Naoaki Tamura

Distinct roles of osteopontin fragments in the development of the pulmonary involvement in sarcoidosis.

Osteopontin (OPN) is a secreted glycoprotein with cell adhesive and chemoattractive functions and is expressed in granulomas of sarcoidosis. It is well documented that full-length OPN (F-OPN) is susceptible to proteolytic fragmentation resulting in carboxyl-terminal OPN (C-OPN). We have previously revealed that C-OPN suppresses cell adhesion mediated by F-OPN. However, the implication of F-OPN and C-OPN in the progression of pulmonary involvement in sarcoidosis has not yet been elucidated. In this study, we demonstrated that (l) OPN was expressed in granulomas of sarcoidosis, (2) plasma F-OPN level in patients with sarcoidosis, especially in stage II patients, was significantly elevated compared with those of the controls, (3) plasma C-OPN levels in patients of stages 0, I, and III were significantly higher than those of the controls, and (4) in vitro recombinant F-OPN induces macrophage migration and that C-OPN inhibits cell migration mediated by F-OPN. These results suggest that F-OPN may promote granuloma formation in sarcoidosis, while C-OPN may suppress it. Thus, OPN and its fragment may play distinct roles in the development of sarcoidosis.

Flow Cytometric Analysis of Lymphocyte Subsets in the Bronchoalveolar Lavage Fluid and Peripheral Blood of Healthy Volunteers

The lymphocyte subsets in the bronchoalveolar lavage fluid (BALF) and the peripheral blood of 25 healthy volunteers were examined by analysis with a fluorescence‐activated cell sorter. Comparison of the lymphocyte subsets in the BALF with those of the peripheral blood revealed much higher values for the ratios of each Leu. 3A+ (CD4). Leu. 3+ 8− and Leu 2+ 15− cells, while the ratios of Leu 1+ (CD5). Leu 2a+ (CD8). Leu 7+. Leu 8+. Leu 10+. Leu 11a+ (CD16), Leu 12+ and Leu 2+ 15+ cells were low in the BALF. The above results indicate that the lymphocyte subsets in the BALF from healthy individuals are mainly composed of cells with surface phenotypes of helper T cells and cytotoxic T cells with virtual absence of cells carrying suppressor T and NK cell phenotypes. and with low B cell ratio. Therefore, it is assumed that the local immune mechanism of the lung is different from that of the peripheral blood.

Detection of type C retroviral particles in the lung cells of a patient with systemic lupus erythematosus.

Novel type C retroviral particles were detected in the bronchoalveolar lavage fluid (BALF) of a patient who had systemic lupus erythematosus (SLE) with interstitial pneumonia. Syncytial cell formation in the BALF and positive reverse transcriptase activity in the supernatant of the cultured cells were observed. No antibody to known human retroviruses or proviral sequences was detected.Serum antibody to this putative type C retrovirus was also detected in 23.5 % of SLE patients and 26.9 % of idiopathic pulmonary fibrosis patients. This novel type C retroviral particle could be one of the pathogenic agents for SLE or interstitial pneumonia.