Release of slow-reacting substance of anaphylaxis in the rat: polymorphonuclear leukocyte.

The antigen-induced release of slow-reacting substance of anaphylaxis was studied in rats previously treated with different biological and pharmacological agents to deplete these animals of specific cellular elements. The polymorphonuclear leukocyte appears necessary as a crucial cell type for optimum release of the slow-reacting substance of anaphylaxis, whereas the mast cell and lymphocyte are not required.

Neutrophils: their role in the formation of a tick feeding lesion.

Dogs infested with adtult Rhipicephalus sanguineus were given nitrogen mustard to reduce leukocyte numbers. In the treated animals the tick lesions were insignificant, lacking the collagen destruiction found in untreated hosts, bitt the ticks engorged normally. Feeding results from tick secretions causing vascitlar trauima and is independent of tissute damage associated with inflammatory responses.

Lipoxygenation of arachidonic acid as a source of polymorphonuclear leukocyte chemotactic factors in synovial fluid and tissue in rheumatoid arthritis and spondyloarthritis.

The predominant lipoxygenase products of arachidonic acid were extracted and purified from synovial fluid and sonicates of synovial tissue of patients with rheumatoid arthritis (RA), spondyloarthritis (SA), or a noninflammatory arthropathy (NIA). The concentration of 5(S),12(R)-dihydroxy-6,8,10-(trans/trans/cis)-14-cis-eicosatetraenoic acid (leukotriene B4) in synovial fluid was elevated significantly in patients with RA and a positive latex test for rheumatoid factor (P < 0.05, n = 14) and in patients with SA (P < 0.05, n = 10), compared with that of subjects with NIA (n = 9). The content of 5(S)-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE), but not of leukotriene B4, was elevated significantly in synovial tissue of seven patients with RA in comparison with that of four subjects with NIA (P < 0.05). A single intra-articular injection of corticosteroid significantly lowered the synovial fluid level of leukotriene B4 in six patients with RA. These data suggest an involvement of the potent chemotactic factors 5-HETE and leukotriene B4 in human inflammatory disease.

Hyperactivity of neutrophil leukotactic responses during active bacterial infection.

To determine if changes in neutrophil leukocyte function occur during active bacterial infection, the neutrophils of 25 patients with active bacterial infection and 25 age-matched controls were compared for leukotactic activity, random mobility, and nitroblue tetrazolium reduction. The neutrophil leukocytes of patients with bacterial infection were hyperactive in unidirectional movement toward a chemotactic stimulus as measured in the leukotactic assay and usually had increased nitroblue tetrazolium reduction. The mean leukotactic index was 165+/-56 in patients with bacterial infection and 70+/-11 in controls (P < 0.001). After 7-10 days of appropriate therapy with clinical and bacteriological response, leukotactic activity returned to normal values. A hyperactive leukotactic response continued, however, in patients with persisting bacterial infection. The hyperactive leukotactic response of circulating neutrophils appears to be an early and sensitive event in the inflammatory cycle stimulated by bacterial infection and may aid in the localization of invading bacteria.

Phagocytic function of polymorphonuclear leukocytes in rheumatic diseases.

Phagocytosis of yeast particles by peripheral blood and synovial fluid neutrophils was compared in the sera and synovial fluids from 16 osteoarthritis, 23 rheumatoid arthritis, and 12 miscellaneous arthritis patients. Phagocytosis by normal peripheral blood neutrophils was decreased equally and significantly in all synovial fluids. All synovial fluid neutrophils demonstrated decreased phagocytic capacity in all media. Rheumatoid arthritis synovial fluid neutrophils showed significantly less phagocytosis than miscellaneous arthritis synovial fluid neutrophils. Normal peripheral blood neutrophils which in vitro had previously ingested monosodium urate crystals or oil red O, subsequently exhibited a normal yeast phagocytic capacity. Normal peripheral blood neutrophils, which had ingested preformed immunoglobulin G-rheumatoid factor complexes exhibited significantly less yeast phagocytic capacity than control cells or cells preincubated with the individual complex components. There was a significant correlation between the log of the reciprocal of the rheumatoid factor titer in sera used to produce complexes and the phagocytic capacity exhibited by test neutrophils. Ingestion of immunoglobulin G-rheumatoid factor complexes may be important in the production of the cellular phagocytic defect which this study has demonstrated in rheumatoid arthritis synovial fluid neutrophils.

Stimulation of the respiratory burst of murine peritoneal inflammatory neutrophils by conjugation with tumor cells.

Murine peritoneal neutrophils (PMNs), elicited by i.p. injection of formalin-killed Corynebacteria parvum, spontaneously lyse teratocarcinoma targets through the secretion of reactive oxygen intermediates. Examination of effector-target interactions at the single cell level revealed that PMNs conjugated to tumor cells were 3-fold more frequently stained by nitroblue tetrazolium compared to nonconjugating PMNs suggesting that tumor targets stimulated a potent tumor-lytic respiratory burst. This notion was confirmed by the detection of superoxide and hydrogen peroxide generation from PMNs as well as a luminol-dependent chemiluminescent response following conjugation with viable tumor targets. Generation of superoxide was dependent upon the presence of dihydrocytochalasin B. In addition to teratocarcinoma cells, comparable stimulation was achieved by conjugation with YAC and P815 targets but not thymocytes. Reactive oxygen intermediate release was also achieved by mixing peritoneal PMNs with heat-killed tumor cells. In contrast to bacteria-induced effectors, PMNs elicited by i.p. injection of thioglycollate were incapable of responding following conjugation with tumor targets although they were competent for reactive oxygen intermediate release when stimulated by phorbol myristate acetate. Teratocarcinoma targets were sensitive to concentrations of H2O2 that could be achieved by PMNs following contact. These data indicate that Corynebacteria-elicited inflammatory PMNs lyse their bound tumor targets by a mechanism similar to a stimulus-secretion model.

Inhibition of polymorphonuclear leukocyte respiratory burst by elevated glucose concentrations in vitro.

Although impaired polymorphonuclear leukocyte (PMN) function may be a cause of infectious complications in diabetic patients, the mechanisms of altered cell function are not understood. Our studies of PMN function in healthy subjects demonstrated significant reduction in the respiratory burst after 30 min of in vitro cell exposure to glucose concentrations greater than 11 mM (200 mg/dl). The respiratory burst was reduced 28 +/- 5 and 74 +/- 7% in PMNs incubated with 11 and 56 mM glucose, respectively. The impairment was independent of the cell stimulus (chemotactic peptide, calcium ionophore, or phorbol ester) and was not affected by sorbinil or myo-inositol. Because both D- and L-glucose had similar inhibitory effects, a nonenzymatic mechanism appeared to be the cause of impaired PMN function. Although mannitol and sorbitol did not affect cell function, monosaccharides (glucose, mannose, fructose) that form Schiff-base adducts with protein inhibited PMN function. These findings suggest a potential role for protein glycosylation in glucose-induced impairment of PMN function.

Thermal regulation of FMLP receptors on human neutrophils.

Polymorphonuclear leukocytes (PMNs) from subjects diagnosed as having juvenile periodontitis (JP) have been categorized on the basis of their chemotactic (CTX) response to f-met-leu-phe (FMLP) when assayed concurrently with PMNs from periodontally healthy subjects (HP). When PMNs from JP groups demonstrating depressed CTX were assayed for lysosomal enzyme secretion (LES) in response to FMLP, there were no significant differences with respect to rate or amount. Significant differences were observed between HP and chemotactically depressed JP cells when assessed for FMLP receptor ligand binding at 23 degrees C, but not at 4 degrees C. Receptor differences observed at 23 degrees C in HP cells included an increase in amount of total binding, number of receptors, and available displaceable binding sites, compared with the chemotactically depressed JP PMNs, whereas the receptor affinities were similar. These data suggest that differences in FMLP receptor density in JP PMN that are chemotactically depressed may be related to processes that modulate receptor mobility and/or expression.

Elevated phagocytosis, oxidative burst, and F-actin formation in PMNs from individuals with intraoral manifestations of HIV infection.

Alterations in polymorphonuclear leucocyte (PMN) function are frequently associated with intraoral disease. The purpose of this study was to evaluate if alterations exist in three early stimulatory events of PMN function in individuals with intraoral manifestations of human immunodeficiency virus (HIV) infection. Peripheral PMNs were isolated from nine HIV-seropositive male homosexuals with HIV-associated periodontitis and intraoral candidiasis and healthy HIV-seronegative age-matched heterosexuals (controls). Phagocytosis was assessed using fluorescent microspheres, oxidative burst was assessed via hydrolysis of 2',7'-dichlorofluorescein (FCDH) to 2',7'-dichlorofluorescein (FCDA) with PMA stimulation, and F-actin formation was assessed with NBD-phallacidin stain after stimulation with f-Met-Leu-Phe. Compared to controls, seven of nine HIV-seropositive patients demonstrated a significant increase in the percentage of phagocytic cells while seven of nine HIV-seropositive patients demonstrated a 5-59% increase in number of beads per cell. In the oxidative burst assay, seven of seven HIV-seropositive patients demonstrated a significant increase over controls in FCDA stain with PMA stimulation. In the F-actin assay, four of five HIV-seropositive patients demonstrated a significant increase over controls in NBD-phallacidin staining after f-Met-Leu-Phe stimulation.

Current view of neutrophil dysfunction: an integrated clinical perspective.

Normal neutrophil function is dependent on the integration of chemotaxis, phagocytosis, degranulation and oxidative metabolism. The availability of in vitro assays for the separate quantitative evaluation of each function has permitted the definition of specific congenital and acquired neutrophil abnormalities, which are associated with defective host resistance. The appreciation of complex and often adverse effects of certain systemic diseases and drugs on neutrophil function as well as the use of new approaches to therapy suggest the importance of assessing the role of the neutrophil in states of impaired host defense.

Transient neutrophil aggregation in a patient with infectious mononucleosis.

Transient neutrophil aggregation is reported in a case of infectious mononucleosis. The phenomenon was observed on a blood film patient just before splenic infarction and decreased after splenectomy. The aggregation was so important that differential blood count could not be done. A high serum level of circulating immune complexes was found, and fluorescent spots inside of granulocytes, presumably engulfed immune complexes, could be observed. It is suggested that C activation associated with high immune complexes in infectious mononucleosis is a possible pathogenetic mechanism inducing PMNs aggregation and immune tissue damage.

Neutrophil chemotaxis in sickle cell anaemia, sickle cell beta zero thalassaemia, and after splenectomy.

Neutrophil chemotaxis was evaluated in 28 patients with sickle cell anaemia, 10 patient with sickle cell beta zero thalassaemia, 25 patients who had undergone splenectomy, and 38 controls. The mean distance migrated by patients' neutrophils was not significantly different from that of neutrophils from controls. Although several immunological variables have been reported to be changed after loss of splenic function, we were unable to show a defect in neutrophil chemotaxis that could account for the increased susceptibility to infection.

Abnormal rabbit heterophil chemotaxis following thermal injury. An in vivo model of an abnormality of the chemoattractant receptor for f-met-leu-phe.

Previous studies have shown that the decreased neutrophil migratory responsiveness seen in burned patients correlates with the extent of thermal injury and the extent of the neutrophil-specific granule deficiency. To understand better the relationship between the neutrophil dysfunction, degranulation, and thermal injury, a rabbit model was studied. Eighteen rabbits were burned over 20% of their surface area. Assay of peripheral blood heterophils disclosed decreased migratory activity compared with preburn levels and decreased lysozyme content vs preburn levels, but no change in the beta-glucuronidase content. The specific binding of tritiated formyl-methionyl-leucyl-phenylalanine to peripheral blood heterophils was increased fivefold over that of control cells. These studies indicate that, following thermal injury, there is a selective decrease of specific granule contents and an increase in chemoattractant binding to the cell and also suggest an abnormality in chemoattractant receptor processing. The rabbit provides a convenient model for the study of compromised host defenses following thermal injury.

Leukocyte abnormalities.

Certain qualitative abnormalities in neutrophils and blood monocytes are associated with frequent, severe, and recurrent bacterial infections leading to fatal sepsis, while other qualitative defects demonstrated in vitro may have few or no clinical sequelae. These qualitative defects are discussed in terms of the specific functions of locomotion, phagocytosis, degranulation, and bacterial killing.

Biochemical and ultrastructural aspects of the inhibited phagocytosis by neutrophil granulocytes in acute brain-damaged patients.

In a study of 60 head-injured patients inhibition of phagocytosis by neutrophil granulocytes was observed over a period of up to 5 weeks. This inhibition of phagocytosis could be correlated with the severity of head injury as well as with the state of unconsciousness at the time of the investigation. No correlation was found between neutrophil granulocyte counts and the inhibition of phagocytosis. A good correlation could be demonstrated between the level of lumbar CSF 5-HIAA and the inhibition of phagocytosis. After in vitro incubation with albumin the cells showed a recovery of phagocytosis. Electron micrographs of the cells showed ultrastructural appearances suggesting a changed permeability of the plasma membrane and, in addition, alterations in the cytoplasmic region beneath the plasma membrane. It is suggested that head injury may influence the pituitary-adrenal system and the autonomic nervous system, giving changes of neutrophil function and of neurotransmitter metabolism; these changes may represent an adaptation mechanism.

Cerebrospinal fluid shunts interfere with host defenses.

Despite advances in neurosurgical therapeutics, cerebrospinal fluid shunt infections have continued to complicate the management of patients with shunted hydrocephalus. Although various factors have been proposed to explain the pathogenesis of these infections, they have remained poorly understood. This in vitro study determined the ability of human neutrophils and monocytes to adhere to two types of shunt catheters and to phagocytose bacteria. These white blood cells failed to adhere in normal numbers to the catheters and failed to ingest fully a bacterial inoculum on the catheters' surfaces. While in contact with the shunt apparatus, the neutrophils also exocytosed myeloperoxidase, a major component of the intracellular microbicidal system. These observations suggest that the shunt apparatus may diminish the effectiveness of the hosts' defenses at the site of implantation.

Immune cellular interactions during sepsis and septic injury.

The cellular activity generated by PMNs and macrophages in association with diverse cytokines has a profound impact on all major functional responses of host cellular components during sepsis and septic injury. It is the modulation of these cellular interactions and their effect on the continuum between appropriate and inappropriate responses during inflammation that will dictate the outcome of humans with sepsis.

Role of myeloperoxidase in respiratory burst of human polymorphonuclear leukocytes. Studies with myeloperoxidase-deficient subjects.

A comparative study of the respiratory burst [monitored as superoxide (O2-) production] of normal and myeloperoxidase (MPO) -deficient polymorphonuclear leukocytes (PMNs) was carried out on 11 MPO-deficient subjects that represent the largest sample of this kind ever studied. The rate of O2- production by isolated PMNs and whole blood from normal and MPO-deficient subjects was comparable during the initial 30-40 min of incubation with serum-treated zymosan (STZ). Afterwards, the amount of O2- produced became progressively higher in MPO-deficient cells at least until 120 min incubation with STZ. On the contrary the rate of O2- production by both cell types in response to 4-beta-phorbol-12-myristate-13-acetate (PMA) was the same. The PMNs of four MPO-deficient subjects were tested for their ingestion ability by counting the number of ingested particles on toluidine blue-stained sections of epoxy-embedded PMN suspensions. Both cell types ingested STZ particles at a comparable rate at early postphagocytic times, whereas on prolonged incubation MPO-deficient PMNs ingested more STZ particles than normal PMNs. These results suggest that the ingestion capacity of normal cells may undergo a more rapid deterioration than that of MPO-deficient cells during incubation with STZ. Evidence for a higher deterioration of normal PMNs with respect to MPO-deficient PMNs was obtained also from studies on the effect of storage on O2- generation. After standing at melting ice temperature for 3 h, normal PMNs produced less O2- than MPO-deficient PMNs in response to PMA, and the difference in O2- production by the two cell types in response to STZ was evident at earlier postphagocytic periods than with freshly isolated cells. Taken all together these results suggest that normal PMNs and MPO-deficient PMNs do not intrinsically differ in O2- generating potential and that the difference in the respiratory burst observed during phagocytosis may be accounted for by a more marked deterioration, in normal PMNs, of one or more functions related to the respiratory burst.

Leukotoxicity of an extract from Actinobacillus actinomycetemcomitans for human gingival polymorphonuclear leukocytes.

A soluble extract from Actinobacillus actinomycetemcomitans (designated strain Y4) caused dose-dependent cytotoxic changes in PMN isolated from the gingival crevices (C-PMN) of normal adults. When the toxin was preincubated with sera from patients with juvenile periodontitis, there was a significant inhibition of toxic activity. In contrast a variety of other sera from normal subjects with healthy gingiva, and from patients with chronic gingivitis, chronic periodontitis, recurrent herpes labialis, rheumatoid arthritis, or ulcerative colitis enhanced the leukotoxic activity. The neutralization of toxin by serum from patients with juvenile periodontitis was probably due to specific antibodies. Since Actinobacillus actinomycetemcomitans organisms can be frequently identified in subgingival plaque from patients with juvenile periodontitis, the capacity of Y4 toxin to kill C-PMN may contribute to the pathogenesis of this disease.

Ex vivo effects of nonsteroidal antiinflammatory drugs on arachidonic acid metabolism in neutrophils from a reverse passive Arthus reaction.

Rat neutrophils isolated from 4-h reverse passive Arthus reaction (RPAR) pleural exudates actively metabolize arachidonic acid via cyclooxygenase and lipoxygenase. Utilizing this system, the effect of oral doses of nonsteroidal antiinflammatory drugs on the ability of these cells to produce HHT, 5-HETE, and LTB from exogenously added arachidonic acid has been investigated. In vitro and ex vivo, indomethacin and timegadine inhibit cyclooxygenase activity in rat pleural neutrophils. In vitro, timegadine is a lipoxygenase as well as a cyclooxygenase inhibitor. This dual inhibition is confirmed by the observation that ex vivo timegadine inhibits the production of lipoxygenase as well as cyclooxygenase metabolites. While indomethacin, a cyclooxygenase inhibitor, primarily inhibits edema formation, the inhibition of both pathways of arachidonic acid metabolism by timegadine is reflected in the drug's ability to reduce cellular influx as well as edema formation in the RPAR pleural cavity inflammatory reaction.