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A Waheed

Publications and source records attributed to A Waheed.

At least 145 records · Page 8Linked to original sources
PubMed1987

The effect of colony stimulating factor-1 in vivo.

The present studies were undertaken to determine whether colony stimulating factor-1 (CSF-1) stimulates hemopoietic cell proliferation and differentiation in vivo. Groups of mice were injected with 25,000 units of pure, endotoxin-free L-cell CSF every 6 hours for intervals up to 8 days. Virtually no changes were detected in blood neutrophils or monocytes. No consistent increases in marrow granulopoiesis were noted. Variable but inconsistent changes in marrow and splenic progenitor cells were noted. Serum CSF was elevated 2 hours after injection but returned to baseline values within 4-6 hours. These studies indicate essentially no effect from exogenous administration of purified CSF; however, higher doses of this factor will be required in further studies.

Animals↗
PubMed1987

Macrophage colony-stimulating factor enhances the expression of Fc receptors on murine peritoneal macrophages.

Experiments were performed to test the postulate that macrophage colony-stimulating factor (M-CSF) modulates the expression of specific membrane structures on mature murine macrophages. Resident peritoneal macrophages were incubated with M-CSF for 48-72 hr and analysed for Fc receptor and Ia antigen expression. M-CSF treatment of macrophages increased the expression of Fc receptors two- to three-fold over that of unstimulated macrophages. The effect was detected at 1 U/ml of M-CSF, with maximal expression between 100 and 500 U/ml. The specificity of the enhancement was indicated by two sets of experiments. Purified rabbit anti-M-CSF IgG, but not normal rabbit IgG, inhibited the M-CSF-mediated Fc receptor enhancement. Also, a highly purified M-CSF preparation, which was essentially free of endotoxin and interferon, was active in these assays. M-CSF augmented both major types of IgG Fc receptors, FcR I (recognizing IgG 2a) and FcR II (recognizing IgG 2b/IgG1). A second membrane marker, the Ia antigen, was induced by recombinant IFN-gamma (rIFN-gamma) but not by M-CSF. These results indicate that M-CSF is an inducer of two classes of IgG Fc receptors on mature tissue macrophages.

Animals↗
PubMed1987

The influence in vivo of murine colony-stimulating factor-1 on myeloid progenitor cells in mice recovering from sublethal dosages of cyclophosphamide.

Pure murine colony-stimulating factor-1 (CSF-1) was assessed for its effects in vivo in mice pretreated seven days earlier with a sublethal dosage of cyclophosphamide. The multipotential (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells in these mice were in a slowly cycling or noncycling state. Intravenous administration of 20,000 units of CSF-1 to these mice stimulated the hematopoietic progenitors into a rapidly cycling state in the marrow and spleen within three hours. Significant increases in absolute numbers of marrow and spleen CFU-GM and spleen BFU-E and CFU-GEMM were also detected. No endotoxin was detected in the CSF-1 preparation by Limulus lysate assay, and treatment of CSF-1 at 100 degrees C for 20 to 30 minutes completely inactivated the in vitro and in vivo stimulating effects. The effects of CSF-1 were not mimicked by the in vivo administration of 0.1 to 10 ng Escherichia coli lipopolysaccharide. These results suggest that the effects of CSF-1 in vivo were not due to contaminating endotoxin or to a nonspecific protein effect. CSF-1 did not enhance colony formation by BFU-E or stimulate colony formation by CFU-GEMM in vitro, thus suggesting that at least some of the effects of CSF-1 noted in vivo are probably indirect and mediated by accessory cells.

Animals↗
PubMed1986

Peritoneal macrophages exposed to purified macrophage colony-stimulating factor (M-CSF) suppress mitogen- and antigen-stimulated lymphocyte proliferation.

The effect of M-CSF-exposed macrophages on murine splenic lymphocyte responses was determined. Resident peritoneal macrophages incubated with purified M-CSF for 48 hr inhibited lymphocyte proliferation to Con A, PHA, and listerial antigen as determined by [3H]TdR uptake, and inhibited Con A-stimulated lymphocyte IL 2 production. The inhibition was similar to that observed with macrophages from BCG-infected mice. Maximal suppression occurred at M-CSF concentrations of 500 U/ml or greater and when the incubation time with M-CSF was 48 hr or more. M-CSF effect was specific because rabbit anti-M-CSF IgG blocked the suppression whereas control rabbit IgG did not. Secretory products of macrophages could not be implicated in this interaction. Catalase and indomethacin, alone or together, did not reverse the inhibition. In addition, putative suppressive factors were not detected in supernatants of M-CSF-stimulated macrophages. Lymphocytes that were removed from macrophage monolayers and were recultured in medium plus Con A were able to proliferate. Macrophages stimulated by M-CSF therefore appear to have inhibitory activity for proliferating lymphocytes, and may play a role in immunoregulatory mechanisms.

Animals↗
PubMed1986

Persistent production of colony-stimulating factor (CSF-1) by cloned bone marrow stromal cell line D2XRII after X-irradiation.

The adherent stromal layer in long-term bone marrow cultures (LTBMC) provides the cellular environment necessary for the in vitro proliferation and differentiation of pluripotential hematopoietic stem cells. The role of humoral hematopoietic growth factors, colony-stimulating factors (CSF) in the regulation of hematopoietic cell production in this system is poorly understood. We have recently isolated and cloned an adherent cell line, D2XRII, derived from murine LTBMC. Plateau phase 25 cm2 cultures of 2 X 10(6) D2XRII cells in 8.0 ml produced CSF-1 (M-CSF) at around 100-150 units/0.1 ml medium. Following X-irradiation there was a dose-dependent decrease in the production of CSF-1 to a plateau of 50% of control levels at 10,000 rad. Higher doses did not produce a further decrease. The X-ray dose reducing CSF-1 production to 50% was 100-fold above the lethal dose as measured by clonagenic survival following trypsinization and replating. Trypsinized replated viable adherent but nondividing X-irradiated D2XRII cells were maintained for up to 8 weeks after irradiation and demonstrated continuous production of CSF-1. The data indicate significant divergence of two biologic effects of X-irradiation on plateau-phase marrow stromal cells: physiologic function of adherence and CSF-1 production, versus proliferative integrity. This divergence of effects may be very relevant to understanding the mechanism of X-irradiation-associated marrow suppression and leukemogenesis.

Animals↗
PubMed1986

Stimulatory effects of purified macrophage colony-stimulating factor on murine resident peritoneal macrophages.

A purified preparation of macrophage colony-stimulating factor (M-CSF) free of interferon and endotoxin activity was studied for its effects on resident murine peritoneal macrophages. M-CSF was found to induce profound morphologic alterations in resident macrophages. These changes included a marked increase in cell size, membrane ruffling, and cytoplasmic vacuolization. Further, after 72 hr of incubation with 1000 U/ml of M-CSF, there were significant increases in macrophage DNA synthesis as measured by autoradiography (P less than 0.001), and in macrophage monolayer protein content (P less than 0.01). None of these changes was seen in control macrophages or those exposed to recombinant interferon-gamma (IFN). Low activity levels of the ectoenzymes 5'-nucleotidase (5'NTD) and alkaline phosphodiesterase I (APD) have been associated with certain macrophage functions, particularly the expression of tumor cytotoxicity. Macrophage monolayers exposed to M-CSF demonstrated an unaltered level of 5'NTD activity from controls and a significantly increased level of APD activity (P less than 0.01) and did not demonstrate an increased ability to kill tumor cells, as measured by the 51Cr-release assay. On the other hand, IFN caused significant decreases in both 5'NTD (P less than 0.05) and APD (P less than 0.01) and also induced marked tumoricidal activity in macrophage monolayers. These results indicate that purified M-CSF induces highly specific alterations in the functional activity and morphologic appearance of resident macrophages and these changes are distinct from those induced by IFN.

5'-Nucleotidase↗
PubMed1986

The effects in vivo of purified preparations of murine macrophage colony stimulating factor-1, recombinant murine granulocyte-macrophage colony stimulating factor and natural and recombinant murine interleukin 3 without and with pretreatment of mice with purified iron-saturated human lactoferrin.

The influence of purified natural colony stimulating factor-1 (CSF-1), purified recombinant granulocyte-macrophage (GM)-CSF, purified recombinant interleukin 3 (IL3) and natural IL3 were assessed in mice that were untreated or pretreated with purified iron-saturated human lactoferrin (LF) in order to first suppress myelopoiesis in the mice. S1/S1d mice responded to recombinant GM-CSF and recombinant IL3 in a manner similar to the response of their +/+ littermates. These 4 factors increased the cycling status of hematopoietic progenitors in vivo. The effects were more noticeable if myelopoiesis was first decreased by LF. The effects do not appear to be due to endotoxin contamination. It cannot be discerned from these studies whether the effects are direct ones on the progenitor cells or indirect ones mediated through growth-factor releasing accessory cells. It is possible that effects can be both direct and indirect.

Animals↗
PubMed1986

Biosynthesis and processing of prostatic and lysosomal acid phosphatases in a prostate carcinoma cell line PC-3SF12.

The biosynthesis of distinct prostatic and lysosomal acid phosphatases is demonstrated using a human prostatic carcinoma cell line, PC-3SF12. The biosynthesis and maturation of the acid phosphatases was studied by metabolic labeling with radioactive leucine, specific immunoprecipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography. Of the tartrate-inhibitable acid phosphatase activity in PC-3SF12 cells, 60% is lysosomal and 10% is prostatic. The lysosomal-type acid phosphatase is synthesized as precursor with a molecular weight of 68,000, some of which is converted to higher-molecular-weight precursor polypeptides (Mr 71,000 and 77,000). The multiple forms of the precursors are due to differences in the carbohydrate chains on the enzyme because biosynthesis in the presence of tunicamycin eliminates the precursor multiplicity. The initial precursor (Mr 68,000) is processed to a mature polypeptide (Mr 49,000), via intermediates with molecular weights of 62,000 and 59,000. The mature polypeptide is degraded to smaller polypeptides with molecular weights of 30,000, 28,000, and 25,000. Precursor polypeptides of the lysosomal-type enzyme are secreted in the medium. Prostatic acid phosphatase is synthesized as a precursor with a molecular weight of 110,000, which is processed via several intermediates (Mr 99,000-93,000, 77,000, and 55,000) to a mature polypeptide with a molecular weight of 49,000. Particularly during cell homogenization, or lysis, the mature polypeptide is rapidly degraded to an immunoprecipitable polypeptide with a molecular weight of 20,000. None of these polypeptides is secreted in detectable amounts into the medium. Precursors and mature and smaller polypeptides are present in human prostate extract and seminal fluid. Proteolytic degradation of prostatic acid phosphatases in cells and tissues is probably catalyzed by a plasmin-like or related trypsin-like enzyme because degradation of the mature prostatic phosphatase polypeptide is completely prevented by addition of the plasmin inhibitor bovine pancreatic trypsin inhibitor. Prostatic- and lysosomal-type acid phosphatases are eventually stored at least in part in two different types of cell organelles. Testosterone does not influence the biosynthesis and secretion of either acid phosphatase in this cell line.

Acid Phosphatase↗
PubMed1986

The effects of interleukins and other soluble factors on T-lymphocyte colony formation.

When plated in semi-solid media, PHA-stimulated human peripheral blood mononuclear cells (PBMC) form discrete T-cell colonies. By contrast, Sephadex G-10 non-adherent (NA) cells (greater than 96% T lymphocytes) show virtually no clonal growth unless cocultured with soluble factors derived from either normal adherent cells or tumour cell lines. Purified IL-1 was able to initiate colony growth of mitogen-stimulated NA cells; cultures containing 20 U of human IL-1 yielded colony counts that were only slightly less than those with PBMC. In addition, recombinant IL-2, free of measurable IL-1, was able to provide the initiating signal required for clonal expansion. Both recombinant and lymphocyte-derived IL-2 were able to enhance the clonal growth of PBMC. Colony growth could be initiated by supernatants derived from short-term cultures of either monocytic (U937, HL60) or B-cell (Raji, Daudi) tumour cell lines. The abilities of these tumour cell lines to promote clonal responses did not correlate with their contents of either IL-1 or IL-2. By contrast, supernatants derived from either K562 (an erythroleukaemic line) or MOLT 4 (a T-cell lymphoma) cells did not provide the initiating signal.

Antibodies, Monoclonal↗
PubMed1986

Regulation of diffusion-chamber granulopoiesis by colony-stimulating factor.

Studies were undertaken to examine the role of colony-stimulating factor (CSF) in controlling murine peritoneal diffusion-chamber (DC) granulopoiesis. Serum CSF was unchanged for 1-3 days after 700-750 rad total body irradiation. Variable increments were noted on the fourth and seventh days after irradiation. DC CSF increased four- to fivefold over serum activity within 24 h of implantation in control mice. An eight- to tenfold increment over serum levels was noted in DC CSF from irradiated mice. Both serum and DC CSF were neutralized completely by repeated injections of anti-CSF serum. DC granulopoiesis was studied by immobilizing marrow cells in plasma clots in peritoneal DC. Repetitive administration of anti-CSF serum or a purified monospecific anti-CSF antibody caused a marked reduction in DC granulopoiesis. This was characterized by a decrease in both the number and size of granulocyte colonies, with a 40%-80% decrease in total granulocytes per chamber. These findings indicate that the granulopoiesis observed in the DC of irradiated hosts is associated with an increase in local rather than systemic CSF production. Neutralization of the CSF reduces proliferation of the granulocyte progenitor cell and maturation of more differentiated granulocytic cells.

Animals↗
PubMed1985

Biosynthesis of prostatic acid phosphatase in a normal human cell-line.

The biosynthesis of the prostatic form of human acid phosphatase was studied in normal embryonic lung cells, WI-38, by metabolic labeling with tritiated leucine and [32P]phosphate, followed by specific immunoprecipitation, gel electrophoresis, and fluorography. Of the total tartrate-inhibitable acid phosphatase activity in WI-38 cells, 30% is due to the prostatic form. The primary translation product that leads eventually to the mature prostatic enzyme is a precursor polypeptide of 112 kDa. The precursor polypeptide is processed to mature polypeptides of 59, 55, and 49 kDa via an intermediate 91-kDa precursor. WI-38 cells also secrete a 113-kDa peptide into the medium. The precursor and mature polypeptides are glycosylated and phosphorylated. Upon treatment with endo-beta-hexosaminidase H, the apparent molecular weighs of the polypeptides are reduced by approximately 4 kDa and phosphate is lost.

Acid Phosphatase↗
PubMed1985

Biosynthesis and processing of lysosomal acid phosphatase in cultured human cells.

The biosynthesis of lysosomal acid phosphatase was studied in a normal human embryonic lung cell line, WI-38. Cells were labeled with radioactive leucine under a variety of conditions, the enzyme was immunoprecipitated using a monospecific antiserum raised against human liver lysosomal acid phosphatase, and the products were separated by electrophoresis and were visualized by fluorography. Lysosomal acid phosphatase constitutes 60% of the total tartrate-inhibitable acid phosphatase in WI-38. It is initially synthesized as a high-molecular-weight precursor polypeptide of 69 kDa. The precursor polypeptide is rapidly glycosylated and processed to a mature enzyme of 53-45 kDa via intermediates of 65 and 60 kDa in WI-38 cells. The 69-kDa precursor polypeptide is also converted to larger precursor polypeptides of 74 and 80 kDa. The multiplicity of precursor polypeptides is due at least in part to differences in the glycosylation and phosphorylation of the polypeptides. Sensitivity of phosphorylated oligosaccharide chains from precursor, mature and small polypeptides to endo-beta-hexosaminidase H-catalyzed cleavage suggests the presence of high-mannose phosphorylated oligosaccharide chains similar to those present on many other lysosomal enzymes. The effects of tunicamycin and ammonium chloride were also studied. In contrast to the effect of ammonium chloride on arylsulfatase A secretion, the lysosomal acid phosphatase in WI-38 cells was not secreted in the presence of NH4Cl. This is consistent with the existence of an alternate route for the transfer of lysosomal acid phosphatase into lysosomes. This alternate route may be the reason that I-cell fibroblasts contain a normal level of lysosomal acid phosphatase.

Acid Phosphatase↗
PubMed1985

Phosphorylation and sulfation of arylsulfatase A accompanies biosynthesis of the enzyme in normal and carcinoma cell lines.

Arylsulfatase A (arylsulfate sulfohydrolase, EC 3.1.6.1), a mammalian lysosomal enzyme, is initially synthesized as a 69, 67 and 64 kDa precursor polypeptide in a prostate carcinoma cell line PC-3SF12, in HeLa cells and in a normal human embryonic lung cell line WI-38, respectively. These precursor polypeptides are secreted into the medium or processed to mature enzymes of apparent molecular mass 66, 64 or 62 kDa in PC-3SF12, HeLa or WI-38 cells, respectively. The precursor and mature polypeptides in WI-38 cells are phosphorylated, and the phosphate is lost upon treatment with endo-beta-hexosaminidase H. Arylsulfatase A is also shown to be sulfated in WI-38 cells. The presence of castanospermine, an inhibitor of sulfation of the second N-acetylglucosamine residue of the chitobiose core, does not reduce the extent of sulfation of arylsulfatase A, suggesting that either terminal sugars or the protein is sulfated. Sulfation may have a protective function similar to that of terminal sialic acid residues in glycoproteins. Although the subcellular location of arylsulfatase A is identical in PC-3SF12 and in WI-38 cells, pulse-chase experiments indicate that arylsulfatase A protein has a slower turnover in the prostate carcinoma cell line than it does in the normal human lung cell line. The differences in the apparent molecular weights of arylsulfatase A in the normal and carcinoma cell lines are shown to be due to variations in the carbohydrate content of the enzyme. The apparent molecular mass of the polypeptide chain obtained after endo-beta-hexosaminidase H treatment is 59 kDa, a value which is identical for all three cell lines studied here. These results suggest the possibility of an enhanced activity of terminal glucosyltransferase enzymes in carcinoma cell lines and in tumor tissues. Arylsulfatase A may be a useful marker for studying transformation-related processes in human cell lines.

Cell Line↗
PubMed1985

Sulfhydryl groups of rabbit liver arylsulfatase A.

Rabbit liver arylsulfatase A (aryl-sulfate sulfhydrolase, EC 3.1.6.1) monomers of 130 kDa contain two free sulfhydryl groups as determined by spectrophotometric titration using 5,5'-dithiobis(2-nitrobenzoate) and by labeling with the fluorescent probe 5-(iodoacetamidoethyl)aminonaphthalene-1-sulfonic acid. Fluorescence quenching data indicate that the reactive sulfhydryl is present in proximity to one or more tryptophan residues. Chemical modification of the sulfhydryl groups does not alter the distinctive pH-dependent aggregation property of the arylsulfatase A. The free sulfhydryls of the enzyme react with numerous sulfhydryl reagents. Based on the reactions of iodoacetic acid, methyl methanethiosulfonate, 5,5'-dithiobis(2-nitrobenzoate) and 5-(iodoacetamidoethyl)aminonaphthalene-1-sulfonic acid with the sulfhydryl groups of arylsulfatase A, it is concluded that free sulfhydryls are not essential for the enzyme activity. In contrast, the observed inactivation of the enzyme by p-hydroxymercuribenzoate or p-hydroxymercuriphenylsulfonate is probably due to a modification of a histidine residue, consistent with previous reports that histidine is near the active site of arylsulfatase A. p-Hydroxymercuribenzoate and p-hydroxymercuriphenylsulfonate are able to react both with cysteine and with histidine residues of the protein molecule.

Animals↗
PubMed1985

Structural and immunochemical characterization of human urine arylsulfatase A purified by affinity chromatography.

Arylsulfatase A (aryl-sulfate sulfohydrolase, EC 3.1.6.1) was isolated from an ammonium sulfate precipitate of urinary proteins using two different affinity chromatography methods. One method involved the use of concanavalin A-Sepharose affinity chromatography at an early stage of purification, followed by preparative polyacrylamide gel electrophoresis. The other procedure employed arylsulfatase subunit affinity chromatography as the main step and resulted in a remarkably efficient purification. The enzyme had a specific activity of 63 U/mg. The final preparation of arylsulfatase A was homogeneous on the basis of polyacrylamide gel electrophoresis at pH 7.5, and by immunochemical analysis. However, when an enzyme sample obtained by either method of purification was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing or non-reducing conditions, peptide subunits, of 63.5 and 54.5 kDa, were observed. Immunological tests with 125I-labeled enzyme established the presence of a common protein component in both of the electrophoretically separable peptide subunits of human urine arylsulfatase. The amino acid analysis of homogeneous human urine arylsulfatase A showed only a few differences between it and the human liver enzyme. However, immunological cross-reactivity studies using rabbit anti-human urine arylsulfatase revealed immunological difference between the human urine and liver arylsulfatase A enzymes.

Amino Acids↗
PubMed1985

Immunological characterization of human acid phosphatase gene products.

The immunological cross-reactivity of heterogeneous acid phosphatase isozymes from different human tissues has been studied using monospecific antisera prepared against four homogeneous acid phosphatases. The enzyme characterized as tartrate-inhibitable, prostatic acid phosphatase is also found to be present in leukocytes, kidney, spleen, and placenta. The tartrate-inhibitable (liver) lysosomal enzyme is also found in kidney, fibroblasts, brain, placenta, and spleen, but it is not detectable in erythrocytes and prostate. In several tissues, 10-20% of the tartrate-inhibitable enzyme is not precipitated by any of the antisera used; an exceptionally high amount (54%) of such an enzyme is present in human brain. Antiserum against a low molecular weight tartrate-resistant liver enzyme (14 kDa) does not crossreact with the erythrocyte enzyme. (10-20 kDa). All other tissues except placenta, prostate, and fibroblast cells show a cross-reactivity with the 14-kDa acid phosphatase antiserum. Thus, the low molecular weight human liver acid phosphatase is distinct from the erythrocyte enzyme, and there are also at least three different tartrate-inhibitable acid phosphatases in human tissues. Chromosomal assignments have been made for only two of the (at least) five acid phosphatases that are present in adult human tissues.

Acid Phosphatase↗