Mannose receptor is a novel ligand for L-selectin and mediates lymphocyte binding to lymphatic endothelium

H Irjala, EL Johansson, R Grenman, K Alanen… - The Journal of …, 2001 - rupress.org
H Irjala, EL Johansson, R Grenman, K Alanen, M Salmi, S Jalkanen
The Journal of experimental medicine, 2001rupress.org
Continuous lymphocyte recirculation between blood and lymphoid tissues forms a basis for
the function of the immune system. Lymphocyte entrance from the blood into the tissues has
been thoroughly characterized, but mechanisms controlling lymphocyte exit from the
lymphoid tissues via efferent lymphatics have remained virtually unknown. In this work we
have identified mannose receptor (MR) on human lymphatic endothelium and demonstrate
its involvement in binding of lymphocytes to lymphatic vessels. We also show that the …
Continuous lymphocyte recirculation between blood and lymphoid tissues forms a basis for the function of the immune system. Lymphocyte entrance from the blood into the tissues has been thoroughly characterized, but mechanisms controlling lymphocyte exit from the lymphoid tissues via efferent lymphatics have remained virtually unknown. In this work we have identified mannose receptor (MR) on human lymphatic endothelium and demonstrate its involvement in binding of lymphocytes to lymphatic vessels. We also show that the binding requires L-selectin, and L-selectin and MR form a receptor–ligand pair. On the other hand, L-selectin binds to peripheral lymph node addressins (PNAds) on high endothelial venules (HEVs) that are sites where lymphocytes enter the lymphatic organs. Interestingly, MR is absent from HEVs and PNAds from lymphatic endothelium. Thus, lymphocyte L-selectin uses distinct ligand molecules to mediate binding at sites of lymphocyte entrance and exit within lymph nodes. Taken together, interaction between L-selectin and MR is the first molecularly defined mechanism mediating lymphocyte binding to lymphatic endothelium.
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