It is known that two different types of tissue macrophages occur in the organs of the adult organism. Macrophages are a special class of immune cells that are of embryonic origin. They are responsible for the innate immune response to pathogens, but also fulfill generic roles in tissue development and homeostasis. They originate from three sources: the yolk sac,⁽¹⁾ the fetal liver and hematopoietic stem cells (HSC) in the bone marrow.⁽²⁾ Macrophages are present in almost all tissues and are essential not only for homeostasis but also for development. They produce antimicrobial reactive oxygen and nitrogen species to fight pathogens, as well as intercellular messengers to coordinate innate and adaptive immune responses as well as tissue remodeling and repair.

Prof. Radisic and her team have already found that human pluripotent stem cell-derived primitive yolk sac-like macrophages in vascularized heart-on-chip platforms affected the functionality and permeability of the engineered cardiac tissue. Among others, matrix remodeling cytokines promoting vascularization were upregulated.^{(3, 4)}

Prof. Radisic is one of five Visiting Fellows of Stiftung Charité, who are each funded with up to 600,000 euros.⁽⁵⁾

Sources:
(1) Schuchert, R. A. (2017). Formation, development and migration of macrophages from the embryonic yolk sac in vivo. Dissertation LMU Munich.
(2) https://www.trillium.de/zeitschriften/trillium-immunologie/archiv/trillium-immunologie-ausgaben-2020/heft-12020/aus-der-geschichte/makrophagen-am-anfang-war-die-fresszelle.html
(3) Landau S, Zhao Y, Hamidzada H, Kent GM, Okhovatian S, Lu RXZ, Liu C, Wagner KT, Cheung K, Shawky SA, Vosoughi D, Beroncal EL, Fernandes I, Cummins CL, Andreazza AC, Keller GM, Epelman S, Radisic M. (2024). Primitive macrophages enable long-term vascularization of human heart-on-a-chip
heart-on-a-chip platforms. Cell Stem Cell. Jun 20:S1934-5909(24)00208-X. doi: 10.1016/j.stem.2024.05.011. epub ahead of print. PMID: 38908380. https://www.cell.com/cell-stem-cell/abstract/S1934-5909(24)00208-X
(4) https://radisiclab.com/
(5) https://www.mdc-berlin.de/de/news/news/vaskularisierte-organe-auf-chips-zuechten