Monoclonal antibody that defines a unique human T-cell leukemia antigen

We have generated and characterized a hybridoma monoclonal antibody, termed SN1, that defines a unique human T-cell leukemia antigen. This antibody was generated by using a human leukemia antigen preparation isolated from cell membranes of MOLT-4, a leukemia T-cell line derived from a patient with T-cell-type acute lymphoblastic leukemia (T-ALL). SN1 was characterized by a sensitive microscale radioimmunoassay using a variety of cultured and uncultured human cells. In selected cases, the cell specimens were further tested by immunoperoxidase staining and an immunofluorescence staining test. The results of the radioimmunoassay were in agreement with those of the two other tests. Among the various cultured malignant and nonmalignant cell lines, SN1 reacted only with leukemia T-cell lines derived from patients with T-ALL; it reacted with all six T-ALL cell lines tested-i.e., JM, CCRF-CEM, CCRF-H-SB2, RPMI 8402, PEER, and MOLT-4. In the case of uncultured cell specimens derived from cancer patients, SN1 reacted with four of four cases of T-ALL but did not react with specimens derived from 41 patients with other types of cancer. SN1 did not react with any normal human cell specimens tested, both cultured and uncultured. These specimens include normal lymphoblastoid cell lines, thymocytes, bone marrow cells, spleen cells, lymph node cells, peripheral blood mononuclear cells, lymphocytes containing B and T cells, purified T cells, monocytes, granulocytes, erythrocytes, and platelets. Furthermore, SN1 did not react with phytohemagglutinin-activated T cells nor with concanavalin A-activated T cells. The results show that monoclonal antibody SN1 defines a type of human leukemia antigen that is expressed on the cell surface of T-cell-type ALL cells. The results further show the usefulness of SN1 in the diagnosis of cancer patients and suggest its therapeutic potential. We designate this antigen TALLA, a T-cell ALL antigen.     

Detection of luxol-fast-blue positive cells in human promyelocytic leukemia cell line HL-60

Differentiation of HL-60 cells toward the eosinophilic series has not been reported previously. Eosinophil granule specific staining with Luxol-fast-blue was used to determine if HL-60 cells could differentiate into the eosinophilic lineage. The specificity of the Luxol-fast-blue stain for cells of the eosinophilic series was substantiated by comparison of the staining of cells from a patient with an eosinophilic syndrome by Wright-Giemsa and Luxol-fast-blue. Luxol-fast-blue positivity was most notable in cells found in colonies formed from HL-60 clonogenic cells in semisolid agar medium. Colony and cluster formation was spontaneous but in the presence of medium conditioned by either human placental cells or the human monocyte-like cell line, GCT, Luxol-fast-blue positive colonies and clusters were detected at a higher frequency.     

Induction of differentiation of the human promyelocytic leukemia cell line (HL-60) by retinoic acid.

The HL-60 cell line, derived from a patient with acute promyelocytic leukemia, proliferates continuously in suspension culture and consists predominantly (greater than 90%) of promyelocytes. These cells can be induced to differentiate to morphologically and functionally mature granulocytes by incubation with a wide variety of compounds, including butyrate and hypoxanthine and polar planar compounds such as dimethyl sulfoxide and hexamethylene bisacetamide. We have now found that retinoic acid (all-trans-retinoic acid) induces differentiation (as measured morphologically and by the ability to reduce nitroblue tetrazolium) of HL-60 at concentrations as low as 1 nM. Maximal differentiation (approximately 90%) occurs at 1 micro M, a concentration 1/500th to 1/160,000th the concentrations of butyrate (0.5 mM) and dimethyl sulfoxide (160 mM) that promote a similar increase in differentiation. Continuous exposure to retinoic acid is necessary for optimal differentiation, with the percentage of mature cells in the culture directly related to the length of time of exposure to retinoic acid. Retinoic acid and 13-cis-retinoic acid are equally effective in inducing differentiation of HL-60. Retinol (vitamin A), retinal, and retinyl acetate are approximately 1/1000th less potent. This study suggests that retinoids could provide a therapeutic tool in the treatment of acute myeloid leukemia, a disease that has been looked upon as primarily involving a block in myeloid differentiation, and indicates that retinoids, in addition to their well-characterized involvement in epithelial cell differentiation, may also be involved in the differentiation of certain hematopoietic cells.     

Insulin binding to the HL-60 human promyelocytic cell line

The HL-60 cell is a human leukemic promyelocyte that can be grown in liquid suspension culture. This cell line binds radiolabeled insulin in a rapid, reversible specific manner indicating that it contains cells surface insulin-binding sites. These sites show a pH optimum of 7.8–8.0.Maximal binding was achieved in approx. 60 min at 22°C and was linear with cell number between 5 × 10⁶ and 10⁸ cells per ml. Displacement of labeled insulin by unlabeled hormone was consistent with a ‘two site’ model with a high affinity site of 2.71 ± 0.55 × 10⁸ M^? and 8700 sites per cell. Release of labeled insulin from its binding site was accelerated by unlabeled insulin at temperatures above 22°C, but not at 4 or 15°C.We conclude that the HL-60 cell contains cell surface binding sites for insulin with properties similar to other well-described insulin receptors of other tissues.     

Characterization of the continuous, differentiating myeloid cell line (HL-60) from a patient with acute promyelocytic leukemia.

In a prelminary communication, we described the establishment of a continuous human myeloid cell line (HL-60). Here we report the detailed properties of this cell line and document its derivation from the peripheral blood leukocytes of a patient with acute promyelocytic leukemia. As characterized by light and electron microscopy, the predominant cell type in both the fresh and cultured sources is a neutrophilic promyelocyte with prominent nuclear/cytoplasmic asynchrony. Up to 10% of the cultured cells spontaneously differentiate beyond the promyelocyte stage, and the proportion of terminally differentiated cells is markedly enhanced by compounds known to stimulate differentiation of mouse (Friend) erythroleukemia cells. The HL-60 cells lack specific markers for lymphoid cells, but express surface receptors for Fc fragment and complement (C3), which have been associated with differentiated granulocytes. They exhibit phagocytic activity and responsiveness to a chemotactic stimulus commensurate with the proportion of mature cells. As characteristic of transformed cells, the HL-60 cells form colonies in semisolid medium and produce subcutaneous myeloid tumors (chloromas) in nude mice. A source of colony-stimulating activity stimulated the cloning efficiency in soft agar 5--30-fold. Despite adaptations to culture, the morphological phenotype and responsiveness to chemical induction of differentiation is essentially unchanged through at least 85 passages. Cytogenetic studies reveal aneuploidy. Metaphases with 44 chromosomes predominated in vivo and in early culture passages; however, clones with 45 or 46 chromosomes became predominant with continued passaging. The most consistent karyotypic abnormalities were the deletion of chromosomes 5, 8, and X and the addition of a marker resembling a D-group acrocentric and of a submetacentric marker, most likely an abnormal E-group chromosome. No DNA herpesvirus or RNA retrovirus was isolated in the fresh or cultured cells. The HL-60 cultured cell line provides a continuous source of human cells for studying the molecular events of myeloid differentiation and the effects of physiologic, pharmacologic, and virologic elements on this process.     

Characteristic expression of glycosphingolipid profiles in the bipotential cell differentiation of human promyelocytic leukemia cell line HL-60

Changes of glycosphingolipids (GSLs) in the bipotential cell differentiation of human promyelocytic leukemia cell line HL-60 cells were investigated by high-performance thin-layer chromatography (HPTLC), with special reference to morphological and functional changes, such as phagocytosis and nitroblue tetrazolium (NBT) reduction. Nine molecular species of neutral GSLs and 13 or more species of sialo-GSLs, ie, gangliosides, were detected on the HPTLC chromatograms for untreated HL-60 cells. The major components were ceramide dihexoside (CDH), GM3, and sialo-paragloboside (SPG). When HL- 60 cells were induced to differentiate into both myeloid mature cells and macrophage-like cells in vitro, no new molecular species of GSLs specific for one of the cell differentiations was induced, but distinctive quantitative changes in the GSL composition were definitely observed between the two cell differentiations. During the myeloid differentiation induced by either dimethylsulfoxide (DMSO) or retinoic acid (RA), CDH, paragloboside (PG), and gangliosides having longer sugar moieties characteristically increased with a concomitant decrease of GSLs with shorter sugar chains, such as ceramide monohexoside (CMH) and GM3, and the GSL composition profile of myeloid differentiation- induced HL-60 cells became more similar to that of normal human granulocytes. However, some marked differences were noted between the induced HL-60 cells and the normal granulocytes, especially in the ganglioside compositions. These differences might reflect either some deficiency in the in vitro myeloid differentiation or some leukemic properties of HL-60 cells. In marked contrast to the change of GSL composition during myeloid differentiation, a remarkable increase of GM3, with a concurrent marked decrease of CDH, was observed in the process of cell differentiation into macrophage-like cells with 12-O- tetradecanoyl-phorbol-13-acetate (TPA), which suggested an increase in the biosynthesis of GM3. These results demonstrate that HL-60 cells express distinct GSL profiles, depending not only on maturation stages but also on differentiation directions.     

Immunoreactive calcitonin production by a human promyelocytic leukemia cell line HL60

Using a sensitive radioimmunoassay, we detected human immunoreactive calcitonin in cell extracts and in cell-exposed media of the HL60 cell line derived originally from a patient with acute promyelocytic leukemia. The cell extract was chromatographed on a reverse-phase high- pressure liquid chromatography system. Radioimmunoassay of the fractions showed that the immunoreactive calcitonin was heterogeneous but had peaks corresponding to those of synthetic human calcitonin monomer and its sulphoxide. We have previously shown that levels of immunoreactive calcitonin are elevated in the plasma of the majority of patients with acute and chronic myeloid leukemias. Our studies with the HL60 cell line add further support to the concept that leukemic cells can synthesize immunoreactive calcitonin "ectopically."     

cGMP-induced differentiation of the promyelocytic cell line HL-60.

cGMP is a second messenger that mediates numerous metabolic events; in the present work a role in myeloid cell differentiation was demonstrated. Nitroprusside and NaNO2, which activate cytosolic guanylate cyclase and increase the intracellular cGMP concentration, induced granulocytic differentiation of the human promyelocytic cell line HL-60; differentiation was measured by acquisition of the OKM1 antigen, morphological changes, and nitroblue tetrazolium reduction. When theophylline, a phosphodiesterase inhibitor, which by itself induced modest differentiation, was added to nitroprusside or NaNO2, differentiation increased in an additive fashion. The degree of differentiation correlated with the increase in the intracellular cGMP concentration. 8-Bromoguanosine 3',5'-cyclic monophosphate, a membrane-permeable cGMP analogue, also induced differentiation of HL-60 cells but was much more effective in the presence of theophylline, with the two agents interacting synergistically. The effect of theophylline in these studies could not be attributed to increasing the intracellular cAMP concentration. Dimethyl sulfoxide, and established inducer of differentiation of HL-60 cells, markedly enhanced the differentiation induced by nitroprusside and NaNO2.     

Combinations of recombinant human interferons and retinoic acid synergistically induce differentiation of the human promyelocytic leukemia cell line HL-60

The human acute promyelocytic leukemia cell line HL-60 is induced to differentiate into morphologically and functionally mature monocytelike cells by incubation with a combination of 10 nmol/L retinoic acid (RA) and various concentrations of recombinant immune interferon (rIFN- gamma). These induced cells show marked increases in antibody-dependent cellular cytotoxicity (ADCC), antibody-coated erythrocyte (EA) rosettes, nonspecific esterase, and 5'-nucleotidase activity. rIFN- gamma alone at concentrations of 10 to 1,000 U/mL has essentially no effect on morphological maturation, nitroblue tetrazolium reduction, and immunophagocytosis. However, rIFN-gamma at these concentrations increases EA rosetting in a concentration-dependent manner that is not affected by 10 nmol/L RA. At a concentration of 1,000 U/ml, rIFN-gamma induces moderate increases in nonspecific esterase, 5'-nucleotidase, and ADCC. These parameters are markedly increased by the addition of 10 nM RA, a concentration which alone has no effect on these markers. Based on units of antiviral activity, rIFN-gamma is tenfold more active than rIFN-alpha D in inducing EA rosettes and 40-fold more active in inducing nitroblue tetrazolium reduction and immunophagocytosis. These results, indicating that combinations of rIFN-gamma or rIFN-alpha and RA synergistically induce differentiation of HL-60, suggest that this combination may have clinical utility in the treatment of patients with certain leukemias.     

Sodium butyrate and a T lymphocyte cell line-derived differentiation factor induce basophilic differentiation of the human promyelocytic leukemia cell line HL-60

Sodium butyrate induces basophilic differentiation of HL-60 promyelocytic leukemia cells that have been previously passaged in alkaline medium. A factor present in Mo conditioned medium (Mo-CM) acts synergistically with sodium butyrate to promote basophilic maturation in a dose-dependent fashion. The induced HL-60 cells exhibit nuclei at various stages of maturity and cytoplasmic granules staining azurophilic with May-Grunwald-Giemsa and metachromatically with toluidine blue. The histamine content of induced HL-60 cells is 50 ng/10(6) cells with sodium butyrate alone or 190 ng/10(6) cells with butyrate in combination with Mo-CM. Induced cells release histamine in response to anti-IgE and have receptors for the Fc portion of human IgE. The basophilic cell-differentiating activity present in Mo-CM appears to be distinct from several other cytokines including recombinant human interleukin-1 alpha, interleukin-2, interferon-gamma, interferon-alpha, murine interleukin-3, erythroid-potentiating activity, and purified human granulocyte/macrophage colony-stimulating factor. This is the first demonstration of a cell line that is capable of differentiation along the basophil lineage and could provide a useful model for examining biochemical and molecular events associated with basophil differentiation.     

Monoclonal antibodies against the human leukemia cell line K 562

Three monoclonal antibodies raised against K 562, a cell line originally established from a patient with chronic myeloid leukemia (CML) in terminal blast crisis, were selected according to their distinct reaction pattern. Whereas two antibodies (ZIK-C1-A/C5 and ZIK-C1-A/H5 also designated C and H) recognized antigens, present on K 562 cells and other immature and mature hematopoietic cells (cell lines and normal blood and bone marrow cells), antibody ZIK-C1-A/D9 also designated Y showed an exclusive binding to K 562 cells. The results obtained (here and in the following paper) indicate, that antibody ZIK-C1-A/D9 defines an early differentiation antigen of hematopoiesis or a leukemia-associated antigen.     

The HL-60 promyelocytic leukemia cell line: proliferation, differentiation, and cellular oncogene expression

The HL-60 cell line, derived from a single patient with acute promyelocytic leukemia, provides a unique in vitro model system for studying the cellular and molecular events involved in the proliferation and differentiation of normal and leukemic cells of the granulocyte/monocyte/macrophage lineage.     

CD7 false-positive acute myelogenous leukemia and promyelocytic leukemia cell line HL-60: characterization of CD7 epitopes by four monoclonal antibodies.

Phenotypes of cells from 12 patients with acute myelogenous leukemia (AML) were analysed by means of a fluorescence-activated cell sorter utilizing a panel of monoclonal antibodies (MAbs). A majority of the cells from peripheral blood coexpressed the antigens against MAbs CD11, CD13, and CD33 but did not express the antigens against CD1, CD3, CD4, CD5, CD8, CD19, CD20, CD21, CD41 and 42, and glycophorin A. Three out of the 12 cases expressed CD7 antigen. However, one of them showed no reaction with Tp40 MAb, whereas the others showed reaction with Leu9 and T55. The discrepancy of reactivities between Leu9 and Tp40 MAbs prompted us to study the promyelocytic leukemia cell line HL-60, which showed similar reactions against Leu9 and Tp40 MAbs. Leu9, OKT16, and T55 MAbs reacted strongly with HL60 cells, whereas Tp40 MAb, which reacted strongly with T-cell leukemia cell line Jurkat, showed no reaction. The reactivity of Leu9, OKT16, and T55 MAbs with HL-60 cells was completely inhibited after preincubation with aggregated human immunoglobulin G (AHIG), which clearly shows the existence of nonspecific binding between these 3 MAbs and HL-60 cells via Fc gamma R. On the basis of our experiments, we conclude that HL-60 cells bind nonspecifically with Leu9, OKT16, and T55 MAbs via FcRI, and this is suggestive that de novo AML cells probably behave in the same fashion. Hence, we recommend that the utilization of murine IgG2a and IgG3 MAbs should be avoided especially in cell surface analysis of myeloid leukemic cells.     

HL-T, a new cell line derived from HL-60 promyelocytic leukemia cell cultures expressing terminal transferase and secreting suppressor activity

A cell line with immature blast cell morphology was isolated from HL-60 promyelocytic leukemia cell cultures and designated HL-T. This new cell type is biphenotypic, expressing terminal transferase (TdT) together with myelomonocytoid immunologic features. TdT enzymatic activity, undetectable in HL-60, was determined to be 140 to 180 units/10(8) HL-T cells by the dGTP-assay, approximately 20% of the activity found in lymphoblastoid cell lines. HL-T predominantly synthesize the known 58- kDa TdT-protein plus a minor 54/56-kDa doublet. The 58-kDa steady state form is nonglycosylated and is phosphorylated. Precursor antigens S3.13 and MY-10, absent on HL-60, are expressed by HL-T; however, the cells are negative for HLA-Dr. Southern blot analysis by hybridization with immunoglobulin heavy chain (JH) and T cell-receptor chain gene (T beta) probes shows JH to be in the germ-line configuration in both cell lines and the T beta gene to be in germ-line in HL-60 but to be rearranged in HL-T. Truncation of the gene encoding the granulocyte-macrophage-colony- stimulating factor (GM-CSF), as found in HL-60, is not observed in HL- T. HL-T are resistant to differentiation-induction by retinoic acid and 1,25-dihydroxyvitamin D3. Cytogenetically HL-T share with HL-60 a deletion of the short arm of chromosome 9 at breakpoint p13, an aberration frequently found in patients with T cell leukemia. In addition, HL-T display t(8;9)(p11;p24) and trisomy 20. Tetraploidy is observed in 80% of HL-T metaphases with aberrations identical to those in the diploid karyotype. Like HL-60, the new line shows some surface- antigenic-T cell characteristics. Despite an antigenic pattern most consistent with that of helper-inducer T cells (T4+, D44+/-, 4B4+, 2H4- , TQ1+/-), HL-T cells and their conditioned culture medium suppress antigen, mitogen, and mixed-leukocyte-culture-mediated lymphocyte proliferation.     

Induction of differentiation of human promyelocytic leukemia cell line HL-60 by retinoyl glucuronide, a biologically active metabolite of vitamin A.

We examined the differentiation activity of retinoyl beta-D-glucuronide, a biologically active physiological metabolite of vitamin A, using the human promyelocytic leukemic cell line HL-60, which can be induced to differentiate with retinoic acid. Retinoyl beta-D-glucuronide (1 microM) inhibited HL-60 cell proliferation by 55-75%, inhibited tritiated thymidine incorporation into DNA by 63-80%, and induced 38-50% of the cells to differentiate into mature granulocytes. The potency of growth inhibition and induction of differentiation by retinoyl beta-D-glucuronide was similar to that of all-trans-retinoic acid. The continuous presence of either retinoyl beta-D-glucuronide or all-trans-retinoic acid was not required to obtain maximum growth arrest and differentiation: a 1-hr exposure of HL-60 cells to the retinoids gave the same response (measured after a total incubation time of 48 hr) as a 24-hr or 48-hr continuous treatment. Retinoyl beta-D-glucuronide (0.1-0.2 mM) was 50% less cytotoxic to HL-60 cells than all-trans-retinoic acid at an equimolar concentration. Retinoyl beta-D-glucuronide was not significantly metabolized to other retinoids; retinoic acid was not formed during incubation. We conclude that retinoyl beta-D-glucuronide can arrest HL-60 cell proliferation and induce their differentiation into mature granulocytes; it may act by itself or by being hydrolyzed to retinoic acid, which could be immediately utilized and metabolized. The therapeutic use of this retinoid as an antineoplastic agent is suggested.     

Effects of human bone marrow stromal cell line (HFCL) on the proliferation,differentiation and apoptosis of acute myeloid leukemia cell lines U937, HL-60 and HL-60/VCR

This study investigated the effects of human bone marrow fibroblastoid stromal cell line (HFCL) on the proliferation, differentiation and chemosensitivity of acute myeloid leukemia cells (AML) in vitro coculture. By setting up coculture system of sensitive U937, HL-60 cell line and multidrug-resistant (MDR) HL-60/VCR cells in direct contact with human bone marrow fibroblastoid stromal cell line HFCL, or separated by transwell, the proliferation of AML cells cocultured with HFCL cells was inhibited, compared with AML cells alone. And NBT positive cells increased slightly. The percentage of G1 phase cells of AML cells cocultured with HFCL cells was higher than that without HFCL cells, and that of S phase cells was lower. The expression of CD11b and CD14 increased. Meanwhile HL-60 and HL-60/VCR cells treated by TPT were observed to have apoptosis characteristic morphological changes. The proportion of G0/G1 HL-60 and HL-60/VCR cells treated with TPT increased and the sub-G1 increased. The percentage of Annexin V-positive cells and apoptotic cells increased with expression of activated Caspase-3 and the reduced expression of Bcl-2. But when they were cocultured with HFCL cells, the percentage of Annexin V-positive cells and apoptotic cells decreased and sub-G1 reduced. After indirect contact with HFCL cells the expression of activated Caspase-3 decreased and the expression of Bcl-2 increased. After direct contact with HFCL cells for 96 h, the expression levels of 582 genes in HL-60 cells were up-regulated, and 1,323 genes were down-regulated at least twofold by Affymetrix GeneChip Human Genome U133 set A. The expression change in some genes, such as HL14, was confirmed by RT-PCR and northern blot. In a word, HFCL cells could inhibit the proliferation, induce the monocytic differentiation of U937, HL-60 and HL-60/VCR cells, and prevent TPT-induced apoptosis in HL-60 and HL-60/VCR cells via modulation of Bcl-2 and active Caspase-3. Many genes might take part in the influence of HFCL cells on AML cells, which may give important insights into the interaction of bone marrow stromal cells and leukemic cells.     

Monoclonal antibody to a human osteogenic sarcoma cell line

Monoclonal antibodies against a human osteogenic sarcoma cell line were prepared by production of a somatic cell hybrids between the spleen cells from U-393OS--immunized mice and the mouse myeloma cells SP2/0. From 7 producing and well-growing clones only one--B-0S12--produced antibodies, reactive preferentially with osteosarcoma cells as identified by binding second antibodies and 125I-labeled Protein A. This antibody was tested against a panel of normal and tumor cell targets to determine the pattern of the antigen detected. The monoclonal antibody reacted strongly against U-3930S cells and another human sarcoma in vitro and more weakly against human fibroblasts, peripheral lymphocytes, red blood cells and was negative against mouse fibroblasts. When tested against a panel of unrelated human tumor cell lines, B-0S12 antibody was positive with melanoma cells and negative with cells from bladder, cervix and mammary carcinoma. These cross reactions suggested, that the antibody is reactive with a protein, expressed on different tumor types. This protein is not expressed on the cell surface and is probably associated with cytoskeleton, as revealed by immunofluorescence experiments. Western-blot analysis of a cytoskeletal preparation of U-3930S cells suggests, that B-0S12 antibody recognizes a protein with Mr 55 kD. Further studies are needed to characterize the molecules, carrying the epitope, identified by this monoclonal antibody.     

Monoclonal antibodies against MHC class II antigens elicited with a human non-T, non-B acute lymphoblastic leukemia cell line

A series of seven monoclonal antibodies recognizing cell surface antigens of similar distribution on a panel of leukemia/lymphoma and lymphoblastoid human cell lines was prepared by hybridoma technique after immunization with non-T, non-B acute lymphoblastic leukemia cell line REH. Immune reactivity of these monoclonal antibodies with B-lymphoblastoid and lymphoma cell lines, as well as with non-T, non-B leukemia cell lines but not with T-leukemic and myeloid leukemic cell lines (with the exception of myeloid leukemia cell line KG 1) was demonstrated by indirect immunofluorescence. No reactivity was observed with the examined human non-hemopoietic tumor cell lines, except melanoma cell lines HMB-2 and SK 1477. These antibodies immunoprecipitated a similar cell surface bimolecular glycoprotein complex consisting of two glycosylated chains (gp30, 35), as demonstrated by immunoprecipitation of cell surface 125I-lactoperoxidase radioiodinated, periodate/tritiated borohydride radiolabeled and 35S-methionine metabolically radiolabeled proteins of REH cells. These properties, typical of MHC class II antigens correspond also to immunoperoxidase staining of lymph nodes with some selected antibodies.     

Glycosyltransferase alterations are cell type related when human promyelocytic leukemia (HL-60) cells are treated with various inducers of differentiation

We have assayed glycosyltransferase activities during the granulocytic and macrophage-like differentiation of human promyelocytic leukemia (HL-60) cells. Functional granulocytic differentiation was assayed by the decarboxylation of 2-deoxyglucose in addition to nitroblue tetrazolium reduction. Dimethylsulfoxide (DMSO) treated HL-60 cells, induced to granulocytic differentiation, had higher 2-deoxy-glucose decarboxylation activity, and contained less sialyltransferase (ST), more fucosyltransferase (FT), and more N-acetylglucosaminyltransferase (NGT) activities than untreated cells. HL-60 cells treated with another granulocytic differentiator, retinoic acid, also had higher 2-deoxyglucose decarboxylation activity, and contained less ST, more FT, and more NGT activities than untreated cells. In contrast, cells treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) reported to differentiate HL-60 to macrophage-like cells, but did not show an increased level of 2-deoxyglucose decarboxylation activity, but contained more galactosyltransferase (GT) and FT activities as compared to untreated cells. These findings suggest that the alterations of glycosyltransferase levels during the differentiation of precursor cells may not depend upon different inducers, but are characteristic of the phenotypic expression of the mature cell type.