Discovery of a Novel Immune Cell in Mice May Help Slow Aging Process

Aging is not limited to an accumulation of years. It is a complex biological process, influenced by cellular mechanisms that are still widely unknown. Among them, the chronic inflammation that settles with age increasingly intrigues researchers. A recent discovery in fatty fabrics may well turn our understanding of this silent dynamic. For the first time, a new type of cell comes to light up the links between immunity and aging an unexpected day.

Macrophages (these white blood cells known to swallow pathogens) in young and elderly mice, they did not expect to identify thirteen distinct cell types. And yet, one of them had never been described before.

This completely new population existed only in elderly individuals. It presented inflammatory markers characteristic of the phenomenon of chronic inflammation of low grade, associated with aging. According to immunobiologist Vishwa Deep Dixit, co-author of the study published in Nature Aging on September 2, 2025, this discovery was completely unforeseen, revealing an still unexplored part of age-related immunity.

Using a fine RNA analysis of these cells, the team was able to determine their genetic profile, revealing their function in the body. The fact that they only appear with age suggests that they are activated or produced by specific signals of aging.

How certain cells maintain inflammation with age

With age advancement, the immune system loses its precision. He continues to react, but in a diffuse, inappropriate way, sometimes even self -destructive. This imbalance promotes the emergence of persistent, deleterious long -term inflammation. The newly discovered macrophages would participate in this silent drift.

Among the types identified in visceral fat, some protect the organism by maintaining the metabolic balance, others on the contrary seem to amplify inflammation. One cell in particular, associated with nerves, is becoming rarely with age in females, but remains stable in males. This difference could explain certain metabolic disparities between the sexes over time.

To better understand their protective role, scientists have eliminated macrophages associated with nerves in the visceral fat of young female mouse. Result, a metabolic imbalance and a rise in inflammatory markers, a sign that their disappearance contributes to creating a ground conducive to chronic low grade inflammation (inflammageing). This observation was reported by Elsie Gonzalez-Hurtado, also a researcher at Yale, who highlights the importance of better characterizing these cells hitherto ignored.

Aging and immunity: a therapeutic track to explore

The study is not content to describe a phenomenon. It opens up concrete perspectives. If certain cells promote age -related inflammation, why not try to brake them? And conversely, if others contain it, could we preserve them longer?

For Miriam Merad, immunologist at the Icahn School of Medicine in New York, this discovery opens a new field of research. She suggests that restoring or maintaining the balance between different macrophage populations could limit the metabolic effects of aging and improve the health of fatty tissue.

Adipose tissue is no longer just an energy reservoir or a metabolic risk factor. It becomes a real regulator of immunity, whose role evolves over time. By studying these new cells, researchers could not only better understand aging, but also identify levers to slow it down. The fat cells have not finished delivering their secrets.