Fig. 4: Ccl2 expression by IMs is critical for the recruitment of recMacs.
From: Chemokine-defined macrophage niches establish spatial organization of tumor immunity
a, Xenium spatial transcriptomic analysis showing the expression of Ccl2, Il1b, Nos2, Arg1 and Ccl24 in the lungs of C57BL/6 WT mice at day 16 post-intravenous injection of 4 × 105 KPAR1.3 adenocarcinoma cells. b, UMAP visualization of Ccl2 expression in myeloid cells as in Fig. 1a. c, Spatial transcriptomics as in a showing the overlay of C1qb, Cd163 and Ccl2. Scale bar, 1,000 µm. d, High-resolution imaging of spatial transcriptomics as in a showing the expression of Vcan, Mmp12 and Ccl2 within the TME. Red arrows show Ccl2+ CD206lo IMs and Ccl2+ recMacs. Scale bar, 100 µm. e, Representative lung images (left), quantification of surface metastases (middle) and recMacs per lung (right) in mice reconstituted with CD45.2 WT (n = 5) or Ccl2−/− (n = 5) BM on day 16 post-intravenous injection with B16F10 melanoma cells. One of three independent experiments is shown. Statistical significance determined using Student’s two-tailed t-test P < 0.0001 (metastases), P = 0.0097 (recMacs). f, Histogram showing expression of CD45.1 in CD11b+CD64+ IMs, Ly6C+CD11b+ recMacs or CD11c+MHCII+CD64− DCs in C57BL/6 CD45.1 WT mice that were injected intraperitoneally with 25 mg kg−1 busulfan or lethally (900 rad) irradiated, reconstituted with WT CD45.2 BM and analyzed at 4 weeks after busulfan or 6 weeks after lethal irradiation. Three independent experiments with n = 3 mice per group. g, Representative lung images (left) and quantification of surface metastases (right) in irradiated or busulfan-conditioned C57BL/6 CD45.1 WT mice as in f reconstituted with WT (radiation, n = 4; busulfan, n = 5) or Ccl2−/− (radiation, n = 3; busulfan, n = 5) BM at day 16 post-intravenous injection of B16F10 melanoma cells. One of two independent experiments is shown. Statistical significance was determined via one-way analysis of variance (ANOVA) followed by Bonferroni’s multiple comparisons test with P = 0.0012 (radiation WT versus radiation Ccl2−/−), P = 0.001 (radiation Ccl2−/− versus busulfan WT) and P = 0.0034 (radiation Ccl2−/− versus busulfan Ccl2−/−). All data are represented as mean ± s.e.m. **P < 0.01; ****P < 0.0001.
