Lymphohematopoietic stem cells from donor origin are preserved in bone marrow implants beneath the renal capsule of non-conditioned host mice

Abstract

Abstract Renal ossicles are ossified structures developed beneath the murine kidney capsule after the implantation of a bone marrow (BM) plug. We have investigated the origin of the hematopoietic cells lodged in renal ossicles by using sex-mismatched BM implants into Ly5 congenic male mice. Female BM plugs were obtained from two different transgenic mouse lines carrying neomycin gene sequences which provided additional genotypic tracers. Flow cytometry analyses from long-term cultures established with ossicles excised between the 17th and the 40th week post-implantation showed that 5% to 70% of the non-adherent myeloid cells were of donor origin. Genetic analysis of 12 day-spleen colonies generated by ossicles excised between the 10th and the 40th week post-implantation revealed a donor contribution which ranged between 16% and 93% within the CFU-S 12 population. Moreover, the preservation of donor long-term repopulating lymphohematopoietic cells was evidenced in ossicles excised between the 10th and the 19th week post-implantation. Our results indicate that renal ossicles contain a significant proportion of hematopoietic progenitors and long-term repopulating cells from donor origin.