Figure 1: ILC2 in para-aortic adipose tissue and FALCs of atherosclerotic mice.

Flow cytometric analysis (a) and quantification (b,c) of ILC2 present in the para-aortic adipose tissue (AT) show a phenotype similar to KLRG1^hi ST2⁻ ILC2 (iILC2-like) in the lymph node in contrast to KLRG1⁺ ST2⁺ ILC2 (nILC2-like) prevalent in the peri-gonadal WAT. Mean fluorescence intensity (MFI) for ST2 expression in ILC2 is shown in c. Bars represent mean values. (d) Oil red O and Haematoxylin show that FALCs are present in the para-aortic AT of aged Apoe^−/− mice (78–80 weeks of age n=10, scale bar 100 μm) (e) and that Apoe^−/− FALCs are greater in both number and size compared to WT (f). Immunoflorescence staining demonstrates that para-aortic FALCs are rich in CD3⁺ T cells, B220⁺ B cells and CD138⁺ plasma cells. CD35⁺ follicular dendritic cells were absent from these structures (scale bar 50 μm). Additionally, para-aortic FALC-resident CD3⁻ GATA3⁺ ICOS⁺ ILC2 cells were also detected (g, scale bar 10 μm). Representative images shown. Graph data points represent individual mice. Statistical significance was determined by Mann–Whitney U-test.