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F Dieterlen-Lievre

Publications and source records attributed to F Dieterlen-Lievre.

At least 19 recordsLinked to original sources
PubMed1997

Antigenic phenotype and gene expression pattern of lymphohemopoietic progenitors during early mouse ontogeny.

Hemopoiesis, initiated in the early embryo yolk sac (YS) (7.5-8 days postcoitum (pc) in mouse), takes place thereafter in sites successively seeded by extrinsic hemopoietic stem cells (HSC). Since the existence of intraembryonic HSC has been proven experimentally in some vertebrates, it is also likely that not all HSC originate in the YS in mammals, as previously thought. Candidate intraembryonic sites that may be active in producing HSC before liver colonization are the para-aortic splanchnopleura (P-Sp) and the aorta-gonads-mesonephros region (AGM). Here we explore these sites directly for the presence of cells with hemopoietic-specific surface molecules and gene activities. The Ags c-kit, AA4.1, Mac-1, and Sca-1 begin to be expressed on some P-Sp and AGM cells, making it possible to distinguish subpopulations that evolve according to reproducible developmental patterns. On the basis of RAG-1 gene transcription, the first lymphoid precursors in the mouse embryo appear to be present 9.5 to 10 days pc in P-Sp/AGM and YS. Starting B-cell lymphopoiesis (9-12 days pc) is characterized by nonexpression of the surrogate light chain lambda 5-encoding gene and biased usage of IgH DJ4 rearrangements. In the 12.5- to 13.5-day-pc fetal liver (FL), a switch occurs, characterized by the random use of all IgH DJ and the detection of lambda 5 gene transcripts.

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PubMed1996

Lymphoid potential, probed before circulation in mouse, is restricted to caudal intraembryonic splanchnopleura.

Emergence of hemopoietic stem cells in the mammalian embryo has yet to be definitively allocated. Previously, we detected multipotent hemopoietic precursors in the region surrounding the dorsal aorta (paraaortic splanchnopleura) beginning at 8.5 days postcoitum (dpc). However, as circulation is already established, it remained unclear whether hemopoietic precursors arise in situ or are blood-delivered. By adding an organotypic step to our former culture system, we now detect lymphocyte and multipotent myeloid precursors from the intraembryonic splanchnopleura as early as 7.5 dpc. Under identical conditions, yolk sacs from the same embryos are unable to generate lymphoid progeny and have a reduced potential for myeloid differentiation and maintenance. Thus, if isolated before circulation, the yolk sac does not produce multipotent precursors and therefore does not contribute to definitive hemopoiesis in the mouse.

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PubMed1996

Two distinct endothelial lineages in ontogeny, one of them related to hemopoiesis.

We have shown previously by means of quail/chick transplantations that external and visceral organs, i.e., somatopleural and splanchnopleural derivatives, acquire their endothelial network through different mechanisms, namely immigration (termed angiogenesis) versus in situ emergence of precursors (or vasculogenesis). We have traced the distribution of QH1-positive cells in chick hosts after replacement of the last somites by quail somites (orthotopic grafts) or lateral plate mesoderm (heterotopic grafts). The results lead to the conclusion that the embryo becomes vascularized by endothelial precursors from two distinct regions, splanchnopleural mesoderm and paraxial mesoderm. The territories respectively vascularized are complementary, precursors from the paraxial mesoderm occupy the body wall and kidney, i.e., they settle along with the other paraxial mesoderm derivatives and colonize the somatopleure. The precursors from the two origins have distinct recognition and potentialities properties: endothelial precursors of paraxial origin are barred from vascularizing visceral organs and from integrating into the floor of the aorta, and are never associated with hemopoiesis; splanchnopleural mesoderm grafted in the place of somites, gives off endothelial cells to body wall and kidney but also visceral organs. It gives rise to hemopoietic precursors in addition to endothelial cells.

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PubMed1996

An identical effect mediated by thyroid deficiency or oncogene v-erbA in the chick embryo.

We have shown earlier that the association of v-myc and v-erbA (MAHEVA construct) is responsible for the appearance of a specific phenotype in chick embryos inoculated at E3. This phenotype comprises rapidly growing heart rhabdomyomas (induced by v-myc alone) and within these tumors secondarily appearing cartilage nodules (Bachnou et al., Oncogene 6: 1041-1047, 1991). Here we report that v-erbA can be replaced by thyroid deficiency. When decapitated embryos were inoculated with virus MC29 (v-myc alone) or when v-myc inoculated embryos were treated with thiourea, 100% of the embryos reaching E17 to E19 displayed tumoral hearts bearing cartilage nodules. We thus report in vivo evidence that v-erbA acts by antagonizing the effects of thyroid hormones. Remarkably, thyroid deficiency rendered embryos more sensitive to the effect of v-myc, since 100% developed heart rhabdomyomas and cartilage nodules, versus about 70% affected when either v-myc or MAHEVA were inoculated. Thyroid deficiency did not alter the species-specific character of transdifferentiation, since only chick but not quail embryos developed cartilage nodules after thyroidectomy or MAHEVA infection.

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PubMed1995

In vitro survival and multiplication of chicken myeloblasts promoted for several weeks by chick embryo extract.

Growth of hemopoietic cells from chick embryonic aorta, spleen, and bone marrow was obtained in a serum-free culture medium containing 10-d-old chick embryo extract. When cells were cultured in semi-solid medium (plasma clot), they proliferated and differentiated to generate colonies committed to the granuloid or erythroid lineage. Mixed colonies composed either of granulocytes and macrophages or granulocytes and erythroblasts were also obtained. In addition, two different types of colonies composed of immature cells (blast cells) could be distinguished by the size of the cells. These colonies were composed of larger cells originating from the more immature progenitors, because they developed after a longer incubation period. Growth of bone marrow cells up to 3 wk in liquid culture was also obtained in the serum-free culture supplemented with chick embryo extract. These cells retained a very immature phenotype and the ability to differentiate when reseeded in an appropriate medium. These results indicate for the first time that chick embryo extracts contain hematopoietic growth factors that are active in differentiation and proliferation of chick hematopoietic cells.

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PubMed1995

[Intra-embryonic hematopoiesis in mice].

In vertebrate embryos, all hemopoietic tissues that are successively active during ontogeny (fetal liver, thymus, spleen and bone marrow) are colonized by extrinsic hemopoietic stem cells (HSC). The exception to this rule is the yolk sac (YS) whose progenitors arise in situ. Moreover, the YS is the first hemopoietic site to appear in the embryo. In consequence, it was considered as the primary source of the HSC that transfer from one site to the other until the demonstration that, in birds, the source of definitive HSC was located in the aortic region of the embryo. To assess a possible contribution of intraembryonic sites to mouse hemopoietic development, we developed an in vitro approach that permits the detection of multipotent hemopoietic progenitors in the region surrounding the dorsal aorta. This new site, the paraaortic splanchnopleura (P-Sp), is active from the 10 somite stage to the stage of fetal liver colonization by HSC. The in vitro analysis of the hemopoietic potential of the P-Sp revealed that: 1) progenitors present in this region are multipotent since a single micromanipulated P-Sp cell can give rise to mature B and T lymphocytes and various myeloid cells, when cultivated in appropriate conditions; 2) the P-Sp is the only intraembryonic site endowed with this potential; 3) numbering progenitors present in the YS and P-Sp indicated that precursors appear in both locations at the 10-12 somite stage reaching 15 in each site at 9.5 dpc (25 somites), shortly before the beginning of fetal liver colonisation. During a cytological study of the 9-11 dpc embryo aimed to disclose the cellular basis for our experimental results, two potential hemopoietic sites were uncovered. Cells clusters that resemble avian intraaortic hemopoietic clusters were found in the arteries located close to the coelomic cavity (dorsal aorta, umbilical and omphalomesenteric arteries). Moreover, groups of cells strikingly similar to YS blood islands were uncovered in the mesentery. All these sites are located in areas formed from the P-Sp and are fully developed at the onset of fetal liver colonization. These hemogenic sites most probably develop from the hemopoietic precursors present in the P-Sp.

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PubMed1990

Oncogenes and avian development.

In order to detect signs of oncogene activity and elucidate their possible role in avian ontogeny we implemented two different strategies. One was to detect either the protein product or messenger RNA in situ at various stages of development. The other was to try and disturb development with retroviruses carrying one or several oncogenes in their activated forms. Time- and tissue-specific expression of c-myc was apparently not related to particular phases of cell evolution, such as population amplification. Rather the presence of c-myc immunoreactive product at particular stages appeared to depend on cell types. c-myb and c-ets messenger RNAs were found expressed preferentially in the blood system, respectively in hemopoietic and differentiating endothelial cells. The developing embryo heart was found to be uniquely sensitive to the effect of retroviruses provided that two conditions were respected. The first was the injection of the virus or construct prior to E3.5. The second was the presence of the v-myc gene, whether alone or associated with one or several other v-onc. In such cases a large proportion (70%) of chick and all quail embryos developed multiple heart rhabdomyosarcomas within 10 days. In chickens the association of a second v-onc or of two others induced the formation of secondary tumors, whose type was determined by the nature of the other oncogene(s).(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1989

Development of the compartments of the immune system in the avian embryo.

Because of the easily traceable quail-chick marker, the early development of the immune system, in particular the connections between the differentiating organs, has been extensively studied in birds. These earlier studies clarified the origin, movements and potentialities of progenitors, and the colonization of primary lymphoid organs. With the advent of an array of similar markers in mammals, it will now be possible to identify the interactions between the stromal components of lymphoid organs and the progenitors, which give rise to the effector cells of the immune system. Rules established over the last 20 years, such as extrinsic origin of stem cells, periodic colonization of the thymus, unique colonization of the bursal rudiment, are now extended by new cellular and molecular acquisitions. Relationships between vasculogenesis, angiogenesis and hemopoiesis, acquisition of xenogeneic tolerance by thymic epithelium grafting, avian-specific strategy of immunoglobulin diversification, and identification of thymotaxin, the polypeptide responsible for progenitor attraction to the thymus, are reviewed.

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PubMed1989

Relationship between vasculogenesis, angiogenesis and haemopoiesis during avian ontogeny.

Quail-chick intracoelomic grafts of organ rudiments were used to study the origin of endothelia and haemopoietic cells during avian organogenesis in conjunction with the monoclonal antibody QH1 which recognizes the quail haemangioblastic lineage. Results differed according to the germ-layer constitution of the grafted rudiments. In the case of the limb buds, endothelial cells from the host invaded the graft through an angiogenic process. Haemopoietic progenitors from the host also colonized the grafted bone marrow. In contrast, rudiments of internal organs provided their own contingent of endothelial precursors, a process termed vasculogenesis. Nevertheless, haemopoietic cells in these organs were all derived from the host. In the lung, this extrinsic cell population appeared regularly scattered around the parabronchi and had a macrophage-like phenotype. In the pancreas, the granulocytes which differentiate as dense aggregates located in the wall of the largest vessels were extrinsic. Similarly in the spleen, a mesodermal primordium that develops in close association with the pancreatic endoderm, endothelial cells were intrinsic and haemopoietic cells host-derived. This study demonstrates that, in ontogeny, vascularization obeys different rules depending on which germ layer the mesoderm is associated with: in mesodermal/ectodermal rudiments angiogenesis is the rule; in mesodermal/endodermal rudiments, vasculogenesis occurs. However, in these internal organs undergoing vasculogenesis, endothelial and haemopoietic cells have separate origins. We put forward the hypothesis that the endoderm induces the emergence of endothelial cells in the associated mesoderm. Formation of blood stem cells may also involve interactions between endoderm and mesoderm, but in this case the responding capacity of the mesoderm appears restricted to the paraaortic region.

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PubMed1988

Myoblast migration specifically inhibited in the chick embryo by grafted CSAT hybridoma cells secreting an anti-integrin antibody.

We report a teratological method in which mouse hybridoma cells are grafted into a chick host. CSAT (Cell Substratum ATtachment) hybridoma was used. It produces an antibody directed against the avian integrin complex. The grafts were performed during the second and third days of incubation either at the level of the somites or in the coelom of the chick embryo. The anomalies were revealed by means of a monoclonal antibody that recognizes myogenic cells as soon as they become committed in the myotome. When embryos were grafted at the level of the somites, body wall muscles failed to develop on the side of the graft only. After coelomic grafting, total agenesis of abdominal muscles was induced. The anomalies were specific since the engraftment of three control hybridoma clones induced no change in muscle formation. These control hybridomas produce antibodies directed against the same molecular complex but not against the same epitope as CSAT. The injection of hybridoma cells in an embryo appears as a method of general interest to determine the long-term consequences of perturbing a specific developmental process.

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PubMed1988

Early haemopoietic stem cells in the avian embryo.

Using 'yolk sac chimaeras', we have previously demonstrated that stem cells, destined to colonize haemopoietic organs other than the yolk sac, arise in the embryo proper. We have now investigated the emergence and potentialities of these cells in vivo and in vitro. The in vivo approach consisted of interspecies grafting between quail and chick embryos. The cell progeny from the grafts was detected by means of QH1, a monoclonal antibody specific for the quail haemangioblastic lineage. When grafted into the dorsal mesentery of the chick embryo, which is a haemopoietic microenvironment, the region of the aorta from E3-E4 quail embryos generated large haemopoietic foci. When associated with a chick attractive thymic rudiment, cells left the quail aorta, entered this rudiment and underwent lymphopoiesis. Cell suspensions prepared from 40-50 chick aortae, seeded in appropriate semi-solid media, yielded macrophage, granulocyte or erythrocyte clones. These colony forming cells were two to eight times more frequent than in cell preparations from hatchling bone marrow. By contrast, cells prepared from the whole embryonic body deprived of the aorta were not clonogenic. By interspecies grafting of somatopleural (ectoderm + mesoderm, e.g. limb bud) or splanchnopleural rudiments (endoderm + mesoderm, e.g. lung, pancreas, intestine), the endothelial lining of blood vessels was shown to arise by two entirely different processes according to the rudiment considered: angiogenesis, i.e. invasion by extrinsic endothelial cells, in the limb bud, and vasculogenesis, i.e. in situ emergence of endothelial cells, in internal organs. The spleen, which first develops as a continuum to the pancreatic mesoderm, acquires its endothelial network by vasculogenesis, and is colonized by extrinsic haemopoietic stem cells. Granulopoietic cells in the pancreas and accessory cells in the lung are also extrinsic. Thus, in the case of endomesodermal rudiments, interspecies grafting reveals separate origins of endothelial and haemopoietic cells.

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PubMed1987

Vasculogenesis in the early quail blastodisc as studied with a monoclonal antibody recognizing endothelial cells.

QH1, a monoclonal antibody that recognizes quail endothelial and haemopoietic cells, was applied to quail blastodiscs in toto, in order to analyse by immunofluorescence the emergence of the vascular tree. The first endothelial cells were detected in the area opaca at the headfold stage and in the area pellucida at the 1-somite stage. Single cells then interconnected progressively, especially in the anterior intestinal portal and along the somites building up the linings of the heart and dorsal aortas. This study demonstrates that endothelial cells differentiate as single entities 4 h earlier in development than hitherto detected and that the vascular network forms secondarily. The horseshoe shape of the extraembryonic area vasculosa is also a secondary acquisition. A nonvascularized area persists until later (at least the 14-somite stage) in the region of the regressing primitive streak.

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PubMed1985

Functional capacities of chick embryo thymocytes in the mixed lymphocyte reaction.

Thymocytes from chick embryos homozygous for the B19 haplotype of the major histocompatibility locus were tested in a one way MLR either as responder or stimulator cells, against adult peripheral blood lymphocytes from B14/14 or B19/19 strains. 13-day embryonic thymocytes were strongly stimulated by adult allogeneic PBL. By contrast 16-day thymocytes were unresponsive. This difference might be related to the rhythmic waves of stem cell entry and multiplication which characterize the ontogeny of the avian thymus. Mitomycin-treated thymocytes from 13-day or 16-day embryos were both efficient in stimulating thymidine uptake by adult allogeneic PBL.

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