Plasmacytoid dendritic cells induce tolerance predominantly by cargoing antigen to lymph nodes.
Plasmacytoid dendritic cells (pDCs) have been shown to induce tolerance to innocuous antigens. Their migratory properties allow them to take up antigens from the periphery and transport them to the draining lymph nodes or to the thymus. However, pDC-T-cell interaction in the primary and secondary lymphoid organs still remains poorly defined. In this study, we show that resting pDCs loaded with exogenous antigen could induce tolerance when transferred intralymphatically into a single lymph node of wild-type C57BL/6 mice. However, this was a result of antigen transfer from pDCs to endogenous antigen presenting cells and subsequent abortive proliferation of cognate CD4+T cells. pDCs could not directly induce the proliferation of CD4+T cells, as observed in mice lacking MHC class II gene. Moreover, pDCs failed to make physical contacts with OT-II cells as revealed by two-photon imaging. Thus, the role of resting pDCs in tolerance induction seems to be independent of its direct interaction with cognate CD4+T cells.
Institute of Immunology, Hannover Medical School, Hannover, Germany.
Karan
K
Kohli
Institute of Immunology, Hannover Medical School, Hannover, Germany.
Anika
A
Janssen
Institute of Immunology, Hannover Medical School, Hannover, Germany. foerster.reinhold@mh-hannover.de.
Reinhold
R
Förster
D056704:Adaptive Immunity; D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000276:immunology*; D005802:Genes, MHC Class II / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance / Q000235:genetics; D008198:Lymph Nodes / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL
Antigen presentation; Antigen transfer; Delayed-type hypersensitivity; Intralymphatic migration; Resting pDCs; Tolerance; Two-photon imaging