Figure 10. Ovalbumin-coupled anti-DEC-205 requires TLR agonists to trigger efficient endogenous killing responses.

(A) C57BL/6 mice were left untreated (control), or injected with 0.5μg aDEC/OVA per ear alone (untreated, n.t.) or together with topical imiquimod treatment or 25μg poly(I:C). One week later, fluorescently labelled target cells loaded with low (CTO^neg CFSE^low; “SIINFEKL low”) or high (CTO^neg CFSE^high; “SIINFEKL high”) doses of MHC class I peptide SIINFEKL derived from OVA were injected intravenously. By comparing their numbers to that of unloaded targets (CTO⁺ CFSE^neg; “unpulsed”), percentages of specific lysis were calculated two days later in the blood (data not shown) and in skin-draining lymph nodes, with similar results. Numbers quantify events present in a given gate. (B) C57BL/6 mice were left untreated (control) or immunized with 0.5μg OVA-coupled anti-DEC-205 (aDEC/OVA; black bars) or isotype-matched, nonspecific mAb (ISO/OVA; white bars) per ear alone (n.t.), or together with topical imiquimod treatment. One week later, fluorescently labelled target cells loaded with the MHC class I peptide SIINFEKL derived from OVA were injected intravenously. The efficiency of cytotoxic responses was measured, as in (A), in the blood and lymph nodes, one or two days after target cells transfer. Bar graphs show lysis in imiquimod treated mice only. Results are pooled data from at least two experiments, with 3 to 4 mice per group.