TRACKING TRECS

Abstract

Research into the maintenance of tissue-resident memory T-cells (TRMs; CD69+) could provide valuable intel, especially for research focused on tissue-specific immune therapies, such as the improvement of vaccines or treatment against autoimmune diseases. TRECs analysis allows for a great way to measure thymic output, which in turn can give a good indication of the existing effect of longevity or division on the maintenance of these T-cell pools. In this study, a TREC analysis (qPCR) was performed on isolated CD4/CD8, naïve/memory, and CD69+/CD69-cells from murine bone marrow, lymph nodes, spleen, and thymus. Even though statistical analysis was difficult to perform and might prove unreliable due to the low number of data points, No high quantities of TREC DNA were found in memory CD69+ samples, suggesting the TRM pool is maintained through cell division rather than longevity. Some CD69+ naïve cells did contain higher amounts of TREC DNA, while this could be an indication of longevity, these high TREC copy measurements could also be explained by an influx of new T-cells originating from the thymus. Overall, these study results provide a strong argument for division-mediated maintenance of CD69+ and CD69- memory T-cells, especially in cells isolated from the bone marrow.