Fig. 2.

CD137 costimulation increases recruitment of activated effector CD8 T cells into low and disturbed flow (LDF) foci. A: hyperlipidemic CD45.2 wild-type (WT) mice received adoptive transfer of CD45.1 Ova-specific splenocytes 2 wk after partial carotid artery ligation (PCAL) and were immunized with SIINFEKL + rat IgG control or agonist anti-CD137 mAb. B: in vivo CD137 costimulation induces an activated effector population that is resident in spleen and circulates in blood 4 days postimmunization (dpi). Splenocytes and blood cells were stimulated in vitro with media or phorbol 12-myristate 13-acetate + ionomycin (PMAi). *P = 0.02, **P = 0.009, ***P = 0.0004, and ****P < 0.0001 by paired t-test; ###P < 0.0007 by 2-group t-test; n = 6–8 mice/group. C: gating strategy for identifying T cells from PBS-flushed vessels by flow cytometry. CD45.1 indicates transferred population, and CD45.2 indicates an endogenous population and Ova specificity through TCR expression of Vα2β5. Gating scheme is enlarged in Supplemental Fig. S1C, with isotype stains used to establish gates. D: percentage (gated on viable cells) and total cell count of transferred CD8 T cells isolated from PBS-flushed contralateral control vs. ligated carotids 4 dpi. *P ≤ 0.03, **P = 0.004, and ***P = 0.0002 by 2-group t-test; n = 5–6 mice/group. E: %infiltrated transferred CD8 T cells isolated from PBS-flushed aortic arch. Data shown are 1 experiment representative of 2 experimental replicates. ***P = 0.0004 by 2-group t-test n = 6–8 mice/group. Data points from individual mice are as follows: ▲ and ◆, mice with CD137 costimulation; △ and ◇, IgG-treated controls