The morphogenetic events leading to the transendothelial passage of lymphoid and tumoral cells are analyzed in light of a very recent and global theory of intercellular communication designated as the Triune Information Network (
TIN). The
TIN system is based on the assumption that cell-cell interactions primarily occur through cell surface informations or topobiological procesess, whose mechanisms rely upon expression of adhesion molecules, and are regulated by an array of locally-borne (autocrine/paracrine signals and autonomic inputs) and distantly-borne (endocrine secretions) messages. The final aim of the
TIN is to control homeostatic functions crucial for the organism survival, like morphogenesis. Knowledge of the
TIN signals involved in lymphoid and tumoral cell intravasation might offer a new perspetive to study the mechanisms of
tumor immunity. Recognition of
tumor target cells by immune cytotoxic effectors, in fact, can be considered a notable case of
TIN-mediated cell to cell interaction. In particular, Natural Killer (NK) cells play a role in the cell-mediated control of
tumor growth and metastatic spreading. Cell targeting and killing are dependent on the different
NK cell receptors and on the efficacy of NK cells after
cytokine and
monoclonal antibody administration in
cancer therapy. Since efficacy of NK cell-based immunotheraphy has been proven in KIR-mismatch regimens or in TRAIL-dependent apoptosis, the ability to manipulate the balance of activating and inhibitory receptors on NK cells and of their cognate
ligands as well as the sensitivity of
tumor cells to apoptosis, opens new perspectives for NK cell based
immunotherapy.