Thymic Macrophage Populations Change with Age

The thymus atrophies with age, limiting the supply of new T cells to support the adaptive immune system. This is an important aspect of immune aging. Digging deeper into the mechanisms of thymus aging is of interest to the extent that it might reveal practical approaches to intervention. The challenge of the thymus is near entirely its inaccessible location, making it hard to deliver the known factors that can induce thymic regrowth without side-effects in the rest of the body. Here, researchers find that one population of macrophages characteristic of thymic tissue diminishes with age, while another population expands. The researchers theorize that it might be possible to adjust these cell proportions to provoke thymic regrowth, but at this stage that proposal is quite theoretical. More research would be needed to validate the underlying hypothesis regarding how these macrophages are involved in either supporting thymic tissue or encouraging atrophy. Tissue-resident macrophages are essential to protect from pathogen invasion and maintain organ homeostasis. The ability of thymic macrophages to engulf apoptotic thymocytes is well appreciated, but little is known about their ontogeny, maintenance, and diversity. Here, we characterized the surface phenotype and transcriptional profile of these cells and defined their expression signature. Thymic macrophages were most closely related to spleen red pulp macrophages and Kupffer cells and shared the expression of the transc...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs