DC numbers are diminished in acute GVHD and DCs are resistant to MCMV infection. BALB/c (non-GVHD) and DBA/2 (GVHD) were transplanted with BALB/c BM (5 × 10⁶) and CD3⁺ T (2.5 × 10⁶) cells. Four weeks after transplantation, mice were infected with 5 × 10³ pfu MCMV. Numbers of (A) CD8α⁺ DCs, (B) CD11b⁺ DCs, and (C) pDCs were determined for the spleen at the indicated times after MCMV infection. (D-E) Non-GVHD and GVHD mice were infected with 1 × 10⁴ pfu MCMV-expressing GFP. Spleens were collected on day 2 PI and frequency of GFP⁺ DCs was determined by flow cytometry. (D) Representative plots are shown for DCs from an uninfected control and 1 mouse from each group of infected mice. (E) The frequencies of CD8α⁺ DCs and CD11b⁺ DCs that were GFP⁺ are shown. (F-G) The expression of MHC-II was determined for splenic cDCs, CD8α⁺ DCs, and CD11b⁺ DCs prior to infection. (F) Representative histograms for non-GVHD (filled histogram) vs GVHD mice (bold line), as well as MHC-II mean fluorescence intensity (MFI) for cDCs from non-GVHD and GVHD mice. (G) MHC-II MFI values for splenic CD8α⁺ DCs and CD11b⁺ DCs from non-GVHD and GVHD mice are shown. (A-C) 3 to 5 mice per group; (D-E) 3 to 4 mice per group; (F-G) 5 mice per group. Data in D-G are representative of 2 independent experiments. *P = .01-.05, **P = .001-.01, ***P = .0001-.001.