Fig. 3.

Immunization with Lm-LLO-E7 increases surface expression of MHC class I D^b in TC1 by an IFN-γ–dependent mechanism. C57BL/6 mice were injected subcutaneously with Matrigel containing 1×10⁵ TC1 or TC1.mugR tumor cells. After 7 days, mice were injected i.p. with PBS or Lm-LLO-E7. After 5 days, Matrigel plugs were harvested, the surrounding tissue was digested with DNaseI and collagenase, and single-cell suspensions were made. Cells were stained for CD45 and MHC class I D^b. Cells in the live lymphocyte gate (A) were further gated using CD45 and side scatter into a CD45^high (gate R4) or CD45^lo (gate R3) population (B). In C, percentages represent the mean channel fluorescence ± SEM for class I D^b staining on CD45^lo tumor cells; asterisk paired measurements that are statistically different as determined by Student’s t test.