- Research article
- Open Access
Production of hemo- and immunoregulatory cytokines by erythroblast antigen+ and glycophorin A+ cells from human bone marrow
© Sennikov et al; licensee BioMed Central Ltd. 2004
- Received: 27 May 2004
- Accepted: 18 October 2004
- Published: 18 October 2004
Erythroid nuclear cells (ENC) of the bone marrow (BM) have not previously been considered as important producers of wide spectrum of haemo- and immunoregulatory cytokines. The aim of the current work was to confirm the production of the main hemo- and immunoregulatory cytokines in human ENC from BM.
We used native human BM ENC in our experiments. We for the first time have shown, that the unstimulated erythroblasts (Gl A+ or AG-EB+) produced a wide spectrum of immunoregulatory cytokines. Human BM ENC produce cytokines such as interleukn (IL)-1β, IL-2, IL-4, IL-6, interferon (IFN)-γ, transforming growth factor (TGF)-β1, tumor necrosis factor (TNF)-α and IL-10. They can be sub-divided into glycophorin A positive (Gl A+) and erythroblast antigen positive (AG-EB+) cells. To study potential differences in cytokine expression between these subsets, ENC were isolated and purified using specific antibodies to Gl A and AG-EB and the separated cells were cultivated for 24 hours. The cytokine contents of the supernatant were measured by electrochemiluminescence immunoassay. Quantitative differences in TGF-β1 and TNF-α production were found between Gl A+ and AG-EB+ BM ENC. Furthermore, in vitro addition of erythropoietin (EPO) reduced IFN-γ and IL-2 production specifically by the AG-EB+ ENC. Thus, Gl A+ and AG-EB+ ENC produce IL-1β, IL-2, IL-4, IL-6, IFN-γ, TGF-β1 and TNF-α. Gl A+ ENC also produce IL-10.
Cytokine production by erythroid nuclear cells suggests that these cells might be involved in regulating the proliferation and differentiation of hematopoietic and immunocompetent cells in human BM.
- Bone Marrow
- Human Bone Marrow
- Erythroid Cell
- Erythroid Precursor
- Immunoregulatory Cytokine
Haematopoesis is regulated by lymphoid and non-lymphoid cells through a complex network of paracrine and autocrine mechanisms involving cytokines, growth factors and their receptors. However, although stromal [1–6], endothelial [7–10], megakaryocytic [11, 12] and osteogenic cells [13–16] and lymphocytes are known to express cytokines, erythroid nuclear cells (ENC), the major cell population of the BM, are not considered as important producers of hemo- and immunoregulatory cytokines.
Experiments on ENC isolated from mouse spleen undergoing erythroid hyperplasia, and on cells separated from single erythroid colonies, have revealed that mRNAs for cytokines such as IL-1α, IL-1β, IL-4, IL-6, granulocyte-macrophage colony stimulating factor (GM-CSF), TGF-β1 and IFN-γ are present [17, 18]. Production of GM-CSF and IFN-γ has also been reported . Similarly, IL-2 and IL-3 mRNAs were found after erythroid cells were treated with erythropoietin (EPO) [17–20]. Human fetal liver erythroid cells have also been shown to produce such cytokines as IL-1, IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ and TGF-β1 . Stopka and co-authors have demonstrated the ability of burst-forming unit erythroid cells (BFU-E) to express and produce EPO . Also it has been shown that erythroid cells express and produce vascular-endothelial growth factor (VEGF)-A and placental growth factor (PlGF) both in vitro and in vivo. Production of these proteins varies during differentiation and is increased 100-fold by PlGF and 3-fold by VEGF-A . Macrophage colony stimulating factor (M-CSF), fibroblast growth factor (FGF)-2, VEGF-A, hepatocyte (H)GF, insulin-like (I)GF-1, IL-1β, trombopoietin (TPO), TNF-α, IFN-γ, FAS-L, and macrophage inflammatory protein (MIP)-1α mRNAs are also expressed in BFU-E isolated from BM, and VEGF-A and TGF-β1 are produced [23, 24]. All these data allow us to consider erythroid cells as cytokine producers involved in regulating hemo- and immunopoiesis.
Expression of AG-EB and Gl A during erythroid maturation. The percentage of positive cells detected by flow cytometric analysis [25, 26, 27].
% of positive cells
Proerythroblasts → erythroblasts
0 – 4
0 – 4
Increase with maturation
In this article we show which human BM ENC produce the cytokines IL-1β, IL-2, IL-4, IL-6, IFN-γ, TGF-β1, TNF-α and IL-10.
Concentration of cytokines in conditioned medium derived from erythroid cells. Concentration of cytokines (pg/ml) in conditioned medium derived from enriched population of BM erythroid cells (1 × 106/ml) and erythroid cells isolated from erythroid colonies (1 × 106/ml). Results were obtained from at least three independent experiments (Mean ± SEM).
Enriched erythroid nuclear cell population
Erythroid nuclear cells derived from erythroid colonies
78.64 ± 44.84
10.8 ± 0.39
255.36 ± 88
237.73 ± 237.73
62.66 ± 45.28
738.26 ± 640.15
741.08 ± 395.95
324 ± 56.14
121.26 ± 53.22
73.4 ± 73.4
2.59 ± 1.41
766.35 ± 319.45
752.88 ± 492.65
524.88 ± 372.59
479.25 ± 267.75
We have shown that the native BM ENC can produce a wide spectrum of cytokines, which are capable of both stimulating and inhibiting erythropoiesis. Cytokine production has been confirmed using ENC isolated from erythroid colonies cloned from a single BM cell.
TGF-β1 is known to inhibit the proliferation of erythroid precursors and to provoke or accelerate the terminal differentiation of mature erythroid cells [31–33]. The fetal AG-EB+ and Gl A+ erythroid cells produced TGF-β1 in concentrations less than 5 pg/ml and we suggested that this could be related to the increased proliferative activity of erythroid cells in the fetal liver . We propose that the high level of TGF-β1 production by BM erythroid cells is probably related to the need to restrain erythroid cell proliferation in healthy adult individuals. This hypothesis were declared also in review .
It is notable that BM erythroid cells produce not only inhibitors but also high levels of stimulators of erythropoiesis such as IL-4 and IL-6, especially in the presence of EPO [34, 35]. The production of these hemoregulatory molecules suggests that erythroid cells have a capacity for self-regulation. Interestingly, IL-2, which inhibits erythropoiesis , is produced by these cells in smaller quantities or, like IL-10, is not produced at all.
Besides the differences in production of some cytokines by BM erythroid cells, there are parallels with cytokine production from fetal erythroid cells. A similar situation can be observed when TNF-α production by BM erythroid cells is compared with those from fetal liver . In both cases AG-EB+ cells produce significantly less TNF-α than Gl A+ (figure 1). TNF-α is a known inhibitor of precursor cell proliferation and an inducer of cell death in a proportion of these cells [37, 38]. Therefore it is plausible that erythroid cells use this cytokine for autocrine self-regulation, by maintaining a negative feedback loop. If this is so, then relatively small increases in the number of more differentiated Gl A+ cells would lead to a decreased precursor proliferation rate, due to the elevated level of TNF-α. Negative feedback can also be maintained through IFN-γ, which is produced at the same level by both Gl A+ and AG-EB+ cells. However, IFN-γ initiates apoptosis only in BFU-E [39, 40], while in CFU-E cells it increases the expression of Bcl-x and protects these cells from elimination. Thus, IFN-γ enhances the differentiation of erythroid precursors [41, 42]. We found no statistical significant differences between AG-EB+ and Gl A+ cells in the production of IL-1β, IL-2, IL-4, IL-6 and IL-10.
The capacity of erythroid cells to change their cytokine expression profiles quantitatively and qualitatively under different conditions is an important indicator of their active role in the regulation of hemo- and immunopoiesis. Similar data were previously obtained in mouse cells and are presented here for human BM erythroid cells. Treatment with EPO leads to significant changes in IL-2 and IFN-γ production. Notably, IFN-γ and IL-2 secretion by AG-EB+ cells is lowered in the presence of EPO, while Gl A+ cells show no such change. This difference could be related to EPO-R expression in AG-EB+ cells, which are mainly CFU-E and erythroblasts [43–45]. Expression of this receptor ceases in more differentiated early erythroblasts. Indeed, Gl A+ cells do not express EPO-R, since late erythroblasts and more differentiated forms of erythroid cells are prevalent in this population [28, 43, 46]. The EPO-induced changes in cytokine production mainly concern inhibitors of erythroid precursor proliferation, such as IL-2 and IFN-γ. Thus, one mechanism by which erythroid cell proliferation is stimulated could be a decrease in proliferation inhibitor production by these cells as a result of EPO treatment.
Erythroid nuclear cells appear to be active producers of hemo- and immunoregulatory cytokines, involved in regulating the proliferation and differentiation of hematopoietic and immunocompetent cells in human BM. Changes in the cytokines produced by erythroid cells in response to EPO suggests the ability of these cells to respond to microenvironmental changes by altering the cytokine production profile.
This work was approved by the local ethics committee. After obtaining informed consent, sternum BM samples were collected from 8 normal healthy volunteers. All samples used in this study exhibited normal myelograms. The enriched population of erythroid cells was isolated from BM mononuclear cells by depleting of adherent cells and granulocytes as described previously .
Isolation of erythroid cell population carrying a surface erythroid antigen and Glycophorin A
We used indirect panning to obtain cells expressing either the erythroid antigen (AG-EB) or Glycophorin A (Gl A) . Monoclonal mouse anti-red blood cell Glycophorin A (MAS518, Harlan-Sera Lab, England), and monoclonal HAE-9 antibodies against AG-EB (kindly provided by Prof. Mechetner, Russia) were used . Affinity isolated polyclonal rabbit anti-mouse immunoglobulin (Biosan, Russia) was used as a secondary reagent to coat Petri dishes during the panning procedure. To avoid non-specific binding to FcRs, cells were blocked with aggregated normal human IgG and then incubated with anti-Gl A or HAE-9 antibodies for 50 min at 4°C. Cells were transferred to Petri dishes covered with rabbit anti-mouse antibodies for panning for 50 min at 4°C. Subsequently, immobilised cells were collected, cultivated for 24 h in RPMI-1640 with 10% horse serum (Sigma, USA) with and without EPO [19, 47]. Samples were collected after cultivation.
Cultivation of erythroid cells with EPO
1 × 106 cells were placed in culture medium containing 2 U/ml Epo (Boehringer Mannheim, Germany) for a 24-h incubation.
Cells from the enriched erythroid population were maintained as described above [19, 20] at 2·105/ml and then cultivated in MethoCult H4433 medium (Stemcell Tech. Inc. Vancouver, B.C.) for 14 days. Colonies were visually characterised as CFU-E using an inverted microscope. After cultivation, the colonies were harvested and washed twice to remove methyl cellulose. The resulting cellular suspension (1 × 106/ml) was cultivated for 24 h in RPMI-1640 with 10% horse serum, then supernatants were collected. Samples were stored at -20°C.
Cell purity was assessed using Nocht-Maksimov staining of smears  and staining of haemoglobin with benzidin . All cells (Gl A+, AG-EB+ and CFU-E cells) were characterised as erythroblasts and were haemoglobin positive.
Electrochemiluminescence (ECL) method for quantitative determination of cytokines
Quantitative determination of cytokines was performed by the electrochemiluminescent immunoassay [50–52] using an ORIGEN Analyzer (IGEN Inc., USA) according to the manufacturer's protocol. Calibration curves ranged from 10 to 10,000 pg/ml. Assay sensitivity was 2.8 pg/ml, 2 pg/ml, 2 pg/ml and 6 pg/ml for IL-1β, IL-2, IL-4 and IL-6, respectively. Assay sensitivities were 2 pg/ml, 1 pg/ml, 1 pg/ml and 2 pg/ml for IL-10, TNF-α, IFN-γ, and TGF-β1, respectively. The ruthenylated and biotinylated antibodies were diluted to working concentrations (μg/ml) 1:1, 1:1, 1:2 and 2:1 for IL-1β, IL-2, IL-4 and IL-6, respectively. The biotinylated and ruthenylated antibodies were diluted to working concentrations (μg/ml) 2:2, 1:1, 2:1 and 4:2 for IL-10, TNF-α, IFN-γ and TGF-β1, respectively.
For TGF-β1 detection, samples were treated with HCl to obtain intact and easily detectable proteins as described .
All polyclonal and monoclonal antibodies were purchased from R&D Systems (Abington, UK). The following antibodies were used: against recombinant IL-1β, IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, TGF-β1 polyclonal and monoclonal: anti-hIL-1β #AB-201-NA, anti-hIL-1β #MAB201, anti-hIL-2 #AB-202-NA, anti-hIL-2 #MAB202, anti-hIL-4 #AB-204-NA, anti-hIL-4 #MAB204, anti-hIL-6 #AB-206-NA, anti-hIL-6 #MAB206, anti-hIL-10 #AB-217-NA, anti-hIL-10 #MAB217, anti-hTNF-α #AB-210-NA, anti-hTNF-α #MAB210, anti-hIFN-γ #AB-285-NA, anti-hIFN-γ #MAB285, anti-hTGF-β1 #AF-101-NA, anti-hTGF-β1 #MAB240. No antibody used displayed cross-reactivity with other cytokines.
Recombinant cytokines were purchased from R&D Systems (Abington, UK): rhIL-1β #201-IL, rhIL-2 #202-IL, rhIL-4 #204-IL, rhIL-6 #206-IL, rhTNF-α #210-TA, rhIFN-γ #285-IF, rhTGF-β1 #240-B-002; and PeproTech, Inc. (Rocky Hill, NJ): rhIL-10 #200-10 was used for calibration curves. All the recombinant cytokines were diluted to 2 μg/ml in PBS, pH 7.4, supplemented with 0.05% NaN3 and 0.1% BSA (aliquots were kept at -70°C before use).
Results are presented as means ± SEM. Statistical significance was determined using the nonparametric Mann-Whitney U-test. P < 0.05 was considered to be significant.
We thank IGEN Inc. for the equipment and reagents provided that made our research possible.
The authors express gratitude to regional public fund "Sodeystvie otechestvennoy medicine" for support in realisation of researches.
- Watari K, Ozawa K, Tajika K, Tojo A, Tani K, Kamachi S, Harigaya K, Takahashi T, Sekiguchi S, Nagata S: Production of human granulocyte colony stimulating factor by various kinds of stromal cells in vitro detected by enzyme immunoassay and in situ hybridization. Stem cells. 1994, 12: 416-423.View ArticlePubMedGoogle Scholar
- Sensebe L, Deschaseaux M, Li J, Herve P, Charbord P: The broad spectrum of cytokine gene expression by myoid cells from the human marrow microenvironment. Stem Cells. 1997, 15: 133-143.View ArticlePubMedGoogle Scholar
- Rougier F, Cornu E, Praloran V, Denizot Y: IL-6 and IL-8 production by human bone marrow stromal cells. Cytokine. 1998, 10: 93-97. 10.1006/cyto.1997.0262.View ArticlePubMedGoogle Scholar
- Barton BE, Murphy TF: Constitutive expression of IL-6-LIKE cytokines in normal bone marrow: implications for pathophysiology of myeloma. Cytokine. 2000, 12: 1537-1545. 10.1006/cyto.2000.0748.View ArticlePubMedGoogle Scholar
- Denizot Y, Besse A, Raher S, Nachat R, Trimoreau F, Praloran V, Godard A: Interleukin-4 (IL-4), but not IL-10, regulates the synthesis of IL-6, IL-8 and leukemia inhibitory factor by human bone marrow stromal cells. Biohim Biophys Act. 1999, 1449 (1): 83-92. 10.1016/S0167-4889(98)00177-3.View ArticleGoogle Scholar
- Denizot Y, Raher S, Trimoreau F, Praloran V, Godard A: Effect of cytokines and lipid mediators on the synthesis of interlukine 1 beta by human bone marrow stromal cells. Cytokine. 2000, 12: 499-502. 10.1006/cyto.1999.0578.View ArticlePubMedGoogle Scholar
- Davis TA, Black AT, Kidwell WR, Lee KP: Conditioned medium from primary porcine endothelial cells alone promotes the growth of primitive human haematopoietic progenitor cells with a high replating potential: evidence for a novel early haematopoietic activity. Cytokine. 1997, 9: 263-275. 10.1006/cyto.1996.0163.View ArticlePubMedGoogle Scholar
- Davis TA, Robinson DH, Lee KP, Kessler SW: Porcine brain microvascular endothelial cells support the in vitro expansion of human primitive hematopoietic bone marrow progenitor cells with a high replating potential: requirement for cell-to-cell interactions and colony-stimulating factors. Blood. 1995, 85: 1751-1761.PubMedGoogle Scholar
- Candal FJ, Rafii S, Parker JT, Ades EW, Ferris B, Nachman RL, Kellar KL: BMEC-1: a human bone marrow microvascular endothelial cell line with primary cell characteristics. Microvasc Res. 1996, 52: 221-234. 10.1006/mvre.1996.0060.View ArticlePubMedGoogle Scholar
- Li WM, Huang WQ, Huang YH, Jiang DZ, Wang QR: Positive and negative haematopoietic cytokines produced by bone marrow endothelial cells. Cytokine. 2000, 12: 1017-1023. 10.1006/cyto.1999.0678.View ArticlePubMedGoogle Scholar
- Jiang S, Levine JD, Fu Y, Deng B, London R, Groopman JE, Avraham H: Cytokine production by primary bone marrow megakaryocytes. Blood. 1994, 84: 4151-4156.PubMedGoogle Scholar
- Wickenhauser C, Hillienhof A, Jungheim K, Lorenzen J, Ruskowski H, Hansmann ML, Thiele J, Fischer R: Detection and quantification of transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF) release by normal human megakaryocytes. Leukemia. 1995, 9: 310-315.PubMedGoogle Scholar
- Birch MA, Ginty AF, Walsh CA, Fraser WD, Gallagher JA, Bilbe G: PCR detection of cytokines in normal human and pagetic osteoblast-like cells. J Bone Miner Res. 1993, 8: 1155-1162.View ArticlePubMedGoogle Scholar
- Dodds RA, Merry K, Littlewood A, Gowen M: Expression of mRNA for IL1 beta, IL6 and TGF beta 1 in developing human bone and cartilag. J Histochem Cytochem. 1994, 42: 733-744.View ArticlePubMedGoogle Scholar
- Taichman RS, Emerson SG: The role of osteoblasts in the hematopoietic microenviroment. Stem Cells. 1998, 16: 7-15.View ArticlePubMedGoogle Scholar
- Taichman RS, Reilly MJ, Verma RS, Emerson SG: Augmented production of interleukin-6 by normal human osteoblasts in response to CD34+ hematopoietic bone marrow cells in vitro. Blood. 1997, 89: 1165-1172.PubMedGoogle Scholar
- Sennikov SV, Eremina LV, Injelevskaya TV, Krysov SV, Silkov AN, Kozlov VA: Cytokine-Synthesizing Activity of Erythroid Cells. Russ J Immunol. 2001, 6: 193-202.PubMedGoogle Scholar
- Sennikov SV, Eremina LV, Samarin DM, Avdeev IV, Kozlov VA: Cytokine gene expression in erythroid cells. Eur Cytokine Netw. 1996, 7: 771-774.PubMedGoogle Scholar
- Sennikov SV, Krysov SV, Injelevskaya TV, Silkov AN, Kozlov VA: Production of cytokines by immature erythroid cells derived from human embryonic liver. Eur Cytokine Netw. 2001, 12: 274-279.PubMedGoogle Scholar
- Sennikov SV, Krysov SV, Silkov AN, Injelevskaya TV, Kozlov VA: Production of IL-10, TNF-alfa, IFN-gamma, TGF-beta1 by different populations of erythroid cells derived from human embryonal liver. Cytokine. 2002, 17: 221-225. 10.1006/cyto.2001.0975.View ArticlePubMedGoogle Scholar
- Stopka T, Zivny JH, Stopkova P, Prchal JE, Prchal JT: Human Hematopoietic Progenitors Express Erythropoietin. Blood. 1998, 91: 3766-3772.PubMedGoogle Scholar
- Tordjman R, Delaire S, Plouet J, Ting S, Gaulard P, Fichelson S, Romeo PH, Lemarchandel V: Erythroblasts are a source of angiogenic factors. Blood. 2001, 97: 1968-1974. 10.1182/blood.V97.7.1968.View ArticlePubMedGoogle Scholar
- Majka M, Janowska-Wieczorek A, Ratajczak J, Ehrenman K, Pietrzkowski Z, Kowalska MA, Gewirtz AM, Emerson SG, Ratajczak MZ: Numerous growth factors, cytokines, and chemokines are secreted by human CD34(+) cells, myeloblasts, erythroblasts, and megakaryoblasts and regulate normal hematopoiesis in an autocrine/paracrine manner. Blood. 2001, 97: 3075-85. 10.1182/blood.V97.10.3075.View ArticlePubMedGoogle Scholar
- Janowska-Wieczorek A, Majka M, Ratajczak J, Ratajczak MZ: Autocrine/paracrine mechanisms in human hematopoiesis. Stem Cells. 2001, 19: 99-107. 10.1634/stemcells.19-2-99.View ArticlePubMedGoogle Scholar
- Mechetner EB, Tonevitsky AG, Ievleva ES, Rozinova EN, Popova ON: Identification of a human erythroid cell surface antigen by monoclonal antibody HAE9. Exp Hematol. 1987, 15: 355-359.PubMedGoogle Scholar
- Edwards PA: Monoclonal antibodies that bind to the human erythrocyte-membrane glycoproteins glycophorin A and Band 3. Biochem Soc Trans. 1980, 8: 334-335.View ArticlePubMedGoogle Scholar
- Robinson J, Sieff C, Delia D, Edwards PA, Greaves M: Expression of cell-surface HLA-DR, HLA-ABC and glycophorin during erythroid differentiation. Nature. 1981, 289: 68-71.View ArticlePubMedGoogle Scholar
- Lacombe C: Erythropoietin: from molecular biology to clinical use. Eur Cytokine Netw. 1997, 8: 308-310.PubMedGoogle Scholar
- Papayannopoulou T, Finch CA: On the in vivo action of erythropoietin: a quantitative analysis. J Clin Invest. 1972, 51: 1179-1185.PubMed CentralView ArticlePubMedGoogle Scholar
- Moritz KM, Lim GB, Wintour EM: Developmental regulation of erythropoietin and erythropoiesis. Am J Physiol. 1997, 273R (6 pt 2): 1829-1844.Google Scholar
- Ohta M, Greenberger JS, Anklesaria P, Bassols A, Massague J: Two forms of transforming growth factor-beta distinguished by multipotential haematopoietic progenitor cells. Nature. 1987, 329: 539-541. 10.1038/329539a0.View ArticlePubMedGoogle Scholar
- Zermati Y, Fichelson S, Valensi F, Freyssinier JM, Rouyer-Fessard P, Cramer E, Guichard J, Varet B, Hermine O: Transforming growth factor inhibits erythropoiesis by blocking proliferation and accelerating differentiation of erythroid progenitors. Exp Hematol. 2000, 28: 885-894. 10.1016/S0301-472X(00)00488-4.View ArticlePubMedGoogle Scholar
- Krystal G, Lam V, Dragowska W, Takahashi C, Appel J, Gontier A, Jenkins A, Lam H, Quon L, Lansdorp P: Transforming growth factor beta 1 is an inducer of erythroid differentiation. J Exp Med. 1994, 180: 851-860. 10.1084/jem.180.3.851.View ArticlePubMedGoogle Scholar
- Ikebuchi K, Ihle JN, Hirai Y, Wong GG, Clark SC, Ogawa M: Synergistic factors for stem cell proliferation: further studies of the target stem cells and the mechanism of stimulation by interleukin-1, interleukin-6, and granulocyte colony-stimulating factor. Blood. 1988, 72: 2007-2014.PubMedGoogle Scholar
- Rennick D, Yang G, Muller-Sieburg C, Smith C, Arai N, Takabe Y, Gemmell L: Interleukin 4 (B-cell stimulatory factor 1) can enhance or antagonize the factor-dependent growth of hemopoietic progenitor cells. Proc Natl Acad Sci U S A. 1987, 84: 6889-6893.PubMed CentralView ArticlePubMedGoogle Scholar
- Burdach S, Levitt L: T cell regulated hematopoiesis--molecular interactions in hematopoietic control by CD2 and interleukin 2. Behring Inst Mitt. 1988, 83: 56-67.PubMedGoogle Scholar
- Allen DA, Breen C, Yaqoob MM, Macdougall IC: Inhibition of CFU-E colony formation in uremic patients with inflammatory disease: role of IFN-gamma and TNF-alpha. J Investig Med. 1999, 47: 204-211.PubMedGoogle Scholar
- Otsuki T, Nagakura S, Wang J, Bloom M, Grompe M, Liu JM: Tumor necrosis factor-alpha and CD95 ligation suppress erythropoiesis in Fanconi anemia C gene knockout mice. J Cell Physiol. 1999, 179: 79-86. 10.1002/(SICI)1097-4652(199904)179:1<79::AID-JCP10>3.0.CO;2-O.View ArticlePubMedGoogle Scholar
- Dai CH, Price JO, Brunner T, Krantz SB: Fas ligand is in human erythroid colony-forming cells and interacts with Fas induced by interferon-gamma to produce erythroid cell apoptosis. Blood. 1998, 91: 1235-1242.PubMedGoogle Scholar
- De Maria R, Testa U, Luchetti L, Zeuner A, Stassi G, Pelosi E, Riccioni R, Felli N, Samoggia P, Peschle C: Apoptotic role of Fas/Fas ligand system in the regulation of erythropoiesis. Blood. 1999, 93: 796-803.PubMedGoogle Scholar
- Barcena A, Park SW, Banapour B, Muench MO, Mechetner E: Expression of Fas/CD95 and Bcl-2 by primitive hematopoietic progenitors freshly isolated from human fetal liver. Blood. 1996, 88: 2013-2025.PubMedGoogle Scholar
- Choi I, Muta K, Wickrema A, Krantz SB, Nishimura J, Nawata H: Interferon gamma delays apoptosis of mature erythroid progenitor cells in the absence of erythropoietin. Blood. 2000, 95: 3742-3749.PubMedGoogle Scholar
- Broudy VC, Lin N, Brice M, Nakamoto B, Papayannopoulou T: Erythropoietin receptor characteristics on primary human erythroid cells. Blood. 1991, 77: 2583-2590.PubMedGoogle Scholar
- Wu H, Klingmuller U, Acurio A, Hsiao JG, Lodish HF: Functional interaction of erythropoietin and stem cell factor receptors is essential for erythroid colony formation. Proc Natl Acad Sci U S A. 1997, 94: 1806-1810. 10.1073/pnas.94.5.1806.PubMed CentralView ArticlePubMedGoogle Scholar
- Liboi E, Carroll M, D'Andrea AD, Mahtey-Prevot B: Erythropoietin receptor signals both proliferation and erythroid-specific differentiation. Proc Natl Acad Sci USA. 1993, 90: 11351-11355.PubMed CentralView ArticlePubMedGoogle Scholar
- Wickrema A, Krantz SB, Winkelmann JC, Bondurant MC: Differentiation and erythropoietin receptor gene expression in human erythroid progenitor cells. Blood. 1992, 80: 1940-1949.PubMedGoogle Scholar
- Peschle C, Marone G, Genovese A, Cillo C, Magli C, Condorelli M: Erythropoietin production by the liver in fetal-neonatal life. Life Sci. 1975, 17: 1325-1130. 10.1016/0024-3205(75)90146-0.View ArticlePubMedGoogle Scholar
- Woronzoff-Dashkoff KP: The Ehrlich-Chenzinsky-Plehn-Malachowski-Romanowsky-Nocht-Jenner-May-Grunwald-Leishman-Reuter-Wright-Giemsa-Lillie-Roe-Wilcox stain. The mystery unfolds. Clin Lab Med. 1993, 13: 759-771.PubMedGoogle Scholar
- Khayat MC, Laforet F, Bureau F, Thomas M, Drosdowsky M: Plasma hemoglobin. Comparison between 2 methods of determination. Pathol Biol (Paris). 1989, 37: 236-240. FrenchGoogle Scholar
- Obenauer-Kutner LJ, Jacobs SJ, Kolz K, Tobias LM, Bordens RW: A highly sensitive electrochemiluminescence immunoassay for interferon alfa-2b in human serum. J Immunol Methods. 1997, 206: 25-33. 10.1016/S0022-1759(97)00081-1.View ArticlePubMedGoogle Scholar
- Deaver DR: A new non-isotopic detection system for immunoassays. Nature. 1995, 377: 758-760. 10.1038/377758a0.View ArticlePubMedGoogle Scholar
- Sennikov SV, Krysov SV, Injelevskaya TV, Silkov AN, Grishina LV, Kozlov VA: Quantitative analysis of human immunoregulatory cytokines by electrochemiluminescence method. J Immunol Methods. 2003, 275: 81-88. 10.1016/S0022-1759(03)00007-3.View ArticlePubMedGoogle Scholar
- Su HC, Ishikawa R, Biron CA: Trasforming growth factor-beta expression and natural killer cell responses during virus infection of normal, nude, and SCID mice. J Immunol. 1993, 151: 4874-4890.PubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.