Chronic Infection Contributes to Age-Related Hematopoietic Stem Cell Dysfunction

Hematopoietic stem cells (HSCs), resident in the bone marrow, are at the base of a complicated tree of descendant progenitor cells that collectively produce immune cells and red blood cells. With age, the HSC population becomes damaged and dysfunctional. The number of competent stem cells diminishes, while mutational damage followed by clonal expansion causes issues such as myeloid skew in the hematopoietic populations, in which too many myeloid cells are produced at the expense of needed lymphoid cells. This all contributes to an age-related decline in immune system function. Given the importance of the immune system to health and aging, there is considerable interest in finding ways to restore a more youthful, functional state of hematopoiesis in older people. Today's research materials discuss chronic infection as one of the contributing causes of HSC dysfunction. In the study of aging, the more interesting chronic infections are viral, meaning persistent herpesviruses such as cytomegalovirus that the immune system cannot fully clear. The presence of infection puts a stress on the immune system, as cells replicate more rapidly, and a greater number of replacement somatic cells are required to ensure continued function. Over longer periods of time, this can lead to exhaustion of these cell populations, both the somatic cells that only replicate a limited number of times, and the stem cells that use a fine balance of mechanisms to ensure their self-renewal and continu...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs