Fig. 1.

Vaccination with irradiated, GM-CSF-secreting B16 melanoma cells is abrogated in CD1d-deficient mice. (A) Female C57BL/6 WT, CD1d-, or Jα281-deficient mice were immunized with irradiated, GM-CSF-secreting B16 cells and challenged 1 week later with WT B16 cells. Vaccination with irradiated, WT B16 tumor cells failed to elicit protective immunity in any strain, and CD1d was not expressed on WT or transduced melanomas (data not shown). (B) Splenocytes isolated from vaccinated CD1d- or Jα281-deficient mice secreted significantly less (P < 0.05 Mann–Whitney test) IL-13, IL-5, IL-10, and GM-CSF, but equivalent amounts of IFN-γ, compared with splenocytes isolated from vaccinated WT mice. (C) CD1d-deficient mice show intact anti-B16 melanoma cytotoxicity. Splenocytes were harvested after vaccination and cultured in vitro for 5 days with irradiated B16 cells; ⁵¹Cr assays were performed against B16 targets.