Factors controlling T-cell migration across rat cerebral endothelium in vitro.
The migration of lymphocytes through primary cultures of rat brain microvascular endothelial cell monolayers was examined in vitro by time-lapse videomicroscopy. Antigen-specific T cell line migration was dependent on the duration of culture (post-antigen stimulation) with exogenous interleukin-2 (IL-2). Peak migration (approximately 50% of T-cells during the 4 h migration assay) occurred after 4 days of culture with IL-2 but did not coincide with maximal expression of LFA-1, VLA-4 or the IL-2 receptor. On unstimulated endothelia antibody blockade of LFA-1 or ICAM-1 inhibited T-cell line migration to 8.0% and 6.8% of control values, respectively, whereas blocking VLA-4 and VCAM-1 had no effect. On IL-beta activated endothelium blocking LFA-1 and ICAM-1 was less effective (24.9% and 27.3% of control values, respectively) and blockade of VLA-4 and VCAM-1 brought about a reduction to 63.0% and 68.3% of controls respectively. Inhibition of IL-2-dependent proliferation with an IL-2 receptor blocking antibody also significantly inhibited T-cell migration to 22.2% of controls. Peripheral lymph node (PLN) lymphocytes could also be induced to migrate through untreated cerebral endothelial cell monolayers by cross-linking CD3 which was also time and IL-2-dependent with maximal migration (22.7%) occurring after three days in the presence of exogenous IL-2. Blocking LFA-or ICAM-1 resulted in a significant reduction in migration across IL-1 beta-activated endothelial cells to 17.4% and 20.9% of control values respectively although blocking the VLA-4/VCAM-1 interaction had no significant effect. Activation of PLN lymphocytes with concanavalin A for up to 5 days did not induce migration but when left in contact with the endothelial monolayer for 24 h migration reached 31.0%. These studies indicate that T-cells require a combination of signals to trigger the migratory phenotype which is necessary to enable them to penetrate the blood-brain barrier.
Pryce
G
G
Department of Clinical Ophthalmology, University College London, UK.
Male
D
D
Campbell
I
I
Greenwood
J
J
D000818:Animals; D001921:Brain / Q000166:cytology*; D017252:CD3 Complex / Q000276:immunology; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology; D005260:Female; D039041:Integrin alpha4beta1; D016023:Integrins / Q000276:immunology / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology; D007376:Interleukin-2 / Q000494:pharmacology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000276:immunology / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology
D017252:CD3 Complex; D039041:Integrin alpha4beta1; D016023:Integrins; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D015375:Receptors, Interleukin-2; D016201:Receptors, Lymphocyte Homing; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1