Identification of residues within ligand‐binding domain 1 (LBD1) of the <i>Borrelia burgdorferi</i> OspC protein required for function in the mammalian environment

Earnhart, Christopher G.; LeBlanc, DeLacy V.; Alix, Katie E.; Desrosiers, Daniel C.; Radolf, Justin D.; Marconi, Richard T.

doi:10.1111/j.1365-2958.2010.07103.x

Cited by 57 publications

(80 citation statements)

References 100 publications

(140 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Curiously, though, this work revealed a critical role for OspC in the colonization of some of the tissues examined, particularly in the heart, which is consistent with previously published results from two other laboratories (2,28). A specific function for OspC in infection is supported by the recent demonstration that a site-directed change of one residue in a putative ligandbinding pocket rendered the bacteria noninfectious in the mouse model of infection (17). Despite intensive investigation, however, the role of OspC in B. burgdorferi infection remains unclear.…”

supporting

confidence: 78%

Effect of Borrelia burgdorferi OspC at the Site of Inoculation in Mouse Skin

et al. 2010

View full text Add to dashboard Cite

The Borrelia burgdorferi surface lipoprotein OspC is a critical virulence factor, but its precise role in the establishment of B. burgdorferi infection remains unclear. To determine whether OspC affects the host response at the site of inoculation of the bacterium, the recruitment of macrophages and neutrophils and the production of cytokines were examined at the site of infection by wild-type, ospC mutant, and complemented mutant B. burgdorferi strains. Of the 21 cytokines tested, monocyte chemoattractant protein 1 (MCP-1), keratinocyte-derived chemokine (KC, CXCL1), and vascular endothelial growth factor (VEGF) were found at increased levels at the site of inoculation of B. burgdorferi, and the levels varied with the production of OspC at one or more time points over the 1-week course of infection. The kinetics of expression and the dependence on OspC production by B. burgdorferi varied among the cytokines. The production of KC and MCP-1, and the appearance of monocytic infiltrates, correlated with the presence of the bacteria rather than with OspC specifically. In contrast, VEGF production was not correlated simply to the presence of the bacteria and is influenced by the presence of OspC. In in vitro assays, OspC and B. burgdorferi expressing OspC stimulated the growth of endothelial cells more than did the controls. These data suggest the possibility of a novel role for OspC in the life of B. burgdorferi at the interface of its mammalian and tick hosts.

show abstract

supporting

confidence: 78%

Effect of Borrelia burgdorferi OspC at the Site of Inoculation in Mouse Skin

et al. 2010

View full text Add to dashboard Cite

show abstract

“…In addition, constitutive expression of heterologous lipoproteins in the ospC mutant was shown to restore infection in SCID mice, suggesting that OspC may have a nonspecific structural role for B. burgdorferi (14,19). On the other hand, another study suggested that the residues within the putative ligand-binding domain are important for OspC function (25). Despite all research efforts, the precise biological function of OspC during infection remains unclear.…”

mentioning

confidence: 99%

“…For example, OspC binds to a tick salivary protein, Salp15, which can protect spirochetes from complementand antibody-mediated killing (23,24). OspC was shown to bind host plasminogen (25,26), and this phenotype correlates with invasiveness of spirochetes in mice (27). In addition, constitutive expression of heterologous lipoproteins in the ospC mutant was shown to restore infection in SCID mice, suggesting that OspC …”

mentioning

confidence: 99%

Outer Surface Protein OspC Is an Antiphagocytic Factor That Protects Borrelia burgdorferi from Phagocytosis by Macrophages

et al. 2015

View full text Add to dashboard Cite

cOuter surface protein C (OspC) is one of the major lipoproteins expressed on the surface of Borrelia burgdorferi during tick feeding and the early phase of mammalian infection. OspC is required for B. burgdorferi to establish infection in both immunocompetent and SCID mice and has been proposed to facilitate evasion of innate immune defenses. However, the exact biological function of OspC remains elusive. In this study, we showed that the ospC-deficient spirochete could not establish infection in NOD-scid IL2r␥ null mice that lack B cells, T cells, NK cells, and lytic complement. The ospC mutant also could not establish infection in anti-Ly6G-treated SCID and C3H/HeN mice (depletion of neutrophils). However, depletion of mononuclear phagocytes at the skin site of inoculation in SCID and C3H/HeN mice allowed the ospC mutant to establish infection in vivo. In phagocyte-depleted mice, the ospC mutant was able to colonize the joints and triggered neutrophilia during dissemination. Furthermore, we found that phagocytosis of green fluorescent protein (GFP)-expressing ospC mutant spirochetes by murine peritoneal macrophages and human THP-1 macrophage-like cells, but not in PMN-HL60, was significantly higher than parental wild-type B. burgdorferi strains, suggesting that OspC has an antiphagocytic property. In addition, overproduction of OspC in spirochetes also decreased the uptake of spirochetes by murine peritoneal macrophages. Together, our findings provide evidence that mononuclear phagocytes play a key role in clearance of the ospC mutant and that OspC promotes spirochetes' evasion of macrophages during early Lyme borreliosis. L yme disease, the most prevalent vector-borne illness in the United States (1), is a multisystem inflammatory disorder caused by infection with the spirochete Borrelia burgdorferi (2, 3). This spirochete is maintained in nature through a complex enzootic cycle involving Ixodes ticks and various small-mammal hosts. Humans, as accidental hosts, become infected after B. burgdorferiinfected ticks feed on them (4). Spirochetes replicate in the skin, spread locally, and induce an inflammatory response with a symptom known as erythema migrans, observed in most patients (2, 4). During disseminated infection, B. burgdorferi colonizes multiple tissues, leading to different clinical manifestations, including arthritis, myocarditis, and neurological and/or cutaneous abnormalities (2, 4). This acute, disseminated stage of human Lyme disease is largely recapitulated using inbred mouse strains which are susceptible to B. burgdorferi infection and develop carditis and subacute arthritis (5). Thus, the murine model provides a powerful tool to elucidate the role of spirochete virulence factors and host immunological responses during Lyme disease pathogenesis (4).The B. burgdorferi genome encodes a large number of surface lipoproteins, many of which are expressed during mammalian infection (4, 6, 7). One of these lipoproteins is the major outer surface protein C (OspC), whose production is induced within inf...

show abstract

“…B. hermsii YOR (an isolate derived from a human TBRF patient in the United States) is an extensively characterized genomic group II strain (14,15,32). B. hermsii was cultivated in BarbourStoenner-Kelly-H (BSK-H) complete medium supplemented with 12% rabbit serum (37°C; 5% CO 2 ) in sealed bottles (9). Antibiotic selection of transformants was achieved with kanamycin (200 g ml…”

Section: Methodsmentioning

confidence: 99%

“…Enzyme-linked immunosorbent assay (ELISA) plates were coated with a suspension of wild-type B. hermsii YOR (B. hermsii YOR-wt) cells and screened with a dilution series of sera collected from each mouse. All methods were as previously described (9).…”

Section: Gcattaagtaagcggtttgtgagcmentioning

confidence: 99%

Genetic Transformation of the Relapsing Fever Spirochete Borrelia hermsii: Stable Integration and Expression of Green Fluorescent Protein from Linear Plasmid 200

2011

Self Cite

View full text Add to dashboard Cite

Tick-borne relapsing fever (TBRF) is a spirochetal disease caused by at least 15 different Borrelia species. It is a serious human health concern in regions of endemicity throughout the world. Transmission to humans occurs through the bites of infected Ornithodoros ticks. In North America, the primary Borrelia species associated with human disease are B. hermsii and B. turicatae. Direct demonstration of the role of putative TBRF spirochete virulence factors in the disease process has been hindered by the lack of a genetic manipulation system and complete genome sequences. Expanding on recent developments in these areas, here we demonstrate the successful generation of a clone of B. hermsii YOR that constitutively produces green fluorescent protein (GFP) (B. hermsii YOR::kan gfp). This strain was generated through introduction of a kan-gfp cassette into a noncoding region of the 200-kb B. hermsii linear plasmid lp200. Genetic manipulation did not affect the growth rate or trigger the loss of native plasmids. B. hermsii YOR::kan gfp retained infectivity and elicited host seroconversion. Stable production of GFP was demonstrated both in vitro and in vivo. This study represents a significant step forward in the development of tools that can be employed to study the virulence mechanisms of TBRF spirochetes.

show abstract

Identification of residues within ligand‐binding domain 1 (LBD1) of the Borrelia burgdorferi OspC protein required for function in the mammalian environment

Cited by 57 publications

References 100 publications

Effect of Borrelia burgdorferi OspC at the Site of Inoculation in Mouse Skin

Effect of Borrelia burgdorferi OspC at the Site of Inoculation in Mouse Skin

Outer Surface Protein OspC Is an Antiphagocytic Factor That Protects Borrelia burgdorferi from Phagocytosis by Macrophages

Genetic Transformation of the Relapsing Fever Spirochete Borrelia hermsii: Stable Integration and Expression of Green Fluorescent Protein from Linear Plasmid 200

Contact Info

Product

Resources

About