Migration on extracellular matrix surface and infiltration into matrix - two distinguishable activities of human T cells

Abstract: Migration of T-lymphocytes on a surface coated with extracellular matrix (ECM) components (two-dimensional (2-D) migration) and migration (infiltration) into a matrix (Three-dimesional (3-D) migration) are complex events and the underlying mechanisms are not yet fully understood. Here 2-D and 3-D migration were studied by use of seven leukemic T-cell lines representing discrete differentiation stages, a non-leukemic T-cell clone, and normal peripheral blood T cells. peripheral blood lymphocytes and the T-cell clone produced nanogram quantities of various chemokines, as compared to a production of ≤ 0.05 ng/ml by the T leukemia cell lines. In a Boyden chamber system, the leukemic T-cell lines showed haptotactic migration on fibronectin. The migration was augmented bu exposure to chemokines, including RANTES, MIP-1α, MIP-1β, and IL-8. The T-cell lines showed a peak response at a chemokine concentration of 10-50 ng/ml, whereas the T-cell clone responded optimally at 100 ng/ml. In contrast to a general capability of T-cells to migrate on 2-D ECM, only some of the T-cell lines were capable of 3-D migration into Matrigel or a collagen matrix. The infiltrative capacity was unrelated to the capacity to migrate on or adhere to the substrata. T-cell lines with a capacity to infiltrate produced matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), whereas non-infiltrating cell lines did not produce MMP-9. T-cell lines capable of infiltrating Matrigel or collagen responded to chemokines exposure with increased infiltration, but the chemokines did not render non-infiltrative cell lines infiltrative. Stimulation of infiltration of T-cell lines into collagen by the chemokine SDF-1α was inhibited by somatostatin, a neuropeptide with immunosuppressive properties. In conclusion, the ability to migrate on 2-D substrata and to infiltrate into 3.D substrata was found to be distinguishable properties of T cells. failure of some T-cell lines to infiltrate correlated with the lack of expression of MMP-9. Chemokines stimulated infiltration of infiltrative T-cell lines into collagen and Matrigel but did not render non-infiltrative T-cell lines infiltrative. Finally, a possible physiological mechanism for modulation of the chemokine-stimulated 3-D migration was demonstrated.