Intranodal immunization with tumor lysate-pulsed dendritic cells enhances protective antitumor immunity

We developed a technique for direct inguinal lymph node injection in mice t o compare various routes of immunization with tumor lysate-pulsed dendritic cell (DC) vaccines. Syngeneic, bone marrow-derived, tumor lysate-pulsed DC s administered intranodally generated more potent protective antitumor immu nity than s.c, or i.v, DC immunizations. Intranodal immunization with ovalb umin peptide-pulsed DCs induced significantly greater antigen-specific T-ly mphocyte expansion in the spleen than either s.c, or i.v. immunization. Fur thermore, a significantly more potent, antigen-specific TH1-type response t o the ovalbumin peptide was induced by intranodal, compared with s.c. or i. v., immunization. Intranodal immunization, designed to enhance DC-T cell in teraction in a lymphoid environment, optimizes induction of T lymphocyte-me diated protective antitumor immunity. These results support the use of intr anodal immunization as a feasible and effective route of DC vaccine adminis tration.