小鼠骨髓 内皮细胞无血清条件培养液及其超滤组分对粒巨噬系祖细胞？…

本研究通过传代培养小鼠骨髓内皮细胞系细胞,惧无血清条件培养液（ｍＢＭＥＣ－ＣＭ）,将其作多级串联超滤,获得分子量大于１０、３￣１０、１￣３、０．５￣１ｋＤ和小于０．５ｋＤ超滤组分。进行粒巨噬系造血祖细胞集落形成试验。检测了它们的ｍＢＭＥＣ－ＣＭ和３￣１０组分对粒巨噬系祖细胞（ＣＦＵ－ＧＭ）生长未见明显影响,而分子量大于１０ｋＤ和０．５￣１ｋＤ组分促进ＣＦＵ－ＧＭ的增殖,分子量１￣３ｋＤ和小于０．５     

骨髓内皮细胞产物对CFU-F、CFU-GM和WEHI-3细胞生长的作用

为了研究骨髓内皮细胞的造血调控功能,采用串联超波技术脞小鼠骨髓内皮细胞无血清条件培养液（ｍＢＭＥＣ－ＣＭ）中制血出不同相对分子质量（Ｍｇｔ）范围的超滤组分,进行细胞集落形成实难,检测了ｍＢＭＥＣ－ＣＭ及其超滤组分对骨髓成纤维祖细胞（ＣＦＵ－Ｆ）、粒巨噬系造血祖细胞（ＣＦＵ－ＧＭ）和小鼠业单系白现细胞系ＷＥＨＩ－３细胞生长的作用。结果显示：ｍＢＭＥＣ－ＣＭ抑制ＣＦＵ－Ｆ的生长,对ＣＦＵ－ＧＭ和ＷＥＨ     

锂对小鼠高增殖潜能集落形成细胞和粒巨噬系祖细胞体外增殖的影响

本文观察了锂对ＢＡＬＢ／Ｃ小鼠骨髓高增殖潜能集落形成细胞（ＨＰＰ－ＣＦＣ）和粒巨噬系祖细胞ＣＦＵ－ＧＭ体外增殖的影响。ＨＰＰ－ＣＦＣ集落由ＩＬ－１、ＩＬ－６、ＷＥＨＩ３条件培养液（ＷＥＨＩ３－ＣＭ,含有ＩＬ－３）及Ｌ９２９条件培养液（Ｌ９２９－ＣＭ,含有Ｍ－ＣＳＦ）所支持,而ＣＦＵ－ＧＭ由ＷＥＨＩ３－ＣＭ所支持。结果显示,ＬｉＣｌ浓度在０．４－２ｍｍｏｌ／Ｌ时呈现剂量依赖性抑制ＨＰＰ－ＣＦＣ增殖;而在０．４－１ｍｍｏｌ／Ｌ的浓度范围内,则对ＣＦＵ－ＧＭ的增殖起剂量依赖性促进作用。这些结果提示ＬｉＣｌ对ＨＰＰ－ＣＦＣ和ＣＦＵ－ＧＭ的作用不同,可能锂有诱导ＨＰＰ－ＣＦＣ向成熟细胞分化的作用     

脐带血清在骨髓造血祖细胞培养中的效应

目的：探讨人脐带清（ＣＢＳ）在骨髓造血祖细胞培养中的效应。方法：用人骨髓细胞进行ＣＦＵ、ＧＭ、ＶＦＵ－Ｅ、ＢＦＵ－Ｅ、ＣＦＵ－ＧＥＭＭ培养。结果：ＣＢＳ能直接刺激骨髓细胞ＣＥＵ－ＧＭ的形成。与血型相同害无关。四人份以上的混合ＣＢＳ（ＭＣＢＳ）,刺激活性高且稳定。１０％ＭＣＢＳ相当于６５．６μｇ／Ｌ ＧＭ－ＣＳＦ、０．２３、０．３、０。．４６ｋＵ／Ｌ ＥｐＯ对ＣＦＵ－ＧＭ、ＣＦＵ－Ｅ、ＢＦＵ－Ｅ、Ｃ     

锂对小鼠高增殖潜能集落形成细胞和粒巨噬系祖细胞体外增殖…

本文观察了锂对ＢＡＬＢ／Ｃ小鼠骨髓高增殖潜能集落形成细胞和粒巨噬系祖细胞ＣＦＵ－ＧＭ体外增殖的影响。ＨＰＰ－ＣＦＣ集落由ＩＬ－１,ＩＬ－６,ＷＥＨＩ３条件培养液及Ｌ９２９条件培养液所支持,而ＣＦＵ－ＧＭ由ＷＥＨＩ３－ＣＭ所支持。结果显示,ＬｉＣｌ浓度在０．４－２ｍｍｏｌ／Ｌ时呈现剂量依赖性抑制ＨＰＰ－ＣＦＣ增殖;而在０．４－１ｍｍｏｌ／Ｌ的浓度范围内,则对ＣＦＵ－ＧＭ的增殖起剂量依赖性促进作用。     

脑肿瘤抑制因子的功能研究

本文证明了胎脑组织中存在一类可以抑制人白血病细胞系的生长的低分子天然抑癌物．这种抑瘤物抑制活性分布在小于１０ｋＤａ组分,经Ｓｅｐｈａｄｅｘ－Ｇ２５凝胶过滤可分离为单一组分,且具有广谱的抗肿瘤效应．体外可抑制人白血病、肝癌、胃癌细胞系和小鼠粒、单核和淋巴系白血病细胞,而对人骨髓ＣＦＵ－ＧＭ和小鼠骨髓ＣＦＵ—ＧＭ的抑制作用较弱。     

SOD对骨髓造血祖细胞在4°C条件下保存损伤的防护作用

为了探讨抗氧化剂对造血干细胞在低温条件下损伤的防护作用,将小鼠骨髓细胞置于４℃条件下保存,观察在保养液中加入不同浓度的Ｃｕ、Ｚｎ、ＳＯＤ对细胞死伤的防护效果和马血清对细胞回收率的影响。结果表明,含２０％的马血清保养液中加入ＳＯＤ１．６５Ｕ或０．１６５Ｕ／ｍｌ,保存３天,ＣＦＵ－ＧＭ、ＣＦＵ－Ｅ、ＢＦＵ－Ｅ、ＣＦＵ－Ｍｅｇ、ＣＦＵ－Ｍｉｘ的产率分别为对照组（不加ＳＯＤ）的６．２、２．６、２．９、４．０和５．１倍,明显提高了造血祖细胞的活存率,其中ＣＦＵ－ＧＭ和ＣＦＵ－Ｍｉｘ达到保存前水平。ＳＯＤ的有效作用机理不是对造血祖细胞增殖调控作用,而是防护了细胞的死亡。这可能与其清除过氧自由基的抗氧化作用有密切关系。     

低分子量硫酸葡聚糖对小鼠造血干细胞动员作用的研究

给小鼠静脉注射低分子量（＜１０￣４ｕ）硫酸葡聚糖（ＤＳ）１５ｍｇ／ｋｇ后外周血中白细胞、单个核细胞（ｍｏｎｏｎｕｃｌｅａｒｃｅｋ,ＭＮＣ）、ＣＦＵ－ＧＭ、ＢＦＵ－Ｅ和ＣＦＵ－Ｍｉｘ产率等指标出现时相性变化。给药后１ｈ开始升高,２ｈ达到高峰、分别为药前值的２．２、２．６、３．８、４．４和３．０倍,７ｈ时趋向正常。给药后２ｈ上述各类细胞在外周血中的含量随着ＤＳ的剂量增加而增加。白细胞、ＭＮＣ计数在ＤＳ１８０ｍｇ／ｋｇ时达到峰值,均为对照组的４倍。２４０ｍｇ／ｋ８时未见明显增加。不同剂量ＤＳ对各系祖细胞均有不同程度的动员作用,ＤＳ剂量１５－３０ｍｇ／ｋｇ效果最好,每升血中ＣＦＵ－ＧＭ、ＢＦＵ－Ｅ、ＣＦＵ－Ｍｉｘ的数量分别相当于对照组的５．０、１１．９和８．８倍。其峰值出现时间与白细胞、ＭＮＣ不同,表明ＤＳ对不同类型细胞的作用机制也不尽一致。经口给小鼠投以ＤＳ２４０和４８ｏｍｇ／ｋｇ后,未见外周血中白细胞、ＭＮＣ计数有显著性升高,提示对造血干细胞没有动员作用。     

骨髓高增殖潜能集落形成细胞（HPP—CFC）分化产生巨核细胞的研究

本研究用正常和５－ＦＵ处理的小鼠骨髓细胞,作血浆凝块培养,对一种称作ＨＰＰ－ｍＣＦＵ－ＭＫ的ＨＰＰ－ＣＦＣ亚型细胞集落进行体外追踪。发现ＨＰＰ－ｍＣＦＵ－ＭＫ不但能形成符合ＨＰＰ－ＣＦＣ标准的巨大集落,而且能产生大量的巨核细胞。该巨大集落的生长,依赖添加再生障碍性贫血猪血清（ＡＡＳ）或合用三种以上的基因重组造血生长因子而增强,在体外不被ＴＧＦ－β１和ＰＦ４抑制。原代培养１２天所得到的ＨＰＰ－ｍＣＦ     

小鼠胎肝基质细胞造血刺激因子体外生物活性研究

本实验对基质细胞造血刺激因子－１（ＳＨＦ－１）的体外生物活性进行了研究。结果表明,ＳＨＦ－１可刺激小鼠骨髓ＣＦＵ－Ｅ、ＢＦＵ－Ｅ、ＣＦＵ－ＧＭ、ＣＦＵ－Ｍｉｘ集落的形成,它产生的这些广泛造血刺激作用是其自身所具活性的直接影响。正常小鼠骨髓细胞与ＳＨＦ－１在体外孵育４ｈ,其中ＣＦＵ－Ｓ的自杀率可提高约１０％,显示它对造血干细胞也有诱导增殖作用。     

Positive and negative hematopoietic cytokines produced by bone marrow endothelial cells

Recently, cytokines and interleukins such as SCF, GM-CSF, G-CSF, TGF-beta, IL-6, IL-7, IL-8, IL-11 have been reported to be elaborated by endothelial cells. For further study, serum free bone marrow endothelial cell conditioned medium (BMEC-CM) was collected and ultrafiltrated by using a centriprep 10. The concentrated retentate (R-BMEC-CM) contained some substances whose molecular weight was more than 10 000 daltons. The filtrate (F-BMEC-CM) contained some substances whose molecular weight was less than 10 000 daltons. The effects of R-BMEC-CM and F-BMEC-CM on the growth of haematopoietic progenitors and the expression of cytokine and interleukin mRNAs of BMEC were investigated. The results showed that R-BMEC-CM stimulated the growth of CFU-GM, HPP-CFC, BFU-E, CFU-E, and CFU-Meg; while F-BMEC-CM inhibited the growth of these progenitors. Using the method of hybridizing to the Atlas cDNA Array, we were able to detect the presence of mRNAs of cytokines and interleukins in bone marrow endothelial cells. Our finding of the existence of mRNAs of SCF, GM-CSF, IL-6, TGF-beta, IL-1, and IL-11 in these cells was in agreement with the data reported previously. Furthermore, we detected mRNAs of MIP-2, Thymosion-beta4, PDGF, MSP-1, IFN-gamma, IL-13 and inhibin, which are related to haematopoiesis. Among these cytokines and interleukins, SCF, GM-CSF, IL-6, IL-1, and IL-11 are haematopoietic stimulators which may be responsible for the stimulative effects on the growth of haematopoietic progenitors. One of our new findings, the thymosin-beta4, is a small molecular haematopoietic inhibitor. It may be responsible for the inhibitory effect of F-BMEC-CM on haematopoietic progenitors. The presence of mRNAs of BMP, MSP-1, MIP-2, PDGF and IL-13 suggests that bone marrow endothelial cells might elaborate these substances. Their influence on haematopoietic progenitors needs further study.     

Protection of 3'-azido-3'-deoxythymidine induced toxicity to murine hematopoietic progenitors (CFU-GM, BFU-E and CFU-MEG) with interleukin-1

3'-Azido-3'-deoxythymidine (AZT) has attained wide clinical utility in the treatment of acquired immunodeficiency syndrome (AIDS). Unfortunately, associated with AZT use, is the development of severe hematopoietic toxicity as manifested by anemia, neutropenia and overall bone marrow suppression. Interleukin-1 (IL-1), a cytokine, primarily produced by activated macrophages, has been involved in the control of hematopoiesis by acting synergistically with other hematopoietic growth factors, and has been demonstrated to be an effective agent in reducing the myelosuppression associated with the therapy for malignant disease. We report here the ability of recombinant human IL-1 alpha to protect normal murine hematopoietic progenitors (CFU-GM, BFU-E, and CFU-Meg) from the toxic effects of AZT. Following the determination of the LD50 dose for each progenitor, IL-1 was added in co-culture studies (10-1000 units; 0.001-1.0 micrograms/ml protein) with adherent cell depleted marrow. Marrow progenitors expressed differences in AZT sensitivity, e.g., BFU-E, LD50 5 x 10(-9)M; CFU-Meg, LD50 10(-7) M; CFU-GM, 5 x 10(-5) M respectively. IL-1 inhibited AZT induced toxicity. The maximum IL-1 dose effect was observed for CFU-GM and CFU-Meg at 300 units, 0.3 micrograms protein; however BFU-E required a dose of 600 units, 0.6 micrograms/ml protein to reverse the effects of AZT. These results demonstrate marrow progenitors respond differently to AZT and identifies the potential efficacy of IL-1 to minimize the hematopoietic toxicity associated with AZT treatment.     

Hematopoiesis in the rat: quantitation of hematopoietic progenitors and the response to iron deficiency anemia

To determine the quantitative effects of iron deficiency on erythropoiesis and to assess the response of erythroid progenitors to sustained anemia, we developed quantitative assays for various hematopoietic progenitors in the adult, Sprague-Dawley rat including erythroid colony- and burst-forming cells (CFU-E and BFU-E), granulocyte/macrophage colony-forming cells (CFU-GM), and megakaryocytic colony-forming cells (CFU-Meg). CFU-E were cultured in methylcellulose and grew best in the presence of fetal calf serum. CFU-GM, BFU-E, and CFU-Meg grew better in normal rat plasma and required the presence of pokeweed mitogen-stimulated rat spleen cell conditioned medium. The numbers of progenitors and nucleated erythroblasts in total marrow were estimated by the ratios of radioactivity in the humerus to the total skeleton as determined by radioiron dilution. The numbers of progenitors and erythroblasts in the spleen were measured by simple dilution. Sustained anemia was brought about through chronic iron deficiency. The response to iron deficiency anemia (IDA) was monitored by the numbers of the various progenitors and their cell cycle characteristics as measured by the tritiated thymidine suicide technique. With IDA, the number of CFU-F in the body (marrow plus spleen) was increased to 3.5 times control, whereas the numbers of BFU-E and CFU-GM were unchanged. There was no difference in the percentage of CFU-E, BFU-E, and CFU-GM in DNA synthesis (68%, 19.4%, and 18.8%, respectively). With iron therapy of IDA, CFU-E numbers in marrow began to decrease by day 1 and fell in a manner reciprocal to changes in the hematocrit. Marrow and spleen erythroblasts, 1.7 times control in IDA, increased further to 3.9 times control by the fourth day after iron administration. There was no change in BFU-E or CFU-GM numbers in response to iron repletion, although the fraction of progenitors increased in the spleen. Thus, IDA does not limit the increase in CFU-E seen with anemia, but does restrict erythroid maturation. Furthermore, the increase in CFU-E and the state of chronic anemia occur without detectable changes in the number of cell cycle state of the more primitive BFU-E.     

Demonstration of a protector effect of interleukin-1 against hematologic toxicity of azidothymidine (AZT)]

3'-azido-3'-deoxythymidine (Azidothymidine or AZT) has attained wide critical utility in the treatment of acquired immunodeficiency syndrome (AIDS). Unfortunately, treatment with AZT is associated with the development of severe hematopoietic toxicity. The AZT sensitivity of marrow progenitors was different with an IC 50 of 10(-8) M and 10(-6) M for respectively BFU-E and CFU-GM/GEMM. Data reported here show that recombinant human interleukin-1 alpha (IL-1 alpha), a pleiotropic cytokine, was demonstrated to be efficient to protect normal human as well as murine hematopoietic progenitors (CFU-GM, CFU-GEMM and BFU-E) from the toxic effect of AZT. The maximal effect was observed with 30 U/ml (Human cells) or 100 U/ml (murine cells) IL-1 alpha for BFU-E and CFU-GM/GEMM, with a marked effect at 1 U/ml. The results demonstrate that marrow progenitors respond differently to AZT and point out the potential efficacy of IL-1 alpha to enhance the proliferation of hematopoietic stem cells treated with growth factors (IL-3, erythropoietin) and to minimize the hematopoietic toxicity associated with AZT treatment.     

Thy-1 is a differentiation antigen that characterizes immature murine erythroid and myeloid hematopoietic progenitors

To determine the role of Thy-1 antigen in murine hematopoietic differentiation, bone marrow was treated with anti-Thy-1.2 antibody and complement or complement alone. Growth of immature hematopoietic progenitors, erythroid burst-forming units (BFU-E), and granulocyte/macrophage colony-forming units (CFU-GM) was greatly reduced following antibody and complement treatment and was not restored by mitogen-stimulated spleen cell supernatants. In contrast, more mature erythroid and myeloid progenitors, the erythroid colony-forming unit (CFU-E) and the macrophage progenitor stimulated by L-cell-conditioned media (LCM), were spared by anti-Thy-1.2 antibody and complement treatment. Here, to separate the effects of anti-Thy-1.2 antibody treatment on accessory cells from those on progenitors, splenic T cells and thymocytes were added to treated marrow at ratios of up to 200%. Growth of BFU-E and CFU-GM was not restored. To more precisely replace required accessory cells, male complement-treated marrow was cocultured with female anti-Thy-1.2 antibody and complement-treated marrow. Even marrow cells failed to restore female BFU-E and CFU-GM growth. Fluorescent-activated cell sorting (FACS) and immune sheep red cell rosetting with anti-Thy-1.2-labeled marrow were then performed to determine if immature hematopoietic progenitors bear Thy-1.2. These techniques revealed enrichment of BFU-E and CFU-GM in the Thy-1.2-positive fraction, demonstrating the presence of Thy-1.2 on early murine hematopoietic progenitors. CFU-E and CFU-M were present in the Thy-1.2-negative fraction following FACS separation. These data demonstrate that Thy-1.2 is a differentiation antigen, present on at least some murine BFU-E and CFU-GM and lost as they mature to CFU-E and CFU-M.     

Suppression of murine hematopoiesis in vivo after chronic administration of zidovudine: evidence that zidovudine-induced anemia is the result of decreased bone marrow-derived, erythropoietin-responsive progenitor cells.

We studied the long-term effect of continued zidovudine exposure in mice on hematopoiesis, as determined by peripheral blood indices, assays of erythroid (colony-forming unit-erythroid [CFU-E] and burst-forming unit-erythroid [BFU-E]), myeloid (CFU-granulocyte-macrophage [GM]), megakaryocyte (CFU-Meg), and plasma titers of erythropoietin, granulocyte-macrophage colony-stimulating factor, megakaryocyte colony-stimulating factor, and tumor necrosis factor-alpha. Dose-escalation of zidovudine (0.1, 1.0, and 2.5 mg/ml) induced a dose-dependent decrease in hematocrit, white blood cells, and platelets. High-dose drug, i.e., greater than 1.0 mg/ml, reduced marrow CFU-E; splenic CFU-E was increased after 1 week, then declined. BFU-E was increased at Weeks 1 and 2, then declined to control levels. Splenic BFU-E rose during the examination period that was dose-dependent. Femoral CFU-GM was cyclic, i.e., low-dose drug, 0.1 mg/ml, was increased gradually, the declined; higher doses of 1.0 and 2.5 mg/ml were lower until Week 5, then were above controls. Splenic CFU-GM was increased initially at Week 2 (1.0 mg/ml), then declined; the higher dose (2.5 mg/ml) increased initially, then declined below controls (Week 6). Femoral CFU-Meg was increased after low-dose drug and inhibited after high dose (2.5 mg/ml). Splenic CFU-Meg was reduced initially, followed by an increase at Week 4. Plasma titer of erythropoietin was elevated, proportional to dose escalation of drug, and inversely proportional to the hematocrit. No difference was observed in plasma levels of granulocyte-macrophage colony-stimulating factor, megakaryocyte colony-stimulating factor, or tumor necrosis factor-alpha. This study demonstrates that zidovudine-induced anemia results from: (i) inadequate numbers of bone marrow-derived, erythropoietin-dependent hematopoietic progenitors, i.e., CFU-E; and (ii) a shift in erythropoietin-responsive progenitors from bone marrow to spleen capable of responding to obligatory growth factors.     

The effect of interleukin-17 on hematopoietic cells and cytokine release in mouse spleen

To evaluate whether the response of hematopoietic cells to interleukin-17 (IL-17) depends on the tissue microenvironment in which hematopoiesis occurs, the influence of recombinant mouse IL-17 on spleen hematopoietic cells and cytokine release was assessed in normal mice in vitro and in vivo. In vitro, IL-17 did not significantly affect the growth of granulocyte-macrophage (CFU-GM) and erythroid (BFU-E and CFU-E) derived colonies. A single injection of IL-17 in vivo exhibited stimulatory effects on hematopoietic cells from both granulocytic and erythroid lineages. The increased number of metamyelocytes 48 h after treatment imply to the IL-17-induced stimulation of granulopoiesis. The number of BFU-E was increased at 24 h, while the number of CFU-E increased 6 h and 24 h after treatment. Since the same treatment in the bone marrow decreased the number of CFU-E, it may be concluded that the local microenvironment plays an important role in IL-17-mediated effects on CFU-E. IL-17 increased the release of IL-6 both in vitro and in vivo, but showed tendency to suppress the constitutive secretion of IL-10 by spleen cells. Our results suggest the complexity of target cell response and interplay of secondary induced cytokines by IL-17 in different hematopoietic organs.     

Retrovirus-induced feline pure red cell aplasia: the kinetics of erythroid marrow failure

Cats viremic with feline leukemia virus subgroup C (FeLV-C) develop pure red cell aplasia (PRCA) characterized by the loss of detectable late erythroid progenitors (CFU-E) in marrow culture. Normal numbers of early erythroid progenitors (BFU-E) and granulocyte-macrophage progenitors (CFU-GM) remain, suggesting that the maturation of BFU-E to CFU-E is impaired in vivo. We have examined the cell cycle kinetics of BFU-E and their response to hematopoietic growth factor(s) to better characterize erythropoiesis as anemia develops. Within 3 weeks of FeLV-C infection, yet 6-42 weeks before anemia, the traction of BFU-E in DNA synthesis as determined by tritiated thymidine suicide increased to 43 +/- 4% (normal 23 +/- 2%) while there was no change in the cell cycle kinetics of CFU-GM. In additional studies, we evaluated the response of marrow to the hematopoietic growth factor(s) present in medium conditioned by FeLV-infected feline embryonic fibroblasts (FEA/FeLV CM). With cells from normal cats or cats viremic with FeLV-C but not anemic, a 4-fold increase in erythroid bursts was seen in cultures with 5% FEA/FeLV CM when compared to cultures without CM. However, just prior to the onset of anemia, when the numbers of detectable CFU-E decreased, BFU-E no longer responded to FEA/FeLV CM in vitro. BFU-E from anemic cats also required 10% cat or human serum for optimal in vitro growth. These altered kinetics and in vitro growth characteristics may relate to the in vivo block of BFU-E differentiation and PRCA. Finally, when marrow from cats with PRCA was placed in suspension culture for 2 to 4 days in the presence of cat serum and CM, the numbers of BFU-E increased 2- to 4-fold although no CFU-E were generated. By 4 to 7 days, CFU-E were detected, suggesting that conditions contributing to the block of erythroid maturation did not persist. The suspension culture technique provides an approach to study further the defect in erythroid differentiation characteristic of feline PRCA.     

Expression of hematopoietic inhibitory factors in mouse fibroblasts,macrophages and endothelial cells

Pure bone marrow fibroblasts, macrophages and endothelial cells were cultured in Iscove-modified Dulbecco's medium. RT-PCR was used to determine the expression of inhibitory cytokine mRNAs in these cell types. Serum-free conditioned medium was collected from each cell type and ultrafiltration was performed with a centriprep 10. The retentate contained substances whose molecular weights were >10 kD, whilst the filtrate contained substances with molecular weights <10 kD. The effect of conditioned media and their components on colony forming unit-granulocyte-macrophage (CFU-GM) were investigated. The results showed: (1) six cytokines, MIP-1alpha, MIP-2, TGF-beta, TNF-alpha, IFN-gamma and Tbeta(4), inhibited the growth of CFU-GM when murine WEHI-3 conditioned medium was added to the culture system as a source of colony stimulation. (2) The original endothelial cell conditioned medium (E-CM) did not affect the production of CFU-GM, but the >10 kD component of E-CM increased its production, and the <10 kD component decreased it. Both fibroblast conditioned medium (F-CM) and the >10 kD component of F-CM stimulated proliferation of CFU-GM, but the <10 kD component suppressed it. All three components of macrophage conditioned medium (M-CM) inhibited the growth of CFU-GM. (3) Expression of four of the mRNAs, namely MIP-2, TNF-alpha, INF-gamma and Tbeta(4), was seen in all three types of stromal cells, while TGF-beta mRNA was only seen in endothelial cells and macrophages, and MIP-1alpha mRNA in endothelial cells and fibroblasts. The inhibitors TGF-beta, MIP-1alpha, and Tbeta(4)have an inhibitory effect on the growth of CFU-GM, but TNF-alpha, INF-gamma and MIP-2 do not.     

In vivo effects of interleukin-17 on haematopoietic cells and cytokine release in normal mice

In order to gain more insight into mechanisms operating on the haematopoietic activity of the T-cell-derived cytokine, interleukin-17 (IL-17) and target cells that first respond to its action in vivo, the influence of a single intravenous injection of recombinant mouse IL-17 on bone marrow progenitors, further morphologically recognizable cells and peripheral blood cells was assessed in normal mice up to 72 h after treatment. Simultaneously, the release of IL-6, IL-10, IGF-I, IFN-gamma and NO by bone marrow cells was determined. Results showed that, in bone marrow, IL-17 did not affect granulocyte-macrophage (CFU-GM) progenitors, but induced a persistant increase in the number of morphologically recognizable proliferative granulocytes (PG) up to 48 h after treatment. The number of immature erythroid (BFU-E) progenitors was increased at 48 h, while the number of mature erythroid (CFU-E) progenitors was decreased up to 48 h. In peripheral blood, white blood cells were increased 6 h after treatment, mainly because of the increase in the number of lymphocytes. IL-17 also increased IL-6 release and NO production 6 h after administration. Additional in vitro assessment on bone marrow highly enriched Lin- progenitor cells, demonstrated a slightly enhancing effect of IL-17 on CFU-GM and no influence on BFU-E, suggesting the importance of bone marrow accessory cells and secondary induced cytokines for IL-17 mediated effects on progenitor cells. Taken together, these results demonstrate that in vivo IL-17 affects both granulocytic and erythroid lineages, with more mature haematopoietic progenitors responding first to its action. The opposite effects exerted on PG and CFU-E found at the same time indicate that IL-17, as a component of a regulatory network, is able to intervene in mechanisms that shift haematopoiesis from the erythroid to the granulocytic lineage.