Borrelia burgdorferi in tick cell culture modulates expression of outer surface proteins A and C in response to temperature - PubMed (original) (raw)

Borrelia burgdorferi in tick cell culture modulates expression of outer surface proteins A and C in response to temperature

M Obonyo et al. J Clin Microbiol. 1999 Jul.

Abstract

The Lyme disease spirochete Borrelia burgdorferi sensu stricto downregulates outer surface protein A (OspA) and upregulates outer surface protein C (OspC) during tick feeding. The switching of these proteins correlates with increased spirochetal infectivity for the mammal. We examined the effect of temperature on differential expression of OspA and OspC by B. burgdorferi cocultivated with a cell line isolated from the vector tick Ixodes scapularis. The effect of incubation at 31, 34, or 37 degrees C on expression of OspA and OspC by B. burgdorferi JMNT and N40 was analyzed by indirect fluorescent-antibody microscopy, polyacrylamide gel electrophoresis, and immunoblotting. The amount of OspA relative to the amount of flagellin was highest in spirochetes cocultivated with tick cells at 31 degrees C and declined with increasing temperature in both strains. OspC production was enhanced in spirochetes cocultivated with tick cells at 37 degrees C. Spirochetes grown axenically in BSK-H medium also produced more OspC at 37 degrees C, but OspA content was not appreciably affected by temperature. Our findings indicate that temperature, along with cultivation in a tick cell culture system, plays a role in the differential expression of OspA and enhances differential expression of OspC by spirochetes.

PubMed Disclaimer

Figures

FIG. 1

FIG. 1

Giemsa-stained B. burgdorferi JMNT (arrowhead) attached to tick cells (ISE6 cells). Bar, 10 μm.

FIG. 2

FIG. 2

Epifluorescent image of rhodamine-labeled B. burgdorferi JMNT attached to tick cells (ISE6 cells). The cells were harvested at selected times and centrifuged onto microscope slides, and the spirochetes reacted with MAb to OspA. Panels A to D are all at the same magnification (bar in panel D, 100 μm). (A) Cells grown at 31°C after 48 h. (B) Cells grown at 37°C and harvested after 48 h. (C) Cells grown at 31°C and harvested after 5 days. (D) Cells grown at 37°C and harvested after 5 days. Panels E and F are at the same magnification (bar, in panel F, 20 μm). (E) Cells grown at 31°C and harvested after 5. (F) Cells grown at 37°C and harvested after 5 days.

FIG. 3

FIG. 3

Analysis of B. burgdorferi JMNT by SDS-PAGE with Rapid Coomassie blue staining (A) or immunoblotting (B) with MAbs to OspA, OspB, OspC, and flagellin as probes. Spirochetes were cocultivated with a vector tick cell line (ISE6 cells) or were grown axenically in BSK medium at 37, 34, or 31°C. Molecular mass markers (in kilodaltons) are shown on the left.

FIG. 4

FIG. 4

Amount of OspC relative to amount of flagellin in B. burgdorferi JMNT (A) and N40 (B). Spirochetes were cocultivated with tick cells (open circles) or were grown axenically in BSK-H medium (closed circles) at 31, 34, or 37°C. The gels were scanned to determine OspA, OspC, and flagellin band intensities by using Kodak Image Analysis Software. Flagellin was used as a reference protein, and the ratio of the amount of a protein band to the amount of flagellin was used to generate these graphs.

FIG. 5

FIG. 5

Amount of OspA relative to amount of flagellin in B. burgdorferi JMNT (A) and N40 (B). Spirochetes were cocultivated with tick cells (open circles) or were grown axenically in BSK-H medium (closed circles) at 31, 34, or 37°C. Gels were scanned to determine OspA, OspC, and flagellin band intensities by using Kodak Image Analysis Software. Flagellin was used as a reference protein, and the ratio of the amount of a protein band to the amount of flagellin was used to generate these graphs.

References

    1. Barbour A G, Hayes S F, Heiland R A, Schrumpf M E, Tessier S L. A Borrelia-specific monoclonal antibody binds to a flagellar epitope. Infect Immun. 1986;52:549–554. -PMC -PubMed
    1. Barbour A G, Tessier S L, Todd W J. Lyme disease spirochetes and ixodid tick spirochetes share a common surface antigenic determinant defined by a monoclonal antibody. Infect Immun. 1983;41:795–804. -PMC -PubMed
    1. Barthold S W, Moody K D, Terwilliger G A, Duray P H, Jacoby R O, Steere A C. Experimental Lyme arthritis in rats infected with Borrelia burgdorferi. J Infect Dis. 1988;157:842–846. -PubMed
    1. Benach J L, Coleman J L, Golightly M G. A murine IgM monoclonal antibody binds an antigenic determinant in outer surface protein A, an immunodominant basic protein of Lyme disease spirochete. J Immunol. 1988;140:265–272. -PubMed
    1. Burgdorfer W, Barbour A G, Hayes S F, Benach J L, Grunwaldt E, Davis J P. Lyme disease—a tick-borne spirochetosis? Science. 1982;216:1317–1319. -PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources