Transgenic Maxi CD8 T cells are maintained at high numbers during latency and exhibit an effector-memory phenotype 10<sup>4</sup> naïve Maxi CD8 T cells were adoptively transferred into naïve C57BL/6J mice followed by i. v. MCMV infection.

<p>Mice were injected i. v. with anti-CD8α antibody three minutes prior to euthanasia. (A) Representative flow cytometry contour plot gating on Maxi cells and their total numbers are depicted in the lungs, liver, spleen and LN at 2, 3, 6 and 9 months post infection and are shown as mean + SEM of n = 3 mice, representative of two independent experiments. Representative flow cytometry contour plots of Maxi cells in the lung (B) and LN (C), and percentage of CD8α-stained Maxis (B), and CD8α-unstained Maxi cells (C) at 6 months post infection are shown. Representative contour plot of KLRG1 and CD127 (D, F), and CD44 and CD62L (E, G) expression on Maxi cells in the lung (D,E) and LNs (F,G) and mean percentages are shown. Representative contour plot of Maxi cell expression of KLRG-1 and CD127 (D, F), and CD44 and CD62L (E, G) in the lung, mean percentages are shown. (F)Data (B-G) are shown as mean + SEM of n = 6 mice pooled from two independent experiments. (A-G) **p<0.01. Statistical analyses were performed using the non-parametric Mann-Whitney <i>U</i> test. (H) Maxi cells are localized in the proximity of CD31<sup>+</sup> endothelial cells in the lungs. Naïve CD45.1 Maxi CD8 T cells were adoptively transferred into WT mice one day prior to i.v. infection with MCMVΔm157. Mice were injected i. v. with 5 μg anti-CD8α-BV421 antibody 3 minutes prior to euthanasia. The localization of Maxi cells in the lungs was determined in the latent phase of MCMV infection. CD45.1 is shown in orange, blue identifies CD8 T cells that were stained upon i.v. injection of αCD8 antibody, CD31 is shown in green and EpCAM in red. Arrows indicate CD45.1<sup>+</sup> Maxi cells that are additionally stained by the i.v. injected CD8 antibody.</p>