The Role of Inter-Cellular Adhesion in the Recirculation of T Lymphocytes

We refine an existing model of T lymphocyte recirculation, in order to incorporate a description of the adhesion between T cells and other cell types in the lymphoid tissue, such as dendritic cells. The new model is able to fit the animal experiments on lymphocyte recirculation. It also allows for the variation of these adhesive properties, as would occur in the presence of antigen, and it is shown that it is possible for the T cell counts in blood to reach very low levels, as a result of increased adhesion between T cells and dendritic or other cells present in the lymphoid tissue. We discuss the implications of this phenomenon for HIV infection.