Identification and characterization of CD4(+)AT2(+) T lymphocyte population in human thoracic aortic aneurysm.

ABSTRACT: Thoracic aortic aneurysm (TAA) is progressive fatal aortic pathological dilation. However, the underlying molecular mechanisms are still largely unknown. Evidences suggest that endothelial cells and renin-angiotensin system may participate in the pathogenesis of TAA. This study aimed to investigate whether angiotensin II type 2 receptor (AT2) positive cells are involved in TAA formation. The mRNA level of AT2 is dramatically elevated in TAA compared with in controls. CD4(+)AT2(+) cells increased in both aortic wall and circulation of TAA patients. The levels of IL-1? and IL-17B in CD4(+)AT2(+) cells were lower than those in CD4(+)AT2(-) cells. When compared with endothelial cells (ECs) cultured alone, CD4(+)AT2(+) cells showed an inhibitory effect on proliferation and MMP2 expression in ECs, but CD4(+)AT2(-) cells promoted proliferation and MMP2 expression in ECs. Both CD4(+)AT2(+) and CD4(+)AT2(-) cells suppressed apoptosis of ECs. In conclusion, we have identified a novel population of CD4(+)AT2(+) T lymphocytes that show protective effect in TAA through inhibition of growth, apoptosis, and MMP2 expression in ECs.

SUBMITTER: Wang C 

PROVIDER: S-EPMC4399088 | biostudies-other | 2015

REPOSITORIES: biostudies-other