Variable opacity (Opa) outer membrane proteins account for the cell tropisms displayed by Neisseria gonorrhoeae for human leukocytes and epithelial cells (original) (raw)
Related papers
PloS one, 2015
Neisseria gonorrhoeae (GC) establishes infection at the mucosal surface of the human genital tract, most of which is lined with polarized epithelial cells. GC can cause localized as well as disseminated infections, leading to various complications. GC constantly change their surface structures via phase and antigenic variation, which has been implicated as a means for GC to establish infection at various anatomic locations of male and female genital tracks. However, the exact contribution of each surface molecule to bacterial infectivity remains elusive due to their phase variation. Using a GC derivative that is genetically devoid of all opa genes (MS11∆Opa), this study shows that Opa expression interferes with GC transmigration across polarized human epithelial cells. MS11∆Opa transmigrates across polarized epithelial cells much faster and to a greater extent than MS11Opa+, while adhering at a similar level as MS11Opa+. When MS11Opa+, able to phase vary Opa expression, was inoculat...
Molecular Microbiology, 2007
Outer membrane protein As (OmpAs) are highly conserved proteins within the Enterobacteriaceae family. OmpA contributes to the maintenance of structural membrane integrity and invasion into mammalian cells. In Escherichia coli K1 OmpA also contributes to serum resistance and is involved in the virulence of the bacterium. Here we describe the identification of an OmpA-like protein in Neisseria gonorrhoeae (Ng-OmpA). We show that the gonococcal OmpA-like protein, similarly to E. coli OmpA, plays a significant role in the adhesion and invasion into human cervical carcinoma and endometrial cells and is required for entry into macrophages and intracellular survival. Furthermore, the isogenic knockout ompA mutant demonstrates reduced recovery in a mouse model of infection when compared with the wild-type strain, suggesting that Ng-OmpA plays an important role in the in vivo colonization. All together, these data suggest that the newly identified surface exposed protein Ng-OmpA represents a novel virulence factor of gonococcus.
The Journal of experimental …, 2000
Lipooligosaccharide (LOS) has been implicated in the adhesion and invasion of host epithelial cells. We examined the adhesive and invasive abilities of isogenic gonococcal opacity-associated outer membrane protein-negative, pilus-positive (Opa Ϫ Pil ϩ) Neisseria gonorrhoeae strains expressing genetically defined LOS. Strain F62 (Opa Ϫ Pil ϩ), expressing the lacto-N-neotetraose and the galNac-lacto-N-neotetraose LOS, and its isogenic derivative that expressed only the lacto-N-neotetraose LOS (F62 ⌬ lgtD), adhered to, and invaded, to the same extent the human cervical epidermoid carcinoma cell line, ME180. While the adhesive abilities of Opa Ϫ Pil ϩ isogenic strains that express LOS molecules lacking the lacto-N-neotetraose structure were similar to that seen for F62, their invasive abilities were much lower than the strains expressing lacto-N-neotetraose. Fluorescence microscopy studies showed that the adherence of F62, but not the strains lacking lacto-N-neotetraose, induced the rearrangement of actin filaments under the adherent sites. Electron microscopy studies demonstrated that F62, but not the strains lacking lacto-N-neotetraose, formed extensive and intimate associations with epithelial cell membranes. Thus, in the absence of detectable Opa protein, the lacto-N-neotetraose LOS promotes gonococcal invasion into ME180 cells. The data also suggest that LOS is involved in the mobilization of actin filaments in host cells, and in the formation of a direct interaction between the bacterial outer membrane and the plasma membrane of ME180 cells.
CGM1a antigen of neutrophils, a receptor of gonococcal opacity proteins
Proceedings of the National Academy of Sciences, 1996
Neisseria gonorrhoeae (GC) or Escherichia coli expressing phase-variable opacity (Opa) protein (Opa + GC or Opa + E. coli ) adhere to human neutrophils and stimulate phagocytosis, whereas their counterparts not expressing Opa protein (Opa − GC or Opa − E. coli ) do not. Opa + GC or E. coli do not adhere to human lymphocytes and promyelocytic cell lines such as HL-60 cells. The adherence of Opa + GC to the neutrophils can be enhanced dramatically if the neutrophils are preactivated. These data suggest that the components binding the Opa + bacteria might exist in the granules. CGM1a antigen, a transmembrane protein of the carcinoembryonic antigen family, is exclusively expressed in the granulocytic lineage. The predicted molecular weight of CGM1a is ≈30 kDa. We observed specific binding of OpaI + E. coli to a 30-kDa band of polymorphonuclear leukocytes lysates. To prove the hypothesis that the 30-kDa CGM1a antigen from neutrophils was the receptor of Opa + bacteria, we showed that a H...
Journal of Bacteriology, 2012
ABSTRACTTo better understand the role of Opa in gonococcal infections, we created and characterized a derivative of MS11 (MS11Δopa) that had the coding sequence for all 11 Opa proteins deleted. The MS11Δopa bacterium lost the ability to bind to purified lipooligosaccharide (LOS). While nonpiliated MS11Δopa and nonpiliated Opa-expressing MS11 cells grew at the same rate, nonpiliated MS11Δopa cells rarely formed clumps of more than four bacteria when grown in broth with vigorous shaking. Using flow cytometry analysis, we demonstrated that MS11Δopa produced a homogeneous population of bacteria that failed to bind monoclonal antibody (MAb) 4B12, a MAb specific for Opa. Opa-expressing MS11 cells consisted of two predominant populations, where ∼85% bound MAb 4B12 to a significant level and the other population bound little if any MAb. Approximately 90% of bacteria isolated from a phenotypically Opa-negative colony (a colony that does not refract light) failed to bind MAb 4B12; the remaini...
Pathogens, 2022
Gonorrhea is the second most common sexually transmitted infection, which is primarily localized but can be disseminated systemically. The mechanisms by which a localized infection becomes a disseminated infection are unknown. We used five pairs of Neisseria gonorrhoeae isolates from the cervix/urethra (localized) and the blood (disseminated) of patients with disseminated gonococcal infection to examine the mechanisms that confine gonococci to the genital tract or enable them to disseminate to the blood. Multilocus sequence analysis found that the local and disseminated isolates from the same patients were isogenic. When culturing in vitro, disseminated isolates aggregated significantly less and transmigrated across a polarized epithelial monolayer more efficiently than localized isolates. While localized cervical isolates transmigrated across epithelial monolayers inefficiently, those transmigrated bacteria self-aggregated less and transmigrated more than cervical isolates but comp...
Binding of vitronectin to opa-expressing Neisseria gonorrhoeae mediates invasion of HeLa cells
Infection and immunity, 1997
Neisseria gonorrhoeae induces local infections in the human genitourinary tract and can disseminate to other organs to cause severe disease. Blood-derived factors present in the genital mucosa have been suggested to facilitate the spread of N. gonorrhoeae in disseminated gonococcal infections. Using gentamicin invasion assays and confocal microscopy, we observed a strong stimulatory effect of fetal calf serum (FCS) on the gonococcal invasion of HeLa cells. FCS-mediated invasion was dependent on the expression of the epithelial cell invasion-associated Opa protein (plasmid-encoded Opa50 or its chromosomal homolog Opa30), while N. gonorrhoeae expressing noninvasive Opa proteins (Opa(51-60)) or no Opa protein (Opa-) was not invasive even in the presence of FCS. Incubation of N. gonorrhoeae MS11 with biotinylated FCS revealed a 78-kDa protein as the prominent protein binding to Opa50- or Opa30-expressing gonococci. This protein was recognized by antibodies against vitronectin (VN) in We...
Infection and Immunity, 2006
The neisserial opacity (Opa) proteins are phase-variable, antigenically distinct outer membrane proteins that mediate adherence to and invasion of human cells. We previously reported that Neisseria gonorrhoeae Opa protein expression appeared to be selected for or induced during experimental murine genital tract infection. Here we further defined the kinetics of recovery of Opa variants from the lower genital tracts of female mice and investigated the basis for this initial observation. We found that the recovery of different Opa phenotypes from mice appears cyclical. Three phases of infection were defined. Following intravaginal inoculation with primarily Opa ؊ gonococci, the majority of isolates recovered were Opa ؉ (early phase). A subsequent decline in the percentage of Opa ؉ isolates occurred in a majority of mice (middle phase) and was followed by a reemergence of Opa ؉ variants in mice that were infected for longer than 8 days (late phase). We showed the early phase was due to selection for preexisting Opa ؉ variants in the inoculum by constructing a chloramphenicol-resistant (Cm r ) strain and following Cm r Opa ؉ populations mixed with a higher percentage of Opa ؊ variants of the wild-type (Cm s ) strain. Reciprocal experiments (Opa ؊ Cm r gonococci spiked with Opa ؉ Cm s bacteria) were consistent with selection of Opa ؉ variants. Based on the absence in mice of human carcinoembryonic antigen cell adhesion molecules, the major class of Opa protein adherence receptors, we conclude the observed selection for Opa ؉ variants early in infection is not likely due to a specific adherence advantage and may be due to Opa-mediated evasion of innate defenses. on July 1, 2015 by guest http://iai.asm.org/ Downloaded from on July 1, 2015 by guest http://iai.asm.org/ Downloaded from FIG. 5. Association of OpaB and OpaI variants with murine vaginal cells. Vaginal smear samples from mice infected with a mixture of OpaI Cm r and Opa Ϫ Cm s gonococci (top panels) or a mixture of OpaB Cm r and Opa Ϫ Cm s gonococci (bottom panels) stained sequentially with Opa-specific antibodies against OpaI (A) or OpaB/D (B) (green) and a polyclonal rabbit antiserum against whole gonococci (GC) (red) (29).
Infection and Immunity, 2010
The neisserial opacity (Opa) proteins are a family of antigenically distinct outer membrane proteins that undergo phase-variable expression. Opa ؉ variants of Neisseria gonorrhoeae strain FA1090 are selected in a cyclical pattern from the lower genital tract of estradiol-treated mice. Here we show that cyclical recovery of Opa ؉ gonococci does not occur in ovariectomized mice; therefore, the reproductive cycle plays a role in the selection kinetics in vivo. As predicted by the selection pattern shown by wild-type gonococci, we demonstrated that a constitutive Opa-expressing strain was more fit than an Opa-deficient mutant in the early and late phases of infection. We found no evidence that Opa-mediated colonization selects for Opa ؉ variants during murine infection based on adherence assays with cultured murine epithelial cells. We also tested the hypothesis that complement selects for Opa protein expression during infection. Although some Opa ؉ variants of a serum-sensitive derivative of strain FA1090 were more resistant to the bactericidal activity of normal human serum, selection for Opa expression was not abrogated in C3-depleted mice. Finally, as previously reported, Opa ؉ gonococci were more sensitive to serine proteases. Thus, proteases or protease inhibitors may contribute to the observed in vivo selection pattern. We concluded that Opa proteins promote persistence of N. gonorrhoeae in the female genital tract and that opa gene phase variation allows gonococci to evade or capitalize upon unidentified host factors of the mammalian reproductive cycle. This work revealed an intimate interaction between pathogen and host and provides evidence that hormonally related factors shape bacterial adaptation.