Endothelial Cell-Mediated Antigen Presentation

Endothelial Cell-Mediated Antigen Presentation*

Immune recognition of endothelial cells (ECs) has been implicated in a number of vascular diseases. Although ECs have been shown to stimulate T lymphocytes in vitro, these conditions were not physiological, and it remained unclear what occurred in vivo. Antigen presentation by ECs in vivo was tested using transgenic mice that express a protein antigen (β-galactosidase, β-gal) exclusively in the...

Uptake Inhibiting Receptor-Mediated Antigen Cross-Presentation and T Cell Responses by CD13 Regulates Dendritic Cell

CD13 regulates dendritic cell cross-presentation and T cell responses by inhibiting receptor-mediated antigen uptake.

Dendritic cell (DC) Ag cross-presentation is generally associated with immune responses to tumors and viral Ags, and enhancement of this process is a focus of tumor vaccine design. In this study, we found that the myeloid cell surface peptidase CD13 is highly and specifically expressed on the subset of DCs responsible for cross-presentation, the CD8(+) murine splenic DCs. In vivo studies indica...

Mast cell-mediated antigen presentation regulates CD8+ T cell effector functions.

The characteristics, importance, and molecular requirements for interactions between mast cells (MCs) and CD8(+) T cells have not been elucidated. Here, we demonstrated that MCs induced antigen-specific CD8(+) T cell activation and proliferation. This process required direct cell contact and MHC class I-dependent antigen cross-presentation by MCs and induced the secretion of interleukin-2, inte...

MHC class II–restricted antigen presentation by plasmacytoid dendritic cells inhibits T cell–mediated autoimmunity

Although plasmacytoid dendritic cells (pDCs) express major histocompatibility complex class II (MHCII) molecules, and can capture, process, and present antigens (Ags), direct demonstrations that they function as professional Ag-presenting cells (APCs) in vivo during ongoing immune responses remain lacking. We demonstrate that mice exhibiting a selective abrogation of MHCII expression by pDCs de...