Relationship between antigen presenting cells and pathogenesis of aplastic anemia

Abstract

Aplastic anemia(AA) is defined as an immune-mediated bone marrow failure syndrome, characterized by pancytopenia and hypocellular bone marrow. At present, the pathogenesis of AA is concerned chiefly with abnormal hematopoietic stem cells, hematopoietic microenvironment abnormality and disorder of immune system. Antigen presenting cell (APC) is the main initiator of adaptive immunity. It plays a role in processing and presenting antigens to T lymphocyte, and leading to an immune response or immune tolerance. Activation of APC may lead to the imbalance and dysfunction of T lymphocyte subsets, such as the polarization of helper T lymphocyte (Th)1, activation of CD8+ T cells and secretion of negative regulators of hematopoiesis. All of these compose a cytokine network to destruct stem/progenitor cells as well as hematopoietic stem cells, mesenchymal stem cells and angioblasts/endothelial progenitor cells. Thus, this article reviews literatures on the relationship between APC including dendritic cells (DC), monocytes, B lymphocytes and the pathogenesis of AA. Key words: Anemia, aplastic; Antigen-presenting cells; Receptor, pattern recognition