High endothelial cells of postcapillary venules express the scavenger receptor in human peripheral lymph nodes.

The macrophage scavenger receptor (MSR) is a multipotent receptor that mediates uptake of macromolecules with clustered negative charges, such as endotoxins and oxidized proteins and lipoproteins. It may also serve as an adhesion molecule for monocytes and macrophages. We have analysed MSR expression in human peripheral lymph nodes and show, by reverse transcription-PCR, that the type I isoform of MSR is abundantly expressed in this tissue. With the use of a new set of isoform-specific peptide antibodies, both isoforms of MSR were detected in the cuboidal endothelium of high-endothelial venules (HEV). MSR antibodies also stained macrophages and follicular dendritic cells of germinal centres. These data indicate that the MSR gene is expressed in HEV endothelium in vivo. It is suggested that MSR expression may be important for antigen uptake and leucocyte adhesion to HEV in the lymph node.