Figure 1.

Interaction of Tp0751-expressing strains with human endothelia under static and shear stress conditions. (a) Mean ± SEM numbers of parent and Tp0751-expressing B. burgdorferi (Bb-Tp0751) adhered to primary human umbilical vein endothelial cell (HUVEC) monolayers after 12 h of co-incubation under static (0 dyn/cm²) conditions (HUVECs + Bb, control). HUVECs+ (Bb + pFn): binding of bacteria pre-incubated with plasma fibronectin (pFn) to HUVECs. (HUVECs + pFn) + Bb: binding of bacteria to HUVEC pre-incubated with pFn. N = 3 independent bacterial and endothelial cultures/strain analyzed in 2 experiments. (b) Mean ± SEM bacterial interactions per minute with HUVEC under typical postcapillary venule shear stress condition (1 dyn/cm²). Videos of representative flow chamber experiments are presented in Supplementary Videos S1–S3. Numbers of bacteria that paused and moved more slowly over endothelia under flow were manually counted in time-lapses acquired at 15 frames per second (fps). Strains: Negative control strain: BBK32-deficient non-infectious adhesion-attenuated B31-A-derived strain (Parent; GCB706: Supplementary Table S1). Positive control strains: Parent expressing B. burgdorferi vascular adhesin BBK32 (Bb-BBK32); BBK32-expressing B31-derived infectious strain (Infectious; GCB726: Supplementary Table S1). Bb-Tp0751: Parent expressing Tp0751. N = 8 independent cultures per strain analyzed in 3 experiments. Statistics: one-way Kruskal-Wallis ANOVA with Dunn’s post-test (a), one-way ANOVA with Holm-Sidak post-test (b). *Indicates p < 0.05 vs. parent within incubation condition (a) and vs. parent (b).