Antigen Presenting Cells Donate Telomeres to T Cells to Increase their Longevity

T cells replicate aggressively in response to infection and other threats, yet these cells must also persist in the body for years in order to maintain immunological memory. Telomeres, repeated DNA sequences at the ends of chromosomes, shorten with each cell division. This mechanism forms a part of the Hayflick limit on somatic cell replication. When telomeres become too short, cells become senescent and self-destruct, or are destroyed by immune cells. T cells can employ telomerase to lengthen telomeres, but not to any great degree. So how do they manage such long lives in an environment of repeated threats by pathogens, and thus repeated bursts of telomere-shortening replication? In today's open access paper, the authors outline a fascinating mechanism by which antigen-presenting B cells, which interact with T cells to coordinate the immune response, donate telomeres to those T cells, thereby increasing their replicative life span. One initial thought in response to this finding is that it should be possible to create telomere-bearing vesicles to replicate this effect, more broadly than it occurs naturally. As is the case for telomerase gene therapy, and all such analogous approaches aimed at lengthening telomeres, there is the issue of selectivity, however. Extending telomeres in cells that probably should be destroyed as well as those that will continue beneficial work is a concern, even given the very positive data in mice resulting from upregulation of telomerase....
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs