Maintenance of peritoneal macrophages in the steady state

• Published in: Journal of leukocyte biology 1988-11, Vol.44 (5), p.367-375
• Main Authors: Melnicoff, Meryle J., Horan, Paul K., Breslin, Elizabeth W., Morahan, Page S.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal; Biological and medical sciences; Cell Count; Cell Division; Female; flow cytometry; fluorescence cell tracking; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Immunobiology; in vivo labeling; Macrophages - cytology; Mice; Mice, Inbred BALB C; Myeloid cells: ontogeny, maturation, markers, receptors; Neutrophils - cytology; Peritoneal Cavity - cytology; Staining and Labeling
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.44.5.367

Resident peritoneal macrophages (Mø) were labeled in situ by intraperitoneal (i.p.) injection of the green fluorescent cell tracking dye PKH‐1. After immunofluorescence staining with Mø specific monoclonal antibodies (Mabs) and phycoerythrin (PE) second antibody, the resident Mø were labeled with both the green dye and red Mab label, while recruited Mø were labeled only with the red Mab tag. These populations were distinguished by two‐color flow cytometry. PKH‐1 labeled resident peritoneal Mø were followed for 1‐49 days in mice that received no further treatment (steady state). Dye labeled Mø were still detectable after 49 days in vivo, although their green fluorescence intensity had decreased steadily over time. The decrease in dye intensity was limited to Mø, as the fluorescence intensity of PKH‐1 labeled peritoneal lymphocytes did not change. Resident Mø populations were clearly separated from recruited Mø by the intensity of their staining with PKH‐1 for up to 28 days. No decrease in the number of resident (dye labeled) peritoneal Mø was observed over 1‐28 days. These data indicate that resident peritoneal Mø were not replaced by recruited blood monocytes in the steady state.