Figure 2.

Immunostaining of type I IFN receptor subunit 1 in non-aneurysmal and aneurysmal human aortae. Formalin-fixed paraffin sections were prepared from aortic specimens harvested at organ donation (n = 2) or AAA repair (n = 6), stained with a rabbit anti-human type I interferon receptor subunit 1 (IFNAR1) polyclonal antibody or negative control antibody (normal rabbit IgG), and visualized with peroxidase substrate 3,3′-diaminobenzidine. (A,B) Rare or no IFNAR1 staining detected in organ donor aortae. (C–H) IFNAR1 staining was localized in the media and adventitia (within and outside of lymphocyte aggregates) of AAA specimens. (I) No staining noted in aneurysmal (I) and non-aneurysmal organ donor aortae (not shown) with negative control antibody. Scale bar: 50 μm.