][17][18]. Although it is widely accepted that most mycoplasmas are strict surface parasites adhering to the surface of epithelial cells, indications that some Mycoplasma species are capable to invade host cells were presented awhile ago [19].…”