title: Detection of burst-promoting activity in spleens of myeloproliferative sarcoma virus-infected mice using serum-free cultures.
abstract: Myeloproliferative syndrome was induced in adult DBA/2 mice by inoculation with myeloproliferative sarcoma virus (MPSV) and Friend murine leukemia virus (F-MuLV) as a helper virus. On day 26 after infection, the spleen weighed a maximum of 2.0 g (about 30 times the control weight). Assay of multipotent stem cells in vitro showed that the more enlarged spleens contained an increased number and concentration of mixed colony-forming units (CFU-mix) (at maximum, 11 times higher than the control). When the supernatant of cultured spleen cells was added to a serum-free bone marrow cell culture with or without erythropoietin (Epo) for detection of burst-promoting activity (BPA), it enhanced erythroid mixed colony (E-mix) formation only in the presence of Epo (p less than 0.05). Even when addition of Epo was delayed, it still induced a significant number of E-mix (p less than 0.05). These findings rule out a mimic effect of Epo resembling BPA and indicate the presence of BPA in the spleen. The culture supernatant also supported the proliferation of interleukin 3 (IL-3)-dependent 32Dcl cells. Therefore, although purification of the BPA substance has not yet been accomplished, BPA in the supernatant seems to depend on the presence of IL-3, which is known to be one of the factors stimulating multipotent hemopoietic stem cells. The presence of BPA- or CFU-mix-stimulating activity in the spleen after infection might be responsible for the development of panmyelosis, which is a characteristic of MPSV-induced myeloproliferative syndrome.
authors.affiliation: Department of Pathology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsuo
authors.forename: H
authors.initials: H
authors.lastname: Oda
authors.forename: T
authors.initials: T
authors.lastname: Fukushima
authors.forename: J
authors.initials: J
authors.lastname: Matsuoka
authors.forename: N
authors.initials: N
authors.lastname: Hashimoto
authors.forename: K
authors.initials: K
authors.lastname: Tadokoro
authors.forename: H
authors.initials: H
authors.lastname: Kohama
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: C
authors.initials: C
authors.lastname: Jasmin
authors.forename: Y
authors.initials: Y
authors.lastname: Urano
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D003114:Colony-Forming Units Assay; D015672:Erythroid Precursor Cells / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D004921:Erythropoietin / Q000494:pharmacology; D005260:Female; D014644:Genetic Variation; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D007377:Interleukin-3 / Q000378:metabolism*; D051379:Mice; D008980:Moloney murine sarcoma virus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D012513:Sarcoma, Experimental / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D013160:Splenic Neoplasms / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000382:microbiology / Q000473:pathology
chemical_list: D007377:Interleukin-3; D011994:Recombinant Proteins; D004921:Erythropoietin