Influence of human plasma kallikrein on lysosomal enzyme release from polymorphonuclear leukocytes

Stimulation of polymorphonuclear leukocytes with kallikrein demonstrated that enzyme acts selectively on the release of lysosomal enzymes of these cells. The release of collagenase, similarly to the release of lysozyme into the incubation medium increased proportionally to kallikrein concentration and the duration of incubation. Kallikrein had a small effect on -glucuronidase secretion. No effect on cytoplasm lactate dehydrogenase release was detected. These results suggest that kallikrein, as a soluble stimulus, predominantly induces degranulation of specific granules containing collagenase capable of degrading the connective tissue. Secretion of lysozyme and collagenase requires the presence of active kallikrein. Soybean trypsin inhibitor diminished the enzyme release.     

Cytochalasin B-dependent release of azurophil granule enzymes from human polymorphonuclear leukocytes

The dose-response effects of phorbol myristate acetate and cytochalasin B on secretion of azurophil and specific granule enzymes from viable human polymorphonuclear leukocytes have been examined. Secretion of the azurophil granule enzymes elastase and-glucuronidase from cells exposed to 50 ng/ml of phorbol myristate acetate is dependent on prior exposure of the cells to greater than 0.5 mg/ml of cytochalasin B. In contrast, the secretion of the specific granule enzyme lysozyme is not dependent on pretreatment with cytochalasin B. The concentration of phorbol myristate acetate needed to elicit maximal secretion of specific versus azurophil granule enzymes differs, being 5.0 ng/ml and 50 ng/ml, respectively. The results suggest that cytochalasin B-sensitive cellular components, possibly microfilaments, may selectively modulate some step in the exocytosis of azurophil granule enzymes from human polymorphonuclear leukocytes exposed to phorbol myristate acetate.     

Biochemical characteristics of ATP-induced secretion of lysosomal enzymes from rabbit polymorphonuclear leukocytes

ATP induces a release of the lysosomal enzymes,β-glucuronidase and lysozyme, but not the cytoplasmic marker, lactic dehydrogenase, from rabbit peritoneal polymorphonuclear leukocytes. The release requires a low-ionic-strength medium but not divalent cations. It occurs to a greater extent in the presence of K⁺ than Na⁺, is greatly enhanced by cytochalasin B, is temperature dependent, and apparently requires a source of metabolic energy as indicated by its inhibition by deoxyglucose. The release is also inhibited by iodoacetate and the organic mercurial, salyrgan. DFP does not inhibit the release, indicating that esterase activation apparently is not involved. ADP and AMP do not sustain the release, nor do the ATP phosphorate analogs in which a methylene group is substituted for the oxygen between theα andβ phosphate groups or theβ andγ phosphates. A tentative explanation for these findings is that ATP induces lysosomal enzyme release in polymorphonuclear leukocytes by reacting directly with an ATPase which needs low ionic strength but not divalent cations for its activity. In doing so, ATP bypasses the proesterase activation and external Ca²⁺-mediated steps required in other forms of induced lysosomal enzyme release in the polymorphonuclear leukocyte but uses the same common final pathway.     

Ultrastructural alterations during ATP-induced secretion of lysosomal enzymes from rabbit polymorphonuclear leukocytes

Rabbit neutrophils incubated in low-ionic-strength media were stimulated by ATP to secrete lysosomal enzymes. This was greatly enhanced in the presence of cytochalasin B. ATP in these circumstances induced the cell to form large cytoplasmic extensions that were largely devoid of granules. In the presence of both ATP and cytochalasin B, however, the projections contained granules in close proximity to the cell membrane. Neutrophils in low-ionic-strength buffer were capable of binding to zymosan particles coated with C3b but not of phagocytizing them. Release of granule enzymes was observed and exocytosis of granules appeared to occur at sites distant from those portions of the plasma membrane adherent to the particle.Support was provided by U.S.P.H.S. grant A1-07007 and GMS 19322-03 and by U.S.P.H.S. Career Development Award 1-KO4GM-42567-05 to Dr. P.M. Henson. This is publication no. 873 from the Department of Immunopathology, Scripps Clinic and Research Foundation, La Jolla, California.Support was provided by U.S.P.H.S. grant A1-09648.     

Enhancement of lymphocyte response to PHA by lysosomal enzymes from polymorphonuclear leukocytes of RA joint fluid

The effect of polymorphonuclear leukocyte (PMN) granule lysates obtained from joint fluid of RA an the in vitro DNA synthesis of PHA-stimulated autologous lymphocytes from joint fluid was studied. Lymphocytes were cultured for 3 days with or without PMN lysates in 2 ml of RPMI-1640 supplemented with 10% heat-inactivated fetal calf serum (FCS). The lymphocytes were stimulated with phytohemagglutinin (PHA-M). The DNA synthesis was measured by counting the [³H]thymidine incorporation. Lymphocytes from RA joint fluid stimulated with PHA-M showed 19,466±987 cpm (mean±SE per 10⁶ cells in the absence of PMN lysates. Upon addition PMN lysates to the PHA-stimulated lymphocytes, the maximum in vitro DNA synthesis increased to 44,877±1338 cpm. The enhancing effect of PMN lysates was abolished by plasma inhibitors or by passage through a column of protease inhibitor (Trasylol). It was concluded, therefore, that the enhancing effect of PMN lysates on PHA-stimulated lymphocytes may be associated with lysosomal proteases. Based on experiments using separated T and B lymphocytes, the enhancing effect of PMN lysates was considered to result from the activation of T lymphocytes. The results obtained in the present study suggest an important role for lysosomal proteases in the perpetuation of rheumatoid synovitis.     

Extracellular release of antimicrobial defensins by human polymorphonuclear leukocytes.

Human polymorphonuclear leukocytes (PMN) contain three antimicrobial and cytotoxic peptides which belong to a family of mammalian granulocyte peptides named defensins. To determine their potential availability for extracellular microbicidal or cytotoxic events, we quantified the extracellular release of defensins after stimulation of human PMN with phorbol myristate acetate and opsonized zymosan. As determined by enzyme immunoassay and confirmed by polyacrylamide gel electrophoresis and densitometry, 10(6) human PMN contained 4 to 5 micrograms of defensins. After stimulation with a high concentration of phorbol myristate acetate (1 microgram/ml), about 8% of PMN defensins were found in the media. Release of defensins correlated best with the release of azurophil granule marker beta-glucuronidase or elastase and poorly with the release of either the specific granule marker lactoferrin or cytoplasmic lactate dehydrogenase. Phagocytosis of opsonized zymosan resulted in the extracellular release of less than 3% of PMN defensins. The factors responsible for less release of defensins into media relative to the release of other azurophil granule proteins may include heterogeneity of azurophil granules and the affinity of defensins for cellular surfaces and opsonized particles. In vivo, defensins are most likely to reach effective microbicidal or cytotoxic concentrations in PMN-rich exudates (pus), in confined environments of the phagolysosomes, or in intercellular clefts between PMN and their targets.     

Asbestos fibers induce release of collagenase by human polymorphonuclear leukocytes

The asbestos fibers chrysotile and crocidolite cause a dose-dependent release of specific granule collagenase by human polymorphonuclear leukocytes (PMNL). Release of azurophil granule elastase was induced by the asbestos fibers at higher concentrations, suggesting that asbestos fibers primarily cause the release of specific granule contents of human PMNL. Wollastonite, a fibrous silicate mineral, causes a weaker collagenase release and no elastase release. The collagenase was released in inactive, latent form. Carboxymethyl cellulose (CMC), an agent known to blunt chrysotile-induced hemolysis and production of reactive oxygen metabolites by human PMNL, specifically inhibits chrysotile-induced release of collagenase. Chrysotile asbestos was found to bind the PMNL serine proteinase cathepsin G. A role of collagenase release, production of reactive oxygen metabolites and cathepsin G binding by chrysotile for the perpetuation of the asbestos-induced alveolitis is suggested.     

Inhibition of lysosomal enzyme release from rat leukocytes by auranofin

Auranofin (SK&F D-39162), a new antiarthritic gold compound reported to be orally effective in animal (adjuvant rat) and human (rheumatoid) arthritic conditions, is a potent in vitro inhibitor of the release of lysosomal enzymes from phagocytizing rat leukocytes. Auranofin, at micromolar concentrations (1–10M), produced a dose-dependent reduction in extra-cellular levels of lysosomal enzyme markers (-glucuronidase and lysozyme) which are selectively released from rat leukocytes during phagocytosis of zymosan particles. The reduction in extracellular levels of lysosomal enzymes appears to be caused by inhibition of their selective cellular release, since effective concentrations of auranofin did not produce leukocyte cytotoxicity or inhibition of cell-free lysosomal enzyme activity. Morphologic and biochemical evidence indicated that auranofin also interferes with phagocytosis of zymosan particles. The potent in vitro activity of auranofin appears to result from its unique gold complex, since neither structurally related nongold compounds nor clinically used gold compounds (gold sodium thiomalate and gold thioglucose) were potent inhibitors of lysosomal enzyme release. The results of this investigation suggest that the antiarthritic activity of auranofin may be caused at least in part, by inhibition of lysosomal enzyme release and/or cellular processing of antigens.SK&F D-39162 (2,3,4,6-tetra-O-acetyl-1-thio--D-glucopyranosato-S) (triethylphosphine) gold.Presented in part at the Federation of American Societies for Experimental Biology, Atlantic City, New Jersey, April 11, 1974 (4).     

Decreased extracellular release of granule enzymes from in vitro-stimulated polymorphonuclear leukocytes in guttate psoriasis

In vitro degranulation of polymorphonuclear leukocytes, which were stimulated either with synthetic chemotactic peptide (N-formyl-methionyl-leucyl-phenylalanine, FMLP) or with C3b-opsonized zymosan as a promoter of phagocytosis, was studied in 66 patients with psoriasis, 18 lesion-free psoriatics, 18 healthy subjects, and 14 other dermatological disorder controls. Stimulated release of lysozyme (from specific granules and azurophil granules) and beta-glucuronidase (from azurophil granules) in the presence of both FMLP and serum-activated zymosan was markedly reduced in patients with actively spreading guttate psoriatic lesions, in whom relapse of lesions lasted for less than 1 month and papules involved about 13–25% of skin surface. In contrast, stimulated degranulation was within normal range in active plaque psoriasis, stationary plaque psoriasis, symptomless psoriatics, and patients with disseminated eczema. Spontaneous release of lysozyme and beta-glucuronidase (background) was found to be not different in all groups studied; however, patients with active guttate psoriasis had significantly lower total lysozyme activity than those with active and stationary plaque psoriasis as well as psoriatics in the remission. These data are in favor of in vivo activation of neutrophils in active guttate psoriasis by some factors related to the early relapse of the lesions. This results in a possible combination of the following phenomena: (1) in vivo partial degranulation of neutrophils; (2) induction of unresponsiveness state of these cells to subsequent in vitro stimulation; and/or (3) migration of highly responsive neutrophils to skin lesions, which leaves in the circulation the subpopulation less reactive to chemotactic and phagocytic stimuli.     

Enhancement of in vitro immunoglobulin synthesis of human lymphocytes by lysosomal enzymes from polymorphonuclear leucocytes.

The effect of human peripheral blood polymorphonuclear leucocyte (PMN) extracts and PMN granule lysates on in vitro immunoglobulin (Ig) synthesis by autologous peripheral blood mononuclear cells was studied. The mononuclear cells were cultured for 3 days with or without autologous plasma. Newly synthesized Ig in the culture supernatants was measured using 14C-labelled amino acids by an immune coprecipitation method. Upon addition of a PMN extract to plasma-free cultures Ig synthesis was stimulated, the mean stimulation index (SI) of cultures from thirteen individuals, including nine normals, three patients with rheumatoid arthritis and one with psoriatic arthritis being 1-8 +/- 0-2 in comparison with control cultures (P less than 0-05). By contrast, in 10% fresh autologous plasma, PMN extracts yielded a mean SI of 0-9 +/- 0-1 indicating inactivation of the active extracts by plasma inhibitors. In experiments using PMN granule lysates containing high concentrations of beta-glucuronidase and cultured in RPMI 1640, the mean stimulation index was 3-2 +/- 0-7. Stimulation of Ig synthesis was also produced by trypsin. Stimulation of Ig synthesis was also produced by trypsin. Stimulating factors in PMN extracts were inhibited by Trasylol, a protease inhibitor. These results indicate that trypsin and proteolytic lysosomal enzymes in PMN increase Ig synthesis of human peripheral blood mononuclear cells. They suggest a possible new role of PMN in the potentiation of immunoglobulin synthesis.     

Initial kinetics of lysosomal enzyme secretion and superoxide anion generation by human polymorphonuclear leukocytes

Human polymorphonuclear leukocytes (PMN) exposed to particulate and soluble stimuli secrete lysosomal enzymes. These stimuli cause prompt (< 10 sec) changes in membrane potential followed 30–45 sec later by superoxide anion (O ₂ ^– ) production. We describe a new technique utilizing flow dialysis apparatus which monitors the first stages of lysosomal enzyme release with a resolution of approximately 6 sec. Secretion of-glucuronidase from cytochalasin B-treated PMN could be detected 19±5 sec after exposure to the chemotactic peptideN-formylmethionylleucylphenylalanine (FMLP). The lag times for release of this enzyme were different for other stimuli: 35±8 sec (BSA/anti-BSA immune complex); 48±8 sec (serum-treated zymosan, STZ); 60±25 sec (calcium ionophore A23187). The lag times for lysozyme release were less dependent upon the stimulus presented (28±16 sec for FMLP, 28±8 sec for BSA/antiBSA, 32±10 sec for STZ, and 38±8 seconds for Con A); only A23187 had a long lag period: 74±27 sec. Lag periods for the onset of O ₂ ^– production (measured by the same mathematical criteria) were comparable to those for-glucuronidase release: 21±4 sec for FMLP, 43±14 sec for BSA/anti-BSA, 61±7 sec for Con A, and 50±13 sec for A23187. Changes in FMLP dose up to 100-fold affected the magnitudes of O ₂ ^– generation and-glucuronidase release, but did not alter the time required for the onset of these processes. A variety of agents, such as corticosteroids, colchicine, 2-deoxyglucose, andN-ethyl maleimide, also affected the magnitudes of the responses, but not the lag periods when FMLP was used as the stimulus. When BSA/anti-BSA immune complex was used as the stimulus, 2-deoxyglucose andN-ethyl maleimide increased the lag period for superoxide anion generation, but not for lysosomal enzyme release. This new flow dialysis technique has permitted us to demonstrate that O ₂ ^- production and lysosomal enzyme secretion are concurrent but dissociable processes which are subsequent to earlier responses of the granulocyte to ligandreceptor interactions as reflected by changes in membrane potential.Aided by grants (AM-11949, HL-19072, HI-19721, GM023211) from the National Institutes of Health, The National Foundation-March of Dimes, the National Science Foundation (76-05621), and the Arthritis Foundation.Recipient of Postdoctoral Fellowship from the Arthritis Foundation.     

Effect of auranofin,a new antiarthritic agent,on immune complex-induced release of lysosomal enzymes from human leukocytes

Auranofin, an oral chrysotherapeutic agent effective in the treatment of rheumatoid arthritis (RA), was found to be a potent, noncytotoxic inhibitor of IgG-RF immune complex-induced lysosomal enzyme release (LER) from human leukocytes. At a concentration of 1 g Au/ml (5M), auranofin produced a marked reduction in-glucuronidase (100%), acid phosphatase (88%), and lysozyme (72%) release. In contrast, gold sodium thiosulfate (GST, an injectable gold compound) had no inhibitory activity on LER at equivalent gold concentrations (i.e., 1g Au/ml) and only modest activity (< 36% inhibition) at concentrations as high as 40g Au/ml. The 50% inhibitory dose (ID₅₀) of auranofin on LER was calculated to be 3–4M (0.6–0.8g Au/ml). Blood gold levels in auranofin-treated RA patients were found to be within the range required for in vitro inhibition of LER, and correlated with decreases in IgG, RF titers, and IgG-RF immune-complex formation in vitro. These results suggest that the therapeutic action of auranofin may be caused, at least in part, by inhibition of LER and/or decreases in immune-complex formation.SK&F D-39162 (2,3,4,6-tetra-O-acetyl-1-thio--D-glucopyranosato-S) (triethylphosphine) Gold.     

中性粒细胞抑制人单个核细胞释放TNF-α及其机理的研究

目的:探讨人中性粒细胞(PMNs)对人外周血单个核细胞(PBMCs)释放TNF-α的影响及其作用机理。方法:采集健康供血者的新鲜外周静脉血,以葡聚糖沉淀和密度梯度离心法分离其PMNs和PBMCs,将PMNs细胞与PBMCs细胞按2:1的数量比与脂多糖共同培育后,分别采用酶联免疫吸附法测定培养上清的TNF-α浓度,并用流式细胞术测定结合荧光标记脂多糖的单核细胞的百分率及单核细胞表面平均荧光强度。结果:PMNs在细菌脂多糖刺激下不释放TNF-α,PMNs可以抑制PBMCs释放TNF-α,其抑制作用具有细胞特异性;经多聚甲醛固定的PMNs仍具有上述的抑制作用。流式细胞术结果显示PMNs并不影响单核细胞与脂多糖结合。结论:PMNs可抑制人PBMCs释放TNF-α,其机理可能是PMNs干扰脂多糖激活PBMCs的信号转导过程,抑制细菌脂多糖对其的活化,从而下调TNF-α的释放。     

Histamine release from human leukocytes by human recombinant interleukin-3]

Human recombinant interleukin-3 (hrIL-3) released histamine from human leukocytes in vitro. The histamine release by hrIL-3 significantly correlated with those by anti-IgE, thrombin, and f-met. peptide, but not by A23187. Histamine release by hrIL-3 was a Ca2(+)-dependent reaction, as was that by anti-IgE, although the time course of histamine release by hrIL-3 was slower than that by anti-IgE. Pre-treatment of leukocytes with hrIL-3 decreased the histamine release by hrIL-3 itself, but enhanced the histamine releases by anti-IgE, f-met. peptide, thrombin and A23187. These results suggested that the mechanism of hrIL-3-induced histamine release was different from those of anti-IgE, f-met. peptide, thrombin, and A23187. There was no significant difference between hrIL-3-induced histamine release of leukocytes from asthmatics and healthy controls.     

Cytokineplasts from human blood polymorphonuclear leukocytes

Cytokineplasts (CKPs) are membrane-bounded, anucleate, granule-poor cytoplasmic fragments, induced from PMNs by brief heat (45°C, 9 min), which retain motile function including chemotaxis and phagocytosis. CKPs can respond to repeated chemotactic stimuli even after having been held overnight at room temperature, and hence outiive control PMNs, We now report that adherent CKPs lack significant oxidase activity, as measured by reduction of nitroblue tetrazolium (NBT) dye, (1)5 min after heat, when they are often still attached to their parent PMNs (which generally do not reduce NBT either); (2) later on, when they are free; and (3) when cells have been pretreated on endotoxin-coated substrata or with phorbol myristate acetate (PMA); both pretreatments cause the large majority of adherent control PMNs to reduce NBT. Moreover, cells harvested from glass just after heat lack the normal increase in oxygen consumption seen on stimulation with PMA or with heat-killed staphylococci. PMA-stimulated respiratory burst activity was not restored to heated cells by exogenous NADPH. Thus, heat applied to normal PMNs can dissociate motile function from oxidase activity; in this respect CKPs resemble PMNs in chronic granulomatous disease. The apparent increased functional stability of CKPs may indicate that normal PMNs are not immune to their own oxidative killing mechanism.This work, part of which has appeared in abstract (26), was supported in part by the U.S. Public Health Service (AM-10493, AM-19742, AM-07107) and by the Arthritis Foundation and its Connecticut Chapter.     

Superoxide generation from human polymorphonuclear leukocytes by liposome-encapsulated hemoglobin

We investigated the interactions between liposome-encapsulated hemoglobin (Neo Red Cells: NRC) and human polymorphonuclear leukocytes as assessed by superoxide generation. NRC triggered superoxide generation from neutrophils in a dose-dependent manner. Empty liposomes also induced superoxide production of neutrophils. Superoxide generation of neutrophils induced by phorbol myristate acetate (PMA) was delayed but intensified both by NRC and empty liposomes. The intensity of superoxide generation induced by NRC was smaller than that by the empty liposomes. As NRC contained superoxide dismutase (SOD) that was copurified with hemoglobin from red blood cells and its activity remained, SOD contained in NRC may partially eliminate superoxide.     

Release of prostaglandins from human polymorphonuclear leukocytes

Human PMNs release prostaglandins E and F to the surrounding medium when these cells are exposed to zymosan. PGE₁ is the prostaglandin compound found in highest concentration in the medium, and the PGE/PGF balance is approximately 3∶1. Release of prostaglandins is not due to platelet contamination. Agents which inhibit prostaglandin synthesis (indomethacin, aspirin) prevent release of prostaglandins from phagocytic cells. Addition to cells of dibutyryl cyclic 3′,5′-adenosine monophosphate produces striking increases in concentrations of prostaglandins released during ingestion of zymosan. Prostaglandins appear to be synthesized by human PMN during phagocytosis, and their release from cells may help regulate the inflammatory response.     

Oxidation of glucosamine by human polymorphonuclear leukocytes

When exposed to a phagocytic stimulus (opsonized zymosan), human polymorphonuclear leukocytes (PMNs) produced¹⁴CO₂ from [1-¹⁴C]glucosamine at a rate 10–25% of that produced from glucose under the same conditions. The production of CO₂ from glucosamine by intact PMNs was inhibited by glucose and dependent upon activation of the hexosemonophosphate shunt (HMPS). However, the metabolic pathways for the oxidation of glucose and glucosamine by PMNs are not identical. This is suggested by the fact that glucose-6-phosphate dehydrogenase, the initiating enzyme for the HMPS, did not utilize glucosamine-6-phosphate as a substrate. In addition, glucosamine was not oxidized by sonically disrupted PMNs whereas oxidation of glucose by the same preparation was increased sevenfold over intact cells. Taken together, the data suggest that PMNs oxidize glucosamine by converting it to a compound compatible with the enzymes of the HMPS. This conversion requires intact PMNs and/or an as yet unidentified cofactor.     

Membrane changes in polymorphonuclear leukocytes during ionophore (A23187)-induced lysosomal release.

Micromolar concentrations of the divalent ionophore A23187 and millimolar concentrations of extracellular calcium caused the rapid exocytosis of lysosomes from rabbit polymorphonuclear leukocytes. In control experiments the larger granules remained within the leukocytes while another class of smaller granules fused with the plasma membrane. Whenever membrane fusion and exocytosis occurred intramembranous particle-free regions developed within the plasma membrane at the sites of fusion. Neither a massive aggregation of intramembranous particles (IMPs), nor the formation of highly symmetrical rosette patterns of IMPs was seen in either experimental or control preparations.