Lymphatic endothelial murine chloride channel calcium-activated 1 is a ligand for leukocyte LFA-1 and Mac-1.

Publication Type:

Journal Article

Source:

Journal of immunology (Baltimore, Md. : 1950), Volume 185, Issue 10, p.5769-77 (2010)

Keywords:

2010, Animals, Cell Adhesion, Center-Authored Paper, Chemotaxis, Leukocyte, Chloride Channels, Comparative Medicine Core Facility, Cytokines, Electrophoresis, Polyacrylamide Gel, Endothelium, Lymphatic, Flow Cytometry Core Facility, Genomics Core Facility, Human Biology Division, Immunoblotting, Immunohistochemistry, Immunoprecipitation, Intercellular Adhesion Molecule-1, Leukocytes, Ligands, Lymphocyte Function-Associated Antigen-1, Macrophage-1 Antigen, mass spectrometry, MICE, Mice, Inbred C57BL, Reverse Transcriptase Polymerase Chain Reaction, Shared Resources, Transfection

Abstract:

The lymphatic circulation mediates drainage of fluid and cells from the periphery through lymph nodes, facilitating immune detection of lymph-borne foreign Ags. The 10.1.1 mAb recognizes a lymphatic endothelial Ag, in this study purified by Ab-affinity chromatography. SDS-PAGE and mass spectrometry identified murine chloride channel calcium-activated 1 (mCLCA1) as the 10.1.1 Ag, a 90-kDa cell-surface protein expressed in lymphatic endothelium and stromal cells of spleen and thymus. The 10.1.1 Ab-affinity chromatography also purified LFA-1, an integrin that mediates leukocyte adhesion to endothelium. This mCLCA1-LFA-1 interaction has functional consequences, as lymphocyte adhesion to lymphatic endothelium was blocked by 10.1.1 Ab bound to endotheliumor by LFA-1 Ab bound to lymphocytes. Lymphocyte adhesion was increased by cytokine treatment of lymphatic endothelium in association with increased expression of ICAM-1, an endothelial surface protein that is also a ligand for LFA-1. By contrast, mCLCA1 expression and the relative contribution of mCLCA1 to lymphocyte adhesion were unaffected by cytokine activation, demonstrating that mCLCA1 and ICAM-1 interactions with LFA-1 are differentially regulated. mCLCA1 also bound to the LFA-1-related Mac-1 integrin that is preferentially expressed on leukocytes. mCLCA1-mediated adhesion of Mac-1- or LFA-1-expressing leukocytes to lymphatic vessels and lymph node lymphatic sinuses provides a target for investigation of lymphatic involvement in leukocyte adhesion and trafficking during the immune response.