Analysis Of Immune Cell Remodeling And Functional Alterations Induced By Aging And Obesity In Mice
As we live longer, and with increasing rates of obesity, our immune systems face a double challenge. Researchers have explored how both aging and excess weight can change the way our bodies fight off disease.
The study involved observing mice across different age groups and feeding them either a regular or a high-fat diet. By carefully examining their immune cells, particularly those found in the spleen (a key immune organ), the scientists uncovered significant shifts.
They found that both aging and obesity led to a different mix of immune cells. For instance, there were fewer of the cells that directly kill infected cells or regulate immune responses (like T cells, NK cells, and monocytes), while other types involved in antibody production and immediate responses (B cells, neutrophils, and eosinophils) increased. Aging specifically saw a rise in “aging-associated B cells” and T cells that appeared “exhausted,” meaning they were less effective at their job. Obesity, on the other hand, was linked to an increase in a certain type of macrophage, which are immune cells that “eat” cellular debris and pathogens, but in this case, they seemed to be contributing to inflammation.
Crucially, both conditions triggered more “chronic inflammation”—a persistent, low-grade inflammatory state throughout the body. This was evident from higher levels of inflammatory signaling molecules (called cytokines, like IL-6 and TNF-α). These changes essentially leave the immune system less capable of responding effectively to new threats and more prone to contributing to age-related diseases. The research also identified specific markers in the blood, like certain liver enzymes, cholesterol, and BMI, alongside specific immune cells and cytokines, that could help distinguish the unique immune changes caused by aging versus obesity.
These findings shed light on how our lifestyle and age combine to weaken our immune defenses, highlighting potential targets for maintaining a healthier immune system as we get older and managing weight.
Source: link to paper