Ablation of Cbl-b provides protection against transplanted and spontaneous tumors
J. Clin. Invest. Jeffrey Y. Chiang, et al. 117:1029 doi:10.1172/JCI29472 [Go to this article.]

Figure 3
Tumor rejection in Cblb^–/– mice is mediated by Cblb^–/– CD8⁺ T cells. (A) Immunohistology of tumor-infiltrating CD8⁺ cells. Shown are sections of tumors stained with H&E (left) or anti-CD8 antibody (right). CD8⁺ cells are FITC positive (green). Tumors were from WT and Cblb^–/– mice at the seventh or nineteenth day after inoculation. (B) Flow cytometric analysis of tumor infiltrates. Tumor infiltrates were prepared from tumors from WT or Cblb^–/– mice. These cells were stained with anti-TCRβ, anti-CD8, anti-CD4, and anti-CD44 antibodies and analyzed on LSR II. Foxp3⁺ (Treg) cells were identified by intracellular staining with an anti-Foxp3 antibody according to manufacture protocol. Shown at the top left are contour plots of CD8 and TCRβ expression on tumor-infiltrating cells from 1 of 3 independent experiments. The percentages of CD8⁺ TCRβ⁺ cells are indicated in the plots. The percentages of CD8⁺ TCRβ⁺, CD4⁺, and Treg infiltrates in total tumor infiltrates are summarized and shown as bars (bottom left). *P < 0.001, **P < 0.005. Histograms show the levels of TCRβ and CD44 expression on the infiltrating CD8⁺ T cells (right). (C) Eradication of established E.G7 tumors by adoptively transferred Cblb^–/– or Cblb^–/– OT1 CD8⁺ T cells. 10⁶ E.G7 cells were inoculated into C57BL/6 mice by s.c. injection. Seven days after the inoculation, 3 × 10⁶ purified WT or Cblb^–/– CD8⁺ T cells (top) or WT OT1 or Cblb^–/– OT1 CD8⁺ T cells (bottom) were transferred into the tumor-bearing mice by i.v. injection. Shown at the left are the tumor volumes at different time points after the CD8⁺ T cell transfer. Genotypes of the donor cells are indicated on the top of each plot. Results are from 1 of 5 or more independent experiments. The plot in the right panel shows percentages of surviving recipient mice (WT, n = 11; Cblb^–/–, n = 13) that received WT or Cblb^–/– CD8⁺ T cells. When the tumor volume reached approximately 5,000 mm³, the mice were euthanized and recorded as dead.