C57BL/6 WT mice received 0 or 15 Gy WTI and were sacrificed at the indicated time points post-irradiation. Whole lung cell (WLC) CD45 and/or CD73 expression were analyzed by flow cytometry. (A) CD73 expression in WLC is shown in the black histogram. (B, C) Normalized percentages of CD45+ (B, n = 11/11, 16/16, 6/6, 6/5, 10/12) or CD45 (C, n = 15/11, 16/16, 6/6, 6/5, 10/12) WLC. (D-H) Normalized percentages of CD45+, CD45, CD4+, CD8+ cells and alveolar macrophages (CD11chi autofluorescent (55)) with CD73 surface expression (D, n = 11/11, 16/16, 6/6, 6/5, 10/12; E, n = 11/11, 16/16, 6/6, 6/5, 9/11; F, G n = 7/7, 7/7, 14/14, 6/6, 15/15; H, n = 10/10, 8/8, 12/12, 6/4, 6/4). (I) Percentages of lung CD4+ regulatory T cells (FoxP3+) (n = 7/6, 11/11, 9/9, 7/7, 13/8) (mean ± SEM . *P ≤ 0.05, **P ≤ 0.01, ****P ≤ 0.0001 by unpaired two-tailed t-test. (J) Gating strategy of CD4+ cells for CD73 and FoxP3+ expression evaluation.