Tumor antigen presentation by dermal antigen-presenting cells

Several phenotypes of antigen-presenting cells are present in the dermis, w here they presumably function to present encountered antigens for immune re sponses. This study examined the ability of dermal antigen-presenting cells to present tumor-associated antigens for the induction of in vivo antitumo r immunity. Total murine dermal cells were exposed either to medium alone o r to medium containing tumor-associated antigens from S1509a tumor cells. S ubsequently, dermal cells were injected subcutaneously at weekly intervals into naive mice for a total of three immunizations. One week following the final immunization, mice were challenged with living tumor cells. In these experiments, dermal cells pulsed with tumor-associated antigens induced pro tective immunity to tumor growth. Dermal cells exposed to tumor-associated antigens were also able to elicit delayed-type hypersensitivity after footp ad injection into mice previously immunized against S1509a tumor cells. The ability to present tumor-associated antigens for both induction of antitum or immunity and elicitation of delayed-type hypersensitivity was dependent on I-A(+) cells and was genetically restricted. Finally, dermal cells tende d towards eliciting a greater antitumor delayed-type hypersensitivity respo nse than epidermal cells. These results show that the murine dermis contain s antigen-presenting cells capable of processing S1509a tumor antigens for the generation of protective antitumor immunity in vivo.