当前位置： SCI文献检索 > EXPERIMENTAL HEMATOLOGY期刊下所有文献 > Alloreactivity following in utero transplantation of cytokine-stimulated hematopoietic stem cells: the role of recipient CD4(-) cells.

Alloreactivity following in utero transplantation of cytokine-stimulated hematopoietic stem cells: the role of recipient CD4(-) cells.

Abstract：

OBJECTIVE:We have previously reported immunity to donor antigens following in utero transplantation (IUT) of cytokine-stimulated allogeneic hematopoietic stem cells (sca(+)/lin(-)) (day 9 of gestation). Transplanted mice showed accelerated rejection of donor skin grafts and high anti-donor cytotoxic response, a finding not seen in the control mice. This was accompanied by an enhancement of Th1 over Th2 cytokine production and persistent donor microchimerism. In order to assess the role of the thymus in allograft rejection, prenatal transplants were performed under similar experimental conditions at a later gestational age, when the thymus is more developed (day 13). MATERIALS AND METHODS:Cytokine-stimulated stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF)-purified sca(+)/lin(-) cells of C57BL/6 (H-2b, 1E(+)) background were injected into MHC-mismatched BALB/c (H-2d, 1E(-)) fetal mouse recipients at day 13 of gestation. Chimerism was determined by highly sensitive (0.001%) semiquantitative polymerase chain reaction (PCR). Mixed lymphocyte reaction (MLR) and cytotoxic T-cell assay (CTL) were used to evaluate tolerance vs immunity. Cytokine levels were quantified in MLR supernatants using ELISA assay. The percent of T cells was determined by flow cytometry (FACS) and CD4/CD8 ratio calculated. Postnatal boosts (transplants without conditioning) were performed at 6 months of age to enhance donor chimerism and test the degree of tolerance. RESULTS:When assayed at 4 months of age, donor-type cells were not detected in the spleen or in the peripheral blood of BALB/c mice inoculated with C57BL/6 sca(+)/lin(-) cells. Transplanted but not control animals demonstrated high anti-donor MLR but not CTL responses. The increase of MLR reactivity was correlated with high levels of IL-2. Furthermore, transplanted mice showed higher resistance to postnatal boosts with allogeneic bone marrow (BM) cells, when compared to the control mice. The later resistance was accompanied by the expansion of host-type CD4 cells. CONCLUSION:These data demonstrate that transplantation of cytokine-stimulated sca(+)/lin(-) allogeneic cells at 13 days of fetal development leads to the allosensitization, characterized by an enhancement of MLR alloreactivity and by the rejection of postnatal boosts (transplants without conditioning). Host-type CD4 cells might play a central role in this rejection. These findings indicate that the late injection of allogeneic cells may result in the development of allosensitization with subsequent donor graft rejection. Precise conditions for the development of tolerance must be established before prenatal transplants in humans with conditions other than SCID can be done.

journal_name

Exp Hematol

journal_title

Experimental hematology

authors

Sefrioui H,Donahue J,Srivastava AS,Gilpin E,Lee TH,Carrier E

doi

10.1016/s0301-472x(02)00803-2

keywords:

subject

Has Abstract

pub_date

2002-06-01 00:00:00

pages

617-24

issue

eissn

0301-472X

issn

1873-2399

pii

S0301472X02008032

journal_volume

pub_type

杂志文章

在线工具

Alloreactivity following in utero transplantation of cytokine-stimulated hematopoietic stem cells: the role of recipient CD4(-) cells.