IgE-mediated enhancement of CD4(+) T cell responses requires antigen presentation by CD8?(-) conventional dendritic cells.

ABSTRACT: 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 (Fc?-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. CD8?(-) conventional dendritic cells (cDCs) were much more efficient in inducing specific CD4(+) T cell proliferation ex vivo than were CD8?(+) 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 CD8?(-) cDCs which induce proliferation of CD4(+) T cells.

SUBMITTER: Ding Z 

PROVIDER: S-EPMC4910288 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature