Lymphocyte recognition of lymph node high endothelium. VI. Evidence of distinct structures mediating binding to high endothelial cells of lymph nodes and Peyer's patches
Chin, Y.H.; Rasmussen, R.; Cakiroglu, A.G.; Woodruff, J.J.
Journal of Immunology 133(6): 2961-2965
1984
ISSN/ISBN: 0022-1767 PMID: 6208268 Document Number: 230203
Lymphocytes migrate from blood into lymph nodes (LN) and Peyer's patches (PP) of rats specifically at segments of venules lined by high endothelium (HEV). A lymphocyte surface component termed high endothelial binding factor (HEBF) that appears to be involved in lymphocyte adhesion to high endothelial cells of LN was previously identified and isolated. HEBF was also isolated from thoracic duct lymph and is antigenically related to the cell surface component. Soluble HEBF derived from detergent lysates of thoracic duct lymphocytes (TDL) or directly from lymph has affinity for HEVLN in vitro, and is able to block sites where lymphocytes would normally attach. Lymphocyte binding sites of HEVLN and HEVPP were investigated through the use of lymph-derived HEBF and rabbit antibody to this factor. Apparently treatment of rat TDL with anti-HEBF Fab did not block binding to HEVPP, even though adhesion to HEVLN was reduced by .gtoreq. 80%. Similarly, HEBF isolated by anti-HEBF F(ab')2 affinity chromatography blocked lymphocyte binding sites of HEVLN but not HEVPP. This material is, therefore, designated HEBFLN; antibody to it is designated anti-HEBFLN Ig. Fractionation of thoracic duct lymph revealed that it contained an antigenically distinct component, HEBFPP, which blocked lymphocyte binding to HEVPP but not to HEVLN. Lymph components precipitating between 40-60% (NH4)2SO4 saturation contained both factors, which were separated from the bulk of lymph proteins by DEAE-Sepharose chromatography and then from each other by fractionation on the anti-HEBFLN F(ab')2-Sepharose column. The unbound fraction from this column contained HEBFPP, which was then partially purified by CM-Sepharose filtration. HEBFPP appeared to be a glycoprotein because it was destroyed by trypsin, bound to lentil lectin and was eluted with .alpha.-methyl-mannoside. The existence of 2 antigenically distinct species of HEBF was demonstrated and apparently, lymphocyte binding sites of HEVLN and HEVPP are structurally different. Evidently, distinct high endothelial adhesion molecules on lymphocytes mediate their entry into LN and PP.