Generation and Identification of Thymic Epithelial Progenitor Cells pTEC by In-Vitro Processing of Human Thymic Fragments for Allotransplantation

The procedure of generation and identification of stromal progenitor cells derived from human thymic fragments (PL patent 378431) has been described in this article. Our aim was to prepare material for transplantation in elderly people. The method is based on in-vitro processing of thymic fragments to get rid of all immunogenic elements of lymphocytes, endothelial cells, macrophages, and fibroblasts. In the thymic culture process, this organ dies out in the incubation medium and epithelial cells emerge out of the organ. After about 4 weeks from the start of the culture, the population of various developmental forms of epithelial cells was generated, namely CK AE1/AE3+, SDF-1 alpha+ and a weak expression of FGF+ S-100+. Finally, we obtained approximately 3 million cells as a monolayer. The progenitor cells were experimentally transplanted into a 72-year-old volunteer in order to prove that they do not induce neither a local nor a systemic rejection response.