lactoferrin has been researched along with Leukemia--Myeloid* in 20 studies
2 review(s) available for lactoferrin and Leukemia--Myeloid
Article | Year |
---|---|
The biological role of lactoferrin.
Lactoferrin (LF)--in various quantities--is present in human milk, secretions and polymorphonuclear neutrophils (PMN). LF's significance lies in its bacteriostatic effect on its environment. Probably it prevents bacterial uptake of iron, leads to damage of bacteria and during phagocytosis helps the organism to combat pathogens. Most likely it regulates iron absorption, and during inflammation it takes part in the plasma iron transport. LF is believed to play an important role in the regulation of granulopoiesis in the bone-marrow. From its biological effects it appears that plasma LF determinations may be useful in the clinical diagnosis of leukaemia and other malignant diseases, as well as in the study of iron metabolism. Topics: Absorption; Animals; Biological Transport; Cell Division; Chronic Disease; Granulocytes; Humans; Inflammation; Iron; Kinetics; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Milk; Pancreatic Neoplasms; Pancreatitis | 1985 |
Normal and leukaemic granulopoiesis.
Topics: Bone Marrow Diseases; Colony-Forming Units Assay; Granulocytes; Growth Inhibitors; Hematopoiesis; Humans; Lactoferrin; Leukemia, Myeloid; Macrophages | 1981 |
18 other study(ies) available for lactoferrin and Leukemia--Myeloid
Article | Year |
---|---|
p120 nucleolar-proliferating antigen is a direct target of G-CSF signaling during myeloid differentiation.
Granulocyte-colony stimulating factor (G-CSF) is an essential cytokine, which contributes to proliferation and differentiation of granulocyte precursor cells in the bone marrow. Despite recent progress in understanding G-CSF signaling events, the mechanisms that underlie the distinct spectrum of biological functions attributed to G-CSF-mediated gene expression remain unclear. Previous studies have identified a number of genes, which are up-regulated in G-CSF-stimulated myeloid precursor cells. In this study, we sought to identify additional target genes of G-CSF-mediated proliferation and/or differentiation. cDNA representational difference analysis was used with the 32Dcl3 cell line as a model system to isolate genes, which are up-regulated in an immediate-early manner upon G-CSF stimualtion. We isolated p120 nucleolar-proliferation antigen (NOL1), a highly conserved, nucleolar-specific, RNA-binding protein of unknown function, and confirmed its expression by Northern blot analysis in 4-h, G-CSF-induced 32Dcl3 cells. Isolation of a mouse p120 genomic clone revealed the presence of a signal tranducer and activator of transcription (STAT)-binding site in the first intron of the gene. We demonstrate the importance of STAT3 and STAT5 in mediating the G-CSF response with respect to p120 expression by transient transfection analysis, oligonucleotide pull-down assays, and the loss of p120 expression in the bone marrow of mice lacking normal STAT3 signaling. In addition, overexpression of p120 in G-CSF-induced 32D cells revealed normal, morphologic maturation and growth characteristics but loss of lactoferrin expression, a marker of normal neutrophil maturation, suggesting that inappropriate expression of the p120 gene can result in aberrant neutrophil maturation. Topics: Animals; Base Sequence; Binding Sites; Cell Differentiation; Gene Expression Regulation; Granulocyte Colony-Stimulating Factor; Humans; Introns; Lactoferrin; Leukemia, Myeloid; Mice; Mice, Transgenic; Myeloid Cells; Myeloid Progenitor Cells; Neutrophils; NIH 3T3 Cells; Nuclear Proteins; Promoter Regions, Genetic; Protein Methyltransferases; Signal Transduction; STAT3 Transcription Factor; STAT5 Transcription Factor; tRNA Methyltransferases; Up-Regulation | 2006 |
Intracellular markers in acute myeloid leukemia diagnosis.
In our study we used a new proposed system of CD45 monoclonal antibody in combination with the side scatter (SSC) parameter as a very useful gating method allowing myeloblast detection especially in cases with low blasts percentage in examined samples. Immunological demonstration of myeloperoxidase (MPO) in the cytoplasm of AML blasts is considered to be a reliable and highly sensitive marker. Using a direct single and double immunofluorescence staining method and flow cytometry we evaluated the intracellular expression of two granular constituents of myeloid cells--MPO and lactoferrin (LF) in leukemia cells from 18 patients at AML diagnosis, two patients in remission after allogenic bone marrow transplantation and in six controls. Two different fixation/permeabilization techniques were used: Fix&Perm, paraformaldehyde and saponin prior to monoclonal antibody staining in order to verify the sensitivity of two labeling methods for MPO. Although both reagents used in this study proved to be efficient tools for the fixation and permeabilization of leukemia cells, the second one was characterized by higher sensitivity in detection of MPO. By double staining of MPO and LF we were able to distinguish undifferentiated cells from the granulomonocytic maturation compartments in bone marrow, since LF is proposed to be selectively expressed from the myelocyte stage of differentiation onward. Cytoplasmic CD13 expression was detectable in AML blasts after their buffered-formaldehyde-acetone fixation/permeabilization. According to our results the detection of MPO and CD13 markers in the cytoplasm of leukemia cells is of great importance in the definition of FAB M0-M1 subtype of AML. Furthermore we described overexpression of CD34 antigen in AML and revealed the characteristic marker combination when CD34 was studied simultaneously with MPO. This finding also coincided with some atypical phenotypic features (CD15/MPO, CD7/cCD13, CD2/cCD13, CD33/cCD13, MPO/cCD13) contributing to the differential diagnosis and allowing the immunologic monitoring of patients for the presence of residual disease. Topics: Acute Disease; Adult; Antibodies, Monoclonal; Antigens, CD34; Biomarkers, Tumor; CD13 Antigens; Child; Cytoplasm; Flow Cytometry; Humans; Immunophenotyping; Lactoferrin; Leukemia, Myeloid; Leukocyte Common Antigens; Permeability; Peroxidase; Tissue Fixation | 1998 |
Binding characteristics of human lactoferrin to the human monocytic leukemia cell line THP-1 differentiated into macrophages.
The characteristics of the binding of human lactoferrin (LF) to the cells of a human monocytic leukemia cell line, THP-1, were investigated. 125I-Labeled LF (125I-LF) bound to THP-1 cells, and the binding increased markedly as the cells matured into macrophages (THP-1 macrophages) by stimulation with phorbol 12-myristate 13-acetate. Scatchard analysis of the binding of 125I-LF to THP-1 macrophages indicated that high and low affinity receptor sites (Kd = 0.57 x 10(-6) and 3.7 x 10(-6) M, respectively) are present on the cells. The number of these high and low affinity receptor sites were 2.4 x 10(6), and 2.5 x 10(6) per cell, respectively. Removal of iron from 125I-LF did not affect its binding to THP-1 macrophages, indicating that the binding is not dependent on Fe(III) ion. The binding of the labeled LF to THP-1 macrophages was markedly decreased following acetylation, suggesting that the amino residues of the polypeptide portion of LF play a major role in the binding. The binding of labeled LF was partially inhibited by the isolated whole oligosaccharides of LF, and by the isolated whole oligosaccharides of band 3 glycoprotein of human erythrocyte membrane which contain poly-N-acetyllactosaminyl saccharide chains, like the LF oligosaccharides. Their inhibitory activity did not depend on the terminal sialyl residues of the saccharide chains. Lacto-N-fucopentaose III and lacto-N-neotetraose, an analogous structure being present in the poly-N-acetyllactosaminyl chains of LF, also artially inhibited the binding of 125I-LF to the THP-1 macrophages. When poly-N-acetyllactosaminyl saccharide chains of 125I-LF were cleaved by endo beta-galactosidase, the binding of 125I-LF was partially reduced. These results suggest that binding of LF to THP-1 macrophages is primarily mediated by its protein component, but a short oligosaccharide structure, possibly Gal beta 1-4GlcNAc beta 1-3Gal, which is contained in the nonreducing terminal region of poly-N-acetyllactosaminyl saccharide chains of LF and band 3, and in lacto-N-fucopentaose III and lacto-N-neotetraose is also recognized by THP-1 macrophages, and this recognition partly contributes to the binding of LF to cells. Topics: Carbohydrate Sequence; Cell Differentiation; Humans; Lactoferrin; Leukemia, Myeloid; Macrophages; Molecular Sequence Data; Tumor Cells, Cultured | 1996 |
Recognition of poly-N-acetyllactosaminyl saccharide chains on iron-oxidized erythrocytes by human monocytic leukemia cell line THP-1 differentiated into macrophages.
The cells of the human monocytic leukemia cell line THP-1 differentiated into macrophages bound to human erythrocytes oxidized with adenosine 5'-diphosphate (ADP)-Fe3+ chelate (ADP/Fe3+) in the absence of serum. The binding was prevented when the cells were treated with ADP/Fe3+ in the presence of antioxidants, indicating that oxidation of the cells is responsible for the increased susceptibility to the THP-1 cell binding. Galactose, fucose, mannose and mannan partially inhibited the binding. Glycoproteins containing poly-N-acetyllactosaminyl saccharide chains such as band 3 glycoprotein isolated from human erythrocyte membrane and lactoferrin, and their oligosaccharides, strongly inhibited the binding. On the other hand, glycoproteins with non-poly-N-acetyllactosaminyl saccharide chains such as glycophorin A isolated from the erythrocyte membrane, fetuin and alpha 1-acid glycoprotein, little or partially inhibited the binding. The inhibitory activity of band 3 oligosaccharides and lactoferrin oligosaccharides was little affected by treatment with endo-beta-galactosidase, which specifically cleaves poly-N-acetyllactosamine to shorter oligosaccharides. Removal of the nonreducing terminal region of the saccharide chains of band 3 on the erythrocyte surface by treatment of the cells with endo-beta-galactosidase resulted in a decrease in the susceptibility of the cells to the THP-1 cell binding. These results suggest that THP-1 cells which have been differentiated into macrophages bind the oxidized erythrocytes primarily through the recognition of poly-N-acetyllactosaminyl saccharide chains of band 3, and the site of the recognition exists in the nonreducing terminal region of the saccharide chains. Clustering of band 3 molecules is proposed as a possible alteration of oxidized erythrocyte membrane which promotes the interaction of the saccharide receptor on THP-1 cells with the saccharide chains of band 3 on erythrocytes. Topics: Adenosine Diphosphate; Anion Exchange Protein 1, Erythrocyte; Erythrocytes; Humans; Iron; Lactoferrin; Leukemia, Myeloid; Macrophages; Oxidation-Reduction; Phagocytosis; Polysaccharides; Tumor Cells, Cultured | 1996 |
Changes in neutrophil granule protein and cytoplasmic fibrils in human acute myeloid leukemias.
Granule protein deficiencies in morphologically mature neutrophil cells of peripheral blood from human patients with acute myeloid leukemia was demonstrated using post-embedding immunocytochemistry. Abnormal immunoreactivity of granule proteins was detected in seven of nine patients. Decreased immunoreactivity patterns were found more for the primary granule markers elastase and myeloperoxidase than for the secondary granule marker lactoferrin. Leukemias with a predominant myeloid component, in contrast to those with a predominant monocytoid component, had more neutrophil cells showing immunodeficiencies for one or more granule markers. The proportion of neutrophil cells showing immunodeficiencies varied greatly for each granule marker; more variation was obtained for elastase, lactoferrin and myeloperoxidase than for lysozyme, possibly because lysozyme is a marker for both granule types. In addition, no correlation could be found between any of the immunoreactivity deficiencies for the neutrophil granule glycoproteins elastase, lactoferrin, lysozyme and myeloperoxidase and the abundance of a particular set of ultrastructural features in the circulating leukemic cells from any of the nine patients. Nonetheless, most of the immature myeloid cells from peripheral blood of leukemic patients showing neutrophil protein immunoreactivity abnormalities in one or more granule markers often and randomly displayed one or more unusual ultrastructural features. The clinical and pathological significance of neutrophil granule protein deficiencies and the abundance of fibrillar structures in malignant myeloid cells presently is uncertain. Topics: Acute Disease; Adolescent; Aged; Cytoplasmic Granules; Female; Humans; Immunohistochemistry; Lactoferrin; Leukemia, Myeloid; Leukocyte Elastase; Male; Microscopy, Electron; Middle Aged; Muramidase; Neutrophils; Pancreatic Elastase; Peroxidase | 1995 |
Multiple forms of lactoferrin in normal and leukemic human granulocytes.
Multiple forms of lactoferrin (Lf) were detected in granulocytes isolated from normal individuals and patients with granulocytic leukemias. One class of Lfs bound iron; a second class did not bind iron but possessed potent ribonuclease activity. The different forms of Lf were similar, if not identical, in their physical, chemical, and antigenic properties. The multiple forms of Lf may relate to the various functions ascribed to the molecule. Topics: Blotting, Western; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Granulocytes; Humans; Iron; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Milk, Human; Molecular Weight; Peptide Fragments; Peptide Hydrolases; Ribonucleases | 1990 |
Lactoferrin binding by leukemia cell lines.
Monocytes and macrophages have receptors for the iron-binding protein lactoferrin. Lactoferrin acts as a potent inhibitor of granulocyte-macrophage colony stimulating factor production when it binds to these cells. Using a rosette assay and immunofluorescence, we have shown that cultured leukemia cells, including the human erythroid leukemia cell line K562, also have lactoferrin binding sites. The number of binding sites on K562 cells was estimated using soluble 59Fe-lactoferrin. Inhibition studies demonstrate that lactoferrin binding sites are distinct and unrelated to receptors for transferrin or the Fc portion of IgG, which are present on K562 cells. However, electrostatic forces may be important for lactoferrin binding, since other polycationic proteins (eg, protamine) inhibit lactoferrin binding. Prior treatment of K562 cells with trypsin nearly abolishes lactoferrin binding. However, these cells recover their ability to bind lactoferrin when trypsin is removed. Unlike transferrin receptors, the expression of lactoferrin binding sites is not regulated by cellular iron status. Cytosine arabinoside arrests the proliferation of K562 cells and simultaneously leads to a reduction in lactoferrin surface binding, suggesting that lactoferrin binding may be dependent on cell proliferation. Topics: Cell Division; Cell Line; Cells, Cultured; Fluorescent Antibody Technique; Humans; Iron Radioisotopes; Lactoferrin; Lactoglobulins; Leukemia, Experimental; Leukemia, Myeloid; Lymphocyte Activation; Lymphocytes; Protein Binding; Receptors, Cell Surface; Rosette Formation; Time Factors; Trypsin | 1987 |
Colony inhibiting factor in mature granulocytes from normal individuals and patients with chronic myeloid leukemia.
Inhibitory activity in extract from human blood granulocytes was tested on granulocyte-macrophage colony formation in vitro. The inhibition depended on the type of serum used. With mouse BMC and FCS in the cultures, extract corresponding to 2.5 X 10(4) granulocytes/ml reduced the colony number by 35%, and extract from 2 X 10(5) cells caused maximal inhibition (80-90%). With HS and mouse BMC the colony number was reduced by only 11-12%, but stronger inhibition (55%) was observed when the serum concentration was reduced. With both types of sera the total cell number per culture plate was reduced relatively more than the colony number. Human GM-CFC were as sensitive as mouse GM-CFC, and extract from CML granulocytes inhibited less (p less than 0.01) than extract from normal cells. Biochemical studies indicated that the inhibitor is a protein with a molecular weight of 30-60,000. Lactoferrin, a putative inhibitor of CSF production, did not inhibit spontaneous or CSF-induced colony formation in these studies. Topics: Animals; Cell Extracts; Cell Survival; Chromatography, Gel; Colony-Forming Units Assay; Female; Granulocytes; Humans; Lactoferrin; Leukemia, Myeloid; Macrophages; Male; Mice; Mice, Inbred Strains; Proteins | 1987 |
Plasma lactoferrin levels in leukaemias.
A solid-phase, one-step radioimmunoassay was developed for the determination of plasma lactoferrin concentration. The detection limit of the assay is 150 micrograms/l. Leakage of cellular lactoferrin was minimal when EDTA was used as anticoagulant, while results obtained from serum and from heparinized plasma were not reproducible. The plasma lactoferrin concentration of 35 female and 44 male healthy adults was measured in order to determine normal values. The geometric mean of lactoferrin levels in men is about 10% higher than in women: 483 (200-1500) micrograms/l in men and 446 (200-870) micrograms/l in women. Patients with acute and chronic leukaemias were also studied. In 38 patients with chronic myeloid leukaemia plasma lactoferrin levels were increased by three times while the neutrophil count was ten times higher than normal. Normal lactoferrin concentrations were measured in plasma samples from 15 patients with chronic lymphocytic leukaemia in incomplete remission while no detectable lactoferrin was found in samples from those in relapse (10 patients). In the untreated patients or those in relapse (19 cases) of both acute lymphocytic and myeloid leukaemias, plasma lactoferrin concentrations were undetectable while they seemed to return to normal during remission (3 cases). The data obtained indicate that the determination of plasma lactoferrin concentration might play an important role in facilitating the assessment of total blood granulocyte pool (TBGP). Topics: Blood Cell Count; Female; Humans; Lactoferrin; Lactoglobulins; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Male; Neutrophils; Prognosis; Radioimmunoassay; Reference Values | 1987 |
Isolation of lactoferrin cDNA from a human myeloid library and expression of mRNA during normal and leukemic myelopoiesis.
Lactoferrin is a major constituent of polymorphonuclear leukocyte granules and is present in mature neutrophils but not in blasts or promyelocytes. We have isolated a cDNA probe for lactoferrin and used it to study the synthesis of lactoferrin mRNA by normal and leukemic granulocyte precursors. The probe pHL-41 has been subcloned in phage m13 and characterized by restriction endonuclease analysis and nucleic acid sequencing. pHL-41 contains approximately 40% of the coding sequence of the lactoferrin gene. The 3' untranslated region includes a stop codon and a possible polyadenylation signal. There is a greater than 98% agreement between the cDNA-deduced amino acid sequence and that determined by analysis of the protein. Myeloid cells from normal bone marrow and circulating leukocytes from patients with chronic granulocytic leukemia contain lactoferrin mRNA transcripts that are indistinguishable in size and relative quantity. The human promyelocytic leukemia cell line HL-60 contains no lactoferrin mRNA. Induction of monocytic or granulocytic differentiation fails to induce the synthesis of detectable lactoferrin message. Similarly, studies with the human myeloblastic leukemia cell line PLB-985 reveal the inability of these cells to produce lactoferrin mRNA even under conditions that bring about morphologically demonstrable granulocytic differentiation. These data suggest that granulocytic differentiation in the leukemic cell lines is incomplete or defective. The presence of lactoferrin may play a role in the orderly expression of the genetic program leading to the development of the normal mature granulocyte. Topics: Base Sequence; Bone Marrow; Bone Marrow Cells; Cell Line; DNA; Humans; Lactoferrin; Lactoglobulins; Leukemia; Leukemia, Experimental; Leukemia, Myeloid; Molecular Sequence Data; RNA, Messenger | 1987 |
Response of granulocyte-committed progenitors from patients with chronic myeloid leukemia to humoral regulators release by macrophages in agar diffusion chamber culture.
We investigated the responsiveness of granulocyte-committed progenitors (CFU-G/D) from patients with chronic myeloid leukemia (CML) and healthy subjects to stimulating and inhibiting activities released by murine macrophages in diffusion chamber culture. CFU-G/D from CML demonstrate a normal response to macrophage-derived stimulation. The responsiveness of CFU-G/D from patients with CML to indomethacin-sensitive inhibition was significantly suppressed. In this regard no difference between CFU-G/D from bone marrow and blood of patients with CML could be observed. Colonies formed both by CFU-G/D from healthy subjects and CML consisted exclusively of cells of granulocyte line: from myeloblasts up to polymorphonuclear granulocytes. Similar cellular composition of colonies could be noted during macrophage-derived stimulation and inhibition of CFU-G/D growth. In conclusion, we have demonstrated that CML CFU-G/D which proliferate and differentiate in diffusion chamber culture show a normal response to macrophage-derived stimulation but are less sensitive to indomethacin-dependent inhibition. Topics: Adult; Animals; Cell Differentiation; Dose-Response Relationship, Immunologic; Female; Granulocytes; Growth Inhibitors; Humans; Indomethacin; Lactoferrin; Leukemia, Myeloid; Macrophages; Male; Mice; Middle Aged; Neoplastic Stem Cells | 1985 |
A monoclonal antibody-based immunoassay for human lactoferrin.
Monoclonal antibodies against human lactoferrin define at least 3 and possibly as many as 6 different epitopes. A sandwich enzyme-linked immunoassay, using monoclonals against different epitopes, has been optimised for the measurement of serum lactoferrin. In 35 samples from healthy adults the mean lactoferrin content of serum from blood clotted overnight was 0.54 +/- 0.26 micrograms/ml. Topics: Adult; Animals; Antibodies, Monoclonal; Enzyme-Linked Immunosorbent Assay; Epitopes; Humans; Hybridomas; Immunization; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Mice | 1985 |
Lactoferrin biosynthesis during granulocytopoiesis.
We examined the synthesis of lactoferrin, an iron binding protein that, among hematopoietic cells, is restricted to secondary granules of polymorphonuclear leukocytes. Lactoferrin biosynthesis was absent from leukemic myeloblasts and promyelocytes but abundant in normal bone marrow and both the bone marrow and peripheral blood of patients with chronic myelogenous leukemia (CGL) if the samples contained substantial numbers of myelocytes and metamyelocytes. Lactoferrin was present in the steady state in normal or CGL bands and polymorphonuclear leukocytes, but no lactoferrin biosynthesis was detectable in these samples. Taken together, these results suggest that lactoferrin accumulation begins with the onset of biosynthesis at the myelocyte stage and is largely complete by the beginning of the band stage of maturation. HL-60 cells, a permanent promyelocytic leukemia cell line, synthesized no lactoferrin. Translation of messenger RNA in Xenopus laevis oocytes revealed that mRNA from patients with chronic myelogenous leukemia and abundant myelocytes and metamyelocytes directed the synthesis of readily detectable amounts of lactoferrin, whereas HL-60 cells contained no translatable lactoferrin mRNA. We thus hypothesize that lactoferrin is a useful marker of gene expression restricted to the terminal stages of granulocyte maturation. Biosynthesis of this protein appears to be mediated by appearance of translatable mRNA at the myelocyte stage, coincident with development of secondary granules. Absence of lactoferrin production by HL-60 cells is due to absence of translatable lactoferrin mRNA, either because of lineage infidelity of these transformed cells or because of arrest before the developmental stage at which secondary granules appear. Topics: Animals; Bone Marrow Cells; Cell Line; Granulocytes; Hematopoiesis; Humans; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Methionine; RNA, Messenger; Sulfur Radioisotopes; Xenopus | 1984 |
Quantitative cytochemistry of blood neutrophils in myelodysplastic syndromes and chronic granulocytic leukaemia.
Quantitative cytochemistry of components of blood neutrophil azurophilic granules (myeloperoxidase, chloroacetate esterase, beta-glucuronidase, and acid phosphatase) and specific granules (lactoferrin) has been performed by scanning and integrating microdensitometry in 13 patients with a myelodysplastic syndrome and 11 patients with chronic granulocytic leukaemia. Both patient groups showed a reduction of enzyme activity in azurophilic granules, and also of lactoferrin, consistent with abnormal development of neutrophil granules. These cytochemical changes in blood neutrophils are similar to those found in acute myeloid leukaemia, are consistent with a leukaemic maturation defect, and may be of diagnostic value. Topics: Acid Phosphatase; Adult; Anemia, Aplastic; Carboxylic Ester Hydrolases; Cytoplasmic Granules; Densitometry; Glucuronidase; Histocytochemistry; Humans; Hydrolases; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Leukocyte Count; Neutrophils; Peroxidase; Peroxidases | 1983 |
Lactoferrin, transferrin and acidic isoferritins: regulatory molecules with potential therapeutic value in leukemia.
In the process of evaluating roles for purified preparations of lactoferrin, transferrin and acidic isoferritins in the regulation of myelopoiesis, it was found that: (1) values reported for lactoferrin in the serum and plasma of normal donors are in most cases an over-estimation, (2) lactoferrin suppresses the production/release of granulocyte-macrophage colony stimulatory factors (GM-CSF) from monocytes in the absence of T-lymphocytes and also suppresses the production/release of acidic isoferritin-inhibitory activity from monocytes, (3) lactoferrin, transferrin and acidic isoferritins act on their specific target cells which express Ia-like antigens, (4) lactoferrin and transferrin act in vivo to suppress rebound myelopoiesis in mice recovering from sublethal dosages of Cytoxan, with preliminary observations suggesting that lactoferrin has a greater apparent effect on the bone marrow and transferrin has a greater apparent effect on the spleen, (5) active lactoferrin derives from Fc receptor positive subpopulations of PMN from patients with CML as well as from normal donors, but the percentage of Fc receptor containing PMN is lower in CML, as is the amount of active lactoferrin found in their PMN, and (6) lactoferrin, transferrin and acidic isoferritins suppress the colony formation of U937 clonogenic cells, with lactoferrin and transferrin decreasing the release of growth factors from U937 cells which are needed to stimulate U937 colony formation, and lactoferrin and acidic isoferritins suppress the colony formation of WEHI-3 cells, with lactoferrin decreasing the release of growth factors from WEHI-3 cells which are needed to stimulate WEHI-3 colony formation. Speculation on the potential usefulness of these iron binding glycoproteins to control of disease progression is given in the discussion. Topics: Animals; Cell Transformation, Neoplastic; Colony-Stimulating Factors; Ferritins; Hematopoiesis; Histocompatibility Antigens Class II; Humans; Hydrogen-Ion Concentration; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Mice; Monocytes; Neutrophils; Receptors, Fc; T-Lymphocytes; Transferrin | 1983 |
Specificity of lactoferrin as an inhibitor of granulocyte-macrophage colony-stimulating activity production from fetal mouse liver cells.
Fetal mouse liver cultures capable of producing both erythropoietin (Ep) and granulocyte-macrophage colony stimulating activity (GM-CSA) were used to study the specificity of lactoferrin as an inhibitor of the production of GM-CSA. Both a granulocyte-derived colony-inhibiting activity (CIA) and lactoferrin inhibited GM-CSA production while having no effect on Ep production. These results demonstrate the specificity of lactoferrin for GM-CSA production. Topics: Animals; Colony-Stimulating Factors; Erythropoietin; Female; Fetus; Granulocytes; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Liver; Macrophages; Mice; Neutrophils; Transferrin | 1979 |
Myeloperoxidase and lactoferrin of blood neutrophils and plasma in chronic granulocytic leukaemia.
Myeloperoxidase, restricted to primary granules, and lactoferrin, restricted to secondary granules, were determined in plasma and neutrophils of peripheral blood in chronic granulocytic leukaemia (CGL). Plasma myeloperoxidase was increased 2-3 times while plasma lactoferrin increased 2-8 times. This discrepancy indicates different modes of release or elimination. A correlation was found between the leucocyte count and plasma myeloperoxidase or lactoferrin. A correlation was also found between cellular and plasma levels of lactoferrin but not for myeloperoxidase indicating the source for plasma lactoferrin to be circulating leucocytes, which may not be the case for plasma myeloperoxidase. Decreased neutrophil lactoferrin was found in 71% of the CGL cases while myeloperoxidase was decreased in 18%. Serial studies on individual CGL subjects showed low cellular lactoferrin during phases with rapidly expanding leucocytosis indicating defective maturation of neutrophils or abnormal release because of prolonged intravascular life-span. Topics: Adult; Female; Humans; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Leukocyte Count; Male; Middle Aged; Neutrophils; Peroxidase; Peroxidases | 1977 |
A solid-phase radioimmunoassay for the measurement of lactoferrin in human plasma: variations with age, sex, and disease.
A solid-phase radioimmunoassay is described for measuring lactoferrin levels in normal human plasma. The sensitivity of the assay was 6 ng. per milliliter with an intraassay coefficient of variation of 4 per cent and an interassay value of 9 per cent. Healthy adult males had a mean plasma level of 1.62 mug per milliliter which was significantly higher than adult females, 1.07 mug per milliliter. Postmenopausal females had levels similar to men, 1.74 mug per milliliter, while younger women had a significantly lower mean value, 0.75 mug per milliliter. Two menstruating women and 2 pregnant women had moderately elevated levels. Consistently elevated levels were found in patients with untreated or relapsing chronic myeloid leukemia--all over 12.0 mug per milliliter, while patients on marrow suppressant therapy tended to have subnormal levels. The collection of serum specimens as opposed to plasma, resulted in inconsistently elevated levels: EDTA was the anticoagulant of choice, as heparin interfered in the radioimmunoassay system. Topics: Adult; Age Factors; Blood Specimen Collection; Female; Humans; Immune Sera; Iodine Radioisotopes; Lactoferrin; Lactoglobulins; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Male; Menopause; Menstruation; Middle Aged; Pregnancy; Radioimmunoassay; Sex Factors | 1976 |