Blocking integrin α4 partially corrects the defective maintenance of Tgfbr2 ^−/− Tcf-1 ⁺ CD8 ⁺ T cells. (A) Experimental design. Same P14 co-transfer and LCMV infection setup as in Fig. 1. Starting from day 10 after infection, integrin α4 blocking antibody was administrated every 3 d and examined on day 22. (B) The virus titer in the serum before (d9) and after (d22) αItga4 blocking are shown. (C) Representative FACS profiles of pre-gated donor splenic P14 T cells are shown. (D) The percentage of Tcf-1⁺ cells among P14 T cells is shown. (E) The ratios of Tcf-1⁺ percent in control P14s over Tcf-1⁺ percent in Tgfbr2^−/− P14s are shown. (F) The percentage of Tcf-1⁺ (left) and Tcf-1⁻ (right) donor P14 T cells in total splenic CD8⁺ population are shown. (G) Experimental design for delayed integrin α4 blocking. (H) The percentage of Tcf-1⁺ subset in donor P14 T cells at day 30 after infection in the presence or absence of delayed α4 blocking. Each pair of symbols in D and H, and each symbol in B, E, and F represent the results from an individual mouse. Representative or pooled results from five independent experiments are shown in (C–F; n = 15–20). Pooled results from two independent experiments are shown in B (n = 5/each) and H (n = 5/each). *, P < 0.05; **, P < 0.01; and ***, P < 0.001 by Student’s t test in D, E, and H, or by ordinary one-way ANOVA in B and F.