Laminin-211 controls thymocyte—thymic epithelial cell interactions

Laminin-211 controls thymocyte—thymic epithelial cell interactions

Ocampo J.S.P., de Brito J.M,  Corrêa-de-Santana E., Borojevic R., Serra Villa-Verde D.M., Savino W.
Cellular Immunology, 2008

Thymocyte differentiation occurs within the thymic microenvironment. Previous experiments showed that laminin mediates interactions between thymocytes and thymic epithelial cells (TEC) in mice. Here, the authors show constitutive gene expression of various laminin chains in TEC preparations, comprising laminin-111 and laminin-211 isoforms. Immunocytochemistry revealed a selective laminin-211 distribution in the thymic lobules. In vitro, functional assays revealed that laminin-211 enhances TEC/thymocyte adhesion and thymocyte release from thymic nurse cells, as well as the reconstitution of these complexes. Conversely, these interactions are blocked by monoclonal antibodies specific for laminin-211 and the laminin receptor VLA-6. The results show that distinct laminin isoforms in the human thymus are relevant for lymphoepithelial interactions.