The variable antigens Vmp7 and Vmp21 of the relapsing fever bacterium <i>Borrelia hermsii</i> are structurally analogous to the VSG proteins of the African trypanosome

Burman, Nils; Bergström, Sven; Restrepo, Blanca I.; Barbour, Alan G.

doi:10.1111/j.1365-2958.1990.tb00549.x

Cited by 70 publications

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“…The low-density, scattered distribution of the IMPs in the OMFs of B. hermsii, and the observation that these fell into two distinct size classes, does not seem to account for the amount of VMP expressed by the organism. As the VMPs appear to be lipoproteins (10), and, therefore, may not form IMPs (19), our results suggest that at least two species of transmembrane proteins exist in the OM of B. hermsii, possibly as minor constituents relative to the VMP.…”

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Analysis of outer membrane ultrastructure of pathogenic Treponema and Borrelia species by freeze-fracture electron microscopy

et al. 1991

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We analyzed the outer membrane (OM) ultrastructure of four pathogenic members of the family Spirochaetaceae by freeze fracture. The OM of Treponema pallidum subsp. pertenue contained a low intramembranous particle concentration, indicating that it contains few OM transmembrane proteins. The concave OM fracture faces of Treponema hyodysenteriae and Borrelia burgdorferi contained dense populations of particles, typical of gram-negative organisms. A relatively low concentration of particles which were evenly divided between a small and a large species was present in the concave OM fracture face of Borrelia hermsii; the convex OM fracture face contained only small particles. As for gram-negative bacteria, the convex OM fracture face particle concentrations of these pathogens were low. These spirochetes cleaved preferentially within the OM, in contrast to typical gram-negative bacteria, which tend to fracture within the inner membrane. The OM ultrastructure of T. palldum subsp. pertenue provides an explanation for the lack of antigenicity of the treponemal surface and may reflect a mechanism by which this pathogen evades the host immune response.Treponema pallidum subsp. pertenue, Treponema hyodysenteriae, Borrelia burgdorferi, and Borrelia hermsii are the etiologic agents of yaws, swine dysentery, Lyme borreliosis, and relapsing fever, respectively. Although the diseases caused by these spirochetes (family Spirochaetaceae) have been well described, research on the biology of these pathogens has been hampered by several factors. Rich, serum-containing media are required to cultivate the agents of Lyme borreliosis, relapsing fever, and swine dysentery; none of the treponemes responsible for disease in humans can be cultivated continuously in vitro. No systems for introducing DNA into members of the family Spirochaetaceae have been developed. The spirochetal outer membrane (OM) tends to be easily damaged by mild physical and chemical manipulations (3,12,14,15,27,28,32). Work with spirochetes such as Treponema pallidum subsp. pallidum, the etiologic agent of syphilis, has indicated that this fragility has not been adequately addressed by the techniques used to define the OM constituents of gram-negative bacteria (12, 26-28, 30, 38).Freeze-fracture electron microscopy has allowed examination of the ultrastructure of the OM of T. pallidum subsp. pallidum (30,38). The OM of this spirochete was shown to be unusual in that it contains a low intramembranous particle (IMP) concentration in both the concave and convex fracture faces, indicating that the OM of T. pallidum subsp. pallidum contains few transmembrane proteins (30,38). In this study, we used the techniques of freeze-fracture and freeze-etch electron microscopy to examine the OM of T. pallidum subsp. pertenue provided by Paul H. Hardy, Jr., The Johns Hopkins University School of Medicine, Baltimore, Md. The strain was cultivated by passage in New Zealand White male rabbits and harvested as previously described for T. pallidum subsp. pallidum (23). T. hyodysenteriae ...

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Analysis of outer membrane ultrastructure of pathogenic Treponema and Borrelia species by freeze-fracture electron microscopy

et al. 1991

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“…Two sequences with features of a s 70 promoter are located upstream of the vmp genes of B. hermsii and the operon encoding OspA and OspB of B. burgdorferi (Bergstro È m et al, 1989;Jonsson et al, 1992;Barbour et al, 1991). These genes are located on linear plasmids (Plasterk et al, 1985;Barbour and Garon, 1987) and encode abundant lipoproteins that are exposed at the surface (Barbour et al, 1982;1983a;Burman et al, 1990). Recombinant OspA constitutes the human vaccine against B. burgdorferi infection (Steere et al, 1998).…”

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confidence: 99%

The extended promoters for two outer membrane lipoprotein genes of Borrelia spp. uniquely include a T‐rich region

Sohaskey

Zückert

Barbour

1999

Molecular Microbiology

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SummaryOspA and B proteins of Borrelia burgdorferi and Vmp proteins of Borrelia hermsii are abundant outer membrane lipoproteins, whose expression varies with the environment. The genes for these proteins have thè À358 and`À10' elements of a s 70 -type promoter. Deletions of the promoters for these genes were analysed with a chloramphenicol acetyltransferase (CAT) reporter gene and plasmid constructs that were stably maintained in Escherichia coli or transiently transfected into B. burgdorferi. Reporter expression was measured as susceptibility of transformed E. coli cells to chloramphenicol and the CAT activity of E. coli and B. burgdorferi lysates in vitro. Presence of the`À10' element was essential for full activity in both B. burgdorferi and E. coli. Upstream of the`À358 elements of the ospAB and vmp promoters were tracts with Ts in 16 of 20 positions for B. burgdorferi and 18 of 20 positions for B. hermsii. Deletion of the T-rich region from the ospAB or vmp promoter caused a greater reduction of CAT activity in B. burgdorferi than in E. coli. The ®ndings indicate that ospAB and vmp promoters are extended promoters with two parts: (i) a core region containing typical`À358 and`À10' elements and (ii) a unique T-rich region.

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“…A major surfaceexposed lipoprotein designated the variable membrane protein (Vmp) has been correlated with this antigenic variation (4, 9, 11). This switching from an initial Vmp type to another prior to the establishment of a protective antibody response is thought to enable the escape of these organisms from antibody-mediated opsonization and complement killing.Although the molecular basis of antigenic variation has been thoroughly described by 8,9,11,18,25,33,40,[44][45][46], relatively little is known about other aspects of pathogenesis and immunity. B. hermsii, like other pathogenic spirochetes, has been shown by freeze fracture electron microscopy to have an extreme low density of outer membrane-spanning proteins (400 particles/mm 2 ) (63), like that for Treponema pallidum subsp.…”

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Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog

Shang¹,

Skare²,

Erdjument‐Bromage³

et al. 1997

J Bacteriol

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We report the purification, molecular cloning, and characterization of a 40-kDa glycerophosphodiester phosphodiesterase homolog from Borrelia hermsii. The 40-kDa protein was solubilized from whole organisms with 0.1% Triton X-100, phase partitioned into the Triton X-114 detergent phase, and purified by fastperformance liquid chromatography (FPLC). The gene encoding the 40-kDa protein was cloned from a B. hermsii chromosomal DNA lambda EXlox expression library and identified by using affinity antibodies generated against the purified native protein. The deduced amino acid sequence included a 20-amino-acid signal peptide encoding a putative leader peptidase II cleavage site, indicating that the 40-kDa protein was a lipoprotein. Based on significant homology (31 to 52% identity) of the 40-kDa protein to glycerophosphodiester phosphodiesterases of Escherichia coli (GlpQ), Bacillus subtilis (GlpQ), and Haemophilus influenzae (Hpd; protein D), we have designated this B. hermsii 40-kDa lipoprotein a glycerophosphodiester phosphodiesterase (Gpd) homolog, the first B. hermsii lipoprotein to have a putative functional assignment. A nonlipidated form of the Gpd homolog was overproduced as a fusion protein in E. coli BL21(DE3)(pLysE) and was used to immunize rabbits to generate specific antiserum. Immunoblot analysis with anti-Gpd serum recognized recombinant H. influenzae protein D, and conversely, antiserum to H. influenzae protein D recognized recombinant B. hermsii Gpd (rGpd), indicating antigenic conservation between these proteins. Antiserum to rGpd also identified native Gpd as a constituent of purified outer membrane vesicles prepared from B. hermsii. Screening of other pathogenic spirochetes with anti-rGpd serum revealed the presence of antigenically related proteins in Borrelia burgdorferi, Treponema pallidum, and Leptospira kirschneri. Further sequence analysis both upstream and downstream of the Gpd homolog showed additional homologs of glycerol metabolism, including a glycerol-3-phosphate transporter (GlpT), a glycerol-3-phosphate dehydrogenase (GlpD), and a thioredoxin reductase (TrxB).The pathogenic spirochete Borrelia hermsii is one of the etiologic agents of tick-borne relapsing fever. Infection in humans and other vertebrates is commonly characterized by recurring episodes of high fever and bacteremia with intermittent afebrile periods (55). In humans, other clinical manifestations may include pronounced muscle and joint pains, splenomegaly, hepatomegaly, jaundice, and rash, as well as respiratory, cardiovascular, and central nervous system involvement (7). The well-documented relapse phenomenon is associated with the ability of these organisms to undergo multiphasic antigenic variation during the course of disease (56). A major surfaceexposed lipoprotein designated the variable membrane protein (Vmp) has been correlated with this antigenic variation (4, 9, 11). This switching from an initial Vmp type to another prior to the establishment of a protective antibody response is thought to enable the escape of...

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The variable antigens Vmp7 and Vmp21 of the relapsing fever bacterium Borrelia hermsii are structurally analogous to the VSG proteins of the African trypanosome

Cited by 70 publications

References 58 publications

Analysis of outer membrane ultrastructure of pathogenic Treponema and Borrelia species by freeze-fracture electron microscopy

Analysis of outer membrane ultrastructure of pathogenic Treponema and Borrelia species by freeze-fracture electron microscopy

The extended promoters for two outer membrane lipoprotein genes of Borrelia spp. uniquely include a T‐rich region

Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog

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