T Cells Are Dominant Population in Human Abdominal Aortic Aneurysms and Their Infiltration in the Perivascular Tissue Correlates With Disease Severity

Figures

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  Figure 1. Aortic abdominal aneurysm (AAA) leukocyte infiltration: comparison and relationship between aneurysmal wall and PVT. (A) Gating strategy depicting identification of total leukocytes (CD45+) and leukocyte sub-populations: granulocytes, dendritic cells, B cells, T cells, NK cells and macrophages in AAA (aortic abdominal aneurysm). Gates were applied based on fluorescence minus one (FMO) analysis. (B) Distribution of the main leukocytes: T cells (CD3+), B cells (CD19+), NK cells (CD16+CD56+), macrophages (CD11b+CD64+), dendritic cells (CD83+), granulocytes (CD66b+) in wall and PVT of AAA tissue (n = 8–11), T cell percentages compared to other leukocyte subpopulations, t-test for related samples, p values presented on graphs only for statistically significant comparisons. (C) Bottom panel: example of immunofluorescence staining of T cells (CD3+) shown in red and macrophages (CD68+) shown in green in PVT and wall of an AAA. Nuclear staining (DAPI) is shown in blue. Example of T cell and macrophage co-localization shown by yellow/orange staining; white arrow. Representative of n = 5; Top panel: negative control consisting of secondary antibody staining only with DAPI. Scale bar = 50 μM.

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  Figure 2. Aortic abdominal aneurysm (AAA) leukocyte infiltrate: comparison and relationship between aneurysmal wall and PVT. (A) Example of flow cytometric identification of leukocytes (CD45+), total T cells (CD3+) and CD4+, CD8+ T cell subpopulations in aneurysmal wall and PVT. (B) Leukocyte number per mg of aneurysmal wall vs. PVT, n = 40, **p < 0.01 (Wilcoxon matched paired). (C) T cells number per mg of aneurysmal wall vs. PVT, n = 39, *p < 0.05 (Wilcoxon matched paired). (F) Spearman rho correlation between number of leukocytes in aneurysmal wall and PVT; R = 0.384, n = 40, p = 0.015. (G) Spearman rho correlation between number of T cells in aneurysmal wall and PVT; R = 0.418, n = 39, p = 0.007. (D) CD4+ T cell number per mg of wall and PVT of AAA tissue, n = 39, p < 0.05 (Wilcoxon matched paired). (E) CD8+ T cell number per mg of wall and PVT in AAA, n = 39, NS (Wilcoxon matched paired).

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  Figure 3. Effect of patient gender on immune cell numbers in AAA wall and PVT. Male vs. female total leukocyte and T cell content in AAA PVT and wall. (A) Leukocyte number per mg of aneurysmal wall and PVT in male group n = 31 vs. female group n = 9 (B). T cell number per mg of aneurysmal wall and PVT in male group n = 30 vs. female group n = 9. Mann-Whitney test for comparison male vs. female for wall and PVT, Wilcoxon test for comparison wall vs. PVT within male and female group. p values presented on graphs only for statistically significant comparisons.

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  Figure 4. Relationship between T cell number and AAA size. AAA diameter was determined by preoperative CT. Graphs display relationship between AAA size (tertile 1 ≤ 53 mm; tertile 2 ≤ 60 mm; tertile 3 > 60 mm) and CD3+ cell infiltration in wall (A) and PVT (B) (mean/SEM/25–75 CI); (n = 20/10/9 for tertiles); statistical comparisons were performed by ANOVA with Neuman-Keuls post-hoc analysis.