Abstracts (complete list) - Wissenschaft Online

Fanny Edele, Cindy Reinhold, Stefan F. Martin
Efficiency of T cell defence against melanoma depends on the
DC immunization route
We have recently shown that different routes of DC immunization induce effector/
memory CD8+ T cells expressing different arrays of tissue-specific homing receptors.
This polarization is driven in vivo by tissue-specific DC. In our current study, we
investigate the role of homing receptor polarization by DC vaccination for the efficiency
of anti-tumor immunity in the mouse model of B16.F10 melanoma. We use the parental
tumor as well as B16.F10GP33 that expresses a T cell epitope from the glycoprotein of
lymphocytic choriomeningitis virus (LCMV).
We examined the role of different DC immunization routes for the homing of T cell
receptor transgenic P14 effector/memory T cells and wild type T cells that recognize
GP33 and its correlation with the ability to control tumor growth.
We adoptively transferred naive P14 T cells and activated them in vivo with GP33pulsed
DC via the intracutaneous (i.c.), i.v. or i.p. route. After subcutaneous inoculation
of B16.F10 or B16.F10GP33 melanoma cells into the left and right flanks of C57BL/6
mice, respectively, tumor size was measured every 2 days. DC-GP33 prevented the
growth of B16.F10GP33 tumor in all groups independent of the immunization route.
Thus, induction of skin-specific homing receptors upon i.c. DC injection or the lack of a
tissue-specific polarization or flexible reprogramming when DC are injected i.v. or i.p.,
respectively, allow efficient tumor defence in this setting. However, a different outcome
was observed in recipient mice when no P14 T cells were transferred. In this case, longterm
protective immunity against B16.F10GP33 melanoma required the induction of
skin-specific CD8+ T cells by immunization with DC-GP33 via the i.c. route. Thus, tissuetargeting
of tumor antigen-specific effector T cells by the appropriate DC vaccination
route determines the efficiency of the anti-tumor immune response.
Our findings are relevant for the biological therapy of human cancers.