Extensive expansion of peripheral donor T cells in recipients with cGvHD after viral infection. Recipients with cGvHD and no GvHD were bled on 133 days after transplantation (day 0 prior to infection) and mice were infected with 5 × 104 PFUs MCMV intraperitoneally. Panel A represents the kinetics of peripheral expansion of donor spleen–derived (Thy1.2+ CD45.1+), host-derived (Thy1.2+ CD45.2+) T cells, as well as a mixture of BM-derived (Thy1.1+ CD45.2+) T cells and host-derived non-T cells. The FACS data shown here represent the same mouse in each group that is representative of 4 to 5 mice in each group. Panel B represents the total number of donor spleen–derived T cells per mL of blood. Data from an average of 4 to 5 mice per group are shown for each time point (*P < .001 for uninfected data vs infected data; *P < .05 for cGvHD vs no GvHD on day 10 after infection). Panel C represents the surface expression of CD44 antigen on the donor spleen– and BM-derived CD8+ and CD4+ T cells that were measured prior to MCMV infection (133 days after transplantation) as shown in top 2 panels and 40 days after MCMV infection as shown in bottom 2 panels from the same mouse of each group. Dotted histogram plot represents the isotype control mAb used for CD44. The data are representative from 1 mouse of each group out of 4 to 5 mice used per group.
