(A) Uniform manifold approximation and projection (UMAP) representation of B6 (left) and B6.Sh2d1a-/- (right) γδ T cells from D9 neonatal thymi (n = 3 mice per strain). Cluster annotation is based on comprehensive protein and gene expression data. (B) Feature plots displaying cell surface protein expression patterns of CD24, CD73, SLAMF1, and SLAMF6 on D9 B6 thymus γδ T cells. Data are color-coded based on protein expression level (high: dark blue, low: yellow). (C) UMAP representation of D9 B6 thymic γδ T cells exhibiting selected TRGV4 (left) and TRDV (right) chain V-segment usage (in blue) in individual cells. (D) Frequencies of B6 and B6.Sh2d1a-/- D9 thymic γδ T cell clusters. Bars represent the mean cluster frequency, error bars represent standard deviation, *p ≤ 0.05, **p ≤ 0.01, two-way ANOVA, Sidak multiple comparisons test, 3 mice/strain. (E) Representative contour plots depicting BLK and RORγt expression in B6 and B6.Sh2d1a-/- CD24posCD73neg D9 Vγ4 T cells are shown above. Cumulative frequencies of BLK and RORγt expression are shown below. The mean and standard deviation are indicated. Data are the cumulative data from three independent experiments, n = 13 B6, 16 B6.Sh2d1a-/- mice, ****p ≤ 0.0001, two-way ANOVA, Sidak’s multiple comparisons test. (F) Decreased BLK expression in immature B6.Sh2d1a-/- γδ T cells. Data represent the mean expression of the indicated proteins in D6 neonate BLKpos, RORγtpos, or cMafpos thymic γδ T cells, **p ≤ 0.01.
Figure 4—source data 1. Comparison of BLK, RORγt, and cMaf expression among neonatal thymic γδ T cells.