Original Research ARTICLE
T Cells Are Dominant Population in Human Abdominal Aortic Aneurysms and Their Infiltration in the Perivascular Tissue Correlates With Disease Severity
- 1University of Glasgow, United Kingdom
- 2Jagiellonian University Medical College, Poland
- 3Saint John Grande Hospital, Poland
- 4Queen Elizabeth University Hospital, United Kingdom
- 5John Paul II Hospital, Poland
- 6Jagiellonian University, Poland
Abdominal Aortic Aneurysm (AAA) is a major cause of cardiovascular mortality. Adverse changes in vascular phenotype act in concert with chronic inflammation to promote AAA progression. Perivascular adipose tissue (PVAT) helps maintain vascular homeostasis but when inflamed and dysfunctional, can also promote vascular pathology. Previous studies suggested that PVAT may be an important site of vascular inflammation in AAA; however, a detailed assessment of leukocyte populations in human AAA, their anatomic location in the vessel wall and correlation to AAA size remain undefined.
Accordingly, we performed in depth immunophenotyping of cells infiltrating the pathologically altered perivascular tissue (PVT) and vessel wall in AAA samples at the site of maximal dilatation (n=51 patients). Flow cytometry revealed that T cells, rather than macrophages, are the major leukocyte subset in AAA and that their greatest accumulations occur in PVT. Both CD4+ and CD8+ T cell populations are highly activated in both compartments, with CD4+ T cells displaying the highest activation status within the AAA wall. Finally, we observed a positive relationship between T cell infiltration in PVT and AAA wall. Interestingly, only PVT T cell infiltration was strongly related to tertiles of AAA size.
In summary, this study highlights an important role for PVT as a reservoir of T lymphocytes and potentially as a key site in modulating the underlying inflammation in AAA.
Keywords: Adaptive Immunity, perivascular adipose tissue (PVAT), Adaptive immunity and cardiovascular disease, T cell, Inflammation, Abdominal aortic aneursym
Received: 29 Mar 2019;
Accepted: 05 Aug 2019.
Edited by:Claudio Mauro, University of Birmingham, United Kingdom
Reviewed by:Stephanie W. Watts, Michigan State University, United States
Massimiliano Ruscica, University of Milan, Italy
Copyright: © 2019 Sagan, Mikolajczyk, Mrowiecki, Macritchie, Daly, Meldrum, Migliarino, Urbanski, Filip, Kapelak, Maffia, Touyz and Guzik. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Tomasz J. Guzik, University of Glasgow, Glasgow, G12 8QQ, United Kingdom, email@example.com