Developmental fate of hematopoietic stem cells: the study of individual hematopoietic clones at the level of antigen-responsive B lymphocytes.
We have shown previously that hematopoiesis in mice reconstituted with retrovirally marked hematopoietic stem cells (HSCs) is provided by multiple, mainly short-lived clones, as measured by retroviral insertion site analysis of individual spleen colony-forming unit (CFU-S)-derived colonies. However, the CFU-S is the relatively early progenitor and the contribution of each CFU-S in the steady-state hematopoiesis is uncertain. Here, we have studied the fate of individual mature B cells, as well as CFU-S, representing the progeny of retrovirally transduced marrow-repopulating cells (MRC). B-cells-generated hybridomas and CFU-S-derived colonies were used to determine the clonal composition of hematolymphopoiesis at the single-cell level. Bone marrow (BM) cells and splenocytes (approximately 1/3-1/2 of spleen at a time) from mice reconstituted with retrovirally marked syngeneic BM cells were repeatedly collected at 3, 10, and 16 months post-transplant. The percentage of retrovirally marked CFU-S and B-cell-produced hybridomas was about 50% at 3 months and decreased to 10-15% at 10 months after reconstitution in spite of stable degree of chimerism. The clonal origin of BM-derived CFU-S and spleen-derived B-cell hybridomas was detected by Southern blot analysis. Overall, DNA obtained from 159 retrovirally marked spleen colonies, 287 hybridomas and 43 BM samples were studied. Multiple simultaneously functioning clones of MRC-derived B cells were observed. The same individual clones among hybridomas and CFU-S were identified in three out of 11 mice. Thus, hematopoiesis is generated by multiple hematopoietic clones some of which can simultaneously contribute to both mature lymphoid cells and myeloid progenitors. These data establish that the stem cell compartment functions by continuously producing progeny, which fully but transiently repopulate all lineages.
Hematological Scientific Centre, Moscow, Russia.
Natalia I
NI
Olovnikova
Nina J
NJ
Drize
Maxim A
MA
Ershler
Irina N
IN
Nifontova
Elena V
EV
Belkina
Tatiana N
TN
Nikolaeva
Natalia V
NV
Proskurina
Joseph L
JL
Chertkov
D000818:Animals; D000941:Antigens / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D001854:Bone Marrow Cells; D019070:Cell Lineage; D002999:Clone Cells / Q000166:cytology; D005260:Female; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006825:Hybridomas / Q000166:cytology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D023461:Myeloid Progenitor Cells; D013154:Spleen / Q000166:cytology; D014161:Transduction, Genetic
D000941:Antigens