Anti-RMA, a murine monoclonal antibody, activates rat macrophages: II. Induction of DNA synthesis and formation of multinucleated giant cells.
Anti-RMA is a murine anti-rat monoclonal antibody that binds to a 120-kD surface membrane antigen expressed primarily by alveolar macrophages. Saline-lavaged alveolar macrophages (AM) formed clusters after incubation with anti-RMA. Anti-RMA produced multinucleated giant cells (MGC) in approximately 15% of adherent AM, and the F (ab')2 fragment of anti-RMA yielded MGC in approximately 9% of AM. The Fab fragment of anti-RMA did not promote MGC formation, nor did the murine anti-rat monoclonal antibodies OX41 and W3/25 (anti-CD4). Although anti-RMA produced a tenfold increase in [3H]thymidine incorporation by AM, it yielded a minimal increase in the number of AM. Autoradiography of AM stimulated with anti-RMA showed heterogeneous labeling of nuclei in MGC, suggesting that 3H-labeled AM may fuse with AM that are not actively synthesizing DNA. These findings suggest that binding of anti-RMA to AM may activate DNA synthesis, and promote clustering and fusion of AM, leading to MGC formation.
Lazarus
D
D
Department of Pathology, Massachusetts General Hospital, Boston 02114.
Yamin
M
M
McCarthy
K
K
Schneeberger
E E
EE
Kradin
R
R
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D015726:Giant Cells / Q000378:metabolism* / Q000648:ultrastructure; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008854:Microscopy, Electron; D051381:Rats; D011917:Rats, Inbred Lew; D013936:Thymidine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007140:Immunoglobulin Fab Fragments; D008070:Lipopolysaccharides; D004247:DNA; D013936:Thymidine