Mouse embryo fibroblasts made to produce a protein called forkhead box N1 (FOXN1), which controls the expression of certain genes, could be reprogrammed into functional thymic epithelial cells that support the development of both CD4+ and CD8+ T cells of the immune system in vitro (Brendenkamp N et al. Nat Cell Biol. 2014;16:902-908).
The UK-led team that made the discovery also found that transplantation of these thymic epithelial cells into mice, in combination with growth factor–producing tissue, resulted in the formation of a complete, fully organized, and functional thymus that contained all subtypes of cells required to support T-cell differentiation and populate the immune system with T cells. An analysis of the cells present in the spleen and lymph nodes of treated mice indicated a diverse T-cell repertoire capable of secreting cytokines.
Hampton T. Reprogrammed Fibroblasts Form a Functional Thymus. JAMA. 2014;312(13):1291. doi:10.1001/jama.2014.13445