Fig. 6.

Etaa1-deficient T cells exhibit normal proliferation and tissue migration. (A and B) CD45.2⁺ C57BL/6 mice were injected i.v. with 5 × 10⁴ CD45.1⁺ Etaa1^+/+ or Etaa1^ΔEx2/ΔEx2 P14 cells before infection with LCMV-Arm. (A) Splenic P14 cells enumerated at days 5 and 8 postinfection showing mean and SD (n = 10–14/group). (B) P14 numbers in the indicated tissues on day 8 postinfection (C) CD45.1⁺ wild-type and CD45.2⁺ Etaa1^ΔEx2/ΔEx2 splenocytes were mixed in a 50:50 ratio, labeled with CTV, and stimulated with 1 µg/mL anti-CD3. Then 3–4 d later, CTV dilution in CD4⁺ and CD8⁺ T cells from wild-type (CD45.1⁺) and mutant (CD45.2⁺) cells was compared. (D) Etaa1^+/+ and Etaa1^ΔEx2/ΔEx2 P14 cells were stimulated in vitro with GP_33–41 peptide and IL-2, live P14 cells were enumerated (expressed as fold change over starting cell number), and Ki67 expression and viability (% 7AAD⁻ Live/Dead dye⁻) were measured by flow cytometry at each timepoint. (E) CD45.2⁺ C57BL/6 mice were injected i.v. with 8 × 10⁵ CTV-labeled CD45.1⁺ Etaa1^+/+ or Etaa1^ΔEx2/ΔEx2 P14 cells before infection with LCMV-Arm. At day 2.5 postinfection, CTV dilution in the transferred P14 cells was measured by flow cytometry, with the CTV MFI in divided P14 cells from each mouse normalized to the average MFI in wild-type P14 cells in the same experiment. Data are pooled from two experiments. (F) The percentage of Ki67⁺ P14 cells at day 5 postinfection in the experiment outlined in A and B. ***P < 0.001; ns, not significant, two-way ANOVA (A) or t test (B, E, and F).