A Small Molecule α4β1 Antagonist Prevents Development of Murine Lyme Arthritis without Affecting Protective Immunity

Abstract

After infection with Borrelia burgdorferi, humans and mice under certain conditions develop arthritis. Initiation of inflammation is dependent on the migration of innate immune cells to the site of infection, controlled by interactions of a variety of adhesion molecules. In this study, we used the newly synthesized compound S18407, which is a prodrug of the active drug S16197, to analyze the functional importance of α4β1-dependent cell adhesion for the development of arthritis and for the antibacterial immune response. S16197 is shown to interfere specifically with the binding of α4β1 integrin to its ligands VCAM-1 and fibronectin in vitro. Treatment of B. burgdorferi-infected C3H/HeJ mice with the α4β1 antagonist significantly ameliorated the outcome of clinical arthritis and the influx of neutrophilic granulocytes into ankle joints. Furthermore, local mRNA up-regulation of the proinflammatory mediators IL-1, IL-6, and cyclooxygenase-2 was largely abolished. Neither the synthesis of spirochete-specific Igs nor the development of a Th1-dominated immune response was altered by the treatment. Importantly, the drug also did not interfere with Ab-mediated control of spirochete load in the tissues. These findings demonstrate that the pathogenesis, but not the protective immune response, in Lyme arthritis is dependent on the α4β1-mediated influx of inflammatory cells. The onset of inflammation can be successfully targeted by treatment with S18407.

Quantification of integrin receptor agonism by fluorescence lifetime imaging

“…This interaction was also detected in cells plated on VCAM-1 (data not shown). FRET was significantly decreased when two small molecule, LDV ligand mimetic inhibitors of ␣4␤1 integrin [S976162 and S9916197 (Gläsner et al, 2005;Lin et al, 1999) see supplementary material Table S1 and Fig. S2 for characterisation] were added to pre-spread cells (Fig.…”

“…Cells were then washed three times in medium and either fixed for FLIM analysis or imaged live in phenol-red free growth media at 37°C. For integrin antagonist studies, cells were pre-treated with concentrations and times specified in figure legend with V0519 (Peyman et al, 2000), S9916197 (Gläsner et al, 2005) or S976162 (Lin et al, 1999) and subjected to FLIM analysis.…”

Identification of a TLR-Independent Pathway forBorrelia burgdorferi-Induced Expression of Matrix Metalloproteinases and Inflammatory Mediators through Binding to Integrin α3β1

“…We are also unaware of specific inhibitors of integrin ␣ 3 that are appropriate for administration to animals. Recently, Glasner et al (51) have shown that a small molecule, S18407, that inhibits integrin ␣ 4 ␤ 1 can reduce the development of Lyme arthritis in a mouse model. S18407 was shown to have specificity for integrin ␣ 4 ␤ 1 , and no significant effect on ␣ 2 ␤ 1 , ␣ 5 ␤ 1 , ␣ v ␤ 3 , ␣ 6 ␤ 1 integrin interactions.…”

CD83 Modulates B Cell Activation and Germinal Center Responses

“…Infection of mice with B. burgdorferi as well as measurement of ankle swelling, B. burgdorferi-specific Ab response, and bacterial load in organs were performed as previously described (31). Cytokine production was assessed using a LEGENDplex assay (BioLegend) following the manufacturer's instructions.…”