21 research outputs found
Glycoprotein IIb-IIIa Is Expressed on Avian Multilineage Hematopoietic Progenitor Cells
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Developmental Expression of IL-2-Receptor Light Chain (CD25) in the Chicken Embryo
Thymocyte differentiation obeys the same fundamental principles in mammals as in avian
species. This parallelism does not only affect the developmentally controlled acquisition of
CD3, 4, 8, and TcR isotype expression, but also concerns CD25, the light chain of the interleukin-2 receptor (IL-2R). On chicken thymocytes, surface CD25, which is recognized by the
monoclonal antibody INN Ch16, is first observed during day 11 of embryonic life, and peaks
at day 14, when it is expressed by about one-third of all lymphoid cells. CD25 is found on
subsets of all ,thymocyte populations as defined by TcRαβ, TcRγδ, 2, CD4, and CD8 expression,
cortical or medullary localization, and is also present on a subset of intrathymic nurse-cell
lymphocytes. These findings suggest phylogenetic conservation of the IL-2/IL-2R-triggered
differentiation pathway previously described for mammalian species, thus under-lining
its probable functional importance
T-Lymphocyte Subsets in the Embryonic Spleen Undergoing a Graft-Versus-Host Reaction
Allogeneic immunocompetent T cells injected into chicken embryos induce a graft-versushost
reaction (GVHR) whose most prominent manifestation is splenic hyperplasia. The
highly inbred CC and CB strains of chickens used here are, respectively, homozygous for
the B4 or B12 MHC haplotypes. By means of a panel of immunological reagents, including
alloantisera and monoclonal antibodies against public domains of the T-cell receptor, CD4,
CD8, and the inducible interleukin-2-receptor light chain (CD25), it is shown that the bulk
of cells in the enlarged spleen are of host origin and do not express markers typical of
mature T or B lymphocytes. Among recipient splenocytes, the quantitatively most important
population consists of TCRαβ-TCRγδ-CD4-CD8+CD25+
(TCR0) lymphocytes. Donor cells
encountered in the spleen prevalently exhibit a TCRαβ+CD4+CD8-CD25+ phenotype and
proliferate in vivo. The data demonstrate that nonspecific host and potentially specific donorderived
cellular elements contribute to splenomegaly
Transcriptome Characterization Uncovers the Molecular Response of Hematopoietic Cells to Ionizing Radiation
International audienceIonizing radiation causes rapid and acute suppression of hematopoietic cells that manifests as the hematopoietic syndrome. However, the roles of molecules and regulatory pathways induced in vivo by irradiation of different hematopoietic cells have not been completely elaborated. Using a strategy that combined different microarray bioinformatics tools, we identified gene networks that might be involved in the early response of hematopoietic cells radiation response in vivo. The grouping of similar time-ordered gene expression profiles using quality threshold clustering enabled the successful identification of common binding sites for 56 transcription factors that may be involved in the regulation of the early radiation response. We also identified novel genes that are responsive to the transformation-related protein 53; all of these genes were biologically validated in p53-transgenic null mice. Extension of the analysis to purified bone marrow cells including highly purified long-term hematopoietic stem cells, combined with functional classification, provided evidence of gene expression modifications that were largely unknown in this primitive population. Our methodology proved particularly useful for analyzing the transcriptional regulation of the complex ionizing radiation response of hematopoietic cells. Our data may help to elucidate the molecular mechanisms involved in tissue radiosensitivity and to identify potential targets for improving treatment in radiation emergencies
Purification of caveolae microdomains from HaCaT keratinocytes followed by proteomic analysis allows the characterization of new markers of human epidermis layers
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