Murine serum obtained from bone marrow-transplanted mice promotes the proliferation of hematopoietic stem cells by co-culture with MS-5 murine stromal cells

Abstract

To examine whether serum obtained from bone marrow-transplanted mice can selectively expand hematopoietic stem cells (HSCs) among whole bone marrow cells in vitro, whole bone marrow cells were cultured with or without MS-5 murine stromal cells in the presence of serum obtained from transplanted mice on day 3 (day 3 serum) or serum from normal mice for 7 days. When whole bone marrow cells and MS-5 cells were co-cultured in day 3 serum for 7 days, the c-kit-positive, Sca-1-positive, lineage marker-negative cells (KSL cells) expanded approximately 25 times; however, when they were co-cultured in normal serum for 7 days, the KSL cells expanded approximately 1.3 times. Direct contact between the whole bone marrow cells and MS-5 cells was essential for expansion of KSL cells in the co-culture, and it upregulated the expression of some cytokines in MS-5. Above all, the day 3 serum specifically upregulated the expression of SCF, SDF-1 alpha, G-CSF, IL-11 and IL-6 in MS-5. The level of testosterone in the day 3 serum was higher than normal serum and the addition of the testosterone in the culture expanded the KSL cells among whole bone marrow cells on MS-5 cells and also upregulated the expression of SDF-1 alpha, IL-11 and IL-6 in MS-5. These data indicates that the serum of bone marrow-transplanted mice contains a factor(s) that induced changes in the expression levels of various cytokines in MS-5 stromal cells and enabled the MS-5 cells to expand the KSL cells among whole bone marrow cells.

Establishment of a sticky, large, oval-shaped thrombocyte cell line from tree frog as an ancestor of mammalian megakaryocytes

“…The method for generating an LTBMC (Allen and Dexter 1982 ; Whitlock and Witte 1982 ) was also useful for the establishment of a hematopoietic cell line in amphibians. Seasonal changes in gonadal steroids have been reported in bullfrogs (Licht et al 1983 ), and testosterone has also been reported to be effective for the maintenance of murine stem cells because it induces the expression of certain cytokines in stromal cells (Nakayama et al 2006 ); therefore, testosterone was used in the LTBMC instead of hydrocortisone. The appearance of the frog LTBMC was almost the same as that of murine LTBMC (Fig.…”

Near-maximal expansions of hematopoietic stem cells in culture using NUP98-HOX fusions

“…For example, the low absolute numbers of HSCs in most cord blood samples [3] [4] restrict the clinical utility of these products. A method for significantly expanding HSCs could not only address these insufficiencies but also broaden the exploitation of reduced conditioning regimens and associated therapeutic benefits.One approach that has allowed some HSC expansion in vitro to be achieved has focused on the identification of optimized combinations and concentrations of externally acting growth factors and related molecules [5][6][7][8][9][10][11][12]. A complementary approach has been to identify intrinsic regulators such as transcription factors [13] and key mediators of signaling pathways [14,15] that can be manipulated to activate or promote HSC self-renewal divisions.…”

Inhibition of CSF-1R and IL-6R prevents conversion of cDC2s into immune incompetent tumor-induced DC3s boosting DC-driven therapy potential

“… 2 It would be interesting to see if DC3s can be obtained from CD34 + HPSCs upon IL-6 and M-CSF exposure, as was demonstrated for GM-CSF. 6 The MS5 cells utilized in the GMDP co-cultures have been reported to produce IL-6 and M-CSF in other studies 40 , 41 ; however, whether IL-6 and M-CSF are involved in GMDP-derived DC3s remains to be elucidated.…”