Present clinical studies of active immunotherapy for malignancies using den
dritic cells (DCs) require elucidation of the sites where DCs localize afte
r injection. We evaluated the pattern of distribution of in vitro-generated
, antigen-loaded, human DCs labeled with indium-lll oxyquinoline after i.v.
, s.c,, and intradermal injection, Whereas the DCs injected i.v, localized
in the lungs and then redistributed to the liver, spleen, and bone marrow,
they were not detected in lymph nodes or tumors. A small percentage of DCs
injected intradermally migrated rapidly to the regional lymphatics in some
individuals. No lymph node activity was detected after s.c. injection. Our
results demonstrate that DC distribution to sites of lymphoid tissue is dra
matically affected by the mode of administration.