Identification and characterization of receptors for granulocyte colony-stimulating factor on human placenta and trophoblastic cells.
نویسندگان
چکیده
Since radioiodination of human granulocyte colony-stimulating factor (G-CSF) is difficult, we synthesized a mutein of human G-CSF that retains full biological activity and receptor-binding capacity for at least 2 weeks after radioiodination. Receptors for human G-CSF were characterized in the plasma membrane fraction from the human term placenta (human placental membranes) and trophoblastic cells by using the 125I-labeled mutein of human G-CSF (KW-2228). The specific binding of 125I-labeled KW-2228 to placental membranes was pH-dependent, with maximal specific binding at pH 7.8; it increased linearly with protein to 3.7 mg of protein per ml and was both time- and temperature-dependent, with maximal binding at 4 degrees C after a 24-hr incubation. When we examined the ability of hematopoietic growth factors to inhibit 125I-labeled KW-2228 binding, we found that KW-2228 and intact human G-CSF inhibited 125I-labeled KW-2228 binding, whereas erythropoietin or granulocyte-macrophage colony-stimulating factor did not. Scatchard analysis revealed a single receptor type with a Bmax of 210 fmol/mg of protein and a Kd of 480 pM. The human G-CSF receptors on human placental membranes were shown to consist of two molecular species of 150 kDa and 120 kDa that could be specifically cross-linked to 125I-labeled KW-2228. Human trophoblastic cells, T3M-3, also possessed a single receptor for G-CSF with a Bmax of 533 receptors per cell and a Kd of 390 pM. Thus we have identified the receptor for human G-CSF on human placental membranes and trophoblastic cells, and the presence of this receptor in these membranes suggests that human G-CSF plays some role in the feto-placental unit during human development.
منابع مشابه
Comparison of T7- and Lac-Based Systems for the Periplasmic Expression of Human Granulocyte Macrophage Colony Stimulating Factor in Escherichia coli
متن کامل
Overexpression of Recombinant Human Granulocyte Colony-Stimulating Factor in E. coli
Bakground: Granulocyte colony-stimulating factor (G-CSF) is a cytokine that stimulates hematopoiesis and induces proliferation and differentiation of granulocyte progenitor cells as well as production of bone marrow neutrophilic granulocyte colonies. Nowadays, human recombinant G-CSF(hr G-CSF)is used for the treatment of chemotherapy- and radiotherapy-induced neutropenia, and also in patients ...
متن کاملSite-Directed Mutagenesis in Human Granulocyte-colony Stimulating Factor, Cloning and Expression in Escherichia coli
Human granulocyte colony stimulating factor (hG-CSF) induces proliferation and differentiation of granulocyte progenitor cells. This glycoprotein is currently being used for treatment of neutropenia, in patients who have undergone bone marrow transplantation. So far, different researchers have tried to enhance hG-CSF biological activity and stability. In this study, Polymerase Chain Reaction (P...
متن کاملAdministration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) for the intracranial hemorrhage in two dogs: a case report
Two dogs with generalized seizures were evaluated. The dogs were diagnosed with traumatic intracranial hemorrhages based on the history, neurological examinations, and magnetic resonance imaging (MRI) of the brain. Treatment was started with oxygen, prednisolone and anticonvulsant agents. No further seizure activity was observed after treatment in both dogs, however cushing reflex was detected ...
متن کاملIn vivo Characterization of Fusion Protein Comprising of A1 Subunit of Shiga Toxin and Human GM-CSF: Assessment of Its Immunogenicity and Toxicity
Background: Most cancer cells become resistant to anti-cancer agents. In the last few years, a new approach for targeted therapy of human cancer has been developed using immunotoxins which comprise both the cell targeting and the cell killing moieties. Methods: In the present study, the recombinant Shiga toxin A1 subunit fused to human granulocyte-macrophage colony stimulating factor (A1-GM-CSF...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 86 23 شماره
صفحات -
تاریخ انتشار 1989