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Updated: Aug 9, 2026
Bioengineering Human Microvascular Networks in Immunodeficient Mice
Published on: July 11, 2011
Dermal microvascular endothelial cells express the 180-kDa macrophage mannose receptor in situ and in vitro
M Gröger1, W Holnthoner, D Maurer
1Department of Dermatology, Divisions of General Dermatology, University of Vienna, Vienna, Austria.
Abstract:
Expression of the 180-kDa mannose receptor (MR) is mainly found on cells of the macrophage lineage. MR mediates the uptake of micro-organisms and host-derived glycoproteins. We demonstrate that endothelium of the human skin in situ and dermal microvascular endothelial cells (DMEC) in vitro expressed MR at both the protein and mRNA levels. In contrast, HUVEC were consistently negative for MR expression. DMEC internalized dextran as well as Escherichia coli by the way of MR into acidic phagosomes, only a few of which fused with CD63- and lysosomal-associated membrane glycoprotein-2-positive lysosomes. This contrasts with the situation in monocyte-derived dendritic cells, where almost all of the MR-Ag complexes reached CD63- and lysosomal-associated membrane glycoprotein-2-positive compartments, indicating differences in the phagolysosomal fusion rate between DMEC and dendritic cells. In conclusion, DMEC express functional MR, a finding that corroborates a role of skin endothelium in Ag capture/clearing.
Insights
Human skin endothelial cells express the mannose receptor (MR), facilitating the uptake of microbes and glycoproteins. These dermal microvascular endothelial cells (DMEC) show functional MR, suggesting a role in antigen capture.
Area of Science:
- Immunology
- Cell Biology
- Dermatology
Background:
- The 180-kDa mannose receptor (MR) is primarily expressed on macrophages and mediates the uptake of microorganisms and glycoproteins.
- The role of MR in endothelial cells, particularly in the skin, is not well-defined.
Purpose of the Study:
- To investigate the expression and function of the mannose receptor (MR) in human skin endothelium.
- To compare MR expression in dermal microvascular endothelial cells (DMEC) with human umbilical vein endothelial cells (HUVEC).
Main Methods:
- Immunohistochemistry and mRNA analysis to detect MR expression in situ and in vitro.
- Functional assays using dextran and Escherichia coli uptake by DMEC.
- Analysis of phagolysosomal fusion using CD63 and lysosomal-associated membrane glycoprotein-2 markers.
Main Results:
- Human skin endothelium and DMEC express MR at both protein and mRNA levels.
- HUVEC consistently showed negative MR expression.
- DMEC internalized dextran and E. coli via MR into phagosomes with limited fusion to lysosomes, unlike dendritic cells.
Conclusions:
- Dermal microvascular endothelial cells (DMEC) express functional mannose receptor (MR).
- This finding supports a role for skin endothelium in antigen capture and clearance.
