FIG. 2.

Maximal numbers of T lymphocytes migrate across HUVEC stimulated with B. burgdorferi within 4 h. HUVEC were treated with a sham preparation of spirochetes or B. burgdorferi (Bb) at 10 bacteria/endothelial cell for 24 h, followed by incubation with T lymphocytes (10⁶ per culture) for the indicated times. The total height of each bar represents the percentage of added T lymphocytes that became associated with each culture. The lower portion depicts the percentage of cells that migrated beneath the endothelium; the upper portion indicates the percentage that were adherent to the apical surface of the endothelium. Bars represent the means ± standard deviations (error bars) of three to four replicate samples. Data shown are representative of two separate experiments. The percentages of T cells migrating across B. burgdorferi-activated endothelium that are significantly different from those traversing sham-treated controls are shown by an asterisk (P < 0.05).