Fig. 6: Subcutaneous injection of AAT in healthy volunteers.
a H&E staining of AAT implants excised from healthy volunteers at early, mid, and late timepoints during a first-in-human Phase 1 study. High magnification insets show cell migration from the adjacent host tissue into the AAT matrix. b Multispectral immunohistochemistry (IHC) reveals formation of blood vessels (CD31+) and migration of adipose stem cells (CD34+). c CD4+ and CD8+ T cell infiltration by multispectral IHC. d Flow cytometry analysis was performed on excised AAT implants from six subjects to quantify immune cells (CD45+) recruited within AAT implant(s) relative to multiple samples of subject-matched adipose tissue collected distally from the injection site. Results for each recovered AAT implant were normalized to the average of multiple samples of subject-matched adipose tissue. Data are shown pooled for all subjects. e Relative abundance of different immune cell subsets including granulocytes (CD45+CD11b+CD15+), macrophages (CD45+CD15−CD11c+MHCII+CD11b+CD14+CD68+), and T cells (CD45+CD3+). Data are shown pooled for all subjects. f Relative expression of intracellular FoxP3 as well as TH1, TH2, and TH17 cytokines in T cells isolated from AAT and matched adipose tissue, shown pooled for all subjects. g Expression of macrophage polarization markers (CD163 and CD80) in AAT and matched adipose tissue. (h) Average distribution of M1 (CD80+CD163−), M2 (CD163+CD80−), double-positive and nonpolarized macrophages in AAT and matched adipose tissue as a frequency of total macrophages. i Expression of macrophage polarization (CD163, CD80) and lineage markers (CD11b, CD14) by MFI, pooled for all subjects. Significance (p-values): * < 0.05, ** < 0.01, *** < 0.001, **** < 0.0001. Median and quartiles are shown in violin plots. Scale bars represent 5 mm in whole sections and 200 µm in enlarged regions.
