Changes in the patterns of protein phosphorylation associated with granulocytic and monocytic-induced differentiation of HL-60 cells

Using two-dimensional gel electrophoresis we have analyzed the pattern of phosphorylated proteins in HL-60 leukemia cells and changes associated with their differentiation into granulocyte and monocyte-like cells. In undifferentiated cells 18 spots with MW ranging from 110 to 17, kDa were individualized with high resolution and reproducibility. Myelocytic differentiation induced by dimethyl sulfoxide (DMSO) and retinoic acid (RA) resulted in a decrease of the overall phosphorylation, the disappearance of two proteins of 42 and 17 kDa, and the appearance of one new acidic protein of 46-48 kDa. These changes seem to be specifically related to this differentiation pathway since they are not found in two HL-60 subclones resistant to DMSO or RA-induced differentiation. Monocytic differentiation induced by 1,25-dihydroxyvitamin D3 [1,25 (OH)2D3] and the combination of RA + 1-B-D-arabinofuranosyl cytosine (Ara-C) was associated with the appearance of 2 proteins of 68 kDa and 2 proteins of 80 kDa located in the acidic region of the gel. The protein of 17 kDa, when disappeared completely in granulocytic-like cells was present in monocytic cells, this suggesting that its phosphorylation state may be involved in the control of the differentiation pathway of HL-60 cells. Data concerning the effect of phorbol myristate acetate (PMA) and histamine on the level of phosphorylation of various proteins in HL-60 cells have also been obtained and discussed. Our results show that the myelocytic and monocytic phenotypes are characterized by a specific pattern of phosphoproteins involving both phosphorylation and dephosphorylation reactions.

Differential expression of HLA-DR and HLA-DC/DS molecules in a patient with hairy cell leukemia: restoration of HLA-DC/DS expression by (12-0-tetradecanoyl phorbol-13-acetate), 5 azacytidine, and sodium butyrate

Biosynthesis and molecular structure of major histocompatibility complex (MHC) class II antigens of DR2/DR7 hairy cells were analyzed by two-dimensional polyacrylamide-gel electrophoresis (2D-PAGE). Two anti-human Ia monoclonal antibodies (mAb) were used to immunoprecipitate DR and DR-linked DC/DS molecules. Monoclonal antibody VI 15 C recognizes DR (I-E-like) molecules and CA 2.06 precipitates DR and DR-linked DC/DS (I-A-like) molecules in DR7 allotypes. Studies were performed on a pure population of hairy cells before and after culture with phorbol ester: 12-O-tetradecanoyl phorbol-13-acetate (TPA), 5 azacytidine (5 Aza), sodium butyrate (NA-BU), and phytohemagglutinin (PHA-P). Before any treatment, hairy cells expressed and synthesized DR antigens: DR alpha and beta subunits appeared both qualitatively and quantitatively normal by 2D-PAGE profile. In contrast, the hairy cells failed to express and synthesized any DC/DS molecule. The lack of DC/DS molecular expression was restored after culture in presence of TPA, sodium butyrate, and 5 azacytidine, but not after PHA-P treatment. Differential molecular expression of MHC class II antigens in leukemic cells provides a model to define further discrete stages of hemopoietic differentiation and study the role of these molecules in the cellular interactions occurring during differentiation.

Inhibitory effects of peripheral blood cells on in vitro colony formation by autologous bone marrow in aplastic anaemia: relation with response to immunosuppressive therapy

The inhibitory activity of peripheral blood lymphocytes on autologous bone marrow was studied in 27 patients with aplastic anaemia after treatment with androgen. Inhibitory activity was hard to assess in 10 patients studied during the first year of treatment. The colony count was too low to be certain of differences between the samples incubated with or without lymphocytes. Among the 17 patients who had more than 10 colonies per 2 x 10(5) mononuclear bone marrow cells, nine showed inhibitory activity by peripheral blood lymphocytes. After 12 months of androgen therapy each of these patients showing inhibitory activity of bone marrow colony forming cells by peripheral lymphocytes responded to antithymocyte globulin. None of nine patients with few colony forming cells or no inhibitory activity of lymphocytes responded to immunosuppression.

Syndrome of neutrophil agranulocytosis, hypogammaglobulinemia, and thymoma

The clinical, hematologic, and immunologic findings of a syndrome of agranulocytosis, hypogammaglobulinemia, and thymoma are described. Neutrophil agranulocytosis predisposing to severe infectious disease resulted from a deficiency of mature cells in bone marrow. Autologous and heterologous stem cell growth in vitro was inhibited by the patient's serum. Immunoglobulin deficiency was secondary to the absence of peripheral blood B lymphocytes, while T-cell subpopulations and cellular immunity were present. Surgical removal of a spindle cell thymoma had no effect on the agranulocytosis and B-cell deficiency. The hematologic findings did not respond to steroid therapy and cyclophosphamide. However, the agranulocytosis improved with repeated plasmapheresis and the patient achieved a clinical remission.

[Mechanisms and prognosis of neutropenia in Felty's syndrome. 27 cases (author's transl)]

Twenty patients with Felty's syndrome were investigated. Isotopic studies of polymorphonuclear neutrophils, bone marrow biopsies and autoradiographies, and cultures of granulous stem cells showed that neutropenia resulted from three mechanisms acting simultaneously: hypermargination of the neutrophils predominantly in the spleen, decreased production of granulocytes in the bone marrow, and peripheral hyperdestruction of the neutrophils. Anti-granulocyte antibodies were detected in 3/12 patients. Other factors present in the serum of 2/4 patients seem capable of inhibiting the growth of granulocytic stem cells. Secondary bacterial infection (77%) may explain the severity of the prognosis: 13 out of 27 patients died 4 years on average after neutropenia was diagnosed.

Granulocyte progenitor compartments after allogeneic bone marrow grafts

Bone marrow granulocyte colony forming cells (CFU-C) were measured in HLA compatible sibling donor-recipient pairs. The regeneration of granulocytes and CFU-C compartments were also studied in order to evaluate haemopoietic recovery. The number of nucleated bone marrow cells in the donation was 23 +/- 4 X 10 cells, which recipients received (3.5 +/- 0.4) X 10(8) nucleated cells/kg and (1.19 +/- 0.32) X 10(5) CFU-C/kg. This produced a bone marrow reconstitution of (67 +/- 26) X 10(5) CFU-C/kg by day 30. There was a significant correlation between CFU-C/kg and (1) granulocyte count on day 30 (P equal less than 0.05) and (2) the first day of reappearance of neutrophils in the blood (P equal less than 0.05). These results indicate that the speed and completeness of granulocyte regeneration can be predicted by measurement of the size of the CFU-C inoculant in the bone marrow graft.

Survival of CFU-C in recipient blood after bone marrow transplantation

In six patients undergoing allogeneic bone marrow transplantation granulocyte colony and cluster forming units were detectable in the blood up to 24 hours after intravenous marrow infusion. The mean surviving fraction 30 minutes after the end of the infusion was 0.3 for colonies and 0.42 for total aggregates. CFU-C declined logarithmically with time, but a small secondary rise in blood CFU-C occurred 2--6 hours after the end of the marrow infusion. Three patients were plasma-exchanged immediately before the marrow graft for major donor-recipient ABO incompatibility. The proportion of total groups remaining in the blood at 30 minutes was significantly higher in the plasma-pheresed patients (P = less than 0.05), and the secondary rise in CFU-C was less marked, but no correlation of the blood CFU-C decay curve with the subsequent fate of the graft was observed.

Functional study and detection of HLA-D products on fractionated human bone marrow cells

Bone marrow cells from nine normal human volunteers obtained from the Iliac crest, were used in this work for antigen determination and functional studies. The bone marrow aspirated cells were sequentially separated: elimination of erythrocyte, granulocytes and monocytes achieved by Ficoll-Isopaque centrifugation followed by plastic adherence. Purified bone marrow cells were finally separated by size using velocity sedimentation. The slow sedimenting small cells were shown to be mainly T lymphocytes, probably of blood origin. The medium sized bone marrow cells were shown to contain myeloid precursors (CFu-c). Large immature cells were in cycle actively synthesizing DNA molecules. HLA-D and HLA-DR detections on the fractionated cells were performed using three techniques: fluorescence with specific anti HLA-DR allo and xeno antisera; primed lymphocyte typing (PLT) with anti HLA-DR monospecific in vitro primed lymphocytes and detection of the HLA-D stimulating product using the bone marrow fractionated cells as stimulators in a mixed leukocyte culture. Concordant results were obtained with the three techniques. Lymphocytes in the bone marrow express HLA-D products a peripheral lymphocytes. Bone marrow fractions depleted of lymphocytes and monocytes also contain approximately 20% of cells expressing HLA-D products The meaning of the expression of HLA-D products on immature precursors non-lymphoid cells is discussed.

Hydroxyurea suicide study of the kinetic heterogeneity of colony forming cells in human bone marrow

The kinetics of granulomonocyte colony forming cells have been studied in unfractionated normal human bone marrow by hydroxyurea suicide and in cells separated by velocity sedimentation. Sequential studies revealed two subpopulations of colony forming cells, having different sizes and different multiplication potentialities. There are large cells with a high suicide rate which develop small granulocyte and monocyte colonies during the first week of culture in semi-solid agar. Smaller cells develop larger colonies of granulocytes, monocytes and eosinophils between 2 and 3 weeks of culture. Only granulocyte progenitors have a substantial suicide rate in this small cell population. This population is also less responsive to stimulation than is the large cell class, which is a more highly differentiated progeny. The role of these different kinetics of colony forming cells is discussed in the context of the heterogeneity of the in vitro differentiation of neutrophil, monocyte and eosinophil lines.

Variations in granulocyte colony forming cell numbers in adult blood

Blood granulocyte colony forming units (CFU-C) were studied in normal adults to establish: (i) a normal range; (ii) variability due to the culture technique; (iii) variability of blood CFU-C within individuals. Thirty men studied had 98 (range 8--300) CFU-C X 10(3)/1, and 28 women studied had 44 (range 0--260) CFU-C X 10(3)/1. This difference was significant (P less than 0.001). There was also a significant sex difference in the total number of cells forming colonies and clusters per litre; and in the incidence of colony formers and of cluster formers in buffy coat and mononuclear cell blood fractions. CFU-C were assayed in four subjects over a 10 week period. When buffy coat cells were used as a source of colony stimulation the week to week variation in the combined growth of the four subjects was wide (+/- 36%) but with conditioned medium the variation was smaller (+/- 14%). In all subjects colony and cluster growth varied in the same way (r = 0.77, P = .001) but there was no correlation with the total leucocyte count. A 3--4 week cyclical change in CFU-C/1 was found which was independent of the variation inherent in the technique. The physiological significance of the sex difference and the apparent cyclical changes in blood CFU-C are not explained, but the results emphasize the wide fluctuations in CFU-C that may occur in normal individuals.

Bone marrow culture in aplastic anemia

Blood and bone marrow granulocyte colony forming units (CFUc) were assayed in 46 patients with aplastic anemia, and the serum was examined for its inhibitory action on normal CFUc growth. All patients showed a gross reduction in colonies and clusters in incidence and absolute number in the bone marrow and blood. Two proliferative abnormalities of CFUc in aplastic anaemia were identified: a significantly higher than normal cluster to colony ratio (P less than 0.05) and a higher than normal ratio of granulocytes to total aggregates in the bone marrow. Eleven out of 34 patients tested had serum inhibitory to normal CFUc. These patients were indistinguishable from the rest on haematological and CFUc culture characteristics, and no correlation between the results of CFUc assay and haematological severity was found. The results suggest that the CFUc is abnormal in aplastic anaemia, the reduction in pool size being related to a failure of self-renewal, but an immunological role in the pathogenesis of aplastic anaemia remains unproven. The close relationship of CFUc incidence to the percentage of granulocyte precursors in the marrow, together with the failure of the CFUc assay to predict clinical severity, limits the practical use of the assay to the confirmation of diagnosis in aplastic anaemia.

Effect of antilymphocyte globulin on granulocyte precursors in aplastic anaemia

Granylocyte colony forming units (CFU-C) were studied in 22 patients with severe aplastic anaemia before and after treatment with antilymphocyte globulin (ALG). Nine patients showed a clinical response to ALG characterized by a rise in the granulocyte count to over I X 10(9)/1 within 30 d. These patients were distinguished in vitro from non-responders by an increase in CFU-C numbers after incubation of bone marrow cells with ALG, and by the presence of inhibitors of normal CFU-C in the serum in six out of seven patients tested. In responding patients bone marrow CFU-C rose while most non-responding patients showed no change or a fall in CFU-C after treatment. In addition in three out of four responding patients examined serum inhibitors disappeared after treatment. The horse ALG used in this study also stimulated normal CFU-C in vitro. This evidence is contrary to the hypothesis that ALG stimulates CFU-C in aplasia by inactivating an abnormal suppressor lymphocyte population. The nature of the stimulation by ALG remains unclear. But in practice the effect of ALG on bone marrow cells and study of CFU-C inhibitors in serum could be used to select patients likely to respond to ALG treatment.

Marrow graft rejection and inhibition of growth in culture by serum in aplastic anaemia

The sera of 28 patients with aplastic anaemia were examined for their effect on granulocyte colony growth in soft agar. Normal sera did not affect colony growth, but 13 sera from patients with aplastic anaemia, three from multiparous women, and six from patients polytransfused for various disorders caused colony inhibition. This inhibition was not due to the presence of HLA antibodies in aplasia patients because some sera inhibited HLA compatible bone marrow, and polyspecific HLA antibodies were not found in all inhibitory sera. All patients who failed to show engraftment or who rejected their bone marrow graft within three weeks had serum inhibitory to normal bone marrow cell culture, but inhibition could not be demonstrated against autologous bone marrow cells in these patients with aplastic anaemia. The results show that patients with serum inhibitors have an increased risk of early graft rejection and suggest that this rejection is mediated by antibodies directed against bone marrow stem cells.

Treatment of severe aplastic anemia with antilymphocyte globulin and androgens

The etiology of aplastic anemia is unknown. A stem cell lesion caused by a toxin, virus or microenvironment defect is the main hypothesis. An autoimmune origin has been recently suspected. In an attempt to demonstrate the autoimmune origin of the disease, 17 patients with severe aplastic anemia were treated with antilymphocyte globulin (ALG). Nine patients showed no improvement, developed infectious or hemorrhagic complications and died within 1 to 7 months. In contrast, eight patients had a prompt rise of granulocyte and reticulocyte counts. Although the hematological reconstitution is not complete, these eight patients are still alive between 11 months and 24 months after treatment. This study shows that ALG may have a beneficial effect in the treatment of patients with severe aplastic anemia.

Prognostic value of in vitro bone marrow culture in refractory anaemia with excess of myeloblasts

Bone marrow from 17 patients with refractory anaemia with excess of myeloblasts (RAEM) was cultured in methylcellulose semi-solid medium. Compared with normal bone marrow, 3 patterns of growth occurred corresponding with different clinical stages of the condition. Patients whose bone marrow grew normal colonies and those who produced a predominance of microclusters had the longest life expectance, while those who produced a predominance of macroclusters had the shortest life expectancy with a high rate of acute leukaemic transformation. Colony culture appears to be a useful prognostic tool in the condition.

[The action of antilymphocyte serum in severe aplastic anemia (author's transl)]

The etiology of aplastic anemia is unknown. A stem cell lesion caused by a toxic or a virus or a microenvironment defect are the main hypothesis. An auto-immune origin has been recently suspected but never proved. To demonstrate the auto-immune origin of the disease. We have treated 17 patients with severe aplastic anemia with antilymphocyte serum (ALS). Nine patients showed no improvement and seven patients died within two months of infectious or hemorrhagic complications. In contrast, eight patients had a prompt rise of granulocytes and reticulocytes counts. Although the hematological reconstitution is not complete. This eight patients are still alive between 4 months and 15 months after treatment. This study shows that A.L.G. may have a beneficial effect in the treatment of patients with severe aplastic anemia.

[Stimulation of hematopoietic stem cells by antilymphocyte serum]

The physiopathogeny of aplastic anemia is still unknown, it can be related to a stem cell defect or a microenvironment disease. An autoimmune origin is suspected but not as yet proved. To demonstrate the autoimmune origin of some cases of aplastic anemia, we have studied the effect of antilymphocyte globulin (ALG) on the hematopoiesis of aplastic patients by serial hematological and bone marrow investigation including blood counts, bone marrow cellularity, scanning with indium and technetium and granulocytic colonies in agar, 8 out of 17 patients had a response to ALG as shown by a rise of granulocytes and reticulocytes counts, increase of bone marrow cellularity and number of granulocytic colonies. This study tends to show that ALG has a stimulating effect on hematopoiesis in some cases of severe aplastic anemia.