Expression and function of the IL-2 receptor in activated human plasmacytoid dendritic cells.
Human and mouse plasmacytoid dendritic cells (PDC) express IL-2 mRNA specifically upon TLR stimulation, but not under CD40L stimulation. Even though the expression of the IL-2R by PDC has been described, the functional implications of this expression remain unknown. Here, we investigated the expression and function of the IL-2R in activated human PDC. The IL-2Ralpha chain, CD25, is expressed in both CpG- and CD40L-activated PDC. CD25 expression is a relatively rapid event, as the receptor was detected 6 h after the initial activation signal. Exogenous IL-2 added to CD40L-activated PDC increased the expression of CD25, enhanced the secretion of pro-inflammatory cytokines and promotes PDC survival. CpG-activated PDC cultured in the presence of IL-2R-blocking monoclonal antibodies showed a reduced expression of pro-inflammatory cytokines, especially TNF-alpha. This reduction was dose and time dependent, suggesting a regulatory role of IL-2 in TNF secretion that might occur at the post-transcriptional level. These results indicate that the expression of the IL-2R is relevant to human PDC activation, and that IL-2 may be an important auto- and/or paracrine factor modulating the activation and survival of PDC. Finally, CD25 expression may be considered as a useful early activation marker for human PDC.
Naranjo-Gómez
Mar
M
Laboratory of Immunobiology for Research and Applications to Diagnosis, Blood and Tissue Bank, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.
Oliva
Harold
H
Climent
Nuria
N
Fernández
Marco A
MA
Ruiz-Riol
Marta
M
Bofill
Margarita
M
Gatell
José M
JM
Gallart
Teresa
T
Pujol-Borrell
Ricardo
R
Borràs
Francesc E
FE
D000276:Adjuvants, Immunologic; D023201:CD40 Ligand / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D018899:CpG Islands / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology
D000276:Adjuvants, Immunologic; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D023201:CD40 Ligand