Testicular macrophages are guardians of fertility

August 11, 2017, CNRS
Cross section of newborn mouse's testis (Ø = 20 µm), 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 —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 are special 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 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.

The testis is divided into two compartments. One kind of testicular macrophage is found in the interstitial spaces, where testosterone-producing Leydig cells are also located. These interstitial macrophages are of embryonic origin: they are present from the beginning of the individual's life. The other kind is peritubular—that is, located on the surface of the seminiferous tubules that house sperm cell precursors. Each macrophage population has distinctive cellular markers.

The researchers used a new cell tracing method to follow the movement of peritubular macrophages from the bone marrow to the testes. They discovered that these macrophages only appear two weeks after the mice are born, which corresponds to the pubescent stage in human males. Surprisingly, once they have been established in the testes, macrophages of both populations remain there for the rest of their long lives. Sieweke's team will next focus their research efforts on the relationships between macrophages, sperm, and testosterone production, which may yield innovative treatments for certain kinds of male infertility.

Explore further: New study reveals how specialized cells help each other survive during times of stress

More information: Noushin Mossadegh-Keller et al. Developmental origin and maintenance of distinct testicular macrophage populations, The Journal of Experimental Medicine (2017). DOI: 10.1084/jem.20170829

Related Stories

New study reveals how specialized cells help each other survive during times of stress

November 3, 2015
Nov. 3, 2015 - A team led by scientists from the Florida campus of The Scripps Research Institute (TSRI) and the University of Pittsburgh has shown for the first time how one set of specialized cells survives under stress ...

Embryonic white blood cells needed in adulthood

October 17, 2016
Leukocytes which arise during the embryonic period regulate iron metabolism and the growth of the mammary gland in adults.

Identifying underlying causes of immune deficiencies that increase shingles risk

June 12, 2017
Early life infections with varicella zoster virus cause chickenpox, but the virus can remain dormant in the nervous system for decades and reactivate to cause herpes zoster, commonly known as shingles. Shingles is characterized ...

The surprising ability of blood stem cells to respond to emergencies

April 10, 2013
A research team of Inserm, CNRS and MDC lead by Michael Sieweke of the Centre d'Immunologie de Marseille Luminy (CNRS, INSERM, Aix Marseille Université) and Max Delbrück Centre for Molecular Medicine, Berlin-Buch, today ...

Recommended for you

Space-like gravity weakens biochemical signals in muscle formation

May 23, 2018
Astronauts go through many physiological changes during their time in spaceflight, including lower muscle mass and slower muscle development. Similar symptoms can occur in the muscles of people on Earth's surface, too. In ...

Hotter bodies fight infections and tumours better—researchers show how

May 21, 2018
The hotter our body temperature, the more our bodies speed up a key defence system that fights against tumours, wounds or infections, new research by a multidisciplinary team of mathematicians and biologists from the Universities ...

Deep space radiation treatment reboots brain's immune system

May 21, 2018
Planning a trip to Mars? You'll want to remember your anti-radiation pills.

Receptor proteins that respond to nicotine may help fat cells burn energy

May 21, 2018
The same proteins that moderate nicotine dependence in the brain may be involved in regulating metabolism by acting directly on certain types of fat cells, new research from the University of Michigan Life Sciences Institute ...

Atomic-level study reveals why rare disorder causes sudden paralysis

May 21, 2018
A rare genetic disorder in which people are suddenly overcome with profound muscle weakness is caused by a hole in a membrane protein that allows sodium ions to leak across cell membranes, researchers at the University of ...

New era for blood transfusions through genome sequencing

May 18, 2018
Most people are familiar with A, B, AB and O blood types, but there are hundreds of additional blood group "antigens" on red blood cells—substances that can trigger the body's immune response—that differ from person to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.