Monomeric IgG2a promotes maturation of bone-marrow macrophages and expression of the mannose receptor.

作者：Stefan Schreiber, Janice S. Blum, William F. Stenson, Richard P. MacDermott, Philip D. Stahl, Steven L. Teitelbaum, S L Perkins · 发表于：Proceedings of the National Academy of Sciences · 年份：1991 · DOI：10.1073/pnas.88.5.1616 · 被引用次数：26 · 研究领域：Glycosylation and Glycoproteins Research、Monoclonal and Polyclonal Antibodies Research、Carbohydrate Chemistry and Synthesis

The macrophage mannose receptor, a 172-kDa lineage-specific glycoprotein, partakes in nonopsonin-mediated phagocytosis by recognition of terminal mannose residues on targeted particles. Because appearance of the receptor progresses with monocyte/macrophage differentiation, its expression is indicative of the maturational state of the cell. Monomeric IgG2a and IgG2b up-regulate mannose-receptor surface expression and biosynthesis by murine bone-marrow macrophage precursors as much as 7- to 12-fold in a dose-dependent manner. IgG2a accelerates macrophage mannose-receptor expression by several days during in vitro bone-marrow differentiation; however, treated and control cells ultimately express equivalent levels of receptor. Moreover, the effect is independent of cell cycle or ambient levels of colony-stimulating factor 1. The coinduction of another maturation-dependent lineage-specific antigen, F4/80, and the fact that macrophage precursors respond to IgG2a only within the first day of culture, indicate that the targeted cell is an early myelomonocytic precursor, responsive only during a short, early developmental window. The effect is specific for immunoglobulin molecules of the IgG2a and IgG2b subclasses and probably involves an Fc gamma-receptor signal-transduction pathway but not macrophage priming or activation. Most importantly, a paracrine mechanism of immunoglobulin-mediated bone-marrow macrophage differentiation is suggested by experiments in which basal levels of man...