Modeling of T-lymphocyte extravasation into a lymph node: The connection between the morphological basis of the process and the clonal selection theory

Abstract

A model of the process of T-lymphocyte extravasation into a lymph node via the high endothelial venules in the course of the immune response has been developed. The histological structure and the morphometric parameters of the lymph node and its venules, as well as the presence of adhesion molecules on the endothelial cells and the speed of T-lymphocyte movement, were taken into account in the model and compared to the basic postulates of the clonal selection theory of immune surveillance. The inability of the venules of the lymph node to provide the passage of a sufficient number of T lymphocytes has been demonstrated; thus, the concept of immune surveillance formulated within the existing immunological theory has been proven inadequate. This finding points to the need for revision of the widely accepted concepts of the emergence of T-lymphocyte specificity and the very foundations of the clonal selection theory.