Rapid lymphocyte reconstitution of unconditioned immunodeficient mice with non-self-renewing multipotent hematopoietic progenitors.
The replacement of abnormal hematopoietic stem cells (HSCs) with normal transplanted HSCs can correct a wide range of hematologic disorders. Here, we provide evidence that transplantation of more differentiated progenitor cells can be used to more rapidly correct lymphoid deficiencies in unconditioned immunocompromised mice. Transplantation of flk2+ multipotent progenitors led to robust B and T cell reconstitution that was maintained for at least 16 weeks. Antigenic challenge at 16 weeks post-transplantation revealed that reconstituted lymphocytes maintained a functional repertoire. In contrast to the persistent lymphocytic engraftment, myeloid chimerism was lost by 12 weeks post-transplantation consistent with the fact that flk2+ progenitors are non-self-renewing. Thus, while more differentiated progenitors are capable of rescuing lymphoid deficiencies, transplantation of HSCs must be used for the correction of non-lymphoid disorders, and, we propose, very long-term immune reconstitution. Based on recent evidence, we discuss novel strategies to achieve the replacement of abnormal HSCs without the use of cytotoxic conditioning regimens.
Bhattacharya
Deepta
D
Institute of Cancer and Stem Cell Biology and Medicine, Department of Pathology, Stanford University School of Medicine, Stanford, California, USA. deepta@stanford.edu
Bryder
David
D
Rossi
Derrick J
DJ
Weissman
Irving L
IL
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000502:physiology; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D007153:Immunologic Deficiency Syndromes / Q000628:therapy*; D016130:Immunophenotyping; D038041:Lymphopoiesis; D051379:Mice; D018345:Mice, Knockout; D039902:Multipotent Stem Cells / Q000637:transplantation*; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology