Abdominal aortic aneurysm (AAA) is a chronic dilation of the aorta with a tendency to enlarge and eventually rupture, which constitutes a major cause of cardiovascular mortality. Although T-cell infiltrates have been observed in AAA, the cellular, phenotypic, and functional characteristics of these tissue-infiltrating T cells are not fully understood. Here, we investigated the proportional changes of T-cell subsets-including CD4⁺ T cells, CD8⁺ T cells, and γδ T cells-and their effector functions in AAAs. We found that Vδ2⁺ T cells were presented at a higher frequency in aortic aneurysmal tissue compared to normal aortic tissue and PBMCs from patients with AAA. In contrast, no differences were observed in the frequencies of CD4⁺, CD8⁺, and Vδ1⁺ T cells. Moreover, we observed that the Vδ2⁺ T cells from AAA tissue displayed immunophenotypes indicative of CCR5⁺ non-exhausted effector memory cells, with a decreased proportion of CD16⁺ cells. Finally, we found that these Vδ2⁺ T cells were the main source of IL-17A in abdominal aortic aneurysmal tissue. In conclusion, our results suggest that increased Vδ2⁺ T cells that robustly produce IL-17A in aortic aneurysmal tissue may contribute to AAA pathogenesis and progression.

中文翻译：

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在晚期腹主动脉瘤组织中强烈产生IL-17A的Vδ2+ T细胞的增加。

腹主动脉瘤（AAA）是主动脉的慢性扩张，具有扩大并最终破裂的趋势，这是导致心血管疾病死亡的主要原因。尽管已在AAA中观察到T细胞浸润，但尚未完全了解这些组织浸润T细胞的细胞，表型和功能特征。在这里，我们研究了T细胞亚群（包括CD4 ⁺ T细胞，CD8 ⁺ T细胞和γδT细胞）的比例变化及其在AAA中的效应功能。我们发现，与AAA患者的正常主动脉组织和PBMC相比，在主动脉瘤组织中Vδ2 ⁺ T细胞的出现频率更高。相反，在CD4 ⁺，CD8的频率上未观察到差异⁺和Vδ1 ⁺ T细胞。此外，我们观察到，来自AAA组织的Vδ2 ⁺ T细胞表现出指示CCR5 ⁺未耗尽效应记忆细胞的免疫表型，而CD16 ⁺细胞的比例降低。最后，我们发现这些Vδ2 ⁺ T细胞是腹主动脉瘤组织中IL-17A的主要来源。总之，我们的结果表明，增加的Vδ2 ⁺ T细胞在主动脉瘤组织中强烈产生IL-17A，可能有助于AAA发病机理和进展。