Figure 7.

Depletion of NKp46⁺ Cells, but Not of CD4⁺ and CD8⁺ T Cells, Retards Tumor Regression following Myc De-activation

(A) Flow cytometric quantification of CD3⁺, CD4⁺, and CD8⁺ T cells and NKp46⁺ NK cells in spleen and blood after systemic administration of, respectively, CD4/CD8 (left)- or asialo-GM1 (right)-blocking antibodies in mice up to 3 days after 7 days of tamoxifen (Myc on) treatment. Representative flow profiles of spleen CD3⁺/CD4⁺, CD3⁺/CD8⁺, NKp46⁺, and CD3⁺ cells are shown.

(B) (Left) Quantitation of immunostaining for CD3⁺ T cells in tumors after 7 days Myc activation (7d tam, red squares) then following 3 days Myc de-activation in IgG control-treated mice (black circles) versus mice treated with αCD4/αCD8 antibody (black squares). Bottom panel shows representative immunohistology. Arrows depict CD3⁺ T cells. T = tumor. Right: Quantification of immunostaining for NKp46⁺ NK cells in tumors after 7 days Myc activation (7d tam), then following 3 days Myc de-activation in IgG control-treated mice versus mice treated with α-asialo-GM1. Bottom panel shows representative examples of the immunohistology. A = airway. T = tumor.

(C) (Left) Quantification and representative immunostaining for tumor cell death (TUNEL) following Myc de-activation for 3 days in tumors in CD4⁺/8⁺ T cell competent (IgG-control) versus CD4⁺/8⁺ T cell-deficient mice (αCD4/αCD8). Right: Quantification and representative immunostaining for cell death (TUNEL) following Myc de-activation for 3 days in NKp46⁺ NK cell-competent (IgG-control) versus NKp46⁺ NK cell-deficient mice (α-asialo-GM1 treated).

Quantification graphs: FoV = field of view. Small symbols = individual tumors, large symbols = average per mouse. (A) n = 4 (IgG) or 5 (αCD4/αCD8 or α-asialo-GM1). (B) n = 20 or 25 individual tumors from 4 (7d Tam, IgG) or 5 (αCD4/αCD8) mice per time point, respectively. (C) n = 5 mice per treatment group. n = 30 individual tumors from 5 mice per treatment group. Error bars represent the median with interquartile range (CD3, TUNEL) or mean ± SD (NKp46). p values are based on Student’s t test (CD3, TUNEL) or two-way ANOVA (NKp46). NS = non-significant. ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001.

See also Figures S1, S6, and S7.