Adhesion of T lymphocytes to human endothelial cells is regulated by the LFA-1 membrane molecule.
Human T lymphocyte adhesion to human endothelial cells is the initial event in T cell migration to areas of extravascular inflammation. The molecular basis for T cell-endothelial cell adhesion was investigated using two different cell-cell adhesion assays: a) a fluorescein cell-cell adhesion assay using nonadherent endothelial cells and fluorescein-labeled T lymphocytes, and b) a radionuclide cell-cell adhesion assay using adherent endothelial cells and 51Cr-labelled T cells. Both assay systems demonstrated comparable quantitative assessment of cell-cell adhesions. The assays were performed at 22 degrees C and adhesions were maximal at 30 min. The results of these adhesion assays confirmed previous reports that T cells adhere to endothelial cells. In addition, we have shown that T cells adhere only marginally to foreskin fibroblasts or bone marrow derived fibroblasts. T cell-endothelial cell adhesions were significantly stronger than either monocytes or B lymphoblastoid cells adhesion to endothelial cells. To demonstrate the molecular mechanisms involved in regulating T cell-endothelial cell adhesions, a panel of function-associated monoclonal antibodies (MAb) were tested for their ability to inhibit T cell adhesion. MAb reactive with the leukocyte surface glycoprotein LFA-1 significantly inhibited T cell-endothelial cell adhesions in both assay systems. In contrast, MAb directed at other surface antigens did not inhibit T cell adhesion. The involvement of the LFA-1 glycoprotein in T lymphocyte adhesion to endothelial cells suggest that the LFA-1 molecule may be important in the regulation of leukocyte interactions.
D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology / Q000502:physiology*; D001808:Blood Vessels / Q000502:physiology; D001853:Bone Marrow; D002448:Cell Adhesion; D002478:Cells, Cultured; D004727:Endothelium / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology; D019793:Fluorescein; D005452:Fluoresceins; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1; D008297:Male; D008565:Membrane Proteins / Q000276:immunology / Q000502:physiology*; D010413:Penis; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D005452:Fluoresceins; D016169:Lymphocyte Function-Associated Antigen-1; D008565:Membrane Proteins; D019793:Fluorescein