Konference: 2006 48th ASH Annual Meeting - účast ČR
Kategorie: Nádorová biologie/imunologie/genetika a buněčná terapie
Téma: Publikace ve sborníku
Číslo abstraktu: 4164
Autoři: Ko-Tung Chang; Tereza Pelichovska; RNDr. Luděk Šefc, CSc.; Petr Broulik; Prof. MUDr. Emanuel Nečas, DrSc.
The hematopoietic stem/progenitor cells from fetal liver (FL) of
the mouse do not express estrogen receptors in contrast to the
cells from adult bone marrow (BM) [Igarashi H et al: Proc Natl Acad
Sci USA (2001) 98, 15131-15136]. Since estrogen had been shown to
suppress B-lymphopoiesis in vivo [Medina KL et al: Blood (2000) 95,
2059-2067; Erlandsson MC: Immunology (2003) 108, 346-351], we
investigated estrogen action on B-lymphopoiesis derived from FL
cells transplanted to adult mice. FL cells from E14.5 embryos of
C57Bl/6 mice (Ly5.1), or a mixture of FL cells (Ly5.1) with BM
cells (Ly5.2), were transplanted either into sublethally (7 Gy) or
into lethally (11 Gy) irradiated male Ly5.2 recipients,
respectively. Half of the recipients were kept on a diet containing
estradiol (estimated intake of 100 micrograms/day). Peripheral
blood obtained from the retrobulbar venous plexus was analyzed for
presence of Ly5.1 (FL origin) or Ly5.2 (BM origin) WBCs using flow
cytometry (FACS Calibur, Becton Dickinson) from 2 weeks up to 16
weeks after transplantation. The WBCs were also stained with
anti-mouse CD45R/B220 antibody to detect B-lymphocytes. Numbers of
repopulating B-lymphocytes of FL origin were little affected by
estrogen 2 and 4 weeks after transplantation while those of BM
origin were significantly suppressed. However, the difference
between responses of FL or BM origin B-lymphopoiesis to estrogen
became much smaller after 8 weeks and was not evident after 16
weeks. The chimeric bone marrow was further transplanted to
secondary lethally irradiated recipients and effect of estrogen on
B-lymphopoiesis of either FL or BM origin was studied for another
20 weeks. In this case B-lymphopoiesis of FL origin was suppressed
by estrogen immediately after transplantation similarly as that of
BM origin. The results provide a functional confirmation of
previously reported molecular differences between FL and adult BM
stem/progenitor cells dwelling in lack of the expression of
estrogen receptors in the FL cells. They also conclusively
demonstrate that FL stem/progenitor cells become invariably
sensitive to estrogen after being exposed to the environment of the
adult organism for a long enough time.
Datum přednesení příspěvku: 9. 12. 2006
