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Lipoprotein succession in Borrelia burgdorferi: similar but distinct roles for OspC and VlsE at different stages of mammalian infection.

Tilly K, Bestor A, Rosa PA - Mol. Microbiol. (2013)

Bottom Line: Borrelia burgdorferi alternates between ticks and mammals, requiring variable gene expression and protein production to adapt to these diverse niches.These adaptations include shifting among the major outer surface lipoproteins OspA, OspC, and VlsE at different stages of the infectious cycle.In this study, we assessed whether vlsE and ospA could restore infectivity to an ospC mutant, and found that neither gene product effectively compensated for the absence of OspC during early infection.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Zoonotic Pathogens, NIAID, NIH, Rocky Mountain Laboratories, Hamilton, MT 59840, USA. ktilly@niaid.nih.gov

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Shuttle vector retention in isolates from SCID mice. Percent retention of pCpospC by vlsE− vs vlsE−ΔospC isolates from SCID mouse tissues 6 weeks post-inoculation. Each symbol denotes percent shuttle vector retention among 22–24 colonies screened per mouse isolate. All isolates of vlsE−ΔospC retained pCpospC in all colonies screened. The differences between the shuttle vector retention results for isolates of single vlsE mutant vs double vlsE and ospC mutant spirochaetes (vlsE−/pCpospC vs vlsE−ΔospC/pCpospC) pooled from all tissues are statistically significant (P < 0.0001, as determined by the Mann–Whitney test). For one vlsE−ΔospC/pCpospC ear isolate, only 6 colonies were screened, all of which were shuttle vector-positive.
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fig01: Shuttle vector retention in isolates from SCID mice. Percent retention of pCpospC by vlsE− vs vlsE−ΔospC isolates from SCID mouse tissues 6 weeks post-inoculation. Each symbol denotes percent shuttle vector retention among 22–24 colonies screened per mouse isolate. All isolates of vlsE−ΔospC retained pCpospC in all colonies screened. The differences between the shuttle vector retention results for isolates of single vlsE mutant vs double vlsE and ospC mutant spirochaetes (vlsE−/pCpospC vs vlsE−ΔospC/pCpospC) pooled from all tissues are statistically significant (P < 0.0001, as determined by the Mann–Whitney test). For one vlsE−ΔospC/pCpospC ear isolate, only 6 colonies were screened, all of which were shuttle vector-positive.

Mentions: If sustained OspC production is required when VlsE production is not possible, spirochaetes lacking both vlsE and ospC but containing the ospC-carrying shuttle vector pCpospC should retain that shuttle vector, even during infection of SCID mice. To ascertain if this were true, isolates obtained from mice infected with bacteria containing pCpospC were plated for single colonies and colonies were screened by PCR for the presence of pCpospC. In SCID mice, we obtained isolates from all tissues of all mice infected with vlsE-deficient or vlsE- and ospC-deficient spirochaetes containing pCpospC, and compared shuttle vector retention in the presence and absence of the native ospC gene in bacteria lacking vlsE. We found significant loss of pCpospC in SCID mice infected with spirochaetes lacking VlsE alone, but complete retention of the shuttle vector when the vlsE− spirochaetes also lacked the endogenous ospC gene (Fig. 1) (P < 0.0001, as assessed by a two-tailed Mann–Whitney test or one-way anova). This result supports our hypothesis that continued OspC production would be required by bacteria lacking VlsE, if these two outer surface proteins fulfil the same essential function during infection of the mammalian host.


Lipoprotein succession in Borrelia burgdorferi: similar but distinct roles for OspC and VlsE at different stages of mammalian infection.

Tilly K, Bestor A, Rosa PA - Mol. Microbiol. (2013)

Shuttle vector retention in isolates from SCID mice. Percent retention of pCpospC by vlsE− vs vlsE−ΔospC isolates from SCID mouse tissues 6 weeks post-inoculation. Each symbol denotes percent shuttle vector retention among 22–24 colonies screened per mouse isolate. All isolates of vlsE−ΔospC retained pCpospC in all colonies screened. The differences between the shuttle vector retention results for isolates of single vlsE mutant vs double vlsE and ospC mutant spirochaetes (vlsE−/pCpospC vs vlsE−ΔospC/pCpospC) pooled from all tissues are statistically significant (P < 0.0001, as determined by the Mann–Whitney test). For one vlsE−ΔospC/pCpospC ear isolate, only 6 colonies were screened, all of which were shuttle vector-positive.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3713631&req=5

fig01: Shuttle vector retention in isolates from SCID mice. Percent retention of pCpospC by vlsE− vs vlsE−ΔospC isolates from SCID mouse tissues 6 weeks post-inoculation. Each symbol denotes percent shuttle vector retention among 22–24 colonies screened per mouse isolate. All isolates of vlsE−ΔospC retained pCpospC in all colonies screened. The differences between the shuttle vector retention results for isolates of single vlsE mutant vs double vlsE and ospC mutant spirochaetes (vlsE−/pCpospC vs vlsE−ΔospC/pCpospC) pooled from all tissues are statistically significant (P < 0.0001, as determined by the Mann–Whitney test). For one vlsE−ΔospC/pCpospC ear isolate, only 6 colonies were screened, all of which were shuttle vector-positive.
Mentions: If sustained OspC production is required when VlsE production is not possible, spirochaetes lacking both vlsE and ospC but containing the ospC-carrying shuttle vector pCpospC should retain that shuttle vector, even during infection of SCID mice. To ascertain if this were true, isolates obtained from mice infected with bacteria containing pCpospC were plated for single colonies and colonies were screened by PCR for the presence of pCpospC. In SCID mice, we obtained isolates from all tissues of all mice infected with vlsE-deficient or vlsE- and ospC-deficient spirochaetes containing pCpospC, and compared shuttle vector retention in the presence and absence of the native ospC gene in bacteria lacking vlsE. We found significant loss of pCpospC in SCID mice infected with spirochaetes lacking VlsE alone, but complete retention of the shuttle vector when the vlsE− spirochaetes also lacked the endogenous ospC gene (Fig. 1) (P < 0.0001, as assessed by a two-tailed Mann–Whitney test or one-way anova). This result supports our hypothesis that continued OspC production would be required by bacteria lacking VlsE, if these two outer surface proteins fulfil the same essential function during infection of the mammalian host.

Bottom Line: Borrelia burgdorferi alternates between ticks and mammals, requiring variable gene expression and protein production to adapt to these diverse niches.These adaptations include shifting among the major outer surface lipoproteins OspA, OspC, and VlsE at different stages of the infectious cycle.In this study, we assessed whether vlsE and ospA could restore infectivity to an ospC mutant, and found that neither gene product effectively compensated for the absence of OspC during early infection.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Zoonotic Pathogens, NIAID, NIH, Rocky Mountain Laboratories, Hamilton, MT 59840, USA. ktilly@niaid.nih.gov

Show MeSH
Related in: MedlinePlus