Understanding the embryonic development of langerhans cells, the dendritic cells of the epidermis

The Langerhans cells (LCs) belong to the family of dendritic cells (DCs), potent antigen presenting cells that bridges innate and adaptive immune system. Strategically located at the epidermis they form the first immune barrier against external pathogens. Hence revealing the ontogeny of LCs, which remains controversial for decades, would give major implications in the therapeutical use towards related defective immune disease. LCs present an unique homeostasis differs them from other DCs: definitely of hematopoietic origin but their precursors already present in the skin prior to birth and before bone marrow and other DCs have developed. Recently the LCs were shown to arise from monocytes in vivo during inflammation. We aim to identify the precursor that enables LCs to self-repopulate locally in quiescent skin throughout life. The origin of LCs during embryonic hematopoiesis was assessed by intraperitoneally injecting pregnant mice with AFS98, the antibody against macrophage colony-stimulating factor receptor (M-CSFR) that which essential for LC proliferation. Results showed that LCs are derived from E7.5 yolk sac primitive macrophages, but it perhaps not the only origin for LCs.Bachelor of Science in Biomedical Science