Extended Data Fig. 6: PD-1 checkpoint blockade induces apoptosis of CD8+T cells in the tdLN.
From: Inhibitory PD-1 axis maintains high-avidity stem-like CD8+ T cells
a, Multi-panel images showing thin cross-sections (12 µm and 4 µm z-thickness) of two examples of clustering OT-I cells and the co-localization of PD-1 (magenta) on OT-I.CD45.1 (red) with PD-L1 (green) expressed on cDC1 (yellow), as in Fig. 4b. Arrows indicate polarization and punctate microcluster formation of PD-1 and their co-localization with PD-L1 blending into white pixels. Data representative of at least 2 independent experiments (n = 4). b, Cross-section of Day 8 tdLN from mice treated with PBS or anti-PD-L1/PD-L2 blocking antibodies following the experimental scheme from Fig. 4c. Cleaved caspase-3 staining indicates increased apoptosis of the lymph node cells. Dotted box denotes the close-up of cDC1-dense region shown in (c), displayed with (left) or without cDC1 channel (right). Data are representative of 3 independent experiments (n = 5 for PBS; n = 6 for aPD-L1/2). d, Relative expression of cleaved caspase-3 of OVA-tetramer+ SLAMF6+ TSL recovered from Day 10 tdLN treated with PBS (blue) or anti-PD-L1/2 (red) as measured by flow cytometry. Expression level is normalized to CD44- TCF-1+ PD-1- naïve CD8+ T cell population. Error bars: means ± s.d. **p < 0.01; unpaired two-tailed t-test.
