Figure 2.

Conventional αβ T Cells in Fetal Skin Largely Demonstrate a Naive, Proliferative Phenotype

Live, CD4⁺, and CD8⁺ single-positive cells from 23 weeks fetal skin and adult skin processed for CyTOF were identified by surface markers and analyzed as follows.

(A–D) UMAP plots of combined fetal and adult (A) CD4⁺ and (B) CD8⁺ T cells colored by skin age. Principal component analysis (PCA) plots demonstrating the distribution of all (C) CD4⁺ and (D) CD8⁺ T cells from each individual sample by age.

(E) UMAP plots of CD4⁺ T cells from fetal and adult skin, combined. Cells are labeled and colored by cluster, with clusters A and B constituting conventional CD4⁺ T cells and cluster C representing Tregs.

(F and G) Analogous UMAP plots containing only (F) fetal or (G) adult CD4⁺ T cells.

(H) Heatmap demonstrating relative expression of key markers by CD4⁺ clusters A, B, and C.

(I–K) combined and separated UMAP plots of fetal and adult skin CD8⁺ T cells, colored by cluster.

(L) Heatmap demonstrating relative expression of key markers by each CD8⁺ cluster.

(M–R) Median expression intensity (m.e.i.) of Ki-67 (M and P), CD45RO (N and Q), and CD25 (O and R) for fetal versus adult CD4⁺ Tconv and CD8⁺ T cells as revealed by mass cytometric analyses. Each point in (C), (D), and (M)–(R) represents data from an individual donor. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001; ∗∗∗∗p < 0.0001.