IMMUNOBIOLOGY CD8 11b dendritic cells but not CD8 dendritic cells mediate cross-tolerance toward intestinal antigens

Cross-presentation is a critical process by which antigen is displayed to CD8 T cells to induce tolerance. It is believed that CD8 dendritic cells (DCs) are responsible for cross-presentation, suggesting that the CD8 DC population is capable of inducing both cross-priming and cross-tolerance to antigen. We found that cross-tolerance against intestinal soluble antigen was abrogated in C57BL/6 mice lacking mesenteric lymph nodes (MLNs) and Peyer patches (PPs), whereas mice lacking PPs alone were capable of developing CD8 T-cell tolerance. CD8 CD11b DCs but not CD8 DCs in the MLNs present intestinal antigens to relevant CD8 T cells, while CD8 DCs but not CD8 CD11b DCs in the spleen exclusively cross-present intravenous soluble antigen. Thus, CD8 CD11b DCs in the MLNs play a critical role for induction of crosstolerance to dietary proteins. (Blood. 2005; 106:201-206)