Abstracts (complete list) - Wissenschaft Online

Diana Dudziak, Alice O'Kamphorst, Gordon F. Heidkamp, Veit R. Buchholz, Christine
Trumpfheller, Chae Gyu Park, Ralph M. Steinman, Michel C. Nussenzweig
Differential Antigen Processing and Presentation by Dendritic
Cell Subsets in vivo
Dendritic cells (DCs) process and present self and foreign antigens to induce tolerance
or immunity. In vitro models suggest that induction of immunity is controlled by
regulating the presentation of antigen, but little is known about how murine DCs control
antigen presentation in vivo. To evaluate regulation of antigen processing and T cell
activation by CD11c+/CD8+ and CD11c+CD8- DCs in vivo we delivered antigens to the
DCs by using chimeric anti DEC205-Ova or 33D1-Ova antibodies. We could show that
DCs targeted with anti DEC205-OVA or 33D1-OVA in vivo are distinct in their ability to
present antigen on MHCI and MHCII, in that DEC205 expressing CD8+ DCs are
specialized for cross-presentation on MHC class I, and CD8- DCs for presentation on
MHC class II. By using transgenic mice that express human DEC205 under the CD11c
promoter we could demonstrate that the difference in antigen processing is intrinsic to
the DC subsets and independend of the receptor that was targeted. Moreover, we found
an increased expression of proteins involved in MHC class I processing in CD11c+/CD8+
DCs and in MHC class II processing in CD11c+CD8- DCs. This specialization may have
important implications for understanding the initiation of T cell responses in vivo.
This work was supported by the German Research Foundation (D.D., DU548/1-1)