Figure 1.

Chimeric MHC class I constructs induce DC maturation and CTL responses in vitro. Bone marrow-derived DC were electroporated with hβ2 m constructs: TRP-1-Kb and TRP-1-TRL4 (A) or with TYR-Kb and TYR-TLR4 (B) encoding mRNA respectively. Expression kinetics of chimeric-hβ2m constructs on DC was assessed by flow cytometry. Empty electroporated DC (EP only) served as a control. (C) Secretion of IL-12 and IL-10 by immature, LPS-maturated, and mRNA-electroporated DC (TRP-1+TYR EP-DC) was measured by ELISA and expressed as pg/mL (n = 3). (D-F) Expression of DC maturation markers (CD80, CD86, MHC-class II) was measured by flow cytometry 6 h after electroporation. Representative histograms are shown. G and H, CTL were induced by immunization of C57 BL/6 mice with DC electroporated with respective TRP1-Kb/TRL4 or TYR-Kb/TLR4 encoding mRNA (n = 3) and assessed by CTL in vitro killing assay. Results are presented as the percentage of killed syngeneic B16F10.9 and B16MO5 melanoma target cells following co-incubation with CTL induced by TYR-Kb/TLR4 (G) and TRP-1-Kb/TLR4 constructs (H). D122 Lewis lung carcinoma mouse cells that do not express TRP1 and TYR were used as a negative control. Data are representative of two independent experiments.