Figure 5.
Bb strains triggered different levels of cytokine ex vivo and at early robin and white-footed (WF) mouse infection. (a–f) Fibroblasts (2 × 105 cells) from robins and WF mice were incubated with Bb strains (2 × 107 spirochetes) or cell medium (mock). The expression levels of indicated genes were determined at 24 h post incubation (hpi) by reverse transcription-qPCR (RT-qPCR) and normalized to expression of β-actin genes. (g–j) Sera were obtained 7 days post nymph feeding (dpf) to determine levels of cytokines using the enzyme linked immunosorbent assay (ELISA). Data represent the geometric mean ± geometric s.d. Significance (p ≤ 0.05) from the uninfected group (*) or between groups (#) is indicated. MOI, multiplicity of infection.