Open Access

ARTICLE

Double-stranded RNA stimulation or CD40 ligation of monocyte-derived dendritic cells as models to study their activation and maturation process

Anna Maria Megiovanni, Françoise Sanchez, Jean Claude Gluckman, Michelle Rosenzwajg

Institut National de la Recherche Scientifique – Université Paris 7 EMI-0013 and laboratoire d’Immunologie Cellulaire et Immunopathologie de l’Ecole Pratique des Hautes Etudes, Institut Universitaire d’Hématologie, hôpital Saint-Louis, Paris, France

* Corresponding Author: Michelle Rosenzwajg,

European Cytokine Network 2004, 15(2), 126-134.

Accepted 27 February 2004;

Abstract

Monocyte-derived dendritic cells (DCs) were used as an in vitro model of myeloid DCs in order to determine a minimum marker pattern with which to characterize and distinguish different stages of DC activation and maturation. Phenotypic changes induced on immature DCs by two prototypic stimuli, poly I:C and CD40 ligation, were first examined. Both elicited HLA-DR, CD40, CD86 and CXCR4 upregulation, and CCR5 downregulation, but only CD40 ligand-stimulated DCs became CD83⁺ /CCR7⁺ , whereas poly I:C-stimulated DCs expressed lower CD83 levels and were mostly CCR7^– . CD40 ligation and poly I:C elicited increased production of inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor-a, of IL-10 and the CCL5 chemokine, but profiles differed as to higher IL-10, IL-12 and CCL22 (a CCR4 ligand important for T cell recruitment) levels for the former, and of CCL4 and CCL5 for the latter. Thus, a limited set of phenotypic markers, cytokine and chemokine production assays, may be used to distinguish the three stages in the life of DCs: immaturity, activation and full maturation. The ability of purified protein derivative-loaded DCs to stimulate autologous T cells to produce IL-2, IL-4 and interferon-c indeed depended on their activation stage and endocytic activity, which decreased upon maturation. We then examined whether ligation of CD4, CCR5 and/or CXCR4, the receptor and coreceptors of human immunodeficiency virus envelope gp120, respectively, affected DC activation or maturation, neither a monoclonal antibody to the gp120-binding site on CD4 nor CCL5 nor CXCL12, the natural ligands of CCR5 and CXCR4, respectively, nor gp120 altered the DC activation and maturation processes.

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