Fight Aging! Newsletter, September 13th 2021

In this study, mature DCs (mDCs), generated from the GM-CSF and IL-4 induced bone marrow cells, were intravenously injected into wild-type mice. Three days later, assays showed that the mDCs were indeed able to return to the thymus. Homing DCs have been mainly reported to deplete thymocytes and induce tolerance. However, medullary TECs (mTECs) play a crucial role in inducing immune tolerance. Thus, we evaluated whether the mDCs homing into the thymus led to TECs depletion. We cocultured mDCs with mTEC1 cells and found that the mDCs induced the apoptosis and inhibited the proliferation of mTEC1 cells. These effects were only achieved via direct cell-cell contact between mDCs and mTEC1 cells. Furthermore, we observed that an intrathymic injection of the mDCs resulted in acute thymic atrophy and reduced thymocytes and TECs substantially in vivo. In sum, this demonstrated that circulating mDCs migrated into the thymus and induced the degeneration of the thymus. Overall, the findings of this study improve our understanding of the mechanisms underlying thymus degeneration. During infection, activated DCs are mature, and migrate into different lymph nodes through afferent lymphatic vessels. DCs, residing in tissues, can reach the periphery and carry antigens to secondary lymphoid organs through blood. A small number of circulating DCs, capturing pathogens, can migrate into thymus. Although the number of thymic homing DCs is relatively small, given numerous mild or severe infe...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs