Connexin43 is dispensable for phagocytosis

J Immunol. 2013 May 1;190(9):4830-5. doi: 10.4049/jimmunol.1202884. Epub 2013 Apr 3.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 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 / 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


  • Connexin 43
  • Immunoglobulin G
  • Macrophage Colony-Stimulating Factor
  • Zymosan