IgE-mediated enhancement of CD4(+) T cell responses requires antigen presentation by CD8α(-) conventional dendritic cells.
IgE, forming an immune complex with small proteins, can enhance the specific antibody and CD4(+) T cell responses in vivo. The effects require the presence of CD23 (Fcε-receptor II)(+) B cells, which capture IgE-complexed antigens (Ag) in the circulation and transport them to splenic B cell follicles. In addition, also CD11c(+) cells, which do not express CD23, are required for IgE-mediated enhancement of T cell responses. This suggests that some type of dendritic cell obtains IgE-Ag complexes from B cells and presents antigenic peptides to T cells. To elucidate the nature of this dendritic cell, mice were immunized with ovalbumin (OVA)-specific IgE and OVA, and different populations of CD11c(+) cells, obtained from the spleens four hours after immunization, were tested for their ability to present OVA. CD8α(-) conventional dendritic cells (cDCs) were much more efficient in inducing specific CD4(+) T cell proliferation ex vivo than were CD8α(+) cDCs or plasmacytoid dendritic cells. Thus, IgE-Ag complexes administered intravenously are rapidly transported to the spleen by recirculating B cells where they are delivered to CD8α(-) cDCs which induce proliferation of CD4(+) T cells.
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Zhoujie
Z
Ding
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Joakim S
JS
Dahlin
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Hui
H
Xu
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Birgitta
B
Heyman
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016827:CD8 Antigens / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D010047:Ovalbumin / Q000276:immunology; D013154:Spleen / Q000276:immunology
D016827:CD8 Antigens; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D010047:Ovalbumin