In situ analysis reveals physical interactions between CD11b+ dendritic cells and antigen-specific CD4 T cells after subcutaneous injection of antigen.
In situ staining techniques were used to visualize physical interactions between dendritic cell subsets and naive Ag-specific CD4 T cells in the lymph node. Before injection of Ag, CD8(+) dendritic cells and naive OVA-specific CD4 T cells were uniformly distributed throughout the T cell-rich paracortex, whereas CD11b(+) dendritic cells were located mainly in the outer edges of the paracortex near the B cell-rich follicles. Many OVA-specific CD4 T cells were in contact with CD8(+) dendritic cells in the absence of OVA. Within 24 h after s.c. injection of soluble OVA, the OVA-specific CD4 T cells redistributed to the outer paracortex and interacted with CD11b(+), but not CD8(+) dendritic cells. This behavior correlated with the uptake of OVA and the presence of peptide-MHC complexes on the surface of CD11b(+) dendritic cells, and subsequent IL-2 production by the Ag-specific CD4 T cells. These results are consistent with the possibility that CD11b(+) dendritic cells play a central role in the activation of CD4 T cells in response to s.c. Ag.
Department of Pediatrics, University of Minnesota, Minneapolis 55455, USA. ingu1001@umn.edu
Elizabeth
E
Ingulli
Deborah R
DR
Ulman
Michelle M
MM
Lucido
Marc K
MK
Jenkins
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D016827:CD8 Antigens / Q000032:analysis / Q000096:biosynthesis; D002450:Cell Communication / Q000276:immunology*; D002645:Chickens; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000008:administration & dosage / Q000276:immunology*; D019085:Fluorescent Antibody Technique, Direct; D000949:Histocompatibility Antigens Class II / Q000032:analysis / Q000096:biosynthesis; D007279:Injections, Subcutaneous; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000032:analysis* / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D010047:Ovalbumin / Q000008:administration & dosage* / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D010446:Peptide Fragments / Q000032:analysis / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism / Q000637:transplantation
D016827:CD8 Antigens; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; C111389:I-Ad antigen; D016177:Macrophage-1 Antigen; D010446:Peptide Fragments; D010047:Ovalbumin