CD208/dendritic cell-lysosomal associated membrane protein is a marker of normal and transformed type II pneumocytes.
Dendritic cell-lysosomal associated membrane protein (DC-LAMP)/CD208, a member of the lysosomal associated membrane protein (LAMP) family, is specifically expressed by human DCs on activation. However, its mouse counterpart could not be detected in mature DCs. The present study demonstrates that DC-LAMP is constitutively expressed by mouse, sheep, and human type II pneumocytes. Confocal and immunoelectron microscopy showed that mouse DC-LAMP protein co-localizes with lbm180, a specific marker for the limiting membrane of lamellar bodies that contain surfactant protein B, as well as with intracellular MHC class II molecules that accumulate in the same organelles. Expression of DC-LAMP was also occasionally detected at the cell surface of type II pneumocytes. Interestingly, human bronchioloalveolar carcinoma tumor cells, which correspond to transformed type II pneumocytes, express DC-LAMP. Similar observations were made in the Jaagsiekte sheep retrovirus-associated ovine pulmonary adenocarcinoma, a model of human bronchioloalveolar carcinoma. This study establishes that DC-LAMP is constitutively expressed in normal type II pneumocytes. Furthermore, DC-LAMP appears to be a marker of transformed type II pneumocytes as well, an observation that may help the study and the classification of human lung adenocarcinomas.
Laboratory for Immunological Research, Schering Plough Research Institute, Dardilly, France.
Bruno
B
Salaun
Blandine
B
de Saint-Vis
Nathalie
N
Pacheco
Yves
Y
Pacheco
Arnaud
A
Riesler
Sylvie
S
Isaac
Caroline
C
Leroux
Valérie
V
Clair-Moninot
Jean-Jacques
JJ
Pin
Janice
J
Griffith
Isabelle
I
Treilleux
Sophie
S
Goddard
Jean
J
Davoust
Monique
M
Kleijmeer
Serge
S
Lebecque
D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000378:metabolism / Q000473:pathology; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis* / Q000648:ultrastructure; D014408:Biomarkers, Tumor / Q000032:analysis*; D015152:Blotting, Northern; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure*; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000166:cytology* / Q000648:ultrastructure; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D051907:Lysosomal Membrane Proteins; D051379:Mice; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D013045:Species Specificity
D015703:Antigens, CD; D014408:Biomarkers, Tumor; D051907:Lysosomal Membrane Proteins