What is the difference between HLA-DR and Iba1?

Posted April 24, 2020

Answer

HLA-DR and Iba1, which both serve as markers for human microglia, are not expressed evenly in all microglial tissue. HLA-DR, which is an MHC II cell surface receptor, serves mostly as a marker for active microglia. On the other hand, Iba1, or the ionized calcium binding molecule-1, is expressed in all microglia and plays a role in actin-binding and microglial membrane ruffling, rendering it better as a structural marker.

Additional resources

Walker, D.G., & Lue, L. (2015). Immune phenotypes of microglia in human neurodegenerative disease: challenges to detecting microglial polarization in human brains. Alzheimer’s Research & Therapy, 7, 56. doi:10.1186/s13195-015-0139-9

Hendrickx, D., van Eden, C. G., Schuurman, K. G., Hamann, J., & Huitinga, I. (2017). Staining of HLA-DR, Iba1 and CD68 in human microglia reveals partially overlapping expression depending on cellular morphology and pathology. Journal of neuroimmunology, 309, 12-22. doi:10.1016/j.jneuroim.2017.04.007