Comparison of NADH and NADPH oxidase activities in granules isolated from human polymorphonuclear leukocytes with a fluorometric assay

A fluormetric method for the determination of pyridine nucleotides has been adapted for use in studying the reduced pyridine nucleotide oxidases in human polymorphonuclear leukocytes. In the presence of strong base the oxidized forms of the pyridine nucleotides form a highly fluorescent product. The small amounts of NAD(P) formed by the oxidase reactions can be determined with great sensitivity. This method has been compared to the radioisotopic assay for NADPH oxidation. Both methods gave essentially the same results in terms of nanomoles NADP produced by control, resting, and phagocytizing samples. Both NADPH and NADH oxidase activities were insensitive to cyanide. NADPH oxidation had a pH optimum of 5.5, while that for NADH appeared to be 6.0. Granules isolated from phagocytizing cells routinely showed more activity toward both substrates (two to threefold) than granules from resting cells. Both activities were located primarily in a granule fraction prepared by differential centrifugation. Oxidation of NADPH was routinely four to five times that of NADH at all except very high substrate levels. Measurable NADH oxidation was rarely seen below 0.80 mM NADH, while NADPH oxidation was easily measurable at 0.20 mM. One patient with chronic granulomatous disease was studied. At low substrate levels, there was no activity toward either substrate in granules isolated from either resting or phagocytizing cells of this patient, while granules isolated from normal control cells showed substantial activity at these substrate levels. Purification of the activities had been initiated with linear sucrose gradients. Both activities co-sediment to a very dense region of the gradient, a region different from that in which membrane or azurophil granules usually equilibrate. The peak gradient fractions show a 10-30-fold increase in specific activity over comparable granule fractions. These data suggest that the oxidase activities are associated with one enzyme that has different affinities for the two substrates ans support the contention that the oxidation of NADPH is responsible for the metabolic burst accompanying phagocytosis in human PMNL.

Chicken neutrophils: oxidative metabolism in phagocytic cells devoid of myeloperoxidase

Polymorphonuclear leukocytes isolated from chicken peritoneal exudates have been found to catalyze cyanide-insensitive stimulation of respiration and the hexose monophosphate shunt upon exposure to heat-inactivated Staphylococcus aureus. However, there was no demonstrable formate oxidation concomitant with phagocytosis in either the presence or absence of exogenous catalase. Moreover, chicken polymorphonuclear leukocytes failed to oxidize scopoletin concomitant with phagocytosis in the presence of horseradish peroxidase. While oxygen uptake was increased 2- to 3-fold by the stimulus of phagocytosis, the oxidation of [1-(14)C]glucose was increased approximately 20-fold. The cells contain two mechanisms, a glutathione reductase-glutathione peroxidase system and an NADPH-NAD+ transhydrogenase, each of which is present in sufficient capacity to accommodate the enhanced shunt activity. Although chicken polymorphonuclear leukocytes were found to possess a substantial capacity to catalyze the cyanide-insensitive oxidation of either NADH or NADPH, the total or specific activities of such processes were not demonstrably affected by phagocytosis.

Fate of human lactoferrin and myeloperoxidase in phagocytizing human neutrophils: effects of immunoglobulin G subclasses and immune complexes coated on latex beads

Human neutrophils (PMN) degranulated in response to soluble human immune complexes and to myeloma proteins, including subclasses of immunoglobulin G (IgG)1, IgG2, IgG3, and IgG4 coated on 1.09-mum latex beads. Immunochemical measurement of lactoferrin (LF) from specific granules and myeloperoxidas (MPO) from azurophil granules showed that both classes of granule degranulated. Beads with soluble complexes of human anti-pigeon IgG-normal pigeon IgG, prepared from serum of a patient with pigeon breeders disease, induced significantly greater degranulation than did pigeon IgG-coated beads. Up to 40% of LF in the PMN degranulated during phagocytic challenge and 86% of that entered the extracellular fluid. Twenty to 30% of the MPO degranulated, but less than 50% of that entered the extracellular fluid. The degranulated LF and MPO which remained in the PMN were recovered from phagocytic vacuoles. Beads coated with purified human myeloma proteins (12 different ones, three of each subclass) induced degranulation in the order IgG3 greater than IgG1 greater than IgG2 greater than IgG4; however, these differences were found to be a function of the amount of latex ingested. Thus, the amount of degranulation was dependent more on the opsonizing capacity of the immunoglobulins rather than on their intrinsic capacities for inducing degranulation. Degranulation of both LF and MPO in response to IgG subclasses followed patterns similar to those caused by soluble immune complexes, and IgG3 coated on beads caused degranulation equal to that caused by human complex-coated beads. Degranulation to IgG3 and IgG4 was uninfluenced by fresh compared with heat-inactivated human AB serum. This was true although IgG3 beads fixed greater than sixfold more complement than did IgG4 beads. Evidently human IgG subclasses enhance phagocytosis and degranulation of human PMN. The overwhelmingly extracellular degranulation of LF in response to various bead coating suggest that it subserves a major protion of it role outside PMN.

Immunosuppression by hydroxystilbamidine isethionate, a lysosome-stabilizing, anti-proteolytic, antifungal drug

Hydroxystilbamidine (HSB) is a potent suppressor of the plaque-forming cell response of mice injected with heterologous erythrocytes. HSB, given in varying doses and injection schedules, suppressed both the primary and secondary immune responses to bovine serum albumin. Apparently the effect is not simply a toxic effect on spleen cells, because there was no appreciable difference in cell numbers between control and HSB-treated mice. The effect of HSB was most apparent in the early phase of the immune respone.

Ultrastructural localization of cationic proteins in cytoplasmic granules of chicken and rabbit polymorphonuclear leukocytes

Cytoplasmic granules known to contain cationic arginine-rich proteins can be identified by the ammoniacal silver reaction (ASR) which provides a cytochemical marker detectable under the electron microscope. Only the large rod-shaped granules of the chicken polymorphonuclear leukocytes (heterophils) and the large spherical azurophilic granules of the rabbit neutrophilic polymorphonuclear leukocytes show the ASR product as a discrete particulate electron-dense deposit. The other smaller granules are devoid of reaction product, as are membranes and mitochondria. The intracellular localization of the ASR product, as are membranes and mitochondria. The intracellular localization of the ASR product on the large granules coincides with the ASR product localization on the same isolated granule populations, when the ammoniacal silver reaction is applied to these granules after their separation by sucrose-density gradients. The cationic proteins may have intraleukocytic bacteriolytic properties, since ASR product, presumably indicating cationic protein from discharged granules, appears to surround ingested bacteria within cytoplasmic phagosomes.

Intracellular and extracellular degranulation of human polymorphonuclear azurophil and specific granules induced by immune complexes

The nature of the phagocytic stimulus determines the degree of degranulation. Specifically, immune complexes induced more degranulation than did antigen or antibody alone. The release of constituents from the two granule classes represented independent phenomena. Relatively more of the specific granule proteins were released into the medium during phagocytosis, whereas more of the azurophil proteins were associated with the phagosomes.

Association of lactoferrin with lysozyme in granules of human polymorphonuclear leukocytes

Lactoferrin is contained in cytoplasmic granules of human polymorphonuclear leukocytes. Upon centrifugation, it sediments in a band of granules that also contain 50% of the lysozyme activity. This granule class is distinct from others associated with alkaline phosphatase and peroxidase. The granules are latent for lactoferrin as only lysed granules have the capacity specifically to inhibit antigen binding by anti-lactoferrin serum.

Microbicidal activity of peroxidaseless chicken heterophile leukocytes

Polymorphonuclear leukocytes (PMN) of the domestic chicken lack myeloperoxidase and, therefore, may be useful for studies of myeloperoxidase-independent antimicrobial mechanisms. Before such studies were undertaken, it was important to investigate the antimicrobial capacity of these cells against species of opportunistic pathogens that cause infection in humans with defective PMN function. In vitro, chicken PMN, like normal human PMN, readily phagocytized and killed Staphylococcus albus. They also killed Serratia marcescens, Escherichia coli, and Candida albicans. Cytochemical methods confirmed the absence of myeloperoxidase from chicken PMN.

Immunogenicity of Bovine Serum Albumin and Its Oligopolymers in CBA Mice

The monomer of bovine serum albumin (BSA) and its oligopolymers have been examined as immunogens in female CBA mice. When given intravenously the greatest ability not only to stimulate antibody formation but also to induce tolerance resided in the monomer. All forms were equally immunogenic if presented in complete Freund's adjuvant.

These findings are discussed in relation to the elimination rate which became faster with increasing molecular size of the BSA immunogen.

Distribution of lysosomal enzymes, cationic proteins, and bactericidal substances in subcellular fractions of human polymorphonuclear leukocytes

Separation of homogenates of human polymorphonuclear leukocytes (PMN) into different fractions by sedimentation in centrifugal fields that ranged from 126 x g to 50,000 x g resulted in a differential distribution of the lysosomal enzymes. Peroxidase, lysozyme, beta-glucuronidase, and acid phosphatase activity were separated from each other. This demonstrates that the lysosomes of human PMN comprise at least three and possibly four physically and chemically different cytoplasmic particles. Proteins which are more cationic than lysozyme and which may be analogous to cationic lysosomal protein of rabbit PMN were associated with lysozyme and beta-glucuronidase rich granules. Antibacterial activity was present in four of the five cell fractions which this work produced. These results are significant because they differ from those obtained with rabbits and because they directly influence future experimental design and interpretation, in attempts to analyze antibacterial, scavenging, and inflammatory capacities of human PMN. Since lysosomes differ physically, biochemically, and morphologically, they may well differ with respect to their function in the PMN.

Characteristics of complement-dependent release of phospholipid from Escherichia coli

The release of (32)P-labeled bacterial phospholipid from a smooth Escherichia coli by serum components depends on complement activated by antibody. Phospholipid release in excess antibody tends to be proportional to the concentration of complement as does the release of other cellular constituents. Phospholipids are not simply stripped off during cell lysis. Whereas 94% of the total phospholipid freed from E. coli by mechanical lysis sediments at centrifugal forces sufficient to sediment molecules of 10(6) molecular weight, similar centrifugation sediments only 50% of the phospholipid released by antibody-complement. In fact, after mechanical lysis more than 50% of the phospholipid sediments at velocities sufficient to bring down cell envelopes. Although the bulk of the bacterial phospholipid is located in the cell envelopes, isolated (32)P-labeled cell envelopes and phenol-extracted lipopolysaccharide fails to release phospholipids in the presence of antibody-complement. Moreover, ethylenediaminetetraacetic acid, which like antibody-complement causes loss of cellular selective permeability and prepares E. coli cell walls for the action of lysozyme, releases only small amounts of phospholipid from E. coli and these are sedimentable. The most likely mechanism of phospholipid release caused by antibody-complement appears to be the activation directly or indirectly of an enzyme which is present only in the intact cells.

Cationic protein-bearing granules of polymorphonuclear leukocytes: separation from enzyme-rich granules

The cationic, antibacterial proteins of polymorphonuclear leukocytes are associated with a unique subcellular particle that is separable through zonal density gradient centrifugation from acid phosphatase-containing particles as well as from particles that contain alkaline phosphatase and lysozyme. Normal macrophages, macrophages stimulated by bacillus Calmette-Guérin, and liver cells lack this particle and the associated group of cationic proteins. Particles physically and biochemically similar to slower sedimenting enzyme-rich particles of polymorphonuclear leukocytes are shared by all the tlhree cell types.

Molecular and structural damage to Escherichia coli produced by antibody, complement, and lysozyme systems

The antibacterial action of antibody (normal and hyperimmune), complement, and lysozyme has been studied by correlating the ultrastructural and biochemical changes that they cause in smooth Escherichia coli. Both normal and hyperimmune antibody, in the absence of lysozyme, produced complement-dependent release, into the suspending medium, of 63 to 72% of the (32)P-labeled phospholipid and 74 to 85% of the small molecular bacterial constituents. Macromolecular nucleic acid labeled with (32)P was not released. By phase microscopy, these cells appeared as bacilli but their ultrastructure showed general swelling, with smoothing of the normally wrinkled outer cell wall layers. Cytoplasmic membranes were damaged and the internal cell structure was disorganized. Membranous spherules, apparently from the outermost putatively lipopolysaccharide cell layer, were released into the medium. When lysozyme was added to antibody and complement, (32)P-labeled macromolecular constituents were released from the cells. Damage to ultrastructure then included loss of cell wall rigidity, cell wall breakage, and some spheroplast formation. Characteristic fibrillar fragmentation was seen in cell wall mucopeptide layers. The relationships between antibody-complement dependent release of bacterial phospholipid, loss of selective cell permeability, and increase in sensitivity to lysozyme are discussed.

Arginine-rich proteins of polymorphonuclear leukocyte lysosomes. Antimicrobial specificity and biochemical heterogeneity

The cationic antibacterial proteins of rabbit PMN lysosomes have been resolved into at least five subfractions. Each of these showed substantial selectivity in its antibacterial action against several pathogenic bacteria, including two smooth and two rough Escherichia coli strains, three Staphylococcus aureus strains, one S. albus, three proteus species and four different cultures of streptococcus. Each of the subfractions possesses a different electrophoretic mobility. Amino acid analyses of the three most cationic components revealed high contents of arginine consistent with their relative electrophoretic mobilities and very high arginine to lysine ratios. Aromatic amino acids were present in very low concentrations in these proteins and their light absorption at 2800 A was correspondingly weak. The evidence of antibacterial specificity, along with marked differences in the arginine-lysine ratios, shows that the cationic antibacterial components of rabbit PMN lysosomes are biologically and chemically heterogeneous.

Antimicrobial specificity of leukocyte lysosomal cationic proteins

Diflerences in antimicrobial specificities against Staphylococcusaureus, Streptococcus faecalis (groupD),and Proteus vulgaris exist amongthe electrophoretically separable components of lysosomal cationic proteins of polymorphonuclear leukocytes.