The differential susceptibility of gonococcal opacity variants to sex hormones

Salit, Irving E.

doi:10.1139/m82-044

Cited by 30 publications

(24 citation statements)

References 11 publications

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“…P.ll proteins of N. gonorrhoeae have been correlated with increased adherence to buccal epithelial, oonjunctival and phagooytic cells (Bessen and Gotschlich, 1986;Heckels, 1982;Lambden ef al., 1979;Virji and Heckels, 1986;King and Swanson, 1978), autoaggregation (Swanson, 1978a;Swanson, 1982), altered serum resistance (Lambden et al, 1979), and resistance to certain antibiotics (Lambden et ai., 1979) and steroid hormones (Salit, 1982). Less is known about the Class V proteins of N. meningitidis, although it is thought that they may play similar roles (Kawulaef a/., 1988;Stern and Meyer, 1987;Tsai et ai., 1981).…”

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confidence: 99%

Expression and phase variation of gonococcal P.11 genes in Escherichia coli involves ribosomal frameshifting and slipped‐strand mispairing

Belland¹,

Morrison²,

Ley

et al. 1989

Molecular Microbiology

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Expression and phase variation of Neisseria gonorrhoeae P.II genes in Escherichia coli were studied using TnphoA fusions. Fusions were created in the P.IIc gene of N. gonorrhoeae JS3 using lambda TnphoA-1 and were characterized by restriction digestion and dideoxy sequencing. Three fusions were chosen for further study; Tnp7 (fusion junction at mature amino acid 7), Tnp57 (amino acid 57), Tnp66 (amino acid 66). All fusions were in frame with the P.IIc coding sequence but were out of frame with the purported initiation codon. All fusion constructions were shown to phase vary in E. coli in an analogous fashion to that seen in N. gonorrhoeae, i.e. phase changes (in a recA background) at a frequency of c. 10(-3) accompanied by an alteration at the DNA level of the number of coding repeats (CRs). In vitro mutagenesis of the fusion constructions indicated that expression of out of frame P.II genes in E. coli was probably the result of ribosomal frameshifting within the run of 'A' residues immediately preceding the CR region and not due to low-level false initiation at codons other than the ATG initiation codon (as had previously been suggested). The mechanism for P.IIc::phoA phase variation appears to be related to the 'slipped-strand mispairing' mechanism responsible for frameshift mutations in a number of other bacterial genes containing short, direct, tandem repeats.

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Section: Introductionmentioning

confidence: 99%

Expression and phase variation of gonococcal P.11 genes in Escherichia coli involves ribosomal frameshifting and slipped‐strand mispairing

Belland¹,

Morrison²,

Ley

et al. 1989

Molecular Microbiology

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“…The factors responsible for the observed associations between Opa phenotype, culture rate, and the menstrual cycle are not known. Salit (49) showed that opaque colonies were more resistant to progesterone than transparent colonies; however, the resultant hypothesis that Opa proteins directly protect gonococci from progesterone was not supported when gonococci with defined Opa phenotypes were tested (52). It is possible that the expression of Opa protein colonization receptors is hormonally regulated.…”

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Opacity Proteins Increase Neisseria gonorrhoeae Fitness in the Female Genital Tract Due to a Factor under Ovarian Control

2010

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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.

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“…Gonococci expressing PII proteins are generally isolated from infections localized to the surface mucosa, whereas organisms recovered from disseminated infections often lack PII proteins (6,7). The possession of certain PII proteins has been associated with resistance to antibiotics and steroid hormones (12,19), altered-serum resistance (8,12), increased sensitivity to serum proteases (2), and increased adherence to buccal epithelial cells (12) and phagocytic cells (18).…”

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Genetic transformation of genes for protein II in Neisseria gonorrhoeae

Schwalbe¹,

Cannon²

1986

J Bacteriol

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The protein II (PII) outer membrane proteins of Neisseria gonorrhoeae are a family of heat-modifiable proteins that are subject to phase variation, in which the synthesis of different PI' species is turned on The PII proteins of the gonococcus are a family 'of heat-modifiable outer membrane proteins with apparent molecular masses ranging from 24,000'to 30,000 daltons (28). They were initially described as proteins present in the outer membrane of dark-colored (opaque) colony variants and absent in light (transparent) variants of the same strain (28, 30). The gonococcus reversibly oscillates between on and off states of expression of PII proteins in a type of phase variation (11,29). The proteins are apparently not crucial to viability, since in all strains studied there are colony variants that do not express PII proteins.'PII proteins also demonstrate antigenic variation, whereby the synthesis of antigenically different PII proteins of a strain is turned on and off. At least seven distinct'PII species have been described in one gonococcal strain, and an organism can express from zero to at least three PII proteins at one time (22). Gonococci expressing PII proteins are generally isolated from infections localized to the surface mucosa, whereas organisms recovered from disseminated infections often lack PII proteins (6, 7). The possession of certain PII proteins has been associated with resistance to antibiotics and steroid hormones (12, 19), altered-serum resistance (8, 12), increased sensitivity to serum proteases (2), and increased adherence to buccal epithelial cells (12) and phagocytic cells (18).Little is known about the genes for PII proteins or about the mechanisms that regulate PII protein expression. Within a gonococcal population, variants that differ in PII protein profiles (detected by differences in colony opacity) occur at a frequency of approximately 10-3 per cell per generation (16). Switching of 'PII proteins occurs in a nonrandom sequence (1,29). Studies with cloned genes for PII proteins showed that there are multiple' copies of PII-related se-* Corresponding author. quences in the gonococcal chromosome and that structural alterations in DNA accomnpany changes in PIT protein expression (26, 27).Studies on the physical characterization of PIT genes would be complemented by studies on the genetics of PII proteins in the gonococcus itself. However, since the presence of PII proteins does not confer a selectable phenotype on the gonococcus, it has been difficult to apply traditional genetic approaches to the study of PII genes. We have done experiments involving the genetic transformation of PII genes in which transformants expressing a donor-specific PII protein were detected with monoclonal antibodies (MAb) specific for the PII proteins of the donor. This approach has allowed us to investigate the linkage relationships of genes for PII proteins and to determine that the state of expression of a donor PH gene affects the outcome of genetic transformation experiments. We also report that varian...

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The differential susceptibility of gonococcal opacity variants to sex hormones

Cited by 30 publications

References 11 publications

Expression and phase variation of gonococcal P.11 genes in Escherichia coli involves ribosomal frameshifting and slipped‐strand mispairing

Expression and phase variation of gonococcal P.11 genes in Escherichia coli involves ribosomal frameshifting and slipped‐strand mispairing

Opacity Proteins Increase Neisseria gonorrhoeae Fitness in the Female Genital Tract Due to a Factor under Ovarian Control

Genetic transformation of genes for protein II in Neisseria gonorrhoeae

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