Macrophages stimulated by receptor-ligand interactions exhibit differences in cell-cycle kinetics during tumor growth: stimulation at Mac-1 and Mac-3 receptors alters DNA synthesis.

Abstract

Phenotypic and functional changes associated with tumor-bearing host (TBH) macrophages (M phi) are partly responsible for immunosuppression during tumor growth. Flow cytofluorometric analyses revealed differences in cell-cycle kinetics between normal host (NH) and TBH M phi that were stimulated at specific receptors. Receptor-ligand interactions were induced by antibodies against Mac-1, -2, -3, and Ia receptors and changes in DNA synthesis were measured over a 12-h time course by incorporation of propidium iodide. TBH M phi showed higher DNA synthesis than NH M phi over this time course irrespective of the receptor induced. NH M phi stimulated at the Mac-1 receptor demonstrated higher DNA synthesis than control NH M phi although TBH M phi stimulated at this receptor and control TBH M phi failed to show any differences. Both NH and TBH M phi exhibited small, short-term decreases in DNA synthesis when stimulated at the Mac-2 receptor. TBH M phi that were stimulated at the Mac-3 receptor demonstrated higher DNA synthesis than their control counterparts while NH M phi stimulated at this receptor and control NH M phi showed identical levels of DNA synthesis. No differences in DNA synthesis were found among normal or TBH M phi that were stimulated through Ia. Differences in DNA synthesis did not appear to be attributable to differences in receptor expression. Further analysis of Mac-1 and Mac-3 stimulated cells revealed that DNA synthesis in NH M phi stimulated at the Mac-1 receptor returned to control levels at 48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: T M Walker, A D Yurochko, C J Burger, K D Elgert
• Journal: Immunology letters (Immunol Lett) Vol. 31 Issue 3 Pg. 217-25 (Feb 15 1992) ISSN: 0165-2478 [Print] Netherlands
• PMID: 1548036 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• Antigens, Differentiation
• DNA, Neoplasm
• Ligands
• Macrophage-1 Antigen
• Receptors, Immunologic
• Tetrazolium Salts
• Thiazoles
• monocyte-macrophage differentiation antigen
• thiazolyl blue

Topics

• Animals
• Antibodies, Monoclonal
• Antigens, Differentiation (immunology)
• Cell Cycle (immunology)
• DNA, Neoplasm (biosynthesis)
• Fibrosarcoma (immunology, pathology)
• Flow Cytometry
• Fluorescent Antibody Technique
• Ligands
• Macrophage Activation (immunology)
• Macrophage-1 Antigen (immunology)
• Male
• Mice
• Mice, Inbred BALB C
• Receptors, Immunologic
• Tetrazolium Salts
• Thiazoles