The Role of Complement System in Mobilization/Homing of Hematopoietic Stem Cells
28 الي 30 بهمن 1389، شيراز - ايران
Presentation Type: Speech
It is well known that hematopoietic stem/progenitor cells (HSPC) circulate in peripheral blood (PB) under steady-state conditions at very low levels to maintain a pool of stem cells in balance in the bone marrow (BM) microenvironment present in bones throughout the body. Therefore, PB could be envisioned as a “highway” by which HSPCs relocate in the organism between hematopoietic endosteal and endothelial niches usually located in distant bones. It has been calculated that in mice, approximately 400 HSPCs circulate at any given moment in the PB. In addition, recent evidence suggests that while circulating in PB, HSPCs may enter tissues and return back to the PB via the lymphatic system and thoracic duct. This route of “circulation/tissue patrolling” is enforced during infection, in which circulating HSPCs mobilized during infection could be recruited to the affected peripheral tissues and give rise to tissue-resident myeloid and dendritic cells. This mechanism is thus an important part of innate immunity surveillance under steady-state conditions and is enhanced in response to inflammation or organ injuries (e.g. heart infarct, or stroke).