Murine epidermal Langerhans cells and splenic dendritic cells present tumor‐associated antigens to primed T cells

We examined the ability of epidermal Langerhans cells and splenic dendritic cells to present tumor‐associated antigens (Ag) to immune T cells. Methylcholanthrene (MCA)‐induced subcutaneous fibrosarcomas derived from C57BL/6 mice were used as tumor models. Our data demonstrate that both murine Langerhans cells and splenic dendritic cells have the capacity to present tumor‐associated Ag to primed T cells. We found that variously treated tumor preparations (irradiated viable tumor cells, irradiated frozen‐stored tumor cells, mitomycin C‐treated viable tumor cells, and snap freeze‐thawed tumor cell lysates) can be utilized for tumor Ag‐pulsing. Primed CD4⁺ T cells demonstrated in vitro specificity towards their respective tumors and did not cross‐react to other syngeneic MCA‐induced or non‐MCA‐induced tumors. The T cell proliferative response critically depended on the presence of immune CD4⁺ T cells. We discuss the implications of these findings for the adoptive immunotherapy of cancer using immune CD4⁺ T cells.