T lymphocyte infiltration of two- and three-dimensional collagen substrata by an adhesive mechanism

Lymphocytes were plated on two-dimensional (2D) and three-dimensional (3D) collagen substrata and their distribution and behavior determined using light and scanning electron microscopy. When allowed to settle on 2D collagen substrate T-lymphocytes "rapidly" attached and penetrated and thus virtually never remained attached on top of the collagen. As a consequence of this penetration the cells appeared below the collagen. In contrast to lymphocytes, fibroblasts and macrophages allowed to settle on 2D collagen did not penetrate but underwent cytoplasmic spreading on top of the collagen. Lymphocyte attachment and penetration of 2D collagen was specifically inhibited by monoclonal antibodies to beta 1-integrins, indicating that the process depends on molecular adhesion to the collagen. The penetration of 2D collagen appeared to consist of tight binding of collagen fibers to the cells, local reorganization of the collagen carpet, and redistribution of the cell-attached collagen fibers from the "lower" to the "upper" pole/surface of the lymphocyte. Lymphocyte infiltration of 3D collagen substrata was also specifically inhibited by monoclonal antibodies to beta 1-integrins. During the infiltration of 3D collagen lymphocytes exhibited collagen fibers attached to their surface and seemed to provoke perturbation of the collagen. These results show that T lymphocytes are programmed to penetrate and perturb 2D and 3D collagen substrata by a mechanism dependent on adhesive interaction. However, deattachment tends to counteract persistent binding of the cells to 2D collagen.