Immune Netw.  2021 Apr;21(2):e17. 10.4110/in.2021.21.e17.

Increase of Vδ2 ⁺ T Cells That Robustly Produce IL-17A in Advanced Abdominal Aortic Aneurysm Tissues

• Seo IH
• Lee SJ
• Noh TW
• Kim JH
• Joo HC
• Shin EC
• Park SH
• Ko YG

• KMID: 2522163
• DOI: http://doi.org/10.4110/in.2021.21.e17

Abstract

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.

Keyword

Abdominal aortic aneurysm; Gamma Delta T cells; IL-17A