title: Differential adhesion molecule requirements for immune surveillance and inflammatory recruitment.
abstract: Activated CD4 Th1 lymphocytes can enter the brain in the absence of an inflammatory focus. However, the molecular mediators that regulate this early migration of lymphocytes into the brain have remained unclear. We hypothesized that the entry of these 'pioneer' lymphocytes into the brain is regulated by a set of molecular events that are distinct from those used once inflammation has been established. Using cells fluorescently labelled with the lipophilic dye DiI, myelin basic protein (MBP)-specific CD4 lymphocytes that expressed low or high levels of very late antigen-4 (VLA-4) and non-antigen-specific activated splenocytes homed to mouse brain in similar quantities 2 h after adoptive transfer. However, antigen specificity and VLA-4 expression were required for more robust recruitment by 24 h. Immunocytochemistry revealed endothelial and microenvironmental upregulation of vascular cell adhesion molecule (VCAM), intercellular cell adhesion molecule 1 (ICAM-1), MHC class II and interferon-gamma 48 h after transfer of MBP-specific cells. In contrast, expression of meningeal and choroid plexus-associated P selectin was upregulated 2 h after adoptive transfer, but not at 48 h. Monoclonal antibody to P selectin, but not to VLA-4, inhibited early migration of high VLA-4-expressing MBP-specific lymphocytes. These results suggest that early migration occurs independent of the lymphocyte integrin VLA-4 and endothelial VCAM, but does require increased surface expression of endothelial P selectin.
authors.affiliation: Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06520-8011, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Carrithers
authors.forename: I
authors.initials: I
authors.lastname: Visintin
authors.forename: S J
authors.initials: SJ
authors.lastname: Kang
authors.forename: C A
authors.initials: CA
authors.lastname: Janeway
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000276:immunology / Q000378:metabolism; D000911:Antibodies, Monoclonal; D001921:Brain / Q000166:cytology / Q000276:immunology; D001923:Brain Chemistry / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002232:Carbocyanines; D002465:Cell Movement / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007157:Immunologic Surveillance; D039041:Integrin alpha4beta1; D016023:Integrins / Q000276:immunology* / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology / Q000378:metabolism; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D004676:Myelin Basic Protein / Q000276:immunology; D019007:P-Selectin / Q000276:immunology; D010179:Pancreas / Q000166:cytology / Q000276:immunology; D016201:Receptors, Lymphocyte Homing / Q000276:immunology* / Q000378:metabolism; D013154:Spleen / Q000166:cytology; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology; D019010:Vascular Cell Adhesion Molecule-1 / Q000276:immunology* / Q000378:metabolism
chemical_list: D018926:Anti-Allergic Agents; D000911:Antibodies, Monoclonal; C101089:CM-DiI; D002232:Carbocyanines; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II; D039041:Integrin alpha4beta1; D016023:Integrins; D004676:Myelin Basic Protein; D019007:P-Selectin; D016201:Receptors, Lymphocyte Homing; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma