Year: 2002
Type: dissertation
Abstract: Regulatory CD4 + CD25 + T cells are involved in the prevention of autoimmunity, allograft acceptance and T cell homeostasis.These cells have been shown to control the proliferation of CD4 + CD25" lymphocytes in vitro, however their mechanism of action and dynamics remain unclear.Assuming that suppression is dependent on multicellular conjugates with APC, modelling of the dynamics of regulatory and target cells lead us to propose a target cell-dependent growth of regulatory cells.In the present work, we further demonstrate that proliferation of regulatory cells as a function of an interaction with target cells during in vitro suppression assays may increase to realistic levels the otherwise inefficient suppression in multicellular conjugates.We tested our theoretical predictions experimentally by monitoring the proliferative history of individual cells using CFSE-labelling.We show that regulatory CD4 + CD25 + T cells, which are unable to proliferate when stimulated alone, expand when stimulated together with target CD4 + CD25" T cells.Moreover, proliferation of regulatory cells directly correlates with expansion of target cells.These results suggest that a common growth factor controls the expansion of both cell populations, and that its production is specific of the target cells and inhibited by regulatory cells.The significance of these findings for our understanding of regulatory T cell phenomenology and the potential nature of the growth factor are discussed.
Author: Kalet León
Language: English
Topic: T-cell and B-cell Immunology
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W951819563