PTX3 supports DC, NK cell, and T-cell activation in vivo. Phenotypic analysis of total spleen and lung cells (A,C), spleen DCs (B), and spleen NK cells (D) from untreated MCMV-infected BALB/c mice (–) or mice a day after 1 week of treatment (+) with PTX3 (1 mg/kg intraperitoneally). None indicates uninfected mice. Numbers refer to the percentage of positive cells on FACS analysis. Histograms are representative of 1 of 4 independent experiments. Open areas represent control cells stained with irrelevant antibody. (E) Cytotoxic activity (by standard ⁵¹Cr-release assay against YAC-1 targets) and frequency of IFN-γ–producing splenic NK cells by ELISPOT assay from BALB/c mice infected and treated as described in “Pathogens, infections, and treatment.” (F-G) Cytotoxic activity (against ⁵¹Cr-labeled MEF cells) and frequency of IFN-γ–producing splenic CD8⁺ or CD4⁺ T cells by ELISPOT assay from BALB/c mice infected and treated as described in “Pathogens, infections, and treatment.” Bars indicate the standard errors. *P < .05, infected versus uninfected mice. **P < .05, PTX3-treated versus untreated infected mice. The results shown represent 3 representative experiments of 5.