Kettering University

About: Kettering University is a education organization based out in Flint, Michigan, United States. It is known for research contribution in the topics: RNA & Antigen. The organization has 6842 authors who have published 7689 publications receiving 337503 citations. The organization is also known as: GMI Engineering & Management Institute & General Motors Institute.

Cell-to-cell expression variability followed by signal reinforcement progressively segregates early mouse lineages

Abstract: To delineate the characteristics of lineage emergence in the early mammalian embryo, Hiiragi and colleagues analyse the expression profiles of single cells of the inner cell mass as they differentiate into pluripotent epiblast and primitive endoderm. They observe that cells with initially indistinguishable expression profiles, but exhibiting apparently stochastic differences, resolve into distinct lineages in the late blastocyst through the action of Fgf4.

Chemotaxis of primitive hematopoietic cells in response to stromal cell–derived factor-1

Abstract: Stromal cell-derived factor-1 (SDF-1) provides a potent chemotactic stimulus for CD34(+) hematopoietic cells. We cultured mobilized peripheral blood (PB) and umbilical cord blood (CB) for up to 5 weeks and examined the migratory activity of cobblestone area-forming cells (CAFCs) and long-term culture-initiating cells (LTC-ICs) in a transwell assay. In this system, SDF-1 or MS-5 marrow stromal cells placed in the lower chamber induced transmembrane and transendothelial migration by 2- and 5-week-old CAFCs and LTC-ICs in 3 hours. Transmigration was blocked by preincubation of input CD34(+) cells with antibody to CXCR4. Transendothelial migration of CB CAFCs and LTC-ICs was higher than that of PB. We expanded CD34(+) cells from CB in serum-free medium with thrombopoietin, flk-2 ligand, and c-kit ligand, with or without IL-3 and found that CAFCs cultured in the absence of IL-3 had a chemotactic response equivalent to noncultured cells, even after 5 weeks. However, addition of IL-3 to the culture reduced this response by 20-50%. These data indicate that SDF-1 induces chemotaxis of primitive hematopoietic cells signaling through CXCR4 and that the chemoattraction could be downmodulated by culture ex vivo.

Serological demonstration of h-y (male) antigen on mouse sperm.

Abstract: WE have recently overcome certain technical difficulties in applying the cytotoxicity test to mouse spermatozoa and have been able to show directly that H-2 antigens are expressed on these cells1, thus confirming less direct evidence leading to the same conclusion2. We have since applied the cytotoxicity test to sperm with antisera directed against a number of other systems of mouse alloantigens, TL3, θ4, Ly-A5 and Ly-B5, but none of these has given a positive reaction with sperm. This is not surprising because these are all “differentiation antigens”6 expressed primarily on lymphoid cells. Another antigenic system which distinguishes one mouse from another is H-Y. The H-Y antigen is carried by male cells only and is responsible for the rejection of male tissues by females of the same inbred strain7.

Limitation of excessive myelopoiesis by the intrinsic modulation of macrophage-derived prostaglandin E

Abstract: The clonal proliferation of the committed granulocyte-macrophage stem cell is controlled by a balance between mutually opposing factors, colony stimulating factor and prostaglandin E, both of monocyte-macrophage derivation. Increases beyond a critical concentration of colony stimulating factor within the local milieu of the mononuclear phagocyte induces the coincident elaboration of prostaglandin E, a self-regulated response which serves to limit the unopposed humoral stimulation of myelopoiesis.