Js. Pixley et al., TRANSPLANTATION IN-UTERO OF FETAL HUMAN HEMATOPOIETIC STEM-CELLS INTOMICE RESULTS IN HEMATOPOIETIC CHIMERISM, Pathobiology, 62(5-6), 1994, pp. 238-244
Allogeneic and xenogeneic hematolymphoid chimerism has been achieved i
n large and small animals using varied techniques to circumvent immune
mediated graft rejection by the recipient. We show here the establish
ment of long-term chimerism in normal mice transplanted in utero with
human fetal hematopoietic stem cells (HSC). HSCs from fetal (13-20 wee
ks' gestation) human livers were injected into fetal mouse peritoneal
cavities on days 11-13 of gestation. Histologic examination demonstrat
ed human chimerism in 29% of 38 live born mice using fluorescein conju
gated antibodies to both the CD45 and CD14 antigens present on human p
eripheral blood (PB) cells. Further investigation using flow cytometri
c analysis of cells from 70 mice transplanted in utero revealed 28% of
mice greater than 16 weeks of age contained human cells in at least o
ne organ at the following frequencies: 14% PB, 8% bone marrow, 8% sple
en and 12% thymus. These data indicate that human fetal HSC can be eng
rafted into mouse fetuses. Additionally, the identification of circula
ting human cells 18 months following transplantation supports the engr
aftment and proliferation of a primitive hematopoietic progenitor.