FIG. 4.

Virus-infected DC and Mφ process and present the immunodominant antipolyomavirus CTL epitope. (A) Uninfected, MT389-397 peptide-pulsed or virus-infected thioglycolate-elicited Mφ or FACS-sorted CD11c⁺ DC were cocultured with the MT389-397-specific T-cell hybridoma H8-1.18 for 24 h, and IL-2 levels measured by determining [³H]thymidine incorporation by CTLL cells. Splenic CD11c⁺ DC were also FACS sorted at day 2 postinfection and assayed for their capacity to stimulate H8-1.18. Stimulators: ■, uninfected; ⧫, in vitro infected; ●, MT389-397 pulsed; ▴, in vivo infected. (B) DC (5 × 10⁴/well) pulsed with heat-inactivated (HI) virus, pulsed with MT389-397 peptide, infected by polyomavirus, or left untreated were cultured for 24 h with H8-1.18 cells, and IL-2 production was measured by CTLL bioassay.