Fig. 3

Fig. 3 Cd4⁺ T cells are present in the injured cardiac tissue and associate with the activated endocardium.

a Confocal images of representative cryosectioned ventricles from adult TgBAC(cd4-1:mCherry) zebrafish at various time points after cryoinjury, immunostained for mCherry, showing Cd4⁺ T cells in the injured tissue (yellow arrowheads). b Quantification of total cd4-1:mCherry⁺ cells within the injured tissue, showing a peak at 7 dpci. Dots in the graph represent individual ventricles, and the bars represent the mean ± SD; n = 3 (24 hpci), 3 (72 hpci), 3 (96 hpci), 5 (120 hpci), 3 (6 dpci), 5 (7 dpci), 4 (14 dpci), and 3 (30 dpci) biologically independent samples; one-way ANOVA (P = 0.0003) and Tukey’s post hoc test for multiple comparisons; P values included in the graph; full list of multiple comparisons in Supplementary Table 3. c Confocal images of representative cryosectioned ventricles from adult TgBAC(cd4-1:mCherry) zebrafish at various time points after cryoinjury, immunostained for mCherry and Aldh1a2, revealing the close association of Cd4⁺ T cells (yellow arrowheads) with activated EdCs (green). Yellow dashed squares outline the magnified areas; dashed lines mark the border of the injured tissue. Scale bars: 100 µm in (a) and (c) (low magnification); 20 µm in c (high magnification).