Accumulation of CCR4-expressing CD4+ T cells and high concentration of its ligands (TARC and MDC) in bronchoalveolar lavage fluid of patients with eosinophilic pneumonia.
BACKGROUND
Th2 cells are thought to be involved in eosinophilic inflammation of the lung. CC chemokine receptor 4 (CCR4) has been identified as a specific receptor for both thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC), and is preferentially expressed on Th2 cells.


OBJECTIVE
Our aim was to evaluate the role of Th2 cells in the lung of patients with eosinophilic pneumonia (EP).


METHODS
The concentrations of TARC, MDC, and interleukin (IL)-5 were measured in bronchoalveolar lavage fluid (BALF) by ELISA. Proportion of CCR4-expressing CD4+ T cells (CCR4+ CD4+ T cells) was determined by flow cytometry.


RESULTS
TARC and MDC concentrations in BALF were higher in patients with EP than in normal subjects. The proportion of CCR4-expressing cells among CD4+ T cells was higher in BALF than in peripheral blood of patients with EP. There was a significant correlation between the number of CCR4+ CD4+ T cells and the levels of TARC, MDC, and IL-5 in BALF of patients with EP.


CONCLUSIONS
Our data suggest that Th2 cells, which express CCR4 and its ligands (TARC and MDC), contribute to the pathogenesis of EP in the lung.
Katoh
S
S
Third Department of Internal Medicine, Miyazaki Medical College, Miyazaki, Japan.
Fukushima
K
K
Matsumoto
N
N
Matsumoto
K
K
Abe
K
K
Onai
N
N
Matsushima
K
K
Matsukura
S
S
D000328:Adult; D001773:Blood Cells / Q000378:metabolism / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D054414:Chemokine CCL17; D054422:Chemokine CCL22; D019742:Chemokines, CC / Q000378:metabolism; D005260:Female; D006801:Humans; D008024:Ligands; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011657:Pulmonary Eosinophilia / Q000378:metabolism* / Q000473:pathology; D054398:Receptors, CCR4; D019707:Receptors, Chemokine / Q000378:metabolism*
C106230:CCL17 protein, human; C515482:CCL22 protein, human; C515354:CCR4 protein, human; D054414:Chemokine CCL17; D054422:Chemokine CCL22; D019742:Chemokines, CC; D008024:Ligands; D054398:Receptors, CCR4; D019707:Receptors, Chemokine