RT Journal Article SR Electronic T1 Apoptosis and Fas/Fas ligand mRNA expression in acute immune complex alveolitis in mice JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 2351 OP 2359 DO 10.1183/09031936.97.10102351 VO 10 IS 10 A1 Y Nomoto A1 K Kuwano A1 N Hagimoto A1 R Kunitake A1 M Kawasaki A1 N Hara YR 1997 UL http://erj.ersjournals.com/content/10/10/2351.abstract AB Deoxyribonucleic acid (DNA) strand breaks as a characteristic of apoptosis, and Fas antigen (Fas)/Fas ligand (FasL) expression may participate in acute immune complex alveolitis in mice. Male Institute for Cancer Research (ICR) mice were injected intravenously with immunoglobulin G (IgG) antibodies against ovalbumin and inhaled an aerosolized oval albumin (OA) solution. They were killed at 4, 6, 12, 24, 48 h and 7 days after aerosolization. We assessed DNA fragmentation by agarose gel electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labelling (TUNEL). The expression of Fas and FasL messenger ribonucleic acid (mRNA) in lung tissues was assessed by reverse transcriptase (RT) polymerase chain reaction, and by in situ hybridization (ISH) to localize Fas mRNA, and RT in situ polymerase chain reaction to localize FasL mRNA. The fragmentation of DNA extracted from lung tissue was found 6-24 h after OA inhalation. TUNEL detected positive signals in bronchial and alveolar epithelial, endothelial and inflammatory cells in the lung tissue. These positive signals had disappeared 7 days after OA inhalation. TUNEL also detected positive signals in apoptotic neutrophils in bronchoalveolar lavage fluid at 6-12 h. Fas mRNA was expressed in the alveolar epithelial and inflammatory cells, while the expression of FasL mRNA appeared to be upregulated in infiltrating inflammatory cells at 6-24 h. These results suggest that apoptosis may be associated with the resolution of inflammation and with tissue repair and also suggest the involvement of the Fas antigen/Fas ligand pathway in acute immune complex alveolitis in mice.