Adressage et migration : le mouvement perpétuel des lymphocytes.
Résumé
Le contrôle des mouvements
continuels des lymphocytes dans
l'organisme contribue de façon
significative à l'efficacité du
système immunitaire en assurant
une surveillance permanente de
l'ensemble des tissus et en ciblant
les leucocytes aux sites d'invasion
microbienne ou antigénique. Les
études réalisées depuis 20 ans
dans ce domaine ont montré que
l'adressage des lymphocytes dans
un organe est assuré par une
cascade d'étapes impliquant des
molécules d'adhérence et de
signalisation. L'élucidation de ce
processus devrait permettre à
terme de moduler le ciblage des
cellules effectrices notamment
lors de syndromes
inflammatoires. The immune system consists of a complex collection of leukocytes and dendritic cells that surveys most tissues in the body for appearance of foreign antigens. For an efficient immune response the interaction and co-localization of antigen-presenting cells, costimulatory helper cells and effector cells are crucial parameters. Therefore the migration routes of antigen presenting cells and of lymphocytes merge in secondary lymphoid organs in order to increase the likelihood and speed of a lymphocyte, finding its cognate antigen. Additionally, antigen primed effector cells are directed to the tissue where they are most likely to encounter their cognate antigen. This highly organized and efficient antigen encounter is based on continuous re-circulation of lymphocytes between blood, peripheral tissues and secondary lymphoid organs. Moreover, the efficacy of the immune system is further increased by the ability of different lymphocyte subsets to recirculate through distinct tissues. The scope of this review is to outline the concept and mechanisms of lymphocyte homing by underlying the molecular function of implicated cell adhesion molecules, chemokines and chemokine receptors, and to propose mechanisms by which homing physiology regulates the homeostasis of immunological resources.
Pour citer ce document
Dunon, D ; Imhof, BA, Adressage et migration : le mouvement perpétuel des lymphocytes., Med Sci (Paris), 2000, Vol. 16, N° 6-7; p.767-75