Testicular macrophages are guardians of fertility

Cross section of newborn mouse's

 testis (Ø = 20 ?m), where we can see 

the seminiferous tubules 

(red) surrounded by macrophages (green). 

Confocal micrograph.

Credit: © Noushine Mossadegh-Keller

 and Sébastien Mailfert / CIML

"The origin, development, and characteristics of two types of testicular macrophage have been described by a CNRS team at the Centre d'Immunologie de Marseille-Luminy (CNRS / INSERM / Aix-Marseille University). To elucidate the nature of these immune cells, the researchers used a novel cell tracing method. Their findings were published on August 7, 2017, in the Journal of Experimental Medicine, and are of fundamental importance. They may help understand certain kinds of infertility in men and find new treatments for them.

From the start of life, an individual's immune system learns to distinguish self -- that is, native cells -- from other, potentially pathogenic cells. But in males, as sperm only appear at puberty, they may be mistaken for foreign cells by certain elements of the immune system. Testicular macrophages are special immune cells that rush to the defense of sperm. By releasing specific molecules, these guardians of fertility prevent other immune system agents from entering the testes.

Macrophages not only migrate to sites of infection and phagocytose pathogens, but also modulate immune system activity to ensure proper organ function and regeneration. They may arise from either embryonic progenitors or bone marrow cells in adults. Research with mice has enabled the team of Michael Sieweke from the Centre d'Immunologie de Marseille-Luminy (CNRS / INSERM / Aix-Marseille University) to describe both testicular macrophage populations in depth..."

Learn more:https://www.sciencedaily.com/releases/2017/08/170811093711.htm