Hematopoietic stem-cell behavior in nonhuman primates.
Little is known about the behavior of hematopoietic stem cells (HSCs) in primates because direct observations and competitive-repopulation assays are not feasible. Therefore, we used 2 different and independent experimental strategies, the tracking of transgene expression after retroviral-mediated gene transfer (N = 11 baboons; N = 7 rhesus macaques) and quantitation of the average telomere length of granulocytes (N = 132 baboons; N = 14 macaques), together with stochastic methods, to study HSC kinetics in vivo. The average replication rate for baboon HSCs is once per 36 weeks according to gene-marking analyses and once per 23 weeks according to telomere-shortening analyses. Comparable results were derived from the macaque data. These rates are substantially slower than the average replication rates previously reported for HSCs in mice (once per 2.5 weeks) and cats (once per 8.3 weeks). Because baboons and macaques live for 25 to 45 years, much longer than mice ( approximately 2 years) and cats (12-18 years), we can compute that HSCs undergo a relatively constant number ( approximately 80-200) of lifetime replications. Thus, our data suggest that the self-renewal capacity of mammalian stem cells in vivo is defined and evolutionarily conserved.
Shepherd
Bryan E
BE
Department of Biostatistics, Vanderbilt University, Nashville, TN, USA.
Kiem
Hans-Peter
HP
Lansdorp
Peter M
PM
Dunbar
Cynthia E
CE
Aubert
Geraldine
G
LaRochelle
Andre
A
Seggewiss
Ruth
R
Guttorp
Peter
P
Abkowitz
Janis L
JL
D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D003198:Computer Simulation; D005819:Genetic Markers; D005822:Genetic Vectors; D006098:Granulocytes / Q000166:cytology / Q000502:physiology; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology; D008253:Macaca mulatta / Q000235:genetics*; D010215:Papio / Q000235:genetics*; D012190:Retroviridae; D013269:Stochastic Processes; D016615:Telomere; D013997:Time Factors; D014161:Transduction, Genetic; D019076:Transgenes / Q000502:physiology*
D018952:Antigens, CD34; D005819:Genetic Markers