Oxidative Metabolism Of Polymorphonuclear Leukocytes Research Articles

Polymorphonuclear leukocyte response to stimulation in vitro during pregnancy.

Oxidative metabolism of polymorphonuclear leukocytes (PMNLs) isolated from pregnant women in the third trimester and from controls were studied using zymosan-induced chemiluminescence (CL) and f-Met-Leu-Phe-stimulated superoxide (O2-) generation. CL was significantly increased during pregnancy, but a decrease was noted in cytochrome c reduction. Total cellular levels of beta-glucuronidase and lysozyme were diminished in PMNLs from pregnant subjects, with unaltered concentrations of cytosol lactate dehydrogenase. The capacity of PMNLs from pregnant women to degranulate did not differ from controls. It is suggested that during pregnancy, in vivo stimulation of PMNLs may occur to account for these changes.

Serum factor from patients with chronic renal failure enhances polymorphonuclear leukocyte oxidative metabolism.

Sera from patients with chronic renal failure (CRF) contain a factor(s) which enhances the oxidative metabolism of polymorphonuclear leukocytes (PMN) as assessed by chemiluminescence (CL), superoxide anion generation, and hexose monophosphate shunt activity. PMN oxidative metabolic activity was higher in CRF sera than in sera from hospitalized patients with normal renal function or in sera from normal healthy subjects. The enhancement occurred regardless of whether PMN were unstimulated or were stimulated by a nonspecific soluble membrane stimulant (phorbol myristate acetate), or by opsonized Candida albicans. The enhanced CL was significantly reduced in their sera after normal renal function was restored with successful renal transplantation. This CL-enhancing factor was also detected in dialysate fluids from CRF patients and in urine from normal healthy subjects. When serum, urine, dialysate fluids of these CRF patients were fractionated by Sephadex G-25 column chromatography, the specific fraction responsible for enhanced CL was found in the molecular weight range less than 1,000 daltons, and is an ethanol extractable substance with natural fluorescence. Our findings suggest that the enhanced PMN stimulatory activity in CRF serum is specifically associated with renal dysfunction and can be useful, along with other conventional parameters, for monitoring the progression of CRF.

Role of protein kinases in stimulation of human polymorphonuclear leukocyte oxidative metabolism by various agonists. Differential effects of a novel protein kinase inhibitor.

Isoquinoline sulfonamides have recently been shown to exert novel inhibitory effects on mammalian protein kinases by competitively binding to the ATP substrate site (Hidaka, H., M. Inagaki, S. Kawamoto, and Y. Sasaki, 1984, Biochemistry, 23: 5036-5041). We synthesized a unique analog of the previously reported compounds, 1-(5-isoquinolinesulfonyl) piperazine (C-I), in order to assess the role of protein kinases in modulating the agonist-stimulated oxidative burst of human polymorphonuclear leukocytes (PMN). Compound C-I, at micromolar concentration, markedly inhibited the release of superoxide anion from human PMN stimulated with phorbol myristate acetate or the synthetic diacylglycerol, 1-oleoyl-2-acetyl glycerol. These data are consonant with previously reported data which indicate that the calcium and phospholipid-dependent protein kinase, protein kinase C, serves as the intracellular receptor for these agonists. In contrast, superoxide anion production stimulated by the complement anaphylatoxin peptide C5a or the synthetic chemotaxin formyl-methionyl-leucyl-phenylalanine were not inhibited by C-I. These data suggest that parallel pathways exist for the agonist-stimulated respiratory burst of human neutrophils, only one of which utilizes the calcium and phospholipid-dependent protein kinase.

Defective triggering of polymorphonuclear leukocyte oxidative metabolism by Legionella pneumophila toxin.

Preincubation of human polymorphonuclear leukocytes (PMNLs) with Legionella pneumophila toxin impaired activation of the superoxide-generating complex induced by latex particles and by the Ca++ ionophore A23187. The toxin had no effect, however, on activation of the complex induced by phorbol myristate acetate (PMA), concanavalin A, valinomycin, or bromolasalocid. The toxin prevented PMNL plasma membrane depolarization induced by A23187 but failed to influence the membrane depolarization induced by PMA. These observations indicate that Legionella pneumophila toxin selectively impairs activation of the phagocyte superoxide-generating complex without affecting the functional integrity of components of the complex.

Effect of cisplatin on the oxidative metabolism of polymorphonuclear leukocytes in cancer patients.

Peripheral blood polymorphonuclear leukocytes of patients with ovarian or uterine-cervix carcinoma were studied during cisplatin chemotherapy for phagocytic oxidative metabolism. In particular, superoxide production by these leukocytes after stimulation with opsonized Zymosan particles was determined. The basal value of oxidative metabolism of leukocytes from neoplastic patients was lower than in normals. Superoxide production decreased after each dose administration, but returned to normal at the end of the entire chemotherapeutic treatment. It is suggested that cisplatin treatment, despite a short-lived depression of oxidative metabolism in polymorphonuclear cells, improves this function, most probably by interfering with neoplastic growth.

LONGITUDINAL STUDY OF NEUTROPHIL FUNCTION IN CHILDREN WITH ACUTE LYMPHOCYTIC LEUKEMIA (ALL)

Longitudinal studies of polymorphonuclear leukocyte (PMNL) function were done in 45 children with ALL (37 "null" cell, 7 T cell and 1 B cell). The oxidative burst of PMNLs was studied by measuring chemiluminescence (CL) with soluble and particulate stimuli. The capacity of PMNLs to become bipolar in shape in response to the chemoattractant formyl-methionyl-leucyl-phenylalanine (FMLP) was examined. Results from 84 of 90 CL assays were normal. Results were normal regardless of time since initial remission or end of therapy. Too few patients in relapse were studied for statistical analysis. Abnormal results occurred in 6 patients on a single occasion; there were no common features with regard to time from diagnosis, treatment or state of disease. 3 of these 6 had later measurements which were normal. Results from 14 of 89 assays measuring bipolar shape change were abnormal. 11 patients had increased numbers of bipolar shaped cells prior to FMLP stimulation and 3 patients had abnormally low numbers of bipolar PMNLs after FMLP stimulation. Abnormalities were found in 3 of 7 T cell and 10 of 37 "null" cell patients. No patients were infected at the time of these studies. Controls included children and adults not having cancer. These data suggest (1) children with ALL have normal PMNL oxidative metabolism in initial remission and during subsequent chemotherapy (2) 13/45 patients had abnormalities in the bipolar shape change assay suggesting that chemotactic activity may be adversely altered. Studies of chemotaxis are underway.

Asbestos-induced chemiluminescence response of human polymorphonuclear leukocytes

Products of the oxidative metabolism of polymorphonuclear leukocytes (PMN), namely hydrogen peroxide and superoxide, may play a role in tissue injury at sites of inflammation. Oxidant production by PMN was measured by the luminol-enhanced chemiluminescence (CL) of cells exposed in vitro to asbestos fibers. Human peripheral blood PMN were incubated with 1–1000 μg/ml of UICC chrysotile B asbestos fibers opsonized with either normal or heat-inactivated human serum. CL was measured over 210 min and revealed a peak response at 45 min; this response was delayed in comparison to control CL induced by Staphylococcus aureus (5–10 min) and represented approximately 50% of that of the latter. Although maximal CL was generated by asbestos concentrations of 100–500 μg/ml, significant CL was observed at concentrations as low as 0.5–1 μg/ml. Opsonization of asbestos fibers with heat-inactivated serum markedly depressed CL responses, suggesting that complement activation by asbestos fibers may be important in the generation of CL by PMN. In view of the previously reported accumulation of PMN in the lungs of asbestos-exposed animals, this study suggests that oxidant production by PMN may mediate some of the pathological effects of asbestos fibers.

Control of human classical complement pathway C3 convertase: inhibition of C3 cleavage by C3a

Products of the oxidative metabolism of polymorphonuclear leukocytes (PMN), namely hydrogen peroxide and superoxide, may play a role in tissue injury at sites of inflammation. Oxidant production by PMN was measured by the luminol-enhanced chemiluminescence (CL) of cells exposed in vitro to asbestos fibers. Human peripheral blood PMN were incubated with 1–1000 μg/ml of UICC chrysotile B asbestos fibers opsonized with either normal or heat-inactivated human serum. CL was measured over 210 min and revealed a peak response at 45 min; this response was delayed in comparison to control CL induced by Staphylococcus aureus (5–10 min) and represented approximately 50% of that of the latter. Although maximal CL was generated by asbestos concentrations of 100–500 μg/ml, significant CL was observed at concentrations as low as 0.5–1 μg/ml. Opsonization of asbestos fibers with heat-inactivated serum markedly depressed CL responses, suggesting that complement activation by asbestos fibers may be important in the generation of CL by PMN. In view of the previously reported accumulation of PMN in the lungs of asbestos-exposed animals, this study suggests that oxidant production by PMN may mediate some of the pathological effects of asbestos fibers.

Depression of monocyte and polymorphonuclear leukocyte oxidative metabolism and bactericidal capacity by influenza A virus.

Decreased host defense against bacterial disease associated with influenza infection may be related to virus-induced changes in phagocytic cell function. Influenza A virus initiates the respiratory burst in peripheral blood monocytes and polymorphonuclear leukocytes, with a peak chemiluminescent response approximately 3 min after virus is added to the cells in vitro. Electron micrographs of phagocytic cells incubated with influenza virus demonstrated virus attached to the cell membrane and within phagocytic vacuoles. After 20 min of incubation of the virus with phagocytic cells, the chemiluminescent response to opsonized zymosan or phorbol myristate acetate was decreased by 30 to 90%. Phagocytic activity of monocytes and polymorphonuclear leukocytes incubate with influenza virus was normal, but the bactericidal activity was significantly depressed. Influenza A virus therefore stimulates an oxidative burst in monocytes as well as polymorphonuclear leukocytes, leading to a subsequent depression of the oxidative metabolic response and bactericidal capacity of the phagocytic cells.

Granulocyte function in patients with chronic renal failure: surface adherence, phagocytosis, and bactericidal activity in vitro.

The defects in host defense mechanisms that explain the enhanced susceptibility to infection of patients with chronic renal failure are not understood, and previous studies concerning function of polymorphonuclear leukocytes (PMNL), the major antibacterial defense, conflict. Therefore, the antimicrobial functions of PMNL obtained from chronically uremic patients and serum factors essential for PMNL activity were evaluated. The potential modifying effect of high concentrations of serum from uremic patients on PMNL of uremic patients was determined, and granulocyte adherence, an activity related to recruitment of cells to inflammatory sites, was measured. Phagocytosis of 14C-labeled Staphylococcus aureus and bactericidal activity were normal and unaffected by high concentrations of uremic serum. Serum from uremic patients opsonized staphylococci and yeast normally. Oxidative metabolism of PMNL [14C-1]glucose oxidation, O2 consumption, and quantitative protein iodination) was normal, as was PMNL adherence. If the uremic patient has an increased risk of infection, this risk cannot be ascribed to defects of PMNL responses that have been studied in these patients.