PTX3 promotes cytokine production. (A) CD11b⁺ DCs or pDCs, generated from bone marrow progenitors of BALB/c mice, were pre-exposed to 5 μg/mL PTX3 before infection (^a) or were untreated and infected with 5 μg/mL PTX3-treated virus (^b). Cytokines were determined in culture supernatants by ELISA assay and are expressed as picograms per milliliter. Bars indicate the standard errors. *P < .05, cytokine production in MCMV-infected DCs versus uninfected DCs. **P < .05, DCs infected with PTX3-treated virions versus PTX3-treated DCs. (B) Cytokine production in MCMV infection. Cytokine levels (pg/mL) in culture supernatants of spleen cells from mice with primary MCMV infection and treated with PTX3. *P < .05, PTX3 treated versus untreated mice. (C) Cytokine production in the MCMV reactivation model. BALB/c or C57BL6 mice were infected with MCMV. Infected mice were used either as recipients of allogeneic donor uninfected bone marrow cells (MCMV⁺ recipients) or as donors of bone marrow cells (MCMV⁺ donors) to be injected into uninfected recipients. PTX3 (1 mg/kg intraperitoneally) was given daily for 2 weeks, starting the day after HSCT. Cytokine (pg/mL) levels in culture supernatants of spleen cells were determined by ELISA assay. Bars indicate the standard errors. *P < .05, PTX3 treated versus untreated mice.