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A subset of mobilized CD34+ cells present in patient aphereses expresses Thy1 (CDw90). This population contains most long-term culture initiating cells, as assayed with a murine stromal cell line. It also contains a significant proportion of colony-forming unit granulocyte macrophage, but very few burst-forming unit erythroid. The limited differentiation towards the erythroid lineage is further confirmed by the absence of GATA-1 mRNA in the CD34+/Thy1+ subset, and by the low level of c-kit expression. The CD34+/Thy1+ subset appears phenotypically and functionally heterogeneous, a finding consistent with its high representation, compared to phenotypes such as CD34+/CD38-. Therefore, while at least some of CD34+/Thy1+ cells may be infectable by retroviral vectors, as shown by the presence of a transcript for the receptor for murine amphotropic retroviruses, the use of this selection strategy to specifically target human stem cells appears questionable.

To insert a new genetic information by gene transfer into haemopoietic stem cells would result in expression of the transgene in progenitors and progeny of cell blood lineages. If successfull, such an approach would open interesting prospectives in the field of experimental research and in the possibility to treat genetic defects affecting blood lineages such as immune deficiencies (ADA, SCID, AIDS) or enzymes defects. Moreover progenitors could be engineered to become more resistant to chemotherapy or oncogenic process. Many parameters and technical problems are still involved in this issue, including identification, isolation and selection of the most primitive progenitors, and search for the most efficient vectors to insert new genes into the target cells. So far retroviral vectors have been shown to be the most effective but search for better vectors are still underway. Peripheral blood stem cells isolated from patients stimulated by cytokines and/or chemotherapy appear interesting target cells for genetic manipulations aimed to correct an acquired or genetic defect.

A total of 258 aphereses were performed in 79 patients with nonmyeloid malignancies after mobilization of peripheral blood stem cells (PBSC) with recombinant human granulocyte colony-stimulating factor (rhG-CSF). Apheresis products were examined for viable mononuclear cell (VMC), CD34+ cell, and clonogenic cell contents. The number of progenitors in aphereses differs in subgroups of patients with different diagnoses. However, the number of CD34+ or clonogenic cells is dependent on age and amount of chemotherapy delivered to patients before collection rather than on the nature of the disease itself. In addition, the actual dose of rhG-CSF used to mobilize PBSC and the number of VMC in aphereses influenced the clonogenicity of CD34+ cells, although the daily dose of rhG-CSF seems to play little role on the number of clonogenic cells in each individual apheresis product. CD34+ cell and CFU-C (or CFU-GM) numbers are related parameters, and the relation can be described as linear. However, the linear relation varies in different patient groups, and most of the linearity is induced by the highest sets of values. We conclude that mobilization with low doses of rhG-CSF alone is feasible and that the probability of collecting a high number of peripheral blood progenitors is increased in young patients undergoing apheresis early in the course of the disease. Although the relationship between CD34+ cells and CFUs can be described as linear in well-defined situations, its relevance may be limited because it is not a universal finding.

Culture of human hematopoietic progenitors on a large scale could lead to several clinical applications within the near future, including the production of differentiated and functional cells, the increase in the number of early progenitors, especially stem cells, with such use as gene transfer, or the improvement of grafts used to limit the hematological toxicity associated with high-dose chemotherapy. In this case, one can still distinguish different objectives: improvement of grafts that contain low numbers of progenitors because of prior chemotherapies or because of marrow involvement for example, and qualitative changes in the graft content that would allow to envision the disappearance, or the further reduction, in the duration of absolute neutropenia that follows delivery of high dose chemotherapy ("nadir rescue"), despite substitution of mobilized blood cells to marrow cells and the in vivo use of hematopoietic growth factors. Additional advantages may be related to tumor purging in autologous expanded cells, and to the change in the ratio between hematopoietic progenitors and immunocompetent cells in allogeneic expanded populations. Therefore it appears that in vitro expansion currently raises two types of questions: the first ones are related to the definition of clinical or biological endpoints to be achieved, the second ones are related to "bioengineering", and deal with the efficiency and safety of progenitor cell cultures to be used for clinical applications. We here present preliminary results preparing future pilot clinical studies with ex vivo cultured human hematopoietic cells.

T lymphocytes are a promising cell vehicle for gene therapy purposes. By cocultivating retroviral vector producing cells and target cells, highly efficient gene transfer was achieved with activated human T lymphocytes derived from peripheral blood with vectors carrying different forms of the bacterial beta-galactosidase gene including the regular LacZ gene, the Sh-ble::LacZ gene and the nlsLacZ gene. Infection kinetics of T cells activated by a combination of monoclonal antibodies directed against CD2 and CD28 indicated that the highest efficiencies of transduction were obtained when the cocultivation began 4 days after stimulation. In fact, with the FLac vector, a new retroviral vector which expresses the Sh-ble::LacZ gene, we observed up to 78% transduction efficiency assessed by X-gal staining performed 2 days after the end of the cocultivation. Expression of the transduced genes was observed throughout the period of culture. Neither the cocultivation step nor the expression of the transduced Sh-ble::LacZ gene altered cell culture proliferation or the expression of selected cell surface antigens. In addition, we showed that CD4+ and CD8+ T cells were equally transduced.

Few data are available concerning behavior of reimplanted human hematopoietic cells after autologous stem cell transplantation. This paper reports the possibility to transfer gene markers coding for beta-galactosidase (beta-Gal) activity by retroviral vectors into a human leukemic growth factor-dependent cell line, TF-1, and into human hematopoietic progenitors isolated from peripheral blood or bone marrow. Using various combinations of retroviral vectors and packaging cell lines, we demonstrated high expression of a bacterial beta-Gal activity induced by the LacZ gene, the nlsLacZ gene, or the Sh-ble/LacZ gene, in human hematopoietic cells. The expression of the nlsLacZ construct was stable until the end of the culture in infected CD34+ cell-enriched cell populations, and a slow decrease of transgene expression was observed in a transduced TF-1 cell population during a 1-year long-term culture. Data obtained with the nlsLacZ gene demonstrate that both retroviral transfer and corresponding gene expression were not found to modify the pattern of cell proliferation and differentiation. These results open interesting prospectives for the use of the nlsLacZ gene to mark and follow the fate of progenitor cells isolated from patients with cancers prior to reimplantation.

Recombinant granulocyte colony-stimulating factor (rhG-CSF) has been shown to hasten granulocyte recovery after autologous BMT. In current protocols, rhG-CSF treatment starts 1 day after BM reinfusion. Our study retrospectively examined the effects on haematological recovery of a day 6 delayed administration. Seventy-eight patients receiving autologous BMT for malignant lymphoma (21 non-Hodgkin's lymphoma and 9 Hodgkin's disease) or solid tumors (33 breast carcinoma and 5 ovarian carcinoma) were split up into three study groups. Two groups receiving a 5 micrograms/kg/day of rhG-CSF starting either 1 day (day +1 group, n = 25 patients) or 6 days (day +6 group, n = 24 patients) after BM reinfusion were compared with 29 historical control patients. Granulocyte recovery to 0.5 x 10(9)/l was 12 days in day +6 and day +1 groups versus 16 days in control group (p < 0.005) without any difference in other hematological parameters, infectious complications or length of hospitalisation between the three groups. The day +6 administration allows elimination of a median of 7 days rhG-CSF. It has been concluded that the day +6 administration gives the same clinical benefit as day +1 administration with consequent cost reductions.

Uncontrolled proliferation of acute myeloid leukemia (AML) cells is an important step during leukemogenesis. However, little is known about the mechanisms leading to growth autonomy. Studies using immortalized murine hematopoietic cell lines have suggested that autocrine production of growth factors, or the constitutive activation of molecules in growth factor signalling pathways, are involved. We have established six spontaneous factor-independent cell lines from the human growth factor-dependent TF-1 cell line. The factor-independent cells showed no detectable growth factor activity. Immunoblotting analyses of tyrosine phosphorylation, Raf-1 and extracellular signal-regulated kinase 2 (ERK-2) showed a similar pattern in all the cell lines including TF-1 cells. Furthermore, somatic-cell hybrids between TF-1 and the factor-independent cells grew in absence of growth factor. Taken together this data demonstrates that the factor independence in this system is dominant and suggests that the molecular event is located either downstream of the Raf-1 and MAP kinases pathway or on an alternative pathway. Finally, the karyotype analysis of one factor-independent cell line TF-1i1 and TF-1H- (G418 resistant, HAT sensitive TF-1 cells) and their hybrids demonstrated an unstable derivative chromosome [der(19) t(19;?) (q13.1;?)] which seemed to correlate with the factor-independence capacity. This model may help in our understanding of autonomous proliferation by human myeloid leukemias.

High-dose recombinant human Interleukin-2 was given to 21 patients with acute myeloid (n = 11) or lymphoid (n = 10) leukemia in relapse. A rapid decrease in the peripheral leukemic blasts numbers was observed in six patients. We were unable to demonstrate at the bone marrow level a diminution in the percentage of leukemic blasts. However an increase in the expression of the adhesion molecule CD54/ICAM-1(LFA-1 ligand) affected the leukemic bone marrow blasts of these six patients. This increase in CD54 was found in eight of the 11 (73%) AML and four out of the ten (40%) ALL blasts and CD58/LFA-3 (CD2 ligand) to a lesser extent. This increased expression was not associated with modifications in the expression of MHC class II molecules. In vivo IL-2 also dramatically modified the bone marrow T-cell subsets via the increase of CD3+ cells expressing the CD45RO 'memory' marker (six out of the eight tested patients) or CD54 (seven out of the eight tested patients). Altogether these results demonstrate that leukemic blasts can be affected by in vivo IL-2 via mechanisms that could involve T cells.

CD40 is a surface glycoprotein, member of the nerve growth factor receptor family, which is expressed on B cells and plays an important role in their development, growth, and differentiation. Using chromosomal in situ hybridization, we localized the CD40 gene to the long arm of chromosome 20, bands q12-q13.2. This localization correlates well with the mapping of the murine CD40 gene to the distal region of chromosome 2, syntenic to the human 20q11-q13 region.

Colony stimulating factors and especially rHuG-GSF, the first available neutrophil growth factor, have led to considerable interest in the field of stem cell transplantation because of their ability to induce stem cell peripheralization either alone or in association with high-dose chemotherapy. Few data exist, however, on the impact of rHuG-CSF on large scale bone marrow collection and autologous bone marrow transplantation (ABMT). This phase I, non-randomized, dose escalation study of rHu-G-CSF (lenograstim) administered to 30 patients at doses ranging from 1 to 40 micrograms/kg/day for 5 days before bone marrow harvesting showed that priming with rHu-G-CSF in vivo increased the number of bone marrow cells and D14 myeloid restricted progenitors (CFU-GM) and led to a better neutrophil recovery after ABMT compared with a contemporary unprimed control population. Otherwise, this study established that 5 days of rHuG-CSF therapy, as a sole stimulus, induced a tenfold increase in the circulating CFU-GM amongst which immature progenitors, estimated by the Delta assay (secondary CFU-GM grown after 7 days of liquid culture/primary CFU-GM), are detected. These conclusions were valid for doses as low as 2 micrograms/kg/day which induced only mild neutrophilia up to the highest dose (40 micrograms/kg/day) and suggest that a short course of rHuG-CSF is beneficial in increasing the stem cell collection.

The authors report two patients with large granular lymphocyte (LGL) expansion associated with rheumatoid arthritis corresponding to pseudo Felty's syndrome. These cells have natural killer and T cell surface antigen markers. LGL are a heterogeneous population and expansion of these cells is responsible for leukemia, which is generally a monoclonal proliferation. It has been suggested that Epstein-Barr virus (EBV) is a putative agent in this leukemia. No EBV DNA was found with a polymerase chain reaction analysis in the lymphocyte DNA of our two patients. Some cases of pseudo Felty's syndrome have exhibited a monoclonal pattern on Southern blot analysis of the T cell receptor. On the contrary, our two cases showed a polyclonal pattern with TCR beta chain Southern blot analysis. This fact, associated with the mild course seen in both over more than twenty years, suggest that pseudo Felty's syndrome is a disease with a good prognosis.

Acute myeloid leukemia (AML) cells are dependent for their survival and proliferation on hematopoietic growth factors. As tumor necrosis factor alpha (TNF alpha) can increase the proliferation of primary cultures of AML cells, we have investigated the effect of TNF alpha on the autocrine and/or paracrine growth control by one of the major AML growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF). First, a panel of AML cells were analysed with respect to their proliferative response to TNF alpha. We provide experimental evidence that TNF alpha induces both GM-CSF gene expression and up-regulation of high-affinity GM-CSF membrane receptor in TNF alpha-responsive cells. This effect is not restricted to the malignant phenotype, although it could account for the selective growth advantage of the leukemic clone over the normal cells upon TNF alpha stimulation.

Photodynamic induced cytotoxicity by Victoria blue BO (VB-BO), merocyanine 540 (MC540), Nile blue A (NB) and 4-tetrasulfonatophenyl-porphyrin (4-TSPP) has been studied on two human leukemic cell lines: K-562 and TF-1. Cells were incubated with dyes and irradiated with different doses of white light. Cell survival was assessed by propidium iodide (PI) staining using flow cytometry analysis. Concentrations of 5 x 10(-8) M VB-BO were found to kill 75% of cells, and a concentration of 1 x 10(-7) M induced more than 99% of cell killing. To obtain the same cytotoxic level, the presence of 2.6 x 10(-5) M of MC540 during irradiation was needed. Under the conditions used, NB was ineffective as a photosensitizer, although uptake studies showed that this dye was taken by the cells in much greater amounts than any other studied dye. Cell cycle distribution of TF-1 cells, surviving MC540 or VB-BO photosensitization has been studied by flow cytometry analysis after staining with Hoechst 33342 and PI. It was found that cells in G1 phase were slightly more resistant toward MC540- and VB-BO-mediated photosensitization than cells in other phases of the cell cycle.

Objective responses obtained with high-dose in vivo recombinant interleukin 2 (r-IL2) in some leukaemic patients suggest among other hypotheses that blasts might express tumour rejection antigens potentially recognized by cytolytic T lymphocytes. Such antigens have been described in human melanomas and the MAGE-1 gene, coding for a tumour rejection antigen was recently identified. This gene is expressed in various solid tumours, but not in normal cells. We have screened a panel of haematological malignancies by reverse transcription and PCR and we report that MAGE-1 is not expressed in the blasts from 48 patients whereas three cell lines derived from leukaemias express this gene.

We recently cloned an additional member of the receptor type tyrosine kinase class III. This new gene, called Flt3 by our group [Rosnet, O., Matteï, M.G., Marchetto, S. & Birnbaum, D. (1991). Genomics, 9, 380-385; Rosnet, O., Marchetto, S., deLapeyriere, O. & Birnbaum, D. (1991). Oncogene, 6, 1641-1650] and Flk2 by others [Matthews, W., Jordan, C.T., Wieg, G.W., Pardoll, D. & Lemischka, I.R. (1991). Cell, 65, 1143-1152] is strongly related to the important developmental genes Kit, Fms and Pdgfr. The murine 3.2-kb full-length cDNA, when introduced into COS-1 cells, shows the expression of two polypeptides with apparent molecular weights of 155 kDa and 132 kDa. Treatment of cells with N-linked glycosylation inhibitors results in the expression of a 110-kDa protein. We have shown that FLT3 contains an intrinsic tyrosine kinase activity. A point mutation in a highly conserved residue within the phosphoryltransferase domain inactivates the catalytic function of this receptor, whereas activation by way of a chimeric molecule between the ligand-binding domain of colony-stimulating factor type 1 (CSF-1) receptor (CSF-1R) and the kinase domain of FLT3 results, in the presence of CSF-1, in the development of the transforming activity of this receptor as shown by anchorage-independent cell growth. Finally, expression analysis of the FLT3 protein shows that, in addition to the hematopoietic system, FLT3 is strongly expressed in neural, gonadal, hepatic and placental tissues in the mouse.

Haematopoietic growth factors are a family of genetically determined low molecular weight glycoproteins which regulate the proliferation and differentiation of haemopoietic cells through specific membrane receptors. GCSF and GMCSF reduce the morbidity from infections associated with the neutropenia induced by chemotherapy of onco-haematological neoplasia; EPQ totally corrects not only the anaemia of patients with chronic renal failure, but also 50 percent of anaemias related to chemotherapy; finally, the activity of IL 3 on platelet production seems to control the thrombocytopenia which restricts the use of therapeutics.

Twelve HIV-positive patients who either underwent or seroconverted after bone marrow transplantation (BMT) at the University of Marseille between 1981 and 1985 were reviewed in order to observe their rates of development of AIDS. Two patients were HIV positive prior to transplantation, while ten seroconverted after transplantation. Six patients underwent autologous BMT and six underwent allogeneic BMT; all of their respective donors were seronegative. Eleven patients developed AIDS (92%), with a mean AIDS-free time (AFT) of 1 year 8 months after BMT. Seven of those subjects died, with a mean survival over a 5-year follow-up period of 2.14 years after BMT. Five autologous recipients had a mean AFT of 2 years 3 months, with the sixth patient being AIDS free. The mean AFT for the allogeneic recipients was 1 year 2 months (p = NS), all of whom developed AIDS. These data suggest that the development of AIDS was rapid from the time when our patients seroconverted. However, this was not initially accompanied by poor survival. In summary, BMT may be indicated for HIV-positive patients who required myeloablation, despite an enhanced development of AIDS.

The identification and purification of haemopoietic growth regulators have resulted in a better understanding of control mechanisms. Cloning and expression of the corresponding genes have shown that most of the activities observed correspond to specific glycoproteins produced by cells from numerous tissues, including those of bone marrow stroma and immune system. These cytokines activate the responsive cells through specific receptors expressed on their membranes. They exert an accurate control of haematopoiesis in a network of synergistic and antagonistic factors. The exact identification of their biological activities, together with the possibility of producing them in large amounts by genetic recombination, have already resulted in their therapeutic use with, in certain cases, a remarkable efficiency.

FLT3, a receptor belonging to the FMS/KIT family and localized to 13q12, could play a role in the biology of early hematopoietic progenitor cells. Because FMS and KIT are expressed in both normal progenitors and myeloid leukemias, we looked for FLT3 expression in fresh human leukemic cells using Northern blot analysis. High levels of FLT3 expression were detected in 92% of the cases of acute myeloid leukemia (AML) tested, ranging from the M1 to the M5 stages of differentiation assessed in the French-American-British classification. Immature (MO) AML cells, biphenotypic leukemias, and AML with megakaryocytic differentiation (M7 subtype) also expressed the FLT3 transcript. FLT3 was also expressed at high levels in acute lymphoid leukemias of T and B origins. Finally, it was not expressed in chronic myeloid leukemias in chronic phase, whereas it was expressed in most blast crisis samples. This pattern of expression of FLT3 contrasts with the expression of FMS and KIT restricted to myeloid leukemias, and suggests that the FLT3 product could play a role in the expansion of the leukemic blasts of both the myeloid and lymphoid lineages.

The expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene is differentially regulated in various cell types. We investigated the mechanisms controlling its expression in 12-O-tetradecanoylphorbol-13-acetate plus phytohemagglutinin-stimulated Jurkat cells, a human T-cell line. In unstimulated cells, GM-CSF mRNA was undetectable by Northern blot. Upon activation, it was detected from 3 h onward, with a progressive increase in the levels of the transcript up to 24 h of stimulation. Whereas cycloheximide treatment at the time of stimulation blocked mRNA induction, its addition at later times resulted in a marked increase in transcript levels. Run-on analysis showed that transcription of the GM-CSF gene was low to undetectable in unstimulated cells; stimulation led to transcriptional activation, which was weak at 6 h but had increased 16-fold at 24 h. In addition, the mRNA half-life decreased during activation, from 2.5 h at 6 h down to 45 min at 24 h. Cycloheximide treatment increased GM-CSF mRNA half-life (3- and 4-fold, respectively). Our results show: (a) both transcriptional and posttranscriptional signals regulate GM-CSF mRNA levels in activated Jurkat cells, (b) de novo protein synthesis is required for mRNA induction, whereas destabilizing labile proteins control the transcript stability, and (c) a shift from a posttranscriptional to a predominant transcriptional control of GM-CSF gene expression occurs during activation.

Serial cytogenetic studies were performed on 60 leukemic recipients of HLA-matched bone marrow transplants (BMT) who were prepared by high doses of alkylating agents and fractionated total body irradiation (TBI). Forty-three patients were recipients of untreated BMT and 17 were recipients of T-depleted BMT. Donor or host mitoses were identified by examination of sex chromosomes in 54 patients or by evaluation of the polymorphism of other chromosomes after specific banding in six patients. Mixed lymphoid chimerism (MLC) was identified in 29 patients and full donor lymphoid chimerism (FDLC) in 29 patients. Complete donor hematopoiesis was recovered in most patients after 12 months, but two T-depleted patients had persistent host cells at 46 and 52 months after the graft. Acute graft-versus-host disease was significantly less frequent in patients with MLC, especially when more than 10% of residual lymphoid cells were detected. The probability of relapse and survival was identical in patients with MLC and FDLC, except in patients with chronic myeloid leukemia where MLC was significantly associated with an increased risk of relapse.

High-dose recombinant interleukin-2 (rIL-2) therapy can induce long-term remission in patients with melanoma and renal and colon cancer. More recently, in vivo IL-2 therapy was shown to induce complete or partial remission in some cases of relapsed chemotherapy-resistant acute myeloid leukemia. We have investigated the phenotypic modifications of bone marrow cells obtained from five patients with acute myeloid leukemia in relapse receiving high-dose i.v. rIL-2. We found that, in three of five patients, IL-2 could induce, in vivo, an increase in the expression of CD54/ICAM-1 and to a lesser extent of CD58/LFA-3 on bone marrow leukemic blasts. This demonstrates that rIL-2 modifies directly or indirectly the expression of the cell surface molecules of the tumor cells themselves. Upregulation of such adhesion molecules could account for the enhancement of cell interactions between the tumor and effector cells such as T, natural killer, and phagocytic cells as well as being indicators of differentiation signaling.

V pre-B and lambda-like genes are selectively expressed in human pre-B cells and encode polypeptide chains that associate in a mu-pseudolight chain complex that may regulate some crucial steps of early B-cell differentiation. We have followed by polymerase chain reaction and Northern blot analysis the expression of these "pre-B-specific" genes in correlation with the status (rearranged v germline) of Ig gene loci (H, kappa, lambda) in a panel of 32 leukemias pertaining mostly to the B lineage and including a number of ambiguously characterized samples. All cells that had rearranged the H locus only expressed V pre-B and lambda-like transcripts, in agreement with a pre-B status. In this group, some biphenotypic leukemias (mostly My/B) might, in fact, be already engaged in the B lineage. Rearrangement of V kappa or V lambda loci correlated with the disappearance of the pre-B gene products. In a pre-B acute lymphoblastic leukemia cell line that was induced to mature to the B-cell stage in culture upon kappa gene rearrangement, the mu-pseudolight chain complex was actually replaced by the classical mu-kappa molecule. Finally, V pre-B and lambda-like genes were found expressed in two leukemic cells that had retained all Ig loci in germline configuration. This finding raises the possibility of having an early pro-B progenitor in which V pre-B and lambda-like products associate with a H chain surrogate in a complex that would trigger an early event of B-cell differentiation such as the H locus rearrangements.

Leukemic cells isolated from patients with either acute myeloid leukemia (AML) or acute lymphoid leukemia (ALL) were screened for their capacity to express the interleukin 6 (IL-6) and IL-6 receptor genes, both at the RNA and protein levels. Variable levels (10 to greater than 600 U/ml) of an IL-6 activity, inhibited by neutralizing anti-IL-6 antibodies, were detected in AML cell supernatants using the B9 cell bioassay. High levels (greater than 100 U/ml) were observed in differentiated (M4 and M5 stages) AML, as well as in less mature (M1 and M2 stages) AML. Detection of the IL-6 transcript correlated with the biological activity. In addition, both IL-6 activity and IL-6 mRNA were detected in "fresh" leukemic cells, indicating that the glycoprotein was actually synthesized in vivo. In contrast, the IL-6 gene was less frequently expressed in ALL. The IL-6 receptor gene was transcribed in both AML and ALL; binding experiments showed that the protein was present at the cell surface. The spontaneous in vitro proliferation of leukemic cells coexpressing the transcripts for IL-6 and its receptor was not significantly inhibited by a neutralizing anti-IL-6 antibody, suggesting that IL-6 is not primarily implicated in the proliferation of the leukemic clone via an autocrine loop. Synthesis of IL-6 could, however, confer on leukemic cells a selective growth advantage through activation of the cytokine cascade.

We have previously shown that tumor necrosis factor-alpha (TNF alpha) strongly potentiates interleukin-3 (IL-3)-induced short-term proliferation of human CD34+ hematopoietic progenitor cells (HPC). Using longer term cultures of CD34+ HPC, we demonstrate here that this initial potentiation ceases after 10 to 12 days; whereupon TNF alpha displays inhibitory effects. Thus, TNF alpha was found to inhibit cells of granulocytic affiliation while it potentiates the development of maturing cells of the monocytic lineage both in liquid and semi-solid (day 14 colony-forming unit) cultures. TNF alpha was demonstrated to reversibly block granulocytic differentiation at the level of uncommitted CD13-, CD15- blast cells that accumulate in IL-3 + TNF alpha cultures. Furthermore, growth of committed granulocytes (CD15+) from IL-3 cultures was also inhibited by TNF alpha through an arrest of cell cycle in G0/G1. Finally, the use of neutralizing anti-TNF alpha monoclonal antibody and limiting dilution studies indicate that the inhibitory effects of TNF alpha are direct. Taken together, our data demonstrate that, following a phase of potentiation of proliferation of early HPC, TNF alpha displays direct inhibitory effects due to negative interference with both granulocytic differentiation and proliferation of granulocytic cells.

Whether interleukin 6 (IL 6) is an autocrine or paracrine myeloma cell growth factor in vivo remains unresolved. To identify which cells are producing IL 6 in vivo, we have studied the IL 6 gene expression in bone marrow mononuclear cells (BMMC) of 19 patients with multiple myeloma (MM) and in peripheral blood mononuclear cells (PBMC) of 9 patients with plasma cell leukemia (PCL). We found that the IL 6 gene was transcribed by BMMC of most patients with MM (79%). Further, IL 6 mRNA was not produced by purified myeloma cells from patients with either MM (5 patients) or PCL, but by the bone marrow environment, mainly by monocytes and myeloid cells (CD13+CD15+ cells). For 2 patients with PCL, for whom PBMC and BMMC samples were available, IL 6 mRNA could be detected in BMMC but not in PBMC. Finally, no IL 6 mRNA was detected in five freshly established IL 6-dependent myeloma cell lines. The present data give a clear-cut demonstration of the paracrine origin of IL 6 in vivo in human MM.

In vivo use of rIL-2 autologous BMT may be the means of reproducing a kind of "adoptive immunotherapy" from grafted cells after allogeneic BMT. This approach may enhance the spontaneous generation of cytotoxic T-cells and NK cells which are presumably involved in this immunotherapy. Potential risks of such an approach would be to increase the usual toxicity of rIL-2 and to jeopardize the hemopoietic reconstitution. To determine the feasibility of this approach we have treated 19 poor prognosis patients with a succession of autologous BMT followed 78 +/- 12 days later by a continuous infusion of rIL-2. Eighteen million international units (IU) per m2 per day of Proleukine (CETUS, Amsterdam, The Netherlands) were administrated over 6 or 12 days. No patient died of the procedure. Clinical toxicity related to rIL-2 was not increased. Hemopoietic toxicity, significant both for platelets and granulocytes, was transient. Immune stimulation was dramatic for lymphocytes and subpopulations (CD3+ and NK cells) and for cytolytic functions (NK and LAK activity). This trial establishes the feasibility of administration of high doses of rIL-2, 2 months after autologous BMT. In this setting a 6 day period of continuous infusion of 18 million per m2 per day of Proleukine appears to be a regularly tolerable dosage conducting to a major immune activation and invites further studies to determine the clinical impact of such an approach.

Several reports have documented that leukaemic blasts produce a number of cytokines among them the granulocyte-monocyte colony stimulating factor (GM-CSF). We analysed the structure of the gene that codes for GM-CSF in 44 acute myeloid leukaemia (AML) cases in an attempt to establish whether the autocrine production of GM-CSF was due to a structural gene alteration. No structural alteration was detected in the GM-CSF gene in any of the 44 cases studied. We, therefore, conclude that the autocrine production of GM-CSF by leukaemia blasts is not dependent on gene rearrangement.

The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the growth of multiple myeloma (MM) was investigated in 21 patients with MM. In 17 patients with proliferating myeloma cells in vivo, recombinant GM-CSF significantly increased the endogenous-IL-6-mediated spontaneous myeloma cell proliferation occurring in 5-day cultures of tumor cells in vitro (P less than .01). Furthermore, GM-CSF was detected in 5-day culture supernatants of myeloma bone marrow cells. This endogenous GM-CSF was produced by the myeloma bone marrow microenvironment but not by myeloma cells and contributed to the spontaneous myeloma-cell proliferation observed in 5-day cultures. In fact, this proliferation was partially blocked (67%) by anti-GM-CSF monoclonal antibodies. The stimulatory effect of rGM-CSF was mediated through IL-6 because it was abrogated by anti-IL-6 monoclonal antibodies. rGM-CSF did not reproducibly increase the endogenous IL-6 production in short-term cultures of bone marrow cells of MM patients. Using an IL-6-dependent myeloma cell line (XG-1 cell line), rGM-CSF was shown to act directly on myeloma cells stimulating by twofold their IL-6 responsiveness. rGM-CSF did not induce any IL-6 production in XG-1 cells, nor was it able to sustain their growth alone. Although no detectable GM-CSF levels were found in the peripheral or bone marrow blood of MM patients, it is possible that GM-CSF, produced locally by the tumoral environment, enhances the IL-6 responsiveness of myeloma cells in vivo in a way similar to that reported here in vitro.

We report here 16 autologous bone marrow transplantations (ABMT) for poor prognosis B or pre-B malignancies (16 acute lymphoblastic leukemias (ALL), three Burkitt lymphomas, one multiple myeloma) in 11 adults and five children where in vitro purging was accomplished by means of floating immunobeads. This method was developed to avoid non-specific killing by complement or toxin or batch-to-batch variability and provides a 3 log reduction of tumor in a model of B lymphoid malignancies. Low density bone marrow mononuclear cells were incubated for 30 min at 4 degrees C with anti CD10 (ALB2 Immunotech) and/or anti CD19 (Bg4) monoclonal antibodies (MoAb) and then mixed with low density polypropylene beads precoated with a rat antimouse MoAb. After 1 h at 4 degrees C the beads with target cells were decanted; the depleted marrow was collected through a microfilter and cryoperserved. After immunodepletion the recovery of nucleated cells was 75% with a median of 0.75 x 10(8) cells/kg (range 0.3-3.6) and the recovery of hematopoietic progenitors was 83% with a median of 2.9 x 10(4) CFU-GM/kg. The conditioning regimen consisted of busulfan 16 mg/kg and melphalan 140 mg/m2 for three patients, fractionated total body irradiation (TBI) following melphalan 140 mg/m2 for nine patients, TBI and cyclophosphamide 120 mg/m2 for two patients and TBI associated with melphalan and cyclophosphamide for two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The c-fms proto-oncogene product, which is the receptor for the macrophage colony-stimulating factor CSF-1, is always found expressed in acute myeloid leukemia cells, irrespective of their stage of differentiation according to the FAB classification (Dubreuil P, Torrès H, Courcoul M, Birg F, Mannoni P. Blood 1988;72:1081-1085). We have extended this study and looked for c-fms expression in poorly differentiated myeloid leukemias, in a series of acute leukemias of either T or B origin and in biphenotypic leukemias. We now report that expression of c-fms is still related to the myeloid origin of the leukemic proliferation, but that it can also be found in some acute leukemias presenting clonal rearrangements of the T cell receptor gene. Thus expression of the c-fms/CSF-1 receptor may not be exclusively a marker for myeloid proliferations.

Previous studies have shown that tumor necrosis factors (TNFs) inhibit the proliferative effects of crude or purified colony-stimulating factors (CSFs) on low density human bone marrow cell fractions. In the present study we investigated the effects of TNF alpha on the growth of highly purified CD34+ human hematopoietic progenitor cells (HPC) in response to recombinant CSFs. In short-term liquid cultures (5 to 8 days), TNF alpha strongly potentiates interleukin-3 (IL-3) and granulocyte-macrophage-CSF (GM-CSF)-induced growth of CD34+ HPC, while it has no proliferative effect per se. Within 8 days, the number of viable cells obtained in TNF alpha-supplemented cultures is threefold higher than in cultures carried out with IL-3 or GM-CSF alone. Secondary liquid cultures showed that the potentiating effect of TNF alpha on IL-3-induced proliferation of CD34+ HPC does not result from an IL-3-dependent generation of TNF alpha responsive cells. Limiting dilution analysis indicates that TNF alpha increases both the frequency of IL-3 responding cells and the average size of the IL-3-dependent clones. The potentiating effect of TNF alpha on IL-3- and GM-CSF-dependent growth of CD34+ HPC is also observed in day 7 colony assays. Under these short-term culture conditions, TNF alpha does not appear to accelerate cell maturation as a precursor morphology is retained. Finally, TNF alpha inhibits the relatively weak growth-promoting effect of granulocyte-CSF (G-CSF), which acts on a more committed subpopulation of CD34+ HPC different from that recruited by IL-3 and GM-CSF. TNF beta displays the same modulatory effects as TNF alpha. Thus, TNFs appear to enhance the early stages of myelopoiesis.

A group of polypeptide factors that regulate cell growth and differentiation has been tested for their biological activities on the growth and differentiation of leukemic cells isolated from patients with Acute Myeloid Leukemias (AML). The effects of Transforming Growth Factor beta 1 (TGF beta), Tumor Necrosis Factor alpha (TNF alpha), Interferon gamma (IFN gamma) and LIF-HILDA were compared on leukemic cells cultured in vitro for seven days. Spontaneously growing leukemic cells were selected in order to study either inhibition or enhancement of proliferation induced by these factors. Only TGF beta 1 was found to induce a clear inhibition of leukemic proliferation in all cases tested. Recombinant TNF alpha and IFN gamma were found to induce either inhibition or enhancement of the proliferation on separate specimens. Under the conditions of culture, it was not possible to document any effect of LIF-HILDA. Cell differentiation and cell maturation were documented studying the modulation of cell surface antigens. TGF beta did not modify antigen expression on the cells surviving after 3 days in culture. Both TNF alpha and IFN gamma were found to enhance the expression of adhesion molecules and to a lesser extent, the expression of some lineage associated antigens. No effect of LIF-HILDA on antigen modulation was documented in the cases tested. These data confirm that TGF beta is by itself a potent inhibitor of the myeloid leukemia cells proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Following the observation that, besides acute myeloid leukemia cells, acute lymphoid leukemia cells of either B or T phenotype could express the transcript for the colony-stimulating factor 1 (CSF-1), a growth factor known to be restricted to the monocytic-macrophage lineage, various sources of resting and/or activated T cells and thymocytes were screened for expression of this hemopoietic growth factor. We report here that the CSF-1 transcript was rapidly (7 h) induced in T cells by a variety of stimuli, but was not detectable in either resting T cells or thymocytes. In addition, secretion of CSF-1 was detectable in the supernatants of activated T cells by 72 h, with a peak around 92-120 h. In contrast to activated monocytes, the transcript of the c-fms proto-oncogene, the product of which is the receptor for CSF-1, was not detectable in either resting or activated T cells. This observation could be relevant to the intimate relationships between T cells and antigen-presenting cells during immune responses.

A and A1 antigens have been detected on cells of the human erythrocyte series by immunoelectron microscopy. These antigens have been revealed by an indirect method involving various anti-A and anti-A1 antibodies (allo, auto, hetero-antibodies) and peroxidase-conjugated anti-immunoglobulin antibodies. Immunologic labelling has been carried out with erythrocyte or bone marrow cell suspensions which were fixed prior to incubation with reagents. Cells from various A phenotypes were examined. A and A1 antigens were visualized on maturing normoblasts, at every developmental stage. In addition cell to cell variations of the surface labelling of erythrocytes was found in normal phenotypes, suggesting the existence of several populations of cells according to antigenic load.

A successfull bone marrow transplant was achieved in a case of post hepatitic aplastic anemia after cyclophosphamide immunosuppression. Caryotype analysis, erythrocytic phenotype and IgG Gm allotype demonstrated evidence of complete chimerism. Anti-thymocyte serum undoubtly was able to suppress a life threatening episode of graft versus host reaction. Severe long lasting skin lesions are now persisting 2 years after the graft.

The effects of human recombinant granulocyte and granulocyte-macrophage- (G- and GM-CSF), and of purified macrophage-stimulating factors (CSF-1), were tested on populations of leukemia cells isolated from 18 patients with different types of acute myeloid leukemia. Cell proliferation and differentiation were studied by culturing the cells in suspension for 7 days in the presence of CSF or medium alone. Spontaneous cell proliferation, as assessed by tritiated thymidine uptake, was observed in 9 of the 18 cases. GM-CSF induced proliferation in seven of the nine cases without spontaneous growth and increased spontaneous proliferation in nine cases. G-CSF added alone was also found to strongly stimulate leukemic blast cell proliferation, in which a translocation involving the long arm of chromosome 17 was observed. Low levels of CSF-1 stimulation were also observed in some cases. No clear morphological modification supporting evidence of terminal differentiation was observed, whereas modulation of some cell surface antigens was detected by flow cytometry. Thus, most leukemia cells still depend on growth factors for their proliferation, GM-CSF appearing the most effective. On the other hand these factors were not able to induce terminal differentiation.

A1 and A alloantigens were visualized on human erythrocytes and normoblasts by immunoelectron microscopy using peroxidase-coupled antibodies. Specimens were obtained from patients with preleukemia and associated antigen weakening, and from individuals with normal antigen values. Cells were fixed by glutaraldehyde and subsequently reacted with antibodies.

Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315-43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1, 80H.3, and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (IgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (IgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence, i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited CFU-GM growth stimulated by leukocyte feeder layers or placental conditioned media, but did not inhibit BFU-E and CFU-E. Antigens recognized by 80H.3, 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis.

A law issued on december 22, 1976 and aimed at increasing the number of kidney transplantations in France authorizes the removal of kidneys from deceased persons of full age provided they had not expressed refusal while still alive; for decreased persons under age, removal is subject to written consent of the legal representative. In a general teaching hospital of whose than 1 000 beds, 21 kidneys donors were operated upon between January 1, 1971 and December 31, 1975 (an average of 4.2 per year). A kidney transplantation team was developed in 1976. Between January 1, 1976 and August 31, 1979, 83 kidneys donors were operated, an average of 22.6 per year. Ninety-five per cent (59/62) of the kidneys removed and transplanted in the hospital began to function (diuresis greater than 2 ml/min) within minutes of releasing the clamp, no matter how long cold ischaemia had lasted. The increase in kidney removal and transplantation may be attributed to the fact that motivation was maintained among the various units concerned (anaesthesia and intensive care, neurosurgery, neuroradiology) by sustained information and teaching.

The effects of combinations of recombinant human growth factors (colony-stimulating factor (CSF], interleukin 3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granulocyte colony stimulating factor (G-CSF) for inducing proliferation of leukemic cells were compared in 27 acute myeloid leukemias (AMLs). While functional heterogeneity of AML was clearly shown, we further demonstrated that optimal growth may be obtained with combinations of CSF. The most striking feature was that, in both suspension and semisolid cultures, IL-3 and G-CSF acted synergistically in supporting AML cell proliferation except in cases for which G-CSF was found to be an inhibitory factor. In the majority of cases, the proliferative effects of the IL-3 and GM-CSF combination were significantly higher than the most potent of either factor present alone in the cultures. Finally, preincubation with IL-3 greatly potentiated the responsiveness of AML cells to subsequent addition of either GM-CSF or G-CSF. These results indicate that AML cells respond to growth factor in the same way as normal hemopoietic cells and that stimulation by a second late-acting growth factor such as G-CSF is also required to yield optimal growth.

A patient with non-systemic idiopathic glomerulonephritis was found to have a complete deficiency of C2, the second component of complement. The clinical course, histological findings and serological abnormalities are reported in detail. The renal disease was a mild glomerulonephritis with mesangial and subendothelial immune deposits comprising IgG, IgM and C3, increased mesangial matrix without significant cell proliferation. An immunogenetic analysis of the patient's family was carried out. It was demonstrated that the homozygous C2 deficiency was associated with heterozygotism for HLA-A, B and D. Only one of the C2 deficient genes was associated with the expected HLA-A10, B18 haplotype and the propositus was HLA-D2 negative. This report confirms the fact that non-systemic glomerulonephritis should be included in the variety of immunological disorders associated with a complement deficient state. However, C2 deficiency does not seem to be related specifically to a given histological variety of glomerulonephritis.