Human Neutrophilic Polymorphonuclear Leukocytes Research Articles

Assay and Subcellular Localization of Adenosine Diphosphatase in Human Neutrophil Polymorphonuclear Leucocytes

Assay and Subcellular Localization of Adenosine Diphosphatase in Human Neutrophil Polymorphonuclear Leucocytes

Lactoferrin in Human Neutrophilic Polymorphonuclear Leukocytes in Relation to Iron Metabolism

Lactoferrin (LF), the iron-binding protein of external secretions and neutrophilic polymorphonuclear leukocytes (PMN), was studied in 27 patients during granulocytosis caused by acute inflammation and in disorders without granulocytosis (iron deficiency anemia, iron overload and liver diseases). During granulocytosis the LF concentration of PMN was significantly lower than in controls (p less than 0.001). This difference proved to be related to the number of PMN. A relation between the LF concentration of PMN and iron metabolism could be demonstrated: loss of iron by blood donation is accompanied by a significant decrease in the LF concentration in PMN, whereas iron therapy in patients with iron deficiency anemia is accompanied by a significant increase in the LF concentration in PMN.

Enhancing effect of levamisole on the phagocytic activity of human neutrophil polymorphonuclear leucocytes in vitro.

The effect of levamisole on the phagocytic activity of normal human polymorphonuclear neutrophil leucocytes has been studied in vitro. In concentrations comparable with the serum levels obtained in treatment with levamisole perorally, the engulfment of heat-killed yeast cells is moderately but significantly increased. It is shown that levamisole can only stimulate phagocytosis of adequately opsonized particles. The action of the drug is still unknown but appears to be directly linked to the phagocytic cell.

Collagenase is a component of the specific granules of human neutrophil leucocytes

Azurophil and specific granules were isolated from human polymorphonuclear neutrophil leucocytes. Collagenase was almost exclusively a component of the specific granules. This finding is in contrast with the distribution of other proteolytic enzymes, which are localized in the azurophil (or lysosomal) granules.

Abnormal granulocyte feedback regulation of colony forming and colony stimulating activity-producing cells from patients with chronic myelogenous leukemia

Colony inhibiting activity (CIA), which can be obtained from human polymorphonuclear neutrophil leukocytes (PMN), reduces the numbers of bone marrow and blood (density < 1.070 g/cm 3) cells which can spontaneously proliferate in vitro to form colonies and clusters. However, PMN from patients with chronic myelogenous leukemia (CML) were quantitatively deficient in CIA regardless of the patient's clinical status or in vitro growth patterns. Even greater differences in (CIA) between normal and CML-PMN were unmasked by high speed centrifugation of PMN-extracts. Potency of CIA from normal PMN could be enhanced by removal of material pelleted after centrifugation at 160,000 g. Removal of the pellet also decreased the 37°C temperature sensitivity of CIA. CIA from CML-PMN was not enhanced by this procedure. CIA obtained from CML-PMN had the same site of action as that from normal PMN. Although not species specific, CML-CIA was specific in its non-toxic action on the Colony Stimulating Activity (CSA)-producing cell; both CFU-c and cell-free CSA molecules were not affected. A further defect was noted in that target cells (density < 1.070 g/cm 3) from patients with CML were less sensitive than normal targets to inhibition with low concentrations of CIA from normal PMN. However, high concentrations of CIA were as active against CML as against normal targets. The reasons for the decreased sensitivity of CML targets are discussed. These negative feedback abnormalities in vitro may partially explain granulocytic hyperplasia associated with CML.

Localization of Chymotrypsin-Like Cationic Protein, Collagenase and Elastase in Azurophil Granules of Human Neutrophilic Polymorphonuclear Leukocytes

The subcellular localization of granulocyte collagenase, elastase and chymotrypsin-like cationic protein was determined using velocity centrifugation of cytoplasmic granules of human polymorphonuclear leukocytes. The proteases were assayed by immunochemical and enzymatic methods. Measurements of lactoferrin and myeloperoxidase distinguish exactly between constituents of specific and azurophil granules. Collagenase, elastase and chymotrypsin-like cationic proteins showed an almost identical sharp and unimodal distribution. They co-sedimented with myeloperoxidase demonstrating that these enzymes are localized exclusively in the azurophil granules.

Biochemical and morphological characterization of azurophil and specific granules of human neutrophilic polymorphonuclear leukocytes.

Postnuclear supernates from homogenates of purified neutrophil polymorphonuclear leukocytes (PMNs) from human blood were fractionated by zonal sedimentation and isopycnic equilibration in sucrose gradients. The fractions were characterized biochemically by measuring protein content and the activities of eight enzymes. Selected fractions were further analyzed by electron microscopy. In both centrifugation systems, azurophil and specific granules could be resolved almost completely. Azurophil granules sediment three to four times faster than the specifics and have an average density of 1.23. They contain all the peroxidase of the cells, large portions of four lysosomal hydrolases, and about half of the total lysozyme, and therefore appear to be, in biochemical terms, very similar to the azurophil granules of rabbit PMNs. The specific granules, which have an average density of 1.19, contain the remaining half of the lysozyme but appear to be free of the other components of the azurophil granules, and of alkaline phosphatase. Isopycnic equilibration disclosed a minor lysosomal population, which strongly overlaps the specific granules, and made possible the identification of a membrane-fraction which is characterized by the presence of the thiol-sensitive acid 4-nitrophenyl phosphatase and of alkaline phosphatase.

A method for assessing the in vitro chemotactic response of neutrophils utilizing 51cr-labeled human leukocytes.

A method is described for the quantitation of the in vitro chemo-tactic response of human neutrophilic polymorphonuclear leukocytes utilizing modified Boyden chambers, a layer of two micropore filters, and 51Cr-labeled leukocytes. Either human C5a or human kallikrein in the stimulus compartment resulted in migration of labeled neutrophils through the top micropore filter and into the second filter with maximum chemotaxis after 5-6 hrs of incubation at 37°C, measured by counting the 51Cr rzdioactivity in the second filter. The value of the 6 hr chemotactic response was directly proportional to the concentration of chemotactic factor and was reproducible within ±20% of the mean with duplicate OK triplicate chambers at each concentration of chemotactic factor. The development of an objective method for assessing chemotaxis is critical to studies of the relationship of rate of leukocyte migration to dose of chemotactic factors, and ultimately for the evaluation of intrinsic leukocyte responsiveness in various...

Lactoferrin--specific localization in the nuclei of human polymorphonuclear neutrophilic leukocytes.

SummaryLactoferrin, a pink iron binding protein first isolated from bovine milk has been found in the nuclei and/or nuclear membrane of mature polymorphonuclear neutrophilic leukocytes. It is absent from all other cells of the hematopoietic system. Grossly normal amounts of lactoferrin were found to be present in the neutrophiles from patients with a variety of hematological abnormalities.

Lactoferrin, an iron-binding protein in neutrophilic leukocytes.

Lactoferrin, an iron-binding protein previously shown to occur in many external secretions, is identified as one of the major proteins present in human and guinea pig neutrophilic polymorphonuclear leukocytes. The identification of this protein in leukocyte extracts was based upon a comparison of its electrophoretic, antigenic, and iron-combining properties with the corresponding properties of the same protein isolated from human and guinea pig milk. Immunochemical quantitations showed that lactoferrin occurs in human neutrophilic leukocytes at the concentration of 3 microg per 10(6) cells. Tissue cultures from guinea pig bone marrow and spleen actively synthesized the protein, as shown both by net production of lactoferrin and incorporation of labeled amino acids into the protein. Immunohistochemical data indicate that lactoferrin first appears in myeloid cells at the stage of the promyelocyte.

The pathogenesis of strangulation obstruction: Effect of hemoglobin on bactericidal capacity of human leukocytes

<h2>Summary</h2> Hemoglobin in concentrations of 2%, 4% and 6% did not interfere with the bactericidal capacity of human neutrophil polymorphonuclear leucocytes against Escherichia coli or Staphylococcus albus when tested in vitro.