1151. Follistatin-like Protein 1, a Novel Inflammatory Modulator, is an Early Biomarker for Borrelia burgdorferi Infection
Session: Poster Abstract Session: Innate and Adaptive Immunity to Infections
Saturday, October 22, 2011
Room: Poster Hall B1
  • 1151_BrianCampfield.pdf (284.7 kB)
  • Background: Borrelia burgdorferi (Bb) causes Lyme disease (LD), the most common tick-borne illness in the US.  LD manifests most commonly as acute or chronic arthritis.  The host immune response to Borrelia burgdorferi is complex involving innate, humoral and cell-mediated pathways.  The C3H/HeJ murine model of Lyme arthritis has similarities to murine model collagen-induced arthritis (CIA) in the DBA-1 mouse strain.  In the CIA model, follistatin-like protein 1 (FSTL-1), a novel immune modulator, has been found to play a key role in promoting a Th1 response. We have hypothesized that FSTL-1 is an early biomarker of the inflammatory response associated with B. burgdorferi.

    Methods: Bb was subcutaneously injected into 4-5 week old C3H, DBA-1 wild-type (WT) and DBA-1 FSTL-1 hypomorphic (FH) mice.  Infection was evaluated by measurement of tibiotarsal joint swelling (arthritis), bladder culture (bacterial growth), and serology (humoral response).  Serum FSTL-1 levels were assayed by ELISA and FSTL-1 expression in ankles was assayed by qRT-PCR.

    Results: Bladder cultures from all murine strains grew Bb, indicating successful disseminated infection.  Serologic response to Bb proteins was detectable by Western blot.  Upon joint swelling assessment, WT mice demonstrated increased swelling when compared to FH mice (average ΔAP diameter: 0.61 ± 0.05 mm (WT) versus 0.37 ± 0.08 mm (FH)) p=0.02. Serum FSTL-1 levels in C3H mice were significantly elevated at day 7 and subsequently were significantly below normal.  qRT-PCR revealed elevated message for FSTL-1 in ankles at day 14 with a subsequent return below normal by day 42.

    Conclusion: FSTL-1 increases early in response to Bb infection and arthritis in mice suggesting that FSTL-1 might serve as a biomarker of Lyme disease.

    Subject Category: E. Innate and adaptive immunity to infections, including vaccine immunology

    Brian Campfield, MD, Raphael Hirsch, MD and Andrew Nowalk, MD, PhD, Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA


    B. Campfield, None

    R. Hirsch, None

    A. Nowalk, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.