Yersinia invasin, a bacterial beta1-integrin ligand, is a potent inducer of lymphocyte motility and migration to collagen type IV and fibronectin.

The Yersinia pseudotuberculosis invasin protein was found to be a potent inducer of pseudopodia formation and chemotactic and haptotactic migration in human T lymphocytes. Checkerboard analysis confirmed that migration was directional. The Yersinia invasin triggered migration of otherwise poorly migratory normal T cells on fibronectin and in particular on collagen type IV, and augmented the migration of leukemic T cell lines on these components. Invasin-induced lymphocyte migration was inhibited by staurosporin that selectively prevented pseudopodia formation but, noteworthy, augmented adhesion. The motogenic and attractant properties of invasin (Inv) were mediated via beta1-integrins, as shown by lack of effect of Inv on the motility of a beta1-integrin-negative lymphoid cell line and inhibition of invasin-induced lymphocyte motility by anti-beta1 Abs. Inv was markedly more effective than the extracellular matrix components fibronectin, collagen type IV, and laminin, which also interact with lymphocyte beta1-integrins, with respect to induction of pseudopodia, chemotaxis, and haptotaxis. Thus, Yersinia invasin is a model ligand for induction of lymphocyte motility via beta1-integrins. The extraordinary capacity of Inv to trigger and guide T lymphocyte motility and potentiate lymphocyte migration to extracellular matrix components may be of pathogenetic significance for the movement of lymphocytes to extraintestinal sites secondary to Yersinia infection.