title: Treatment with anti-LFA-1 alpha monoclonal antibody selectively interferes with the maturation of CD4- 8+ thymocytes.
abstract: Maturation of T lymphocytes in the thymus is driven by signals provided by soluble factors and by the direct interaction between thymocytes and stromal cells. Although the interaction between T-cell receptor (TCR) and major histocompalibility complex (MHC) molecules on stromal cells is crucial for T-cell development, other accessory molecules seem to play a role in this process. In order to better understand the role of lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) molecules in thymocyte maturation, mice were treated from birth with saturating doses of non-cytolytic-specific monoclonal antibodies. The effect of this treatment on thymocyte subpopulations and the expression of CD3 and TCR-alpha beta by these cells was investigated by flow cytometry. Our data demonstrated that the effective saturation of LFA-1 alpha chain in the thymus, but not ICAM-I or LFA-I beta chain, selectively interfered with the maturation of CD8+ T cells, as manifested by a marked reduction in the frequency of CD4-8+ thymocytes expressing high levels of CD3 and TCR-alpha beta. This selective reduction was also observed in peripheral blood mononuclear cells and spleen cells. The analysis of the frequencies of various V beta TCR showed that CD4-8+ thymocytes were globally affected by the treatment. These results underline the importance of the interaction between LFA-1 and its ligands in the maturation of CD8+ T cells and document the existence of different molecular requirements for the differentiation of CD4+ and CD8+ T cells.
authors.affiliation: Sección de Inmunologia, Hospital Universitario Marqués de Valdecilla, Instituto Nacional de la Salud, Santander, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Revilla
authors.forename: A L
authors.initials: AL
authors.lastname: González
authors.forename: C
authors.initials: C
authors.lastname: Conde
authors.forename: M
authors.initials: M
authors.lastname: López-Hoyos
authors.forename: J
authors.initials: J
authors.lastname: Merino
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D017252:CD3 Complex / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D018655:Lymphocyte Count; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D016169:Lymphocyte Function-Associated Antigen-1; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018799:Intercellular Adhesion Molecule-1