Fig. 3: Blockade of CD200R1-CD200 inhibits tumor growth in vivo.

a–g Tac⁺ WEHI-231 tumor (with or without luciferase expression) were injected intravenously into Rag1^−/− mice, followed by intraperitoneal injection of Tac mAb combined with CD200 mAb or Ctrl mAb every 2 days. Mice were euthanized on day 15 (b–d) or monitored over time using luminescence, if cells were expressing luciferase (e–g), (n = 12, b, c, n = 10, e–g). a Schematic representation of the experimental workflow. I.V., intravenously; I.P., intraperitoneally. b Representative photographs of mice euthanized on day 15, with or without tumor injection, and treated with the indicated mAbs. Scale bar, 1 cm. c Liver weight of mice injected or not with tumor cells. d Hematoxylin and eosin staining of liver sections, showing blood vessels (blue asterisks) and tumor cell aggregates adjacent to blood vessels (outlined in white). Scale bars, 100 µm (10× magnification), and 20 µm (40× magnification). e Representative luminescence images on day 12. f Tumor progression over time as measured by luminescence. sec, second, st, steradian. g Kaplan–Meier analysis of survival. h–j Tac⁺ A20 cells were injected subcutaneously in Rag1^−/− mice followed by intraperitoneal injection of Tac mAb combined with CD200 mAb or Ctrl mAb, every 2 days, (n = 8). h Schematic representation of the experimental workflow. S.C, subcutaneously. i Tumor volume over time. j Tumor weight. Data are from three c or two d–j independent experiments, respectively. Each symbol represents one mouse. Data are presented as mean ± s.e.m. Statistical analysis: one-way ANOVA test, with multiple comparisons (c); two-tailed t-test (f, i, j). log-rank (Mantel–Cox) test (g). ns, not significant. See also Supplementary Figs. 3 and 4.