Role of CD13/aminopeptidase N in rat lymphocytic alveolitis caused by thoracic irradiation.
CD13/aminopeptidase N is a cell surface glycoprotein that is widely distributed in a variety of mammalian cells. It was recently shown to have chemotactic activity for T lymphocytes. This study examined the role of CD13/aminopeptidase N in lymphocytic alveolitis in radiation-induced lung injury caused by a single-dose thoracic irradiation (15 Gy) in rats. Significantly increased aminopeptidase activity was detected in bronchoalveolar lavage fluid obtained from irradiated rats at 4 weeks after irradiation compared to the activity in unirradiated rats. Significantly higher aminopeptidase activity was detected on alveolar macrophages from irradiated rats at 2 and 4 weeks than on those from unirradiated rats. Western blot analysis showed an increased expression of CD13/aminopeptidase N protein in alveolar macrophages from irradiated rats at 4 weeks. Chemotactic activity for normal rat lymphocytes was detected in bronchoalveolar lavage fluid from irradiated rats at 4 weeks, and approximately 60% of the activity was inhibited by pretreatment of bronchoalveolar lavage fluid with bestatin, a specific aminopeptidase inhibitor. This study suggests that CD13/aminopeptidase N may play an important role as a lymphocyte chemoattractant in lymphocyte-mediated alveolitis in experimental radiation-induced lung injury.
Huang
Luping
L
Third Department of Internal Medicine, School of Medicine, Tokushima University, Tokushima, Japan.
Tani
Kenji
K
Ogushi
Fumitaka
F
Ogawa
Hirohisa
H
Shimizu
Teruki
T
Motoki
Yumi
Y
Moriguchi
Hiroki
H
Sone
Saburo
S
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D018826:CD13 Antigens / Q000037:antagonists & inhibitors / Q000502:physiology*; D002630:Chemotactic Factors / Q000032:analysis; D002634:Chemotaxis, Leukocyte / Q000528:radiation effects*; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008168:Lung / Q000528:radiation effects; D008214:Lymphocytes / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000201:enzymology; D011480:Protease Inhibitors / Q000494:pharmacology; D011658:Pulmonary Fibrosis / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D011833:Radiation Injuries, Experimental / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D017564:Radiation Pneumonitis / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013047:Specific Pathogen-Free Organisms
D002630:Chemotactic Factors; D011480:Protease Inhibitors; D018826:CD13 Antigens; D007930:Leucine; C012211:ubenimex