Effect of thrombopoietin on peroxidase activity of cryopreserved peripheral blood stem cells

Autor: Yuji Kishimoto, Shirou Fukuhara, Hiroyuki Kitajima, Kaoruko Katsura, Takashi Kimura, Munehiro Date, Hiroshi Ichiyoshi, Shosaku Nomura
Rok vydání: 1997
Předmět:
Zdroj: Medical Electron Microscopy. 30:194-201
ISSN: 1860-1499
0918-4287
Popis: Transplantation of mobilized peripheral blood stem cells is increasingly used to facilitate hematological recovery following high-dose chemotherapy. In general, peripheral blood stem cells can be maintained by cryopreservation, e.g., at −80°C, until the day of transplantation. We investigated the effect of thrombopoietin (c-Mpl ligand) on cryopreserved peripheral blood stem cells obtained from 10 patients with malignant disease by assessing peroxidase activity by ultrastructual technique. Leukocyte surface markers wre evaluated by flow cytometry. After peripheral blood stem cells had been purified by use of CD34 monoclonal antibody, cells whose size resembled that of monocytes showed low levels of positivity for CD7, CD41a, and CD42b, but high levels of positivity for CD13, CD14, and HLA-DR. The lymphocyte-size cells showed high levels of positivity for CD7 only. Recombinant human thrombopoietin, administered alone and in combination with various cytokines, promoted the expression of CD41a by CD34-positive progenitor cells. No increase in the expression of CD7, CD13, CD14, and HLA-DR was detected following exposure to cytokines. However, the expression of CD41a and CD42b was enhanced by thrombopoietin. Ultrastructural study of peroxidase activity detected CD41a-positive cells. as well as platelet peroxidase-positive cells, following stimulation with thrombopoietin. Stimulation by other cytokines failed to yield platelet peroxidase-positive cells. Results thus suggest that thrombopoietin may be useful for increasing the recovery of platelets following transplantation of cryopreserved peripheral blood stem cells.
Databáze: OpenAIRE
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