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DCIR is endocytosed into human dendritic cells and inhibits TLR8‐mediated cytokine production
Author(s) -
MeyerWentrup Friederike,
Cambi Alessandra,
Joosten Ben,
Looman Maaike W.,
Vries I. Jolanda M.,
Figdor Carl G.,
Adema Gosse J.
Publication year - 2009
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.0608352
Subject(s) - biology , microbiology and biotechnology , cd80 , dendritic cell , cytokine , cd86 , clathrin , immune system , antigen presenting cell , endocytosis , receptor , t cell , cytotoxic t cell , immunology , cd40 , biochemistry , in vitro
C‐type lectin receptors (CLRs) expressed on APCs play a pivotal role in the immune system as pattern‐recognition and antigen‐uptake receptors. In addition, they may signal directly, leading to cytokine production and immune modulation. To this end, some CLRs, like dectin‐1 and dendritic cell immunoreceptor (DCIR), contain intracellular ITIMs or ITAMs. In this study, we explored expression and function of the ITIM‐containing CLR DCIR on professional APCs. DCIR is expressed on immature and mature monocyte‐derived DCs (moDC) but also on monocytes, macrophages, B cells, and freshly isolated myeloid and plasmacytoid DCs. We show that endogenous DCIR is internalized efficiently into human moDC after triggering with DCIR‐specific mAb. DCIR internalization is clathrin‐dependent and leads to its localization in the endo‐/lysosomal compartment, including lysosome‐associated membrane protein‐1+ lysosomes. DCIR triggering affected neither TLR4‐ nor TLR8‐mediated CD80 and CD86 up‐regulation. Interestingly, it did inhibit TLR8‐mediated IL‐12 and TNF‐α production significantly, and TLR2‐, TLR3‐, or TLR4‐induced cytokine production was not affected. Collectively, the data presented characterize DCIR as an APC receptor that is endocytosed efficiently in a clathrin‐dependent manner and negatively affects TLR8‐mediated cytokine production. These data provide further support to the concept of CLR/TLR cross‐talk in modulating immune responses.