Figure 1.

Human brain metastases are well infiltrated by PD-1⁺ CD8⁺ T cells

(A) Experimental schema and distribution of samples among primary tumor histologies.

(B and C) Density of CD45⁺ lymphocytes (B) and CD8⁺ T cells (C) for all 31 brain metastases grouped by primary tumor type.

(D and E) Density of CD45⁺ lymphocytes (D) and CD8⁺ T cells (E) for all 31 brain metastases grouped by patient disease status at time of tumor resection.

(F) Frequency of CD8⁺ cells among lymphocytes grouped by tumor type for all 31 patients.

(G and H) Density of CD4⁺ T cells (G) and B cells (H) for 20 and 16 of the tumors, respectively.

(I) Percentage of CD8⁺ T cells expressing PD-1 in 21 tumors.

(J) Phenotype of PD-1^- versus PD-1⁺ CD8⁺ T cells within brain metastases (n = 12–14 for each marker).

(K) Percentage of tumor-infiltrating TCF-1⁺ CD8⁺ T cells expressing PD-1, TOX, or both (n = 14).

Bars on graphs indicate median. In (B)–(E) and (G), statistics show variance among primary tumor types with the Kruskal-Wallis test. In (F), (H), and (I), statistics show one-way ANOVA. In (J), statistics show a mixed-effects model analysis with Sidak’s multiple comparisons test.

See also Figure S1.