noun, plural: Hofbauer cells
The mononuclear phagocyte system is a system comprised of phagocytic cells located in reticular connective tissue. Reticular connective tissue is a type of connective tissue characterized by the predominance of reticular fibers. Thus, it is part of the immune system and the phagocytic cells found in it are primarily involved in phagocytosis and antigen processing and presentation. Hofbauer cells are example of a mononuclear phagocyte system. Other examples include the adipose tissue macrophages, monocytes in bone marrow, Kupffer cells in liver, histiocytes in connective tissues, etc.
Hofbauer cells are histiocytes located in the mesoderm of the chorionic villi. Histiocytes are phagocytic cells in the reticular connective tissues. Histiocytes came from the stem cells of the bone marrow. They, then, migrate into the bloodstream as monocytes. When they reach and enter a certain organ they undergo differentiation to become histiocytes as influenced by growth factors, GM-CSF, TNF, and IL-4.1
Two major cell types present in the placenta are trophoblasts and Hofbauer cells. The Hofbauer cells were observed to express HLA-DR and CD-4 molecules.2 Thus, they are believed to be involved in preventing vertical transmission, i.e. the transmission of pathogens from the mother to the fetus.
1Histiocyte. Retrieved from [].
2 Miller, R. & Thiede, H. (1994). HIV, perinatal infections, and therapy: the role of the placenta. Rochester, N.Y: University of Rochester Press. p.83