Figure 7. Specific decrease in Vγ4/Vδ7 γδT1 cells in the lungs of SAP-deficient mice.

(A) Uniform manifold approximation and projection (UMAP) representation of B6 (left) and B6.Sh2d1a^-/- (right) lung γδ T cells, pooled from 3 mice per strain. (B) SAP-dependent variation in lung γδ T cell cluster frequencies. The frequency of each B6 and B6.Sh2d1a^-/- cluster as a percentage of all lung γδ T cells is shown. (C) UMAP representation of selected TRG and TRD chain V-segment usage (blue) among B6 and B6.Sh2d1a^-/- lung γδ T cells. (D) SAP-dependent decrease in lung γδT1 TRGV4/TRDV7. Normalized TRDV counts in B6 and B6.Sh2d1a^-/- lung TRGV4⁺ γδT1 clusters (C2/C3/C7/C9). (E) SAP-dependent decrease in SLAMF7⁺ lung Vγ4 T cells. Representative contour plots of CD44 and SLAMF7 expression in B6 (left) and B6.Sh2d1a^-/- (right) lung Vγ4 γδ T cells are shown at left. Relative frequencies and counts of CD44⁺SLAMF7⁺ lung Vγ4 cells is shown at right. Data represent the cumulative data from five independent experiments, ****p < 0.0001 using unpaired t-test. (F) SAP-dependent skewing of the lung γδT17 TCR repertoire. Amino acid length distributions of B6 and B6.Sh2d1a^-/- TRGV4⁺ CDR3γ (left) and TRDV2⁺ CDR3δ (right) sequences in the lung Vγ4 γδT17 C1 cluster. The top 10 clonotypes are color-coded and all other clonotypes are shown in gray. Bars represent the frequency of γδ T cells in the c1 cluster. (G) TCR clonotype bubble plots depicting the top 50 lung TRGV4 clonotypes in the C1 γδT17 cluster. Bubble size indicates clonotype frequency as a percentage of C1 Vγ4 (n = 62 B6, 104 B6.Sh2d1a^-/-) T cells, and colors correspond to specific TRDV chains. Selected clonotypes are numbered and their corresponding CDR3γ and CDR3δ sequences are displayed below.

Figure 7—figure supplement 1. Significant and specific reduction of peripheral TRGV4/TRDV7⁺ γδT1 in B6.Sh2d1a^-/- mice.

(A) The relative expression of the specified TRDV transcripts in adult lung and spleen CD45⁺ leukocytes (normalized to total TRDC transcript levels) in B6 and B6.Sh2d1a^-/- mice, **p < 0.01, ****p < 0.0001, two-way ANOVA followed by Sidak multiple comparisons test. (B) SAP-dependent decrease in CD44⁺SLAMF7⁺ spleen Vγ4 T cells. The relative percentage and count of CD44⁺SLAMF7⁺ Vγ4 cells in B6 and B6.Sh2d1a^-/- spleen subsets are shown. Data are representative of five independent experiments with 3–5 mice per strain per experiment, ****p < 0.0001, as determined by unpaired t-tests. (C) No difference in lung Vγ4 homeostasis in B6.Sh2d1a^-/- mice. Top left, representative contour plots showing the frequency of BrdU staining in B6 and B6.Sh2d1a^-/- lung γδ T cells. Cumulative data from two independent experiments are shown at top right. Bottom left, representative contour plots depicting Annexin V and Live/Dead staining in B6 and B6.Sh2d1a^-/- lung γδ T cells. Cumulative results are shown at bottom right, and are representative of three independent experiments.