Anti-RMA, a murine monoclonal antibody, activates rat macrophages: II. Induction of DNA synthesis and formation of multinucleated giant cells

Am J Respir Cell Mol Biol. 1990 Aug;3(2):103-11. doi: 10.1165/ajrcmb/3.2.103.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antigens, Surface / immunology
  • DNA / biosynthesis*
  • Female
  • Giant Cells / metabolism*
  • Giant Cells / ultrastructure
  • Immunoglobulin Fab Fragments / immunology
  • Lipopolysaccharides / immunology
  • Macrophage Activation*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Microscopy, Electron
  • Rats
  • Rats, Inbred Lew
  • Thymidine / metabolism

Substances

  • Antibodies, Monoclonal
  • Antigens, Surface
  • Immunoglobulin Fab Fragments
  • Lipopolysaccharides
  • DNA
  • Thymidine