Biomedical subjects

U Testa

Publications and source records attributed to U Testa.

At least 55 records · Page 3Linked to original sources

PubMed1994

Combined interleukin-1 beta/interleukin-6 treatment in mice: synergistic myelostimulatory activity and myelorestorative effect after cyclophosphamide-induced myelosuppression.

We have studied the effects of single and combined treatment with recombinant human interleukin 1 beta (IL-1 beta) and recombinant human interleukin-6 (IL-6) on spleen and bone marrow hematopoiesis in normal and cyclophosphamide-treated mice. Injection of IL-1 beta alone resulted in a significant increase in the number of granulocytes and splenic progenitors [burst-forming units-erythroid (BFU-E) and colony-forming units-granulomonocytic (CFU-GM)] as compared with control mice but did not markedly enhance the number of bone marrow BFU-E and CFU-GM. IL-6 alone had little effect on the number of splenic progenitors but significantly increased the number of marrow BFU-E and CFU-GM, especially after a 6-day cytokine treatment. Combined daily administration of IL-1 beta and IL-6 for 3 days resulted in a synergistic stimulation of hematopoiesis as evaluated by the number of spleen and bone marrow CFU-GM and BFU-E colonies. Likewise, IL-1 beta/IL-6 markedly enhanced the number of circulating neutrophils, whereas each cytokine alone had little or no effect. When the numbers of spleen progenitors and peripheral granulocytes were determined 1 day after the last injection, a synergistic myelostimulatory effect of combined IL-1 beta/IL-6 treatment was observed at all doses (IL-1 beta, 0.25-0.5 microgram; IL-6, 1-20 micrograms). Furthermore, combined treatment with IL-1 beta/IL-6 accelerated and potentiated the recovery of myeloid cells after cyclophosphamide injection, whereas the single regimen treatment was not effective. Particularly, the rebound of WBC (especially neutrophilic granulocytes) after cyclophosphamide treatment was markedly enhanced by the combined treatment, whereas the single regimen was ineffective. Altogether these results may contribute to the development of combination therapies with cytokines and antiblastic agents in the treatment of cancer patients.

Animals↗

PubMed1994

Autologous stem cell transplantation: release of early and late acting growth factors relates with hematopoietic ablation and recovery.

We have monitored the serum concentrations of hematopoietic growth factors (HGFs; ie, stem cell factor [SCF], leukemia inhibitory factor [LIF], interleukin-3 [IL-3], IL-6, IL-8, and granulocyte colony-stimulating factor [G-CSF]) in 15 lymphoma/leukemia and 6 ovarian cancer patients undergoing autologous bone marrow (BM) or peripheral blood (PB) stem cell transplantation (SCT). Thus, the analysis was performed during and after high-dose chemotherapy (from day -6 to day -1), at the time of SCT (day 0), and thereafter (through day +17). Despite the heterogeneity of these patients and their conditioning regimens, a consistent kinetic pattern was observed for all analyzed cytokines. Particularly, (1) SCF serum concentration did not significantly fluctuate. (2) High levels of LIF (approximately 250 to 450 pg/mL) before chemotherapy rapidly declined to markedly lower concentrations (approximately 10 ng/mL) starting from day -1 through day +17; (3) conversely, IL-3 level was low before treatment, sharply increased during chemotherapy, and rapidly returned to base-line level after SCT. Hypothetically, the sharp LIF decrease and IL-3 increase during chemotherapy may underlie the induction of stem cell cycling and differentiation caused by hematopoietic ablation. Furthermore, (4) IL-6 concentration was low before and immediately after chemotherapy, but increased starting from day +5, peaked at day +6 through 9 and then declined to baseline level from day +10 onward; (5) a strictly similar pattern was consistently observed for both G-CSF and IL-8 levels, in agreement with our previous studies. It is relevant that peak IL-6, G-CSF, and IL-8 concentrations were directly correlated to peak neutrophil numbers in the recovery phase, thus suggesting an important role for these cytokines in granulocyte rescue; in line with this interpretation, hematologic patients undergoing PBSCT (10 of 15) exhibited higher peaks of IL-6, G-CSF, and IL-8 and a more pronounced increase of neutrophil/platelet number than did hematologic cases undergoing BMSCT (5 of 15). Altogether, these studies indicate a coordinate pattern of cytokine release during hematopoietic ablation/recovery after chemotherapy and autologous SCT, the fluctuations of LIF and IL-3 levels during chemotherapy are seemingly related to stem cell recruitment, whereas the post-SCT increase of IL-6, G-CSF, and IL-8 may underlie the neutrophil recovery.

Adolescent↗

PubMed1994

Blood levels of erythropoietin in congestive heart failure and correlation with clinical, hemodynamic, and hormonal profiles.

Plasma levels of erythropoietin (mU/ml) were measured in patients with congestive heart failure (CHF) (n = 108) and in a control group of normal subjects (n = 45). In normal subjects, plasma levels of erythropoietin were 1.9 +/- 0.2. In patients with CHF, plasma levels of erythropoietin increased progressively according to New York Heart Association (NYHA) class (I: 1.4 +/- 0.2, n = 28; II: 5.4 +/- 0.8, n = 27; III: 9.6 +/- 2, n = 32; IV: 34 +/- 8, n = 21; F = 57.7, p < 0.001) and were significantly higher in NYHA classes II, III, and IV than in normal subjects. Plasma erythropoietin significantly decreased (from 43 +/- 14 to 12 +/- 3 mU/ml, p < 0.01) in patients with severe CHF (n = 9) when enalapril (20 mg/day administered orally) was added to long-term treatment for 3 weeks. Finally, in a subgroup of patients with NYHA class IV CHF (n = 9) and high plasma erythropoietin levels (37 +/- 9 mU/ml), packed red blood cell volume, assessed by the iodine-125-albumin dilution method, was higher than that in normal subjects (n = 11) (2,616 +/- 235 vs 2,028 +/- 119 ml, p < 0.05). The present study demonstrates that plasma erythropoietin levels are elevated in a large cohort of patients with CHF of varying etiology, and that this increase is related to the progression of the disease. The increase in circulating erythropoietin is associated with augmented packed red blood cell volume in patients with severe CHF. These results suggest a participation of erythropoietin in the complex neurohormonal response that occurs in CHF.

Adult↗

PubMed1994

PML/RAR alpha+ U937 mutant and NB4 cell lines: retinoic acid restores the monocytic differentiation response to vitamin D3.

We have analyzed the differentiation program of a U937 promonocytic leukemia clone transduced with the acute promyelocytic leukemia specific PML/RAR alpha fusion gene, the expression of which is under the control of the inducible metallothionine (MT) I promoter (MTPR9 clone). MTPR9 cells treated with Zn2+ hence exhibit levels of PML-RAR alpha protein as high as fresh acute promyelocytic leukemia blasts. In the absence of Zn2+, i.e., upon low level PML/RAR alpha expression, 1,25-dihydroxyvitamin D3 (D3) and particularly D3 plus transforming growth factor beta 1 (TGF-beta 1) induced terminal differentiation of MTPR9 cells (as observed in "wild-type" U937 cells), on the basis of morphology, membrane antigen pattern, and functional criteria. Conversely, in the presence of Zn2+, D3 and D3 plus TGF-beta 1 failed to induce terminal differentiation, as evaluated by the above parameters. Interestingly, retinoic acid (RA) treatment suppresses the differentiation blockade induced by high level PML-RAR alpha protein; indeed, Zn(2+)-treated MTPR9 cells incubated with RA plus D3 exhibited significant terminal monocytic maturation, comparable to that of cells treated with D3 alone or combined with RA in absence of Zn2+. Similar observations were made in NB4, a PML-RAR+ human acute leukemic line. As expected RA treatment of NB4 cells causes granulocytic differentiation. Interestingly, the cell line is only scarcely induced to mature monocytic cells by D3 or D3 plus TGF-beta 1 treatment, whereas it is effectively induced to monocytic maturation by combined treatment with D3 and RA. Accordingly, the rate of NB4 cell proliferation is only slightly affected by D3 or D3 plus TGF-beta 1 treatment, mildly inhibited by RA, and markedly decreased by D3 plus RA. These results indicate that in both U937 and NB4 cells high level PML/RAR alpha expression inhibits the monocytic terminal differentiation program triggered by D3 or D3 plus TGF-beta 1, whereas RA treatment effectively antagonizes this inhibitory PML-RAR alpha action and restores the D3 differentiative effect.

Antigens, CD↗

PubMed1994

Efficient transfer of selectable and membrane reporter genes in hematopoietic progenitor and stem cells purified from human peripheral blood.

We have utilized highly purified hematopoietic progenitor and stem cells (HPCs, HSCs) from normal peripheral blood to develop methodology for: (a) efficient transfer into HPCs of a non-hematopoietic membrane reporter, i.e., the nerve growth factor receptor complementary DNA; and (b) effective gene transduction of putative HSCs, i.e., cells initiating Dexter-type long-term culture (LTC-ICs). Purified HPCs induced into cycling by growth factors (interleukin 3, interleukin 6, c-kit ligand) were transduced with the N2 retroviral vector containing the neomycin resistance (neor) gene. More than 80% of transduced HPCs were resistant to the toxic G418 level. Thereafter, the HPCs were effectively transduced with the LNSN retroviral vector containing a nerve growth factor receptor complementary DNA; the nerve growth factor receptor was detected on > or = 18% of the transduced HPCs. These experiments provide a new tool from which (a) to monitor expression of a transduced membrane report on hematopoietic cells, particularly at the level of HPCs/HSCs, and (b) to characterize the transduced cells by double- and triple-labeling membrane antigen analysis. Purified HPCs/HSCs grown in Dexter-type LTC were transduced at 1 week by exposure to supernatant N2 retroviral particles in the absence of exogenous hematopoietic growth factors. The procedure, devoid of toxic effects, allowed an efficient neor transduction into LTC-ICs. Thus, we consistently detected neomycin-resistant mRNA in the clonal progeny of HPCs produced in LTC at 5-8 weeks in both the nonadherent and adherent fractions; this timing of expression coincides with that of HPC production by LTC-ICs, thereby indicating the effective transduction of the LTC-ICs. These experiments represent a first step toward development of preclinical models for gene transfer into human peripheral blood HSCs by complex retroviral vectors.

Adult↗

PubMed1994

Regulation of leukemia inhibitory factor synthesis in cultured human astrocytes.

We have examined the ability of human astrocytes to synthesize and secrete leukemia inhibitory factor (LIF), which is a multifunctional cytokine that controls cell proliferation and differentiation in many tissues, including the nervous system. Astrocyte-enriched cultures, prepared from 8- to 9-wk-old embryonic brains, expressed LIF mRNA and secreted LIF protein. LIF synthesis was significantly increased by the cytokines IL-1 beta, TNF-alpha, and TGF-beta 1, but not by IFN-gamma, IL-6, or LPS. No major differences in basal and cytokine-inducible LIF production were detected among astrocyte populations obtained from different brain areas. LIF synthesis was lower in serum-free than in serum-containing astrocyte cultures. A role for protein kinase C in the regulation of astrocyte LIF production was suggested by the findings that phorbol esters induced both LIF mRNA and protein and that the cytokine-induced LIF increase was partially antagonized by relatively selective inhibitors of protein kinase C such as H7 and staurosporine. Human leptomeningeal fibroblasts also expressed LIF gene and protein. Astrocytes produced LIF and responded to cytokines with increased LIF synthesis only after being subcultured, and not when grown in primary cultures in close contact with neurons. Our findings suggest that in vivo induction of astrocyte LIF secretion might occur in pathologic conditions as a consequence of both alterations of neuronal-glial interactions and a local increase in the level of inflammatory cytokines.

Astrocytes↗

PubMed1994

Interleukin-6 serum levels in patients with gynecological tumors.

Serum levels of IL-6 were evaluated in a large group of patients with benign or malignant gynecological tumors. The results obtained were correlated with the patients' clinicopathological features and follow-up data. Using a highly sensitive immunoenzymatic method for the evaluation of serum IL-6 levels, we observed that > 95% of normal healthy women exhibited values within the range of 1.9-6 pg/ml. Using a cut-off of 6 pg/ml, elevated levels of serum IL-6 were found in 53% of 45 patients with primary epithelial ovarian cancer and less frequently in patients with endometrial and cervical cancer (37% and 10% respectively). Elevated levels of IL-6 were occasionally seen in patients with benign disease. IL-6 serum levels appeared to be less sensitive than CA 125 in ovarian cancer diagnosis. In cancer patients, increased IL-6 serum levels were related to the presence of the tumor since all post-operative patients exhibited a marked decrease. In patients with advanced ovarian cancer post-operative levels of IL-6 correlated with residual disease. Very high levels of IL-6 were observed in the ascitic fluid of 9 ovarian cancer patients, but IL-6 mRNA was not detected in tumor cells. This suggests that the increased production of IL-6 observed in ovarian cancer is reactive. Higher levels of IL-6 were found in patients unresponsive to chemotherapy, as compared with responsive ones. Univariate analysis of survival data suggests that increased IL-6 serum levels correlate with negative prognosis.

Adult↗

PubMed1994

Retinoic acid downmodulates erythroid differentiation and GATA1 expression in purified adult-progenitor culture.

All-trans retinoic acid (RA) is an important morphogen in vertebrate development, a normal constituent in human adult blood and is also involved in the control of cell growth and differentiation in acute promyelocytic leukemia. We have examined the effects of RA on normal hematopoiesis by using early hematopoietic progenitor cells (HPC) stringently purified from adult peripheral blood. In clonogenetic fetal calf serum-supplemented (FCS+) or -nonsupplemented (FCS-) culture treated with saturating levels of interleukin-3 (IL-3) granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (Ep) (combined with c-kit ligand in FCS(-)-culture conditions), RA induces a dramatic dose-dependent shift from erythroid to granulomonocytic colony formation, the latter colonies being essentially represented by granulocytic clones. This shift is apparently not caused by a recruitment phenomenon, because in FCS+ culture, the total number of colonies is not significantly modified by RA addition. In FCS- liquid-suspension culture supplemented with saturating Ep level and low-dose IL-3/GM-CSF, adult HPC undergo unilineage erythropoietic differentiation: Here again, treatment with high-dose RA induces a shift from the erythroid to granulocytic differentiation pathway. Studies on RA time-response or pulse treatment in semisolid or liquid culture show that early RA addition is most effective, thus indicating that early but not late HPC are sensitive to its action. We then analyzed the expression of the master GATA1 gene, which encodes a finger transcription factor required for normal erythroid development; addition of RA to HPC stimulated into unilineage erythropoietic differentiation in liquid culture caused a virtually complete inhibition of GATA1 mRNA induction. These results indicate that RA directly inhibits the erythroid differentiation program at the level of early adult HPC, and may lead to a shift from the erythroid to granulocytic differentiation pathway. This phenomenon is correlated with inhibition of GATA1 induction in the early stages of erythropoietic differentiation.

Adult↗

PubMed1994

gp120 HIV envelope glycoprotein increases the production of nitric oxide in human monocyte-derived macrophages.

The effect of recombinant gp120 HIV envelope glycoprotein on the generation of free radicals by monocyte-derived macrophages (MDM) was measured by EPR spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). After 1 day in culture, MDM produced a spin trap adduct of DMPO with hyperfine splitting constants superimposable on those of DMPO-OH. The addition of gp120 to MDM increased the production of DMPO-OH and after 1 h, the amount of DMPO-OH produced by 40 micrograms/ml gp120 was about 300% that of untreated MDM. The use of selective inhibitors suggested the participation of the nitric oxide/L-arginine oxidative pathway, but did not provide evidence for trapping of hydroxyl radical or other oxygen free radicals. The specificity of gp120 was proven by two different anti-gp120 antibodies that either inhibited (polyclonal) or increased (monoclonal) the production of free radicals. Dexamethasone inhibited the effect of gp120, suggesting the possible involvement of an inducible nitric oxide (NO) synthase. Moreover, treatment of MDM with gp120 for 15 h increased in a dose-dependent manner the production of NO2-, a stable end product of NO. Soluble CD4 did not modify the intensity of the DMPO-OH adduct, whereas yeast mannan and Ca(2+)-chelators abolished the increase in the DMPO-OH signal induced by gp120. These data suggest the possible involvement of mannose-specific endocytotic lectin of MDM. The reaction of DMPO with sodium nitroprusside, an organic nitrate that releases NO, also produced DMPO-OH. Our findings indicate that gp120 increases free radical production from MDM as detected by spin-trapping methods, and that the spin trap adduct results from a reaction involving NO or closely related oxidized derivatives.

Adult↗

PubMed1994

Coordinate expression and proliferative role of HOXB genes in activated adult T lymphocytes.

We investigated the expression of HOXB cluster genes in purified phytohemagglutinin (PHA)-activated T lymphocytes from normal adult peripheral blood by reverse transcription PCR and RNase protection. These genes are not expressed in quiescent T cells, except for barely detectable B1 RNA. After the PHA stimulus, HOXB gene activation initiates coordinately as a rapid induction wave in the 3'-->5' cluster direction (i.e., from HOXB1 through B9 genes). Thus, (i) expression of the foremost 3'-located B1 and B2 genes peaks 10 min after PHA addition and then rapidly declines, (ii) activation of B3, B4, and B5 begins 10 min after PHA addition and peaks at later times (i.e., at 120 min for B5), (iii) B6, B7, and B9 are expressed at a low level starting at later times (45 to 60 min), and (iv) B8 remains silent. Treatment of PHA-activated T lymphocytes with antisense oligonucleotides to B2 or B4 mRNA causes a drastic inhibition of T-cell proliferation and a decreased expression of T-cell activation markers (i.e., interleukin 2 and transferrin receptors). Similarly, treatment of CEM-CCRF, Peer, and SEZ627 T acute lymphocytic leukemia cell lines with anti-B4 oligomer markedly inhibits cell proliferation. Finally, T cells stimulated by a low dosage of PHA in the presence of 1 microM retinoic acid show a marked increase of both HOXB expression, particularly B2, and cell proliferation. These studies provide novel evidence on the role of HOX genes in adult cell proliferation. (i) Coordinate, early activation of HOXB genes from the 3'-->5' cluster side apparently underlies T-cell activation. (ii) The expression pattern in adult PHA-activated T cells is strikingly similar to that observed in retinoic acid-induced teratocarcinoma cells (A. Simeone, D. Acampora, L. Arcioni, P. W. Andres, E. Boncinelli, and F. Mavilio, Nature (London) 346:763-766, 1990), thus suggesting that molecular mechanisms underlying HOX gene expression in the earliest stages of development may also operate in activated adult T lymphocytes.

Adult↗

PubMed1994

High dose-intense chemotherapy alone or in combination with interleukin-2 for small cell lung cancer: a pilot study.

Given the antitumor activity of interleukin-2 (IL-2) against some drug-resistant cancer cells, 17 previously untreated patients with small cell lung cancer entered a pilot study to evaluate the feasibility, efficacy, and immunological effects of combining 12-week high dose-intense chemotherapy based on a modified Evans regimen (CAV/PE) with different IL-2 schedules (6-12 MU/m2 week as a 48-72-h infusion using the same cumulative dose, 72 MU/m2). Despite significant myelotoxicity, up to 70% of the intended dose intensity was delivered, showing no differences with regard to the IL-2 schedule used. Immunotherapy-induced toxicity was usually mild and manageable. No limiting effects were observed in patients receiving immunotherapy except for a very poor compliance to the 12-week IL-2 regimen. The low-dose 72-h infusion was the optimal IL-2 schedule. As given in this study, neither of the alternating CAV/PE regimens abrogated the effects of IL-2 on T-cell and NK-cell subsets, showing typical kinetics with rebound in lymphocytes following each discontinuation of the IL-2. While immunological changes cannot predict the antitumor effect of IL-2, they are consistent with those described for IL-2 alone, suggesting its compatibility with high dose-intense chemotherapy. Although no definite advantages have been demonstrated in this small pilot study with significant unbalanced prognostic factors (12% 2-year survival), both the preserved immunostimulatory effects and the lack of limiting overlapping toxicity make this combined approach promising and worthy of further clinical investigation.

Adult↗

PubMed1994

Cytoskeletal oxidative changes lead to alterations of specific cell surface receptors.

Electron acceptors in biological systems, termed "oxidants", have been associated with numerous cytopathic conditions. In particular, oxygen-derived free radicals have been shown to induce various subcellular oxidative injuries which can lead to different types of pathologies. It has also been suggested that oxidative stress induced by xenobiotics can determine specific subcellular alterations in in vitro models. An oxidative imbalance in cells seems in fact to affect intracellular functions including the expression of some growth factor surface receptors. In this work, we observed a specific early alteration of the microfilament system and the microtubular network induced in K562 cells by oxidative stress. In particular, we hypothesize that oxidative imbalance could lead to an impairment of the expression of these receptors, such as transferrin receptors, via a modification of the cytoskeleton. This could represent a general mechanism by which a modification of receptor regulation can lead to cell aging, injury or death.

Cell Membrane↗

PubMed1993

Enhanced production of LPS-induced cytokines during differentiation of human monocytes to macrophages. Role of LPS receptors.

In vitro cultivated human monocytes isolated from normal peripheral blood show a time-dependent differentiation into macrophages characterized by an increased expression of transferrin receptors, CD11/CD18, and CD14 Ag. We measured the secretion of TNF-alpha and IL-6 in freshly isolated monocytes and in differentiated macrophages after LPS treatment. Differentiated macrophages produced significantly higher amounts of TNF-alpha and IL-6 than freshly isolated monocytes. This increased secretion was not a result of an enhanced accumulation of TNF-alpha and IL-6 mRNA, as comparative levels of these transcripts were found in both cell types after LPS treatment. Furthermore, LPS did not induce an antiviral state to VSV3 in monocytes, but it reduced by 3 to 5 log10 the virus yield in differentiated macrophages. The addition of antibodies to IFN-beta completely inhibited the LPS-induced antiviral state to VSV, but antibodies to IFN-alpha, TNF-alpha, or IL-6 were ineffective. A marked accumulation of IFN-beta mRNA was found in both cell types after LPS treatment. Binding experiments with FITC-LPS revealed a slightly higher overall binding affinity for LPS in freshly explanted monocytes as compared with differentiated macrophages, even though the maximal binding was higher in macrophages. In both cell types, the LPS binding was partially inhibited by antibodies to CD14. These results demonstrate that: 1) in vitro differentiation of human monocytes to macrophages leads to an enhanced LPS response in terms of (a) progressive increase of IL-6/TNF-alpha production and (b) acquisition of an IFN-beta mediated antiviral state; 2) this enhanced response to LPS, largely CD14-independent, is not linked to any increased accumulation of cytokine mRNA, but is probably a result of an increased synthesis and/or secretion of these cytokines.

Adolescent↗

PubMed1993

The acute promyelocytic leukemia-specific PML-RAR alpha fusion protein inhibits differentiation and promotes survival of myeloid precursor cells.

Acute promyelocytic leukemia is a clonal expansion of hematopoietic precursors blocked at the promyelocytic stage. The differentiation block can be reversed by retinoic acid, which induces blast maturation both in vitro and in vivo. Acute promyelocytic leukemia is characterized by a 15;17 chromosome translocation with breakpoints within the retinoic acid alpha receptor (RAR alpha) gene on 17 and the PML gene, which encodes a putative transcription factor, on 15. A PML-RAR alpha fusion protein is formed as a consequence of the translocation. We expressed the PML-RAR alpha protein in U937 myeloid precursor cells and showed that they lost the capacity to differentiate under the action of different stimuli (vitamin D3 and transforming growth factor beta 1), acquired enhanced sensitivity to retinoic acid, and exhibited a higher growth rate consequent to diminished apoptotic cell death. These results provide evidence of biological activity of PML-RAR alpha and recapitulate critical features of the promyelocytic leukemia phenotype.

Animals↗

PubMed1993

Autologous stem cell transplantation: sequential production of hematopoietic cytokines underlying granulocyte recovery.

We investigated the serum concentrations of a variety of cytokines [granulocyte-macrophage-colony-stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), interleukin (IL) 1 alpha, IL-3, IL-6, IL-8, erythropoietin, tumor necrosis factor alpha, gamma-interferon in 10 patients with advanced ovarian cancer undergoing autologous peripheral blood stem cell (PBSC) harvesting followed by treatment with high-dose cisplatin, etoposide, and carboplatin and PBSC transplantation (chemotherapy was administered on days 1 through 3, PBSCT on day 6). Preliminary observations on cytokine serum levels were performed for 4 patients; on this basis, the kinetics of cytokines was then investigated in greater detail at closely sequential times in 6 further patients. We observed a consistent pattern of sequential GM-CSF, G-CSF, and IL-8 release after chemotherapy/PBSCT in all 10 cases, including the 6 patients monitored in detail: (a) at days 5-10 a GM-CSF peak; (b) at days 12-14 a pronounced release of both G-CSF and IL-8, which always preceded granulocyte recovery by approximately 7 days. At days 17-23, a second GM-CSF peak was monitored in 5 of the 6 patients analyzed in detail, as well as in the other 4 cases. Particularly relevant are the observations that: (a) the peak of G-CSF serum concentration and neutrophil number in the recovery phase are strikingly and directly correlated, thus indicating a key role for G-CSF in granulocyte rescue; (b) the time courses of G-CSF and IL-8 levels are strictly parallel, thereby suggesting a coordinate stimulus for production of granulocytes, mediated by G-CSF, and their activation/migration capacity, mediated by IL-8. Results were essentially negative for IL-3, tumor necrosis factor alpha, and gamma-interferon concentrations (except in one case for each cytokine). An early peak of IL-1 alpha was observed in all 3 analyzed patients, while an IL-6 peak was monitored at days 13-15 in all 4 patients analyzed in detail. The present results indicate a sequential coordinate pattern of cytokine release after ablative therapy and PBSCT and shed light on the mechanisms mediating the recovery of granulocytes, and more generally of hematopoiesis, after stem cell transplantation. Furthermore, these studies may contribute to the design of improved protocols for cytokine administration following myelosuppressive anticancer therapy, as well as to the prediction of granulocytic response.

Adult↗

PubMed1993

Transforming growth factor-beta potentiates vitamin D3-induced terminal monocytic differentiation of human leukemic cell lines.

We have investigated the effects of 1,25-dihydroxyvitamin D3 (D3) and/or transforming growth factor (TGF)-beta on one monocytic (U-937) and two human promyelocytic (HL-60 and AML-193) leukemic cell lines. D3 addition induces a partial monocytic maturation of the cell lines, whereas TGF-beta treatment is largely ineffective. Combined treatment with TGF-beta and D3 causes terminal monocytic maturation, as evaluated both by assessment of a large spectrum of membrane Ag and by functional assays. Furthermore, sequential addition of the two inducers showed that pretreatment with TGF-beta 1 followed by incubation with D3, but not vice versa, induces monocytic maturation as effectively as simultaneous treatment with both agents. In liquid culture the proliferative activity of these cell lines is slightly decreased by D3 and virtually unaffected by TGF-beta, whereas combined treatment with D3 and TGF-beta induces a markedly potentiated inhibitory effect. Furthermore, TGF-beta/D3 treatment (but not D3 alone) elicits the expression of membrane CD14, FcRI, FcRII, CD11a, CD11b, CD11c, ICAM-1, and PECAM-1 Ag at a level comparable to that observed on normal human monocytes. It is noteworthy that several of these Ag play an important role in monocyte physiology (e.g., CD14 Ag mediates the binding of bacterial LPS to monocytes). Treatment with both TGF-beta and D3 (but not D3 alone) induces superoxide anions and H2O2 production similar to that of circulating monocytes. In semisolid culture, D3 and TGF-beta alone cause, respectively, a marked and slight loss of cloning efficiency of the cell lines, whereas their combined addition synergistically results in a complete loss of the cloning capacity. These findings suggest a physiologic role for TGF-beta in monocyte maturation. Furthermore, they may pave the way to the design of clinical protocols combining D3 and TGF-beta in the differentiation therapy of acute promyelocytic/myelomonocytic leukemia.

Adjuvants, Immunologic↗

PubMed1993

Cascade transactivation of growth factor receptors in early human hematopoiesis.

Highly purified progenitors (including erythroid [BFU-E], granulo-monocytic [CFU-GM], multipotent [CFU-GEMM] progenitors, as well as multipotent progenitors with self-renewal capacity [CFU-B]) express high-affinity growth factor receptors (GFRs), with prevalent interleukin-3 receptors (IL-3Rs) (2,700/cell), a > or = 10-fold lower number of IL-6Rs (145/cell) and granulocyte-macrophage colony-stimulating factor receptors (GM-CSFRs) (300/cell), and a barely detectable level of erythropoietin (Ep) receptors (75/cell). Hematopoietic growth factor (HGF) dosages inducing peak clonogenetic effects are associated with partial/subtotal occupancy of the homologous HGF receptor (HGFR). Cross-reactivity between GFRs and heterologous GFs (including IL-6, IL-3, GM-CSF, Ep, and the kit ligand [KL]) was explored by competition experiments on purified progenitors with radiolabeled and excess cold HGFs at +4 degrees C. No cross-reaction was observed between IL-6R, IL-3R, EpR, and the heterologous GFs, whereas the GM-CSFR showed cross-reactivity with IL-3 and, to a lesser extent, KL. Modulation of GFRs was examined after 18 or 40 hours of incubation with GF(s) at 37 degrees C, followed by ligand-binding assay at 20 degrees C. IL-6, IL-3, GM-CSF, and Ep induce a marked down-modulation of their own receptors. Interestingly, each GF induces the transactivation of the R(s) for the "distal" GF(s): (1) IL-6 induces transactivation of IL-3R, but not of GM-CSFR/EpR; (2) IL-3 causes a rapid upmodulation of GM-CSFR/EpR ("pure" progenitors treated with IL-3 show upmodulation of GM-CSFR alpha-chain mRNA by reverse transcriptase-polymerase chain reaction); whereas (3) GM-CSF induces the transactivation of the EpR. This chain upmodulation of HGFRs may underlie the synergistic interactions between the HGFs in clonogenetic culture. It is emphasized that KL does not induce upmodulation of the other GFRs. Finally, Ep, GM-CSF, and IL-3 do not modulate the expression of the "proximal" HGFRs (ie, GM-CSFR/IL-3R/IL-6R, IL-3R/IL-6R, and IL-6R, respectively). These results allow insight into the cellular basis of hematopoiesis, ie, the complex and coordinate interactions between HGFs and their receptors. They are compatible with a model of cascade transactivation via upmodulation of GFRs in the initial key steps of hematopoietic differentiation, whereby the action of each GF enhances the effect of the distal GF(s) by a multistep chain-potentiation mechanism.

Adult↗

PubMed1993

Combined interleukin 1 beta/interleukin 2 treatment in mice: synergistic myelostimulatory activity and protection against cyclophosphamide-induced myelosuppression.

We have studied the effects of single and combined treatment with interleukin 1 beta (IL-1 beta) and interleukin 2 (IL-2) on spleen and bone marrow hematopoiesis in normal mice. Injection of IL-1 beta alone was followed by a significant increase in the number of granulocytes in spleen and progenitors (burst-forming units-erythroid and colony-forming units-granulomonocytic) in both spleen and bone marrow, s compared to control mice. In contrast, IL-2 alone induced only a slight increase in the number of marrow colony-forming units-granulomonocytic and had no significant effect on spleen progenitors. Repeated injections of both IL-1 beta and IL-2 resulted in a synergistic increase in spleen weight and splenocyte number, as compared to mice treated with the single cytokine regimen; in particular, the combined treatment induced a marked rise in the number of neutrophilic granulocytes and erythroblasts, whereas splenic lymphocytes were not affected. This regimen also caused a synergistic increase in the number of spleen and marrow progenitor cells: a time-course analysis showed an elevation in numbers of both burst-forming units-erythroid and colony-forming units-granulomonocytic, first in marrow (day 10) and subsequently in spleen (day 18). Combined IL-1 beta/IL-2 treatment dampened the decrease and accelerated the recovery of myeloid cells after cyclophosphamide injection, whereas the single cytokine regimen was not effective. Similarly, the rebound of WBC (especially neutrophilic granulocytes) after cyclophosphamide treatment was markedly enhanced by the combined treatment, whereas the single cytokine regimen was ineffective. These results, indicating a myelostimulatory effect by the combined cytokine regimen, together with our previous observations showing a synergistic antitumor activity by IL-1/IL-2 treatment in experimental mouse tumors (V. Ciolli et al., J. Exp. Med., 173: 313-322, 1991), may provide the basis for the development of new combination therapies with cytokines and antiblastic agents in the treatment of cancer patients.

Animals↗