Lymphocyte Adherence to High Endothelial Venules: Characterization of a Modified in Vitro Assay, and Examination of the Binding of Syngeneic and Allogeneic Lymphocyte Populations

Abstract

Mouse lymphocytes incubated on fresh frozen sections of mesenteric lymph nodes adhere specifically to the endothelium of high endothelial venules (HEV), specialized vessels through which lymphocytes normally enter lymph nodes from the blood. An assay of the specific binding of lymphocytes to HEV in frozen sections is characterized and is used to compare the capacity of various syngeneic and allogeneic lymphocyte populations to adhere to HEV in mouse mesenteric lymph nodes. The relative adherence of lymphocyte populations to HEV in this in vitro system correlates highly with their localization in HEV a) during single-pass perfusion through the lymph node at 37°C, or b) in vivo 15 min after i.v. injection. With this assay we have shown that the binding of mesenteric node lymphocytes (MNL) to syngeneic mesenteric node HEV is constant: no significant variation was observed between individual mice, between sexes, between mice of various ages (3 weeks to 9 months), or after treatment of the lymphocyte donor with hydrocortisone acetate. B lymphocytes adhered as well as T lymphocytes and exhibited no preference for HEV bordering on B areas in the lymph node section. In general, other syngeneic cell populations bind in proportion to their content of mature lymphocytes. MNL exhibited no preferential adherence to syngeneic as opposed to allogeneic HEV, but A/J and BALB/c MNL demonstrated greater binding than C57BL/6J and AKR/Cum MNL, regardless of the HEV donor strain.