Functional xenogeneic hematopoietic cells maintaining donor-dominant identity and immune tolerance enable therapy.

BACKGROUND: The clinical supply of hematopoietic cells is severely constrained by the limitations of donor donation and inefficient in vitro generation. While generating these cells within interspecies chimeras presents a groundbreaking alternative, the fundamental biological properties and therapeutic potential of the resulting xenogeneic hematopoietic cells remain poorly characterized. METHODS: We generated xenogeneic hematopoietic cells in rodent models via blastocyst complementation and bone marrow transplantation. A comprehensive comparative analysis of these cells was conducted using single-cell RNA sequencing and proteomics. Their functional efficacy was rigorously evaluated through reverse transplantation into a series of donor-species disease models, including hemorrhagic anemia, thalassemia, thrombocytopenia, and leukemia. RESULTS: Bone marrow transplantation yielded significantly higher chimeric efficiency than blastocyst complementation. Xenogeneic hematopoietic cells, including red blood cells, platelets, and white blood cells, exhibited a transcriptional and proteomic profile that was dominantly donor-specific. Crucially, these cells did not elicit significant immune rejection upon reverse transfusion. Functionally, xenogeneic red blood cells rescued models of hemorrhagic anemia and thalassemia, platelets alleviated thrombocytopenia, and xenogeneic T cells engineered with a chimeric antigen receptor effectively suppressed leukemia progression. Furthermore, the implantation of xenogeneic hematopoietic cells partially reconstituted splenic morphology and function in immunodeficient recipients. CONCLUSION: Our study provides the first comprehensive functional validation of xenogeneic hematopoietic cells generated in interspecies bioreactors. We definitively show that these cells possess donor-like molecular identities, evade immune rejection, and serve as effective "seed cells" to rescue a wide spectrum of hematologic diseases. This work establishes a transformative paradigm for utilizing interspecies chimeras to overcome critical shortages in transfusion and cellular therapies.