MURINE EPIDERMAL LANGERHANS CELLS AND SPLENIC DENDRITIC CELLS PRESENTTUMOR-ASSOCIATED ANTIGENS TO PRIMED T-CELLS

We examined the ability of epidermal Langerhans cells and splenic dend ritic cells to present tumor-associated antigens (Ag) to immune T cell s. Methylcholanthrene (MCA)-induced subcutaneous fibrosarcomas derived from C57BL/6 mice were used as tumor models. Our data demonstrate tha t both murine Langerhans cells and splenic dendritic cells have the ca pacity 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 specifi city towards their respective tumors and did not cross-react to other syngeneic MCA-induced or non-MCA-induced tumors. The T cell proliferat ive response critically depended on the presence of immune CD4(+) T ce lls. We discuss the implications of these findings for the adoptive im munotherapy of cancer using immune CD4(+) T cells.