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Distribution and kinetics of SR‐PSOX/CXCL16 and CXCR6 expression on human dendritic cell subsets and CD4 + T cells
Author(s) -
Tabata Sumie,
Kadowaki Norimitsu,
Kitawaki Toshio,
Shimaoka Takeshi,
Yonehara Shin,
Yoshie Osamu,
Uchiyama Takashi
Publication year - 2005
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.1204733
Subject(s) - cxcl16 , microbiology and biotechnology , biology , chemokine , cxc chemokine receptors , t cell , ccl5 , il 2 receptor , immunology , chemokine receptor , immune system
Dendritic cells (DCs) coordinate T cell responses by producing T cell‐attracting chemokines and by inducing the expression of chemokine receptors on T cells. Scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR‐PSOX)/CXC chemokine ligand 16 (CXCL16) is a unique chemokine that also functions as an endocytic receptor and an adhesion molecule in its membrane‐bound form. SR‐PSOX/CXCL16 is the only known ligand of CXC chemokine receptor 6 (CXCR6) that is expressed on activated T cells and thus, may play an important role in enhancing effector functions of T cells. Here, we investigated the expression of SR‐PSOX/CXCL16 on human DC subsets and that of CXCR6 on T cell subpopulations to elucidate the dynamics of CXCL16/CXCR6 interaction in DC/T cell responses. Membrane‐bound SR‐PSOX/CXCL16 was expressed on macrophages, monocyte‐derived DCs, and blood myeloid DCs, and the expression increased after DC maturation. Myeloid antigen‐presenting cells constitutively secreted SR‐PSOX/CXCL16 for an extended period, suggesting the involvement of CXCL16 in peripheral and lymphoid tissues. Plasmacytoid DCs hardly expressed SR‐PSOX/CXCL16 on their surfaces but secreted significant amounts of SR‐PSOX/CXCL16. A subset of CD4 + effector memory T (T EM ) cells constitutively expressed CXCR6, whereas central memory T cells (T CM ) and naïve T cells did not. Upon stimulation with mature DCs, however, the expression of CXCR6 on T CM cells was markedly up‐regulated, whereas the expression on naïve T cells was induced only weakly. These results suggest that the interaction between SR‐PSOX/CXCL16 and CXCR6 plays an important role in enhancing T CM cell responses by mature DCs in lymphoid tissues and in augmenting T EM cell responses by macrophages in peripheral inflamed tissues.