Figure 1. Dgkζ-deficient activated CD8+ T cells demonstrate enhanced tumor responses in vivo.

(A) 20,000 naïve (CD44^lo) CD8+ wt or dgkζ-deficient OT-I cells were injected i.v. into congenically marked (CD90.1) mice. 24 hours later, the mice were injected i.v. with 5000 cfu Listeria-ova, and one week later mice were euthanized, and the presence of donor OT-I T cells (CD90.2+, ova tetramer+) were assessed (n=5, quantitation of 1 of 3 representative experiments is shown). CD90.2+ cells from (A) were isolated magnetically and 1×10⁶ cells were injected i.v. into CD45.1+ mice bearing two week old subcutaneous EL4-ova tumors. One week later, mice were euthanized and assessed for (B) tumor size, (C) persistence of donor (CD45.2+, ova tetramer+) T cells, and (D) tumor-infiltrating donor T cells. “No T cell” mice did not receive donor T cells, and CD45.2 cells were not detected in any organ tissue (data not shown). (B = data from 3 pooled experiments, C and D are data from 1 of 3 representative experiments, n=5 in each group).