Connexin43 is dispensable for phagocytosis

• Published in: The Journal of immunology (1950) Vol. 190; no. 9; pp. 4830 - 4835
• Main Authors: Glass, Aaron M, Wolf, Benjamin J, Schneider, Karin M, Princiotta, Michael F, Taffet, Steven M
• Format: Journal Article
• Language: English
• Published: United States 01.05.2013
• Subjects: Animals; Bone Marrow Cells - metabolism; Cells, Cultured; Connexin 43 - genetics; Connexin 43 - immunology; Connexin 43 - metabolism; Erythrocytes - immunology; Erythrocytes - metabolism; Female; Genes, MHC Class I; Immunoglobulin G - genetics; Immunoglobulin G - metabolism; Listeria monocytogenes; Listeria monocytogenes - genetics; Listeria monocytogenes - immunology; Listeria monocytogenes - metabolism; Liver - metabolism; Macrophage Colony-Stimulating Factor - genetics; Macrophage Colony-Stimulating Factor - metabolism; Macrophages - immunology; Macrophages - metabolism; Mice; Mice, Inbred BALB C; Phagocytosis - genetics; Phagocytosis - immunology; Phagosomes - genetics; Phagosomes - immunology; Phagosomes - metabolism; Sheep; Zymosan - genetics; Zymosan - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1202884

Macrophages that lack connexin43 (Cx43), a gap junction protein, have been reported to exhibit dramatic deficiencies in phagocytosis. In this study, we revisit these findings using well-characterized macrophage populations. Cx43 knockout (Cx43(-/-)) mice die soon after birth, making the harvest of macrophages from adult Cx43(-/-) mice problematic. To overcome this obstacle, we used several strategies: mice heterozygous for the deletion of Cx43 were crossed to produce Cx43(+/+) (wild type [WT]) and Cx43(-/-) fetuses. Cells isolated from 12- to 14-d fetal livers were used to reconstitute irradiated recipient animals. After reconstitution, thioglycollate-elicited macrophages were collected by peritoneal lavage and bone marrow was harvested. Bone marrow cells and, alternatively, fetal liver cells were cultured in media containing M-CSF for 7-10 d, resulting in populations of cells that were >95% macrophages based on flow cytometry. Phagocytic uptake was detected using flow cytometric and microscopic techniques. Quantification of phagocytic uptake of IgG-opsonized sheep erythrocytes, zymosan particles, and Listeria monocytogenes failed to show any significant difference between WT and Cx43(-/-) macrophages. Furthermore, the use of particles labeled with pH-sensitive dyes showed equivalent acidification of phagosomes in both WT and Cx43(-/-) macrophages. Our findings suggest that modulation of Cx43 levels in cultured macrophages does not have a significant impact on phagocytosis.