Tissue-specific expression of IgG receptors by human macrophages ex vivo

Bruggeman, C.W.; Houtzager, J.; Dierdorp, B.; Kers, J.; Pals, S.T.; Lutter, R.; ... ; Kuijpers, T.W. (2019)

Article / Letter to editor

Recently it was discovered that tissue-resident macrophages derive from embryonic precursors, not only from peripheral blood monocytes, and maintain themselves by self-renewal. Most in-vitro studies on macrophage biology make use of in-vitro cultured human monocyte-derived macrophages. Phagocytosis of IgG-opsonized particles by tissue-resident macrophages takes place via interaction with IgG receptors, the Fc-gamma receptors (Fc gamma Rs). We investigated the Fc gamma R expression on macrophages both in-vivo and ex-vivo from different human tissues. Upon isolation of primary human macrophages from bone marrow, spleen, liver and lung, we observed that macrophages from all studied tissues expressed high levels of Fc gamma RIII, which was in direct contrast with the low expression on blood monocyte-derived macrophages. Expression levels of Fc gamma RI were highly variable, with bone marrow macrophages showing the lowest and alveolar macrophages the highest expression. Kupffer cells in the liver were the only tissue-resident macrophages that expressed the inhibitory IgG receptor, Fc gamma RIIB. This inhibitory receptor was also found to be expressed by sinusoidal endothelial cells in the liver. In sum, our immunofluorescence data combined with ex-vivo stainings of isolated macrophages indicated that tissue-resident macrophages are remarkably unique and different from monocyte-derived macrophages in their phenotypic expression of IgG receptors. Tissue macrophages show distinct tissue-specific Fc gamma R expression patterns.

• All authors: Bruggeman, C.W.; Houtzager, J.; Dierdorp, B.; Kers, J.; Pals, S.T.; Lutter, R.; Gulik, T. van; Haan, J.M.M. den; Berg, T.K. van den; Bruggen, R. van; Kuijpers, T.W.
• Date: 2019-10-15
• Journal: PLoS ONE
• Volume: 14
• Issue: 10
• DOI: doi:10.1371/journal.pone.0223264