Could a recent discovery about the body’s natural defenses be a stepping stone toward combating kidney-related health issues? Scientists say yes.

Macrophages are a type of white blood cell central to the immune system that detect and engulf harmful pathogens, like viruses, bacteria and fungi, serving as helpful scavengers to fight infections. They also cause or suppress inflammation and secrete molecules that allow communication between different cell types, all of which provide a healthy immune response in fighting infection and disease.

Scientists have long known the origins of different types of macrophages found in the brain, gut, heart and liver. The origins of those found in kidney tissue, however, are not as well understood. Until now, researchers hadn’t known if these macrophages had traveled from elsewhere in the body or if they were produced during embryonic development. As it turns out, both theories are correct.

In a recent study, Tulane National Primate Research Center (TNPRC) scientists Xuebin Qin, PhD, professor of medicine, and Fengming Liu, PhD, assistant professor of microbiology and immunology, made a new discovery about renal (kidney) macrophages that fundamentally changes the understanding of how these cells populate.

Using a new rapid cell ablation (destruction) technique created by Qin, the team discovered that in a mouse model, half of renal macrophages originate during the embryonic state and the other half derive from bone marrow. They also showed that embryo-derived renal macrophages have a stronger immune response than their bone marrow-derived counterparts. 

“These findings advance our current understanding of tissue-resident macrophages and may lead to promising new directions for the development of new therapeutics for kidney diseases,” explained Qin.

The implications of this discovery are important because while the kidneys help control the volume of blood in the body and maintain the proper concentrations of proteins and electrolytes, they are also subject to infection and disease. The role of macrophages in clearing any infection and supporting kidney function could prove key to future treatments of kidney disease and even infectious diseases that are associated with kidney failure, like human immunodeficiency virus (HIV) and coronavirus (COVID-19).

NPRC scientists across the country are working to combat infectious diseases through a variety of research projects. You can learn more about NPRC’s infectious disease studies at this link, as well as coronavirus-specific studies at this link.