Fig. 5.

T-cell CD137 expression is critical for infiltration of effector CD8 T cells into low and disturbed flow (LDF) foci. A: experimental setup for adoptive transfer of CD45.1 Ova-specific CD8 T cells that are either wild-type (WT) or CD137^−/− into normolipidemic CD45.2 WT mice immunized with SIINFEKL and agonist anti-CD137 mAb. Vessels were harvested 4 days postimmunization (dpi). B: percentage (gated on viable cells) of Ova-specific transferred CD8 T cells within physiological areas LDF (aortic arch) and high laminar flow (linear carotid). Data are pooled from 2 experiments, 2–3 mice/group/experiment. ^nsP = 0.3, **P = 0.004 by 2-group t-test; n = 5/group. C: cell counts of T cells isolated from the aortic arch and linear carotid 4 dpi. Only the population of transferred CD8 T cells achieved statistical significance. Population of “endogenous T cells” is inclusive of endogenous CD8 T cells that are Vα2⁺β5⁺ (and thus likely Ova-specific) and non-Vα2β5 as well as endogenous CD4 T cells. For cells isolated from aortic arch: ^nsP = 0.5 (endogenous T cells) and *P = 0.01 (transferred CD8 T cells); for cells isolated from the linear carotid: ^nsP > 0.1 (transferred and endogenous CD8 T cells) via Mann-Whitney test. Data are pooled from 2 experiments, 2–3 mice/group/experiment; n = 5 mice/group. Data points from individual mice are as follows: ◆, mice with transferred WT cells; ◇, mice with transferred CD137^−/− cells